DNA-binding domain of Signal Transducer and Activator of Transcription 1 (STAT1); This family consists of the DNA-binding domain (DBD) of the STAT1 proteins (Signal Transducer and Activator of Transcription 1, or Signal Transduction And Transcription 1). The DNA binding domain has an Ig-like fold. STAT1 plays an essential role in mediating responses to all types of interferons (IFN), transducing signals from cytoplasmic domains of transmembrane receptors into the nucleus where it regulates gene expression. Thus STAT1 is involved in modulating diverse cellular processes, such as antimicrobial activities, cell proliferation and cell death. STAT1 function is crucial in the innate and adaptive arm of immunity and protects from pathogen infections; phosphorylation of a critical tyrosine by Janus kinases (JAKs) leads to its activation and nuclear translocation, while phosphorylation of a critical serine is required for full transcriptional activation upon IFN stimulation and in response to cellular stress. Transcription of protein-encoding genes (including Stat1 itself) as well as expression of microRNAs (miRNAs) is regulated by activated STAT1. Animal studies have shown that STAT1 is generally considered a tumor suppressor but it can also act as a tumor promoter; its functions are not restricted to tumor cells, but extend to parts of the tumor microenvironment such as immune cells, endothelial cells. STAT1 abundance is a reliable marker for good prognosis in selected tumor types, but it can also correlate with disease progression. In head and neck cancer (HNC) patients, upregulation of STAT1-induced HLA class I enhances immunogenicity and clinical response to anti-EGFR mAb cetuximab therapy. In systemic juvenile idiopathic arthritis (sJIA) characterized by systemic inflammation and arthritis, STAT1 phosphorylation downstream of IFNs is impaired. It exerts anti-oncogenic activities through interferon-gamma and interferon-alpha. STAT1 may inhibit hepatocellular carcinoma cell growth by regulating p53-related cell cycling and apoptosis. Studies also show a significant correlation of high STAT1 activity with longer colorectal cancer patient overall survival. Recent studies have shown that STAT1 suppresses mouse mammary gland tumorigenesis by immune regulatory as well as tumor cell-specific functions of STAT1.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1785411765 317 FVVERQPCMPTHPQRPLVLKTGVQFTVKLRLLVKLQELNYQLKVKALFDKDVNDKNIVKGFRKFNILGTHTKVMNMEEST 396
Cdd:cd16845     1 FVVERQPCMPTHPQRPLVLKTGVQFTVKLRLLVKLQELNYQLKVKVLFDKDVTEKNTVKGFRKFNILGTNTKVMNMEEST 80

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1785411765 397 NGSLAAEFRHLQLKEQKNAGSRTNEGPLIVTEELHCLSFETQLCQLGLVVDLETSSLPIVVISNVSQLPSGWASILWYNM 476
Cdd:cd16845    81 NGSLAAEFRHLQLKEQKNAGTRTNEGPLIVTEELHSLSFETQLCQPGLVIDLETTSLPIVVISNVSQLPSGWASILWYNM 160

                  .
gi 1785411765 477 L 477
Cdd:cd16845   161 L 161

Src homology 2 (SH2) domain; In general, SH2 domains are involved in signal transduction; they bind pTyr-containing polypeptide ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites. They are present in a wide array of proteins including: adaptor proteins (Nck1, Crk, Grb2), scaffolds (Slp76, Shc, Dapp1), kinases (Src, Syk, Fps, Tec), phosphatases (Shp-1, Shp-2), transcription factors (STAT1), Ras signaling molecules (Ras-Gap), ubiquitination factors (c-Cbl), cytoskeleton regulators (Tensin), signal regulators (SAP), and phospholipid second messengers (PLCgamma), amongst others.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1785411765 558 WIEGILELIKKHLLCLWNDGFIVGFISKERERALLKEKAPGTFLLRFSESSKEGAITFTWVERPQN--DPLFHSVEPYTK 635
Cdd:cd10372     1 WIESILELIKKHLLSLWNDGCIMGFISKERERALLKDQQPGTFLLRFSESSREGAITFTWVERSQNggEPDFHAVEPYTK 80

                          90       100       110       120       130       140       150
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 1785411765 636 RELSAVTFPDIIRNYKVMAAENIPENPLRFLYPDTPKDNAFGKYYSRPKEADEPMDLDGPKGTGYIKTELI 706
Cdd:cd10372    81 KELSAVTFPDIIRNYKVMAAENIPENPLKYLYPNIDKDHAFGKYYSRPKEAPEPMELDGPKGTGYIKTELI 151

STAT1 TAZ2 binding domain; This domain family is found in eukaryotes, and is approximately 20 amino acids in length, and the family is found in association with pfam02865, pfam00017, pfam01017, pfam02864. This domain is the C terminal domain of STAT1. This domain binds selectively to the TAZ2 domain of CRB (CREB-binding protein). In this process it becomes a transcriptional activator and can initiate transcription of certain genes.

                          10        20
                  ....*....|....*....|....*
gi 1785411765 714 SRLQttEFLLPMSPDEYAEVARLVG 738
Cdd:pfam12162   1 SRLQ--ENLMPMSPEDYGELERMVR 23

DNA-binding domain of Signal Transducer and Activator of Transcription 1 (STAT1); This family consists of the DNA-binding domain (DBD) of the STAT1 proteins (Signal Transducer and Activator of Transcription 1, or Signal Transduction And Transcription 1). The DNA binding domain has an Ig-like fold. STAT1 plays an essential role in mediating responses to all types of interferons (IFN), transducing signals from cytoplasmic domains of transmembrane receptors into the nucleus where it regulates gene expression. Thus STAT1 is involved in modulating diverse cellular processes, such as antimicrobial activities, cell proliferation and cell death. STAT1 function is crucial in the innate and adaptive arm of immunity and protects from pathogen infections; phosphorylation of a critical tyrosine by Janus kinases (JAKs) leads to its activation and nuclear translocation, while phosphorylation of a critical serine is required for full transcriptional activation upon IFN stimulation and in response to cellular stress. Transcription of protein-encoding genes (including Stat1 itself) as well as expression of microRNAs (miRNAs) is regulated by activated STAT1. Animal studies have shown that STAT1 is generally considered a tumor suppressor but it can also act as a tumor promoter; its functions are not restricted to tumor cells, but extend to parts of the tumor microenvironment such as immune cells, endothelial cells. STAT1 abundance is a reliable marker for good prognosis in selected tumor types, but it can also correlate with disease progression. In head and neck cancer (HNC) patients, upregulation of STAT1-induced HLA class I enhances immunogenicity and clinical response to anti-EGFR mAb cetuximab therapy. In systemic juvenile idiopathic arthritis (sJIA) characterized by systemic inflammation and arthritis, STAT1 phosphorylation downstream of IFNs is impaired. It exerts anti-oncogenic activities through interferon-gamma and interferon-alpha. STAT1 may inhibit hepatocellular carcinoma cell growth by regulating p53-related cell cycling and apoptosis. Studies also show a significant correlation of high STAT1 activity with longer colorectal cancer patient overall survival. Recent studies have shown that STAT1 suppresses mouse mammary gland tumorigenesis by immune regulatory as well as tumor cell-specific functions of STAT1.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1785411765 317 FVVERQPCMPTHPQRPLVLKTGVQFTVKLRLLVKLQELNYQLKVKALFDKDVNDKNIVKGFRKFNILGTHTKVMNMEEST 396
Cdd:cd16845     1 FVVERQPCMPTHPQRPLVLKTGVQFTVKLRLLVKLQELNYQLKVKVLFDKDVTEKNTVKGFRKFNILGTNTKVMNMEEST 80

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1785411765 397 NGSLAAEFRHLQLKEQKNAGSRTNEGPLIVTEELHCLSFETQLCQLGLVVDLETSSLPIVVISNVSQLPSGWASILWYNM 476
Cdd:cd16845    81 NGSLAAEFRHLQLKEQKNAGTRTNEGPLIVTEELHSLSFETQLCQPGLVIDLETTSLPIVVISNVSQLPSGWASILWYNM 160

                  .
gi 1785411765 477 L 477
Cdd:cd16845   161 L 161

Src homology 2 (SH2) domain found in signal transducer and activator of transcription (STAT) 1 proteins; STAT1 is a member of the STAT family of transcription factors. STAT1 is involved in upregulating genes due to a signal by interferons. STAT1 forms homodimers or heterodimers with STAT3 that bind to the Interferon-Gamma Activated Sequence (GAS) promoter element in response to IFN-gamma stimulation. STAT1 forms a heterodimer with STAT2 that can bind Interferon Stimulated Response Element (ISRE) promoter element in response to either IFN-alpha or IFN-beta stimulation. Binding in both cases leads to an increased expression of ISG (Interferon Stimulated Genes). STAT1 has been shown to interact with protein kinase R, Src, IRF1, STAT3, MCM5, STAT2, CD117, Fanconi anemia, complementation group C, CREB-binding protein, Interleukin 27 receptor, alpha subunit, PIAS1, BRCA1, Epidermal growth factor receptor, PTK2, Mammalian target of rapamycin, IFNAR2, PRKCD, TRADD, C-jun, Calcitriol receptor, ISGF3G, and GNB2L1. STAT proteins mediate the signaling of cytokines and a number of growth factors from the receptors of these extracellular signaling molecules to the cell nucleus. STATs are specifically phosphorylated by receptor-associated Janus kinases, receptor tyrosine kinases, or cytoplasmic tyrosine kinases. The phosphorylated STAT molecules dimerize by reciprocal binding of their SH2 domains to the phosphotyrosine residues. These dimeric STATs translocate into the nucleus, bind to specific DNA sequences, and regulate the transcription of their target genes. However there are a number of unphosphorylated STATs that travel between the cytoplasm and nucleus and some STATs that exist as dimers in unstimulated cells that can exert biological functions independent of being activated. There are seven mammalian STAT family members which have been identified: STAT1, STAT2, STAT3, STAT4, STAT5 (STAT5A and STAT5B), and STAT6. There are 6 conserved domains in STAT: N-terminal domain (NTD), coiled-coil domain (CCD), DNA-binding domain (DBD), alpha-helical linker domain (LD), SH2 domain, and transactivation domain (TAD). NTD is involved in dimerization of unphosphorylated STATs monomers and for the tetramerization between STAT1, STAT3, STAT4 and STAT5 on promoters with two or more tandem STAT binding sites. It also plays a role in promoting interactions with transcriptional co-activators such as CREB binding protein (CBP)/p300, as well as being important for nuclear import and deactivation of STATs involving tyrosine de-phosphorylation. CCD interacts with other proteins, such as IFN regulatory protein 9 (IRF-9/p48) with STAT1 and c-JUN with STAT3 and is also thought to participate in the negative regulation of these proteins. Distinct genes are bound to STATs via their DBD domain. This domain is also involved in nuclear translocation of activated STAT1 and STAT3 phosphorylated dimers upon cytokine stimulation. LD links the DNA-binding and SH2 domains and is important for the transcriptional activation of STAT1 in response to IFN-gamma. It also plays a role in protein-protein interactions and has also been implicated in the constitutive nucleocytoplasmic shuttling of unphosphorylated STATs in resting cells. The SH2 domain is necessary for receptor association and tyrosine phosphodimer formation. Residues within this domain may be particularly important for some cellular functions mediated by the STATs as well as residues adjacent to this domain. The TAD interacts with several proteins, namely minichromosome maintenance complex component 5 (MCM5), breast cancer 1 (BRCA1) and CBP/p300. TAD also contains a modulatory phosphorylation site that regulates STAT activity and is necessary for maximal transcription of a number of target genes. The conserved tyrosine residue present in the C-terminus is crucial for dimerization via interaction with the SH2 domain upon the interaction of the ligand with the receptor. STAT activation by tyrosine phosphorylation also determines nuclear import and retention, DNA binding to specific DNA elements in the promoters of responsive genes, and transcriptional activation of STAT dimers. In addition to the SH2 domain there is a coiled-coil domain, a DNA binding domain, and a transactivation domain in the STAT proteins. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1785411765 558 WIEGILELIKKHLLCLWNDGFIVGFISKERERALLKEKAPGTFLLRFSESSKEGAITFTWVERPQN--DPLFHSVEPYTK 635
Cdd:cd10372     1 WIESILELIKKHLLSLWNDGCIMGFISKERERALLKDQQPGTFLLRFSESSREGAITFTWVERSQNggEPDFHAVEPYTK 80

                          90       100       110       120       130       140       150
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 1785411765 636 RELSAVTFPDIIRNYKVMAAENIPENPLRFLYPDTPKDNAFGKYYSRPKEADEPMDLDGPKGTGYIKTELI 706
Cdd:cd10372    81 KELSAVTFPDIIRNYKVMAAENIPENPLKYLYPNIDKDHAFGKYYSRPKEAPEPMELDGPKGTGYIKTELI 151

STAT protein, DNA binding domain; STAT proteins (Signal Transducers and Activators of Transcription) are a family of transcription factors that are specifically activated to regulate gene transcription when cells encounter cytokines and growth factors. This family represents the DNA binding domain of STAT, which has an ig-like fold. STAT proteins also include an SH2 domain pfam00017.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1785411765 330 QRPLVLKTGVQFTVKLRLLVKLQ---ELNYQLKVKALFDKDVNDKNIVKGFRKFNILG--THTKVMNMEESTNGSLAAEF 404
Cdd:pfam02864   2 QPPQVLKTNTKFSVTVRLLVGLPlniELNPQVKVKIVSEKQARELQQIKGFRKFNISGeiLNNKALLEYESQNGGLSAEF 81

                          90       100       110       120       130
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1785411765 405 RHLQLKEQKNAGsrtNEGPLIVTEELHCLSFETQLCQLGLVVDLETSSLPIVVI 458
Cdd:pfam02864  82 RNLSLKEIKRGE---RKGSLSVTEEKFALLFETQFTLGGLVFDLWTLSLPVVVI 132

STAT protein, protein interaction domain; STAT proteins (Signal Transducers and Activators of Transcription) are a family of transcription factors that are specifically activated to regulate gene transcription when cells encounter cytokines and growth factors. STAT proteins also include an SH2 domain pfam00017.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1785411765   2 AQWYELQQIDTKFLEQVHQLYDDSFPMEIRQYLAQWLESQDWEHAANNVSLATILFHGLLSQLDDQYSRFSLENNFLLQH 81
Cdd:pfam02865   1 SLWAQLQQLDGEALEQVQQLYGDHFPIEVRHYLAQWIESQDWEDAAQDESLATVLFHALLSELDSQASRFVQEDNFLLKH 80

                          90       100       110
                  ....*....|....*....|....*....|....*...
gi 1785411765  82 NIRKSKRNLQDHFQEDPVQMAMIINSCLREESKILGNA 119
Cdd:pfam02865  81 KLREIAKNLQSRYQENPLELARIIRNCLREERRILQEA 118

STAT1 TAZ2 binding domain; This domain family is found in eukaryotes, and is approximately 20 amino acids in length, and the family is found in association with pfam02865, pfam00017, pfam01017, pfam02864. This domain is the C terminal domain of STAT1. This domain binds selectively to the TAZ2 domain of CRB (CREB-binding protein). In this process it becomes a transcriptional activator and can initiate transcription of certain genes.

                          10        20
                  ....*....|....*....|....*
gi 1785411765 714 SRLQttEFLLPMSPDEYAEVARLVG 738
Cdd:pfam12162   1 SRLQ--ENLMPMSPEDYGELERMVR 23

DNA-binding domain of Signal Transducer and Activator of Transcription 1 (STAT1); This family consists of the DNA-binding domain (DBD) of the STAT1 proteins (Signal Transducer and Activator of Transcription 1, or Signal Transduction And Transcription 1). The DNA binding domain has an Ig-like fold. STAT1 plays an essential role in mediating responses to all types of interferons (IFN), transducing signals from cytoplasmic domains of transmembrane receptors into the nucleus where it regulates gene expression. Thus STAT1 is involved in modulating diverse cellular processes, such as antimicrobial activities, cell proliferation and cell death. STAT1 function is crucial in the innate and adaptive arm of immunity and protects from pathogen infections; phosphorylation of a critical tyrosine by Janus kinases (JAKs) leads to its activation and nuclear translocation, while phosphorylation of a critical serine is required for full transcriptional activation upon IFN stimulation and in response to cellular stress. Transcription of protein-encoding genes (including Stat1 itself) as well as expression of microRNAs (miRNAs) is regulated by activated STAT1. Animal studies have shown that STAT1 is generally considered a tumor suppressor but it can also act as a tumor promoter; its functions are not restricted to tumor cells, but extend to parts of the tumor microenvironment such as immune cells, endothelial cells. STAT1 abundance is a reliable marker for good prognosis in selected tumor types, but it can also correlate with disease progression. In head and neck cancer (HNC) patients, upregulation of STAT1-induced HLA class I enhances immunogenicity and clinical response to anti-EGFR mAb cetuximab therapy. In systemic juvenile idiopathic arthritis (sJIA) characterized by systemic inflammation and arthritis, STAT1 phosphorylation downstream of IFNs is impaired. It exerts anti-oncogenic activities through interferon-gamma and interferon-alpha. STAT1 may inhibit hepatocellular carcinoma cell growth by regulating p53-related cell cycling and apoptosis. Studies also show a significant correlation of high STAT1 activity with longer colorectal cancer patient overall survival. Recent studies have shown that STAT1 suppresses mouse mammary gland tumorigenesis by immune regulatory as well as tumor cell-specific functions of STAT1.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1785411765 317 FVVERQPCMPTHPQRPLVLKTGVQFTVKLRLLVKLQELNYQLKVKALFDKDVNDKNIVKGFRKFNILGTHTKVMNMEEST 396
Cdd:cd16845     1 FVVERQPCMPTHPQRPLVLKTGVQFTVKLRLLVKLQELNYQLKVKVLFDKDVTEKNTVKGFRKFNILGTNTKVMNMEEST 80

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1785411765 397 NGSLAAEFRHLQLKEQKNAGSRTNEGPLIVTEELHCLSFETQLCQLGLVVDLETSSLPIVVISNVSQLPSGWASILWYNM 476
Cdd:cd16845    81 NGSLAAEFRHLQLKEQKNAGTRTNEGPLIVTEELHSLSFETQLCQPGLVIDLETTSLPIVVISNVSQLPSGWASILWYNM 160

                  .
gi 1785411765 477 L 477
Cdd:cd16845   161 L 161

Src homology 2 (SH2) domain found in signal transducer and activator of transcription (STAT) 1 proteins; STAT1 is a member of the STAT family of transcription factors. STAT1 is involved in upregulating genes due to a signal by interferons. STAT1 forms homodimers or heterodimers with STAT3 that bind to the Interferon-Gamma Activated Sequence (GAS) promoter element in response to IFN-gamma stimulation. STAT1 forms a heterodimer with STAT2 that can bind Interferon Stimulated Response Element (ISRE) promoter element in response to either IFN-alpha or IFN-beta stimulation. Binding in both cases leads to an increased expression of ISG (Interferon Stimulated Genes). STAT1 has been shown to interact with protein kinase R, Src, IRF1, STAT3, MCM5, STAT2, CD117, Fanconi anemia, complementation group C, CREB-binding protein, Interleukin 27 receptor, alpha subunit, PIAS1, BRCA1, Epidermal growth factor receptor, PTK2, Mammalian target of rapamycin, IFNAR2, PRKCD, TRADD, C-jun, Calcitriol receptor, ISGF3G, and GNB2L1. STAT proteins mediate the signaling of cytokines and a number of growth factors from the receptors of these extracellular signaling molecules to the cell nucleus. STATs are specifically phosphorylated by receptor-associated Janus kinases, receptor tyrosine kinases, or cytoplasmic tyrosine kinases. The phosphorylated STAT molecules dimerize by reciprocal binding of their SH2 domains to the phosphotyrosine residues. These dimeric STATs translocate into the nucleus, bind to specific DNA sequences, and regulate the transcription of their target genes. However there are a number of unphosphorylated STATs that travel between the cytoplasm and nucleus and some STATs that exist as dimers in unstimulated cells that can exert biological functions independent of being activated. There are seven mammalian STAT family members which have been identified: STAT1, STAT2, STAT3, STAT4, STAT5 (STAT5A and STAT5B), and STAT6. There are 6 conserved domains in STAT: N-terminal domain (NTD), coiled-coil domain (CCD), DNA-binding domain (DBD), alpha-helical linker domain (LD), SH2 domain, and transactivation domain (TAD). NTD is involved in dimerization of unphosphorylated STATs monomers and for the tetramerization between STAT1, STAT3, STAT4 and STAT5 on promoters with two or more tandem STAT binding sites. It also plays a role in promoting interactions with transcriptional co-activators such as CREB binding protein (CBP)/p300, as well as being important for nuclear import and deactivation of STATs involving tyrosine de-phosphorylation. CCD interacts with other proteins, such as IFN regulatory protein 9 (IRF-9/p48) with STAT1 and c-JUN with STAT3 and is also thought to participate in the negative regulation of these proteins. Distinct genes are bound to STATs via their DBD domain. This domain is also involved in nuclear translocation of activated STAT1 and STAT3 phosphorylated dimers upon cytokine stimulation. LD links the DNA-binding and SH2 domains and is important for the transcriptional activation of STAT1 in response to IFN-gamma. It also plays a role in protein-protein interactions and has also been implicated in the constitutive nucleocytoplasmic shuttling of unphosphorylated STATs in resting cells. The SH2 domain is necessary for receptor association and tyrosine phosphodimer formation. Residues within this domain may be particularly important for some cellular functions mediated by the STATs as well as residues adjacent to this domain. The TAD interacts with several proteins, namely minichromosome maintenance complex component 5 (MCM5), breast cancer 1 (BRCA1) and CBP/p300. TAD also contains a modulatory phosphorylation site that regulates STAT activity and is necessary for maximal transcription of a number of target genes. The conserved tyrosine residue present in the C-terminus is crucial for dimerization via interaction with the SH2 domain upon the interaction of the ligand with the receptor. STAT activation by tyrosine phosphorylation also determines nuclear import and retention, DNA binding to specific DNA elements in the promoters of responsive genes, and transcriptional activation of STAT dimers. In addition to the SH2 domain there is a coiled-coil domain, a DNA binding domain, and a transactivation domain in the STAT proteins. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1785411765 558 WIEGILELIKKHLLCLWNDGFIVGFISKERERALLKEKAPGTFLLRFSESSKEGAITFTWVERPQN--DPLFHSVEPYTK 635
Cdd:cd10372     1 WIESILELIKKHLLSLWNDGCIMGFISKERERALLKDQQPGTFLLRFSESSREGAITFTWVERSQNggEPDFHAVEPYTK 80

                          90       100       110       120       130       140       150
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 1785411765 636 RELSAVTFPDIIRNYKVMAAENIPENPLRFLYPDTPKDNAFGKYYSRPKEADEPMDLDGPKGTGYIKTELI 706
Cdd:cd10372    81 KELSAVTFPDIIRNYKVMAAENIPENPLKYLYPNIDKDHAFGKYYSRPKEAPEPMELDGPKGTGYIKTELI 151

DNA-binding domain of Signal Transducer and Activator of Transcription 2 (STAT2); This family consists of the DNA-binding domain (DBD) of the STAT2 proteins (Signal Transducer and Activator of Transcription 2, or Signal Transduction And Transcription 2). The DNA binding domain has an Ig-like fold. STAT2 activation is driven predominantly by only two classes of cell surface receptors: Type I and III interferon receptors, making it a unique STAT family of transcription factors. Thus, STAT2 plays a critical role in host defenses against viral infections since type I interferon (IFN-I) response inhibits viral replication, and sets the stage for the development of adaptive immunity; viruses target STAT2 by either inhibiting its expression, blocking its activity, or by targeting it for degradation, thus triggering remarkable divergence in the STAT2 gene across species compared to other STAT family members. STAT2 function is regulated by tyrosine phosphorylation which enables STAT dimerization, and subsequent nuclear translocation and transcriptional activation of IFN stimulated genes. Dengue virus (DENV)-mediated degradation of STAT2 has emerged as an important determinant of DENV pathogenesis and host tropism. This vector-borne flavivirus suppresses IFN1 signaling to replicate and cause disease in vertebrates via proteasome-dependent STAT2 degradation mediated by the nonstructural protein NS5 and its interaction partner UBR4, an E3 ubiquitin ligase. The mechanism of Zika virus (ZIKV) NS5 resembles DENV NS5 but through different mechanism - ZIKV does not require the UBR4 to induce STAT2 degradation. It has also been shown that the STAT2 and STAT4 genes are direct targets for transcription factor Oct-1 protein which is involved in the regulation of expression of genes of the JAK-STAT signaling pathway in the Namalwa Burkitt's lymphoma cell line.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1785411765 317 FVVERQPCMPTHPQRPLVLKTGVQFTVKLRLLVKLQELNYQLKVKALFDKDVNDkniVKGFRKFNILGTHTKVMNMEEST 396
Cdd:cd16846     1 FVVETQPCMPQPPRRPLVLKTNTQFSVRVRLLVKLPELNHSLKVEVSVDKNPPN---SKGFRRFNILGTNNKTLNMDEGQ 77

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1785411765 397 NGSLAAEFRHLQLKEQK--NAGSRTNEGPLIVTEELHCLSFETQLCQLGLVVDLETSSLPIVVISNVSQLPSGWASILWY 474
Cdd:cd16846    78 SGGLVADFRHLTLKEQKvgGGGKGSNEGSLSVTEELHLITFTTDYKYQGLKVKLETSTLPVVVISNMSQLSSAWASVLWF 157

                  ...
gi 1785411765 475 NML 477
Cdd:cd16846   158 NLL 160

STAT protein, all-alpha domain; STAT proteins (Signal Transducers and Activators of Transcription) are a family of transcription factors that are specifically activated to regulate gene transcription when cells encounter cytokines and growth factors. STAT proteins also include an SH2 domain pfam00017.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1785411765 143 DKKVTDVRNRALEVEQDVKLLEDLQDEYDFKYKTVQSRENEHNGLAQNELKKEKMLLSNMHIHVLLKRKAIIHKIAELMS 222
Cdd:pfam01017   1 EQRLEELRNRVQETEQDIKQLEDLQDEFDFKYKTLQKLQQERTESEDKELKQQKELLQQMLNALDQKRKEVLDKLKELLN 80

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1785411765 223 VTDHTQNALINEELVEWKHRQQIACIGGPPNACLDQLQSWFTTIAKSLQQVRQQLKKLEELEQKLTYDGDPITCNKQALQ 302
Cdd:pfam01017  81 LLETLQELLLDEELIEWKRRQQLACIGAPPNACLDQLQNWFTALAESLWQLRQQLKKLEELRQKLTYEGDPLTDGLPQLN 160

                  ....*..
gi 1785411765 303 ERTQSLF 309
Cdd:pfam01017 161 ERVTELL 167

Src homology 2 (SH2) domain found in signal transducer and activator of transcription (STAT) 3 proteins; STAT3 encoded by this gene is a member of the STAT protein family. STAT3 mediates the expression of a variety of genes in response to cell stimuli, and plays a key role in many cellular processes such as cell growth and apoptosis. The small GTPase Rac1 regulates the activity of STAT3 and PIAS3 inhibits it. Three alternatively spliced transcript variants encoding distinct isoforms have been described. STAT 3 activation is required for self-renewal of embryonic stem cells (ESCs) and is essential for the differentiation of the TH17 helper T cells. Mutations in the STAT3 gene result in Hyperimmunoglobulin E syndrome and human cancers. STAT3 has been shown to interact with Androgen receptor, C-jun, ELP2, EP300, Epidermal growth factor receptor, Glucocorticoid receptor, HIF1A, Janus kinase 1, KHDRBS1, Mammalian target of rapamycin, MyoD, NDUFA13, NFKB1, Nuclear receptor coactivator 1, Promyelocytic leukemia protein, RAC1, RELA, RET proto-oncogene, RPA2, Src, STAT1, and TRIP10. STAT proteins mediate the signaling of cytokines and a number of growth factors from the receptors of these extracellular signaling molecules to the cell nucleus. STATs are specifically phosphorylated by receptor-associated Janus kinases, receptor tyrosine kinases, or cytoplasmic tyrosine kinases. The phosphorylated STAT molecules dimerize by reciprocal binding of their SH2 domains to the phosphotyrosine residues. These dimeric STATs translocate into the nucleus, bind to specific DNA sequences, and regulate the transcription of their target genes. However there are a number of unphosphorylated STATs that travel between the cytoplasm and nucleus and some STATs that exist as dimers in unstimulated cells that can exert biological functions independent of being activated. There are seven mammalian STAT family members which have been identified: STAT1, STAT2, STAT3, STAT4, STAT5 (STAT5A and STAT5B), and STAT6. There are 6 conserved domains in STAT: N-terminal domain (NTD), coiled-coil domain (CCD), DNA-binding domain (DBD), alpha-helical linker domain (LD), SH2 domain, and transactivation domain (TAD). NTD is involved in dimerization of unphosphorylated STATs monomers and for the tetramerization between STAT1, STAT3, STAT4 and STAT5 on promoters with two or more tandem STAT binding sites. It also plays a role in promoting interactions with transcriptional co-activators such as CREB binding protein (CBP)/p300, as well as being important for nuclear import and deactivation of STATs involving tyrosine de-phosphorylation. CCD interacts with other proteins, such as IFN regulatory protein 9 (IRF-9/p48) with STAT1 and c-JUN with STAT3 and is also thought to participate in the negative regulation of these proteins. Distinct genes are bound to STATs via their DBD domain. This domain is also involved in nuclear translocation of activated STAT1 and STAT3 phosphorylated dimers upon cytokine stimulation. LD links the DNA-binding and SH2 domains and is important for the transcriptional activation of STAT1 in response to IFN-gamma. It also plays a role in protein-protein interactions and has also been implicated in the constitutive nucleocytoplasmic shuttling of unphosphorylated STATs in resting cells. The SH2 domain is necessary for receptor association and tyrosine phosphodimer formation. Residues within this domain may be particularly important for some cellular functions mediated by the STATs as well as residues adjacent to this domain. The TAD interacts with several proteins, namely minichromosome maintenance complex component 5 (MCM5), breast cancer 1 (BRCA1) and CBP/p300. TAD also contains a modulatory phosphorylation site that regulates STAT activity and is necessary for maximal transcription of a number of target genes. The conserved tyrosine residue present in the C-terminus is crucial for dimerization via interaction with the SH2 domain upon the interaction of the ligand with the receptor. STAT activation by tyrosine phosphorylation also determines nuclear import and retention, DNA binding to specific DNA elements in the promoters of responsive genes, and transcriptional activation of STAT dimers. In addition to the SH2 domain there is a coiled-coil domain, a DNA binding domain, and a transactivation domain in the STAT proteins. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1785411765 548 MNDKNFPFWLWIEGILELIKKHLLCLWNDGFIVGFISKERERALLKEKAPGTFLLRFSESSKEGAITFTWVERPQNDPL- 626
Cdd:cd10374     1 MAGKGFSFWVWLDNIIDLVKKYILALWNEGYIMGFISKERERAILSTKPPGTFLLRFSESSKEGGVTFTWVEKDISGKTq 80

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1785411765 627 FHSVEPYTKRELSAVTFPDIIRNYKVMAAENIPENPLRFLYPDTPKDNAFGKyYSRPKEADEPmDLDGPKGTGYIKTELI 706
Cdd:cd10374    81 IQSVEPYTKQQLNNMSFAEIIMGYKIMDATNILVSPLVYLYPDIPKEEAFGK-YCRPESQEHP-EADPGSAAPYLKTKFI 158

                  ...
gi 1785411765 707 SVS 709
Cdd:cd10374   159 CVT 161

STAT protein, DNA binding domain; STAT proteins (Signal Transducers and Activators of Transcription) are a family of transcription factors that are specifically activated to regulate gene transcription when cells encounter cytokines and growth factors. This family represents the DNA binding domain of STAT, which has an ig-like fold. STAT proteins also include an SH2 domain pfam00017.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1785411765 330 QRPLVLKTGVQFTVKLRLLVKLQ---ELNYQLKVKALFDKDVNDKNIVKGFRKFNILG--THTKVMNMEESTNGSLAAEF 404
Cdd:pfam02864   2 QPPQVLKTNTKFSVTVRLLVGLPlniELNPQVKVKIVSEKQARELQQIKGFRKFNISGeiLNNKALLEYESQNGGLSAEF 81

                          90       100       110       120       130
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1785411765 405 RHLQLKEQKNAGsrtNEGPLIVTEELHCLSFETQLCQLGLVVDLETSSLPIVVI 458
Cdd:pfam02864  82 RNLSLKEIKRGE---RKGSLSVTEEKFALLFETQFTLGGLVFDLWTLSLPVVVI 132

STAT protein, protein interaction domain; STAT proteins (Signal Transducers and Activators of Transcription) are a family of transcription factors that are specifically activated to regulate gene transcription when cells encounter cytokines and growth factors. STAT proteins also include an SH2 domain pfam00017.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1785411765   2 AQWYELQQIDTKFLEQVHQLYDDSFPMEIRQYLAQWLESQDWEHAANNVSLATILFHGLLSQLDDQYSRFSLENNFLLQH 81
Cdd:pfam02865   1 SLWAQLQQLDGEALEQVQQLYGDHFPIEVRHYLAQWIESQDWEDAAQDESLATVLFHALLSELDSQASRFVQEDNFLLKH 80

                          90       100       110
                  ....*....|....*....|....*....|....*...
gi 1785411765  82 NIRKSKRNLQDHFQEDPVQMAMIINSCLREESKILGNA 119
Cdd:pfam02865  81 KLREIAKNLQSRYQENPLELARIIRNCLREERRILQEA 118

Src homology 2 (SH2) domain found in signal transducer and activator of transcription (STAT) 2 proteins; STAT2 is a member of the STAT protein family. In response to interferon, STAT2 forms a complex with STAT1 and IFN regulatory factor family protein p48 (ISGF3G), in which this protein acts as a transactivator, but lacks the ability to bind DNA directly. Transcription adaptor P300/CBP (EP300/CREBBP) has been shown to interact specifically with STAT2, which is thought to be involved in the process of blocking IFN-alpha response by adenovirus. STAT2 has been shown to interact with MED14, CREB-binding protein, SMARCA4, STAT1, IFNAR2, IFNAR1, and ISGF3G. STAT proteins mediate the signaling of cytokines and a number of growth factors from the receptors of these extracellular signaling molecules to the cell nucleus. STATs are specifically phosphorylated by receptor-associated Janus kinases, receptor tyrosine kinases, or cytoplasmic tyrosine kinases. The phosphorylated STAT molecules dimerize by reciprocal binding of their SH2 domains to the phosphotyrosine residues. These dimeric STATs translocate into the nucleus, bind to specific DNA sequences, and regulate the transcription of their target genes. However there are a number of unphosphorylated STATs that travel between the cytoplasm and nucleus and some STATs that exist as dimers in unstimulated cells that can exert biological functions independent of being activated. There are seven mammalian STAT family members which have been identified: STAT1, STAT2, STAT3, STAT4, STAT5 (STAT5A and STAT5B), and STAT6. There are 6 conserved domains in STAT: N-terminal domain (NTD), coiled-coil domain (CCD), DNA-binding domain (DBD), alpha-helical linker domain (LD), SH2 domain, and transactivation domain (TAD). NTD is involved in dimerization of unphosphorylated STATs monomers and for the tetramerization between STAT1, STAT3, STAT4 and STAT5 on promoters with two or more tandem STAT binding sites. It also plays a role in promoting interactions with transcriptional co-activators such as CREB binding protein (CBP)/p300, as well as being important for nuclear import and deactivation of STATs involving tyrosine de-phosphorylation. CCD interacts with other proteins, such as IFN regulatory protein 9 (IRF-9/p48) with STAT1 and c-JUN with STAT3 and is also thought to participate in the negative regulation of these proteins. Distinct genes are bound to STATs via their DBD domain. This domain is also involved in nuclear translocation of activated STAT1 and STAT3 phosphorylated dimers upon cytokine stimulation. LD links the DNA-binding and SH2 domains and is important for the transcriptional activation of STAT1 in response to IFN-gamma. It also plays a role in protein-protein interactions and has also been implicated in the constitutive nucleocytoplasmic shuttling of unphosphorylated STATs in resting cells. The SH2 domain is necessary for receptor association and tyrosine phosphodimer formation. Residues within this domain may be particularly important for some cellular functions mediated by the STATs as well as residues adjacent to this domain. The TAD interacts with several proteins, namely minichromosome maintenance complex component 5 (MCM5), breast cancer 1 (BRCA1) and CBP/p300. TAD also contains a modulatory phosphorylation site that regulates STAT activity and is necessary for maximal transcription of a number of target genes. The conserved tyrosine residue present in the C-terminus is crucial for dimerization via interaction with the SH2 domain upon the interaction of the ligand with the receptor. STAT activation by tyrosine phosphorylation also determines nuclear import and retention, DNA binding to specific DNA elements in the promoters of responsive genes, and transcriptional activation of STAT dimers. In addition to the SH2 domain there is a coiled-coil domain, a DNA binding domain, and a transactivation domain in the STAT proteins. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1785411765 558 WIEGILELIKKHLLCLWNDGFIVGFISKERERALLKEKAPGTFLLRFSESSkEGAITFTWVERPQNDP-LFHSVEPYTKR 636
Cdd:cd10373     1 WLDKILELVHDHLKDLWKDGRIMGFVSRNQERRLLKKTISGTFLLRFSETS-EGGITCSWVEHQDDDKvLIYSVQPYTKE 79

                          90       100       110       120       130       140       150
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1785411765 637 ELSAVTFPDIIRNYKVMAAENIPENPLRFLYPDTPKDNAFGKYYSRPKEADEPMDldgpkgtgYIKTELISVS 709
Cdd:cd10373    80 VLQSLPLTEIIRHYQLLTEENIPENPLRFLYPRIPRDEAFGCYYQEKVNLEEREK--------YLKHKLIVVS 144

Coiled-coil domain of Signal Transducer and Activator of Transcription 4 (STAT4); This family consists of the coiled-coil (alpha) domain of the STAT4 proteins (Signal Transducer and Activator of Transcription 4, or Signal Transduction And Transcription 4). STAT4 expression is restricted to spermatozoa, myeloid cells, and T lymphocytes, making it distinct from other STATs. It acts as the major signaling transducing STATs in response to interleukin-12 (IL-12) by inducing interferon-gamma (IFNgamma), and is a central mediator in generating inflammation during protective immune responses and immune-mediated diseases. STAT4 is a critical regulator of Th1 differentiation and inflammatory disease. It is essential for the differentiation and function of many immune cells, including natural killer cells, dendritic cells, mast cells and T helper cells. STAT4-mediated signaling promotes the production of autoimmune-associated components, which are implicated in the pathogenesis of autoimmune diseases, such as rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis and psoriasis, making STAT4 a promising therapeutic target for autoimmune diseases. Variations in STAT4 gene are linked to the development of systemic lupus erythematosus (SLE) in humans. STAT4 activation is detected in chronic liver diseases; polymorphism in STAT4 gene has been shown to be associated with the antiviral response in primary biliary cirrhosis (PBC), HCV-associated liver fibrosis, hepatocellular carcinoma (HCC), chronic hepatitis C and in drug-induced liver injury (DILI). STAT4 may inhibit HCC development by modulating HCC cell proliferation. Studies show that increased expression of STAT4 is positively correlated with the depth of invasion in colorectal cancer (CRC) patients, and the growth and invasion of CRC cells are repressed by inhibition of STAT4 expression, making STAT4 a promising therapeutic target for the treatment of CRC.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1785411765 139 QKELDKKVTDVRNRALEVEQDVKLLEDLQDEYDFKYKTVQSRENEHNGLAQneLKKEKMLLSNMHIHVLLKRKAIIHKIA 218
Cdd:cd16854     1 QRNVEHKVSAIKNSVQMTDQDTKYLEDLQDEFDFRYKTIQTMDQGDKNSIL--MKQEVTTLQEMLNSLDFKRKEALSKMT 78

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1785411765 219 ELMSVTDHTQNALINEELVEWKHRQQIACIGGPPNACLDQLQSWFTTIAKSLQQVRQQLKKLEELEQKLTYDGDPITCNK 298
Cdd:cd16854    79 QIINEIDLLMSSMLTEELKDWKRRQQIACIGGPLHGGLDQLQNWFTLLAESLFQLRRQLEKLDELSTKVTYEGDPIPLQR 158

                         170
                  ....*....|....*
gi 1785411765 299 QALQERTQSLFKQLL 313
Cdd:cd16854   159 PQLLERVTFLIYNLF 173

Src homology 2 (SH2) domain found in signal transducer and activator of transcription (STAT) 6 proteins; STAT6 mediate signals from the IL-4 receptor. Unlike the other STAT proteins which bind an IFNgamma Activating Sequence (GAS), STAT6 stands out as having a unique binding site preference. This site consists of a palindromic sequence separated by a 3 bp spacer (TTCNNNG-AA)(N3 site). STAT6 is able to bind the GAS site but only at a low affinity. STAT6 may be an important regulator of mitogenesis when cells respond normally to IL-4. There is speculation that the inappropriate activation of STAT6 is involved in uncontrolled cell growth in an oncogenic state. IFNgamma is a negative regulator of STAT6 dependent transcription of target genes. Bcl-6 is another negative regulator of STAT6 activity. Bcl-6 is a transcriptional repressor normally expressed in germinal center B cells and some T cells. IL-4 signaling via STAT6 initially occurs unopposed, but is then dampened by a negative feedback mechanism through the IL-4/Stat6 dependent induction of SOCS1 expression. The IL-4 dependent aspect of Th2 differentiation requires the activation of STAT6. IL-4 signaling and STAT6 appear to play an important role in the immune response. Recently, it was shown that large scale chromatin remodeling of the IL-4 gene occurs as cells differentiate into Th2 effectors is STAT6 dependent. STAT proteins mediate the signaling of cytokines and a number of growth factors from the receptors of these extracellular signaling molecules to the cell nucleus. STATs are specifically phosphorylated by receptor-associated Janus kinases, receptor tyrosine kinases, or cytoplasmic tyrosine kinases. The phosphorylated STAT molecules dimerize by reciprocal binding of their SH2 domains to the phosphotyrosine residues. These dimeric STATs translocate into the nucleus, bind to specific DNA sequences, and regulate the transcription of their target genes. However there are a number of unphosphorylated STATs that travel between the cytoplasm and nucleus and some STATs that exist as dimers in unstimulated cells that can exert biological functions independent of being activated. There are seven mammalian STAT family members which have been identified: STAT1, STAT2, STAT3, STAT4, STAT5 (STAT5A and STAT5B), and STAT6. There are 6 conserved domains in STAT: N-terminal domain (NTD), coiled-coil domain (CCD), DNA-binding domain (DBD), alpha-helical linker domain (LD), SH2 domain, and transactivation domain (TAD). NTD is involved in dimerization of unphosphorylated STATs monomers and for the tetramerization between STAT1, STAT3, STAT4 and STAT5 on promoters with two or more tandem STAT binding sites. It also plays a role in promoting interactions with transcriptional co-activators such as CREB binding protein (CBP)/p300, as well as being important for nuclear import and deactivation of STATs involving tyrosine de-phosphorylation. CCD interacts with other proteins, such as IFN regulatory protein 9 (IRF-9/p48) with STAT1 and c-JUN with STAT3 and is also thought to participate in the negative regulation of these proteins. Distinct genes are bound to STATs via their DBD domain. This domain is also involved in nuclear translocation of activated STAT1 and STAT3 phosphorylated dimers upon cytokine stimulation. LD links the DNA-binding and SH2 domains and is important for the transcriptional activation of STAT1 in response to IFN-gamma. It also plays a role in protein-protein interactions and has also been implicated in the constitutive nucleocytoplasmic shuttling of unphosphorylated STATs in resting cells. The SH2 domain is necessary for receptor association and tyrosine phosphodimer formation. Residues within this domain may be particularly important for some cellular functions mediated by the STATs as well as residues adjacent to this domain. The TAD interacts with several proteins, namely minichromosome maintenance complex component 5 (MCM5), breast cancer 1 (BRCA1) and CBP/p300. TAD also contains a modulatory phosphorylation site that regulates STAT activity and is necessary for maximal transcription of a number of target genes. The conserved tyrosine residue present in the C-terminus is crucial for dimerization via interaction with the SH2 domain upon the interaction of the ligand with the receptor. STAT activation by tyrosine phosphorylation also determines nuclear import and retention, DNA binding to specific DNA elements in the promoters of responsive genes, and transcriptional activation of STAT dimers. In addition to the SH2 domain there is a coiled-coil domain, a DNA binding domain, and a transactivation domain in the STAT proteins. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1785411765 558 WIEGILELIKKHLLCLWNDGFIVGFISKERERALLKEKAPGTFLLRFSEsSKEGAITFTWVERPQNDPL-FHSVEPYTKR 636
Cdd:cd10377     1 WFDGVLDLTKRCLRSYWSDRLIIGFISKQYVTSLLLNEPDGTFLLRFSD-SEIGGITIAHVIRGQDGSPqIENIQPFSAK 79

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 1785411765 637 ELSAVTFPDIIRNYKvmaaenipenPLRFLYPDTPKDNAFGKYYSRPKeadepmdldGPKGTGYIKTEL 705
Cdd:cd10377    80 DLSIRSLGDRIRDLA----------QLKNLYPKKPKDEAFRSHYKPEQ---------MKDGRGYVPATI 129

Src homology 2 (SH2) domain found in signal transducer and activator of transcription (STAT) 5 proteins; STAT5 is a member of the STAT family of transcription factors. Two highly related proteins, STAT5a and STAT5b are encoded by separate genes, but are 90% identical at the amino acid level. Both STAT5a and STAT5b are ubiquitously expressed and functionally interchangeable. Mice lacking either STAT5a or STAT5b have mild defects in prolactin dependent mammary differentiation or sexually dimorphic growth hormone-dependent effects, respectively. Mice lacking both STAT5a and STAT5b exhibit a perinatal lethal phenotype and have multiple defects, including anemia and a virtual absence of B and T lymphocytes. STAT proteins mediate the signaling of cytokines and a number of growth factors from the receptors of these extracellular signaling molecules to the cell nucleus. STATs are specifically phosphorylated by receptor-associated Janus kinases, receptor tyrosine kinases, or cytoplasmic tyrosine kinases. The phosphorylated STAT molecules dimerize by reciprocal binding of their SH2 domains to the phosphotyrosine residues. These dimeric STATs translocate into the nucleus, bind to specific DNA sequences, and regulate the transcription of their target genes. However there are a number of unphosphorylated STATs that travel between the cytoplasm and nucleus and some STATs that exist as dimers in unstimulated cells that can exert biological functions independent of being activated. There are seven mammalian STAT family members which have been identified: STAT1, STAT2, STAT3, STAT4, STAT5 (STAT5A and STAT5B), and STAT6. There are 6 conserved domains in STAT: N-terminal domain (NTD), coiled-coil domain (CCD), DNA-binding domain (DBD), alpha-helical linker domain (LD), SH2 domain, and transactivation domain (TAD). NTD is involved in dimerization of unphosphorylated STATs monomers and for the tetramerization between STAT1, STAT3, STAT4 and STAT5 on promoters with two or more tandem STAT binding sites. It also plays a role in promoting interactions with transcriptional co-activators such as CREB binding protein (CBP)/p300, as well as being important for nuclear import and deactivation of STATs involving tyrosine de-phosphorylation. CCD interacts with other proteins, such as IFN regulatory protein 9 (IRF-9/p48) with STAT1 and c-JUN with STAT3 and is also thought to participate in the negative regulation of these proteins. Distinct genes are bound to STATs via their DBD domain. This domain is also involved in nuclear translocation of activated STAT1 and STAT3 phosphorylated dimers upon cytokine stimulation. LD links the DNA-binding and SH2 domains and is important for the transcriptional activation of STAT1 in response to IFN-gamma. It also plays a role in protein-protein interactions and has also been implicated in the constitutive nucleocytoplasmic shuttling of unphosphorylated STATs in resting cells. The SH2 domain is necessary for receptor association and tyrosine phosphodimer formation. Residues within this domain may be particularly important for some cellular functions mediated by the STATs as well as residues adjacent to this domain. The TAD interacts with several proteins, namely minichromosome maintenance complex component 5 (MCM5), breast cancer 1 (BRCA1) and CBP/p300. TAD also contains a modulatory phosphorylation site that regulates STAT activity and is necessary for maximal transcription of a number of target genes. The conserved tyrosine residue present in the C-terminus is crucial for dimerization via interaction with the SH2 domain upon the interaction of the ligand with the receptor. STAT activation by tyrosine phosphorylation also determines nuclear import and retention, DNA binding to specific DNA elements in the promoters of responsive genes, and transcriptional activation of STAT dimers. In addition to the SH2 domain there is a coiled-coil domain, a DNA binding domain, and a transactivation domain in the STAT proteins.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1785411765 558 WIEGILELIKKHLLCLWNDGFIVGFISKERERALLKEKAPGTFLLRFSEsSKEGAITFTW-VERPqnDPLFHSVEPYTKR 636
Cdd:cd10376     1 WFDGVMEVLKKHLKPHWNDGAILGFVNKQQAHDLLINKPDGTFLLRFSD-SEIGGITIAWkFDSP--DRALWNLMPFTTR 77

                          90       100       110       120       130       140       150
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1785411765 637 ELSAVTFPDIIRNYkvmaaenipeNPLRFLYPDTPKDNAFGKYYSrpkeadePMDLDGPKGTGYIKTELISV 708
Cdd:cd10376    78 DFSIRSLADRLGDL----------NYLIYVFPDRPKDEVFSKYYT-------PVLCNPSAVDGYVKPQIKQV 132

Src homology 2 (SH2) domain found in signal transducer and activator of transcription (STAT) 5a proteins; STAT5 is a member of the STAT family of transcription factors. Two highly related proteins, STAT5a and STAT5b are encoded by separate genes, but are 90% identical at the amino acid level. Both STAT5a and STAT5b are ubiquitously expressed and functionally interchangeable. Mice lacking either STAT5a or STAT5b have mild defects in prolactin dependent mammary differentiation or sexually dimorphic growth hormone-dependent effects, respectively. Mice lacking both STAT5a and STAT5b exhibit a perinatal lethal phenotype and have multiple defects, including anemia and a virtual absence of B and T lymphocytes. STAT proteins mediate the signaling of cytokines and a number of growth factors from the receptors of these extracellular signaling molecules to the cell nucleus. STATs are specifically phosphorylated by receptor-associated Janus kinases, receptor tyrosine kinases, or cytoplasmic tyrosine kinases. The phosphorylated STAT molecules dimerize by reciprocal binding of their SH2 domains to the phosphotyrosine residues. These dimeric STATs translocate into the nucleus, bind to specific DNA sequences, and regulate the transcription of their target genes. However there are a number of unphosphorylated STATs that travel between the cytoplasm and nucleus and some STATs that exist as dimers in unstimulated cells that can exert biological functions independent of being activated. There are seven mammalian STAT family members which have been identified: STAT1, STAT2, STAT3, STAT4, STAT5 (STAT5A and STAT5B), and STAT6. There are 6 conserved domains in STAT: N-terminal domain (NTD), coiled-coil domain (CCD), DNA-binding domain (DBD), alpha-helical linker domain (LD), SH2 domain, and transactivation domain (TAD). NTD is involved in dimerization of unphosphorylated STATs monomers and for the tetramerization between STAT1, STAT3, STAT4 and STAT5 on promoters with two or more tandem STAT binding sites. It also plays a role in promoting interactions with transcriptional co-activators such as CREB binding protein (CBP)/p300, as well as being important for nuclear import and deactivation of STATs involving tyrosine de-phosphorylation. CCD interacts with other proteins, such as IFN regulatory protein 9 (IRF-9/p48) with STAT1 and c-JUN with STAT3 and is also thought to participate in the negative regulation of these proteins. Distinct genes are bound to STATs via their DBD domain. This domain is also involved in nuclear translocation of activated STAT1 and STAT3 phosphorylated dimers upon cytokine stimulation. LD links the DNA-binding and SH2 domains and is important for the transcriptional activation of STAT1 in response to IFN-gamma. It also plays a role in protein-protein interactions and has also been implicated in the constitutive nucleocytoplasmic shuttling of unphosphorylated STATs in resting cells. The SH2 domain is necessary for receptor association and tyrosine phosphodimer formation. Residues within this domain may be particularly important for some cellular functions mediated by the STATs as well as residues adjacent to this domain. The TAD interacts with several proteins, namely minichromosome maintenance complex component 5 (MCM5), breast cancer 1 (BRCA1) and CBP/p300. TAD also contains a modulatory phosphorylation site that regulates STAT activity and is necessary for maximal transcription of a number of target genes. The conserved tyrosine residue present in the C-terminus is crucial for dimerization via interaction with the SH2 domain upon the interaction of the ligand with the receptor. STAT activation by tyrosine phosphorylation also determines nuclear import and retention, DNA binding to specific DNA elements in the promoters of responsive genes, and transcriptional activation of STAT dimers. In addition to the SH2 domain there is a coiled-coil domain, a DNA binding domain, and a transactivation domain in the STAT proteins. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1785411765 558 WIEGILELIKKHLLCLWNDGFIVGFISKERERALLKEKAPGTFLLRFSEsSKEGAITFTW-VERPQNDplFHSVEPYTKR 636
Cdd:cd10421     1 WFDGVMEVLKKHHKPHWNDGAILGFVNKQQAHDLLINKPDGTFLLRFSD-SEIGGITIAWkFDSPDRN--LWNLKPFTTR 77

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....*
gi 1785411765 637 ELSAVTFPDIIRNYkvmaaenipeNPLRFLYPDTPKDNAFGKYYS 681
Cdd:cd10421    78 DFSIRSLADRLGDL----------NYLIYVFPDRPKDEVFSKYYT 112

Coiled-coil domain of Signal Transducer and Activator of Transcription 5 (STAT5); This family consists of the coiled-coil (alpha) domain of the STAT5 proteins (Signal Transducer and Activator of Transcription 5, or Signal Transduction And Transcription 5) which include STAT5A and STAT5B, both of which are >90% identical despite being encoded by separate genes. The coiled-coil domain (CCD) of STAT5A and STAT5B appears to be required for constitutive nuclear localization signals (NLS) function; small deletions within the CCD can abrogate nuclear import. Studies show that the CCD binds to the importin-alpha3 NLS adapter in most cells. STAT5A and STAT5B regulate erythropoiesis, lymphopoiesis, and the maintenance of the hematopoietic stem cell population. STAT5A and STAT5B have overlapping and redundant functions; both isoforms can be activated by the same set of cytokines, but some cytokines preferentially activate either STAT5A or STAT5B, e.g. during pregnancy and lactation, STAT5A rather than STAT5B is required for the production of luminal progenitor cells from mammary stem cells and is essential for the differentiation of milk producing alveolar cells during pregnancy. STAT5 has been found to be constitutively phosphorylated in cancer cells, and therefore constantly activated, either by aberrant cell signaling expression or by mutations. It differentially regulates cellular behavior in human mammary carcinoma. Prolactin (PRL) in the prostate gland can induce growth and survival of prostate cancer cells and tissues through the activation of STAT5, its downstream target; PRL expression and STAT5 activation correlates with disease severity. STAT5A and STAT5B are central signaling molecules in leukemias driven by Abelson fusion tyrosine kinases, displaying unique nuclear shuttling mechanisms and having a key role in resistance of leukemic cells against treatment with tyrosine kinase inhibitors (TKI). In addition, STAT5A and STAT5B promote survival of leukemic stem cells. STAT5 is a key transcription factor for IL-3-mediated inhibition of RANKL-induced osteoclastogenesis via the induction of the expression of Id genes. Autosomal recessive STAT5B mutations are associated with severe growth failure, insulin-like growth factor (IGF) deficiency and growth hormone insensitivity (GHI) syndrome. STAT5B deficiency can lead to potentially fatal primary immunodeficiency.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1785411765 137 DKQKELDKKVTDVRNRALEVEQDVKLLEDLQDEYDFKYKTVQSRENEHNGLAQNE----------LKKEKMLLSNMH--- 203
Cdd:cd16855     1 DSHLEIRQQLEELRQRTQETENDLRNLQQKQESFVIQYQESQKIQAQLQQLQQQPqnerieleqqLQQQKEQLEQLLnak 80

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1785411765 204 IHVLL-KRKAIIHKIAELMSVTDHTQNALINEELVEWKHRQQIACIGGPPNACLDQLQSWFTTIAKSLQQVRQQLKKLEE 282
Cdd:cd16855    81 AQELLqLRMELADKFKKTIQLLSKLQSRVLDEELIQWKRQQQLAGNGAPFESNLDTIQEWCESLAEIIWQNRQQIKRAER 160

                         170       180       190
                  ....*....|....*....|....*....|
gi 1785411765 283 LEQKLTYDGDPitcnkqALQERTQSLFKQL 312
Cdd:cd16855   161 LKQKLPIPLPP------EQKDMLPILNKQI 184

Coiled-coil domain of Signal Transducer and Activator of Transcription 6 (STAT6); This family consists of the coiled-coil (alpha) domain of the STAT6 proteins (Signal Transducer and Activator of Transcription 6, or Signal Transduction And Transcription 6). SImilar to STAT3 and STAT5. the coiled-coil domain (CCD) of STAT6 is required for constitutive nuclear localization signals (NLS) function; small deletions within the CCD can abrogate nuclear import. Studies show that the CCD binds to the importin-alpha3 NLS adapter in most cells.STAT6 is essential for the functional responses of T helper 2 (Th2) lymphocyte mediated by interleukins IL-4 and IL-13. STAT6 almost exclusively mediates the expression of genes activated by these cytokines; IL-4 signaling regulates the expression of genes involved in immune and anti-inflammatory responses. Abnormal production of IL-4 and IL-13 play important roles in the pathogenesis of asthma where upregulation of the Th2 response mediated by IL-4/IL-13 is a main characteristic. STAT6 has a unique extended transactivation domain, not found in other STATs, through which it recruits p300/CBP and NCoA-1, two coactivators needed for transcriptional activation by IL-4. STAT6 activation is linked to Kaposi's sarcoma-associated herpesvirus (KSHV)-associated cancers such as primary effusion lymphoma, a cancerous proliferation of B cells. Studies show that Meningeal solitary fibrous tumor (SFT) and hemangiopericytoma (HPC) represent a histopathologic spectrum linked by STAT6 nuclear expression and recurrent somatic fusions of the two genes, NGFI-A-binding protein 2 (NAB2) and STAT6 (NAB2-STAT6), similar to their soft tissue counterparts. It is associated with local recurrence and late distance metastasis of brain tumors to extracranial sites.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1785411765 239 WKHRQQIACIGGPPNACLDQLQSWFTTIAKSLQQVRQQLKKLEELEQKLTYDGdpitcnkqaLQERTQSLFKQLLQSSFV 318
Cdd:cd16856    95 WKRQQQLAGNGAPFDENLSPLQTRCEQLVDVNFQLRQEVMLAGGELGSELLST---------LQERLNSLLQTLIQSSLV 165

                  ..
gi 1785411765 319 VE 320
Cdd:cd16856   166 VE 167

STAT1 TAZ2 binding domain; This domain family is found in eukaryotes, and is approximately 20 amino acids in length, and the family is found in association with pfam02865, pfam00017, pfam01017, pfam02864. This domain is the C terminal domain of STAT1. This domain binds selectively to the TAZ2 domain of CRB (CREB-binding protein). In this process it becomes a transcriptional activator and can initiate transcription of certain genes.

                          10        20
                  ....*....|....*....|....*
gi 1785411765 714 SRLQttEFLLPMSPDEYAEVARLVG 738
Cdd:pfam12162   1 SRLQ--ENLMPMSPEDYGELERMVR 23

Src homology 2 (SH2) domain; In general, SH2 domains are involved in signal transduction; they bind pTyr-containing polypeptide ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites. They are present in a wide array of proteins including: adaptor proteins (Nck1, Crk, Grb2), scaffolds (Slp76, Shc, Dapp1), kinases (Src, Syk, Fps, Tec), phosphatases (Shp-1, Shp-2), transcription factors (STAT1), Ras signaling molecules (Ras-Gap), ubiquitination factors (c-Cbl), cytoskeleton regulators (Tensin), signal regulators (SAP), and phospholipid second messengers (PLCgamma), amongst others.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 1785411765 581 GFISKERERALLKEKAPGTFLLRFSESSKEG-AITFTW-VERPQNDPLFHSVEPYTKRELSAVTFPDI 646
Cdd:cd00173     5 GSISREEAERLLRGKPDGTFLVRESSSEPGDyVLSVRSgDGKVKHYLIERNEGGYYLLGGSGRTFPSL 72