Protein Kinases, catalytic domain; The protein kinase superfamily is mainly composed of the catalytic domains of serine/threonine-specific and tyrosine-specific protein kinases. It also includes RIO kinases, which are atypical serine protein kinases, aminoglycoside phosphotransferases, and choline kinases. These proteins catalyze the transfer of the gamma-phosphoryl group from ATP to hydroxyl groups in specific substrates such as serine, threonine, or tyrosine residues of proteins.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 115532264   1 MLSGQVPFHARSRQESATEIMQRICRAEFSFTGDAWTNVSADAKNLITGLLTVDPKKRLSMQELTAHMWLKSSASM-DTP 79
Cdd:cd14092  198 MLSGQVPFQSPSRNESAAEIMKRIKSGDFSFDGEEWKNVSSEAKSLIQGLLTVDPSKRLTMSELRNHPWLQGSSSPsSTP 277

                         90       100       110
                 ....*....|....*....|....*....|....
gi 115532264  80 LQTPSILPSSADET---FNETLRAFLHANRDGFH 110
Cdd:cd14092  278 LMTPGVLSSSAAAVstaLRATFDAFHLAFREGFR 311

C-terminal catalytic domain of the Serine/Threonine Kinase, Mitogen and stress-activated kinase; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. MSKs contain an N-terminal kinase domain (NTD) from the AGC family and a C-terminal kinase domain (CTD) from the CAMK family. MSKs are activated by two major signaling cascades, the Ras-MAPK and p38 stress kinase pathways, in response to various stimuli such as growth factors, hormones, neurotransmitters, cellular stress, and pro-inflammatory cytokines. This triggers phosphorylation in the activation loop (A-loop) of the CTD of MSK. The active CTD phosphorylates the hydrophobic motif (HM) in the C-terminal extension of NTD, which facilitates the phosphorylation of the A-loop and activates the NTD, which in turn phosphorylates downstream targets. MSKs are predominantly nuclear proteins. They are widely expressed in many tissues including heart, brain, lung, liver, kidney, and pancreas. There are two isoforms of MSK, called MSK1 and MSK2. The MSK subfamily is part of a larger superfamily that includes the catalytic domains of other STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 115532264   1 MLSGQVPFHARSRQESATEIMQRICRAEFSFTGDAWTNVSADAKNLITGLLTVDPKKRLSMQELTAHMWLKSSASM-DTP 79
Cdd:cd14092  198 MLSGQVPFQSPSRNESAAEIMKRIKSGDFSFDGEEWKNVSSEAKSLIQGLLTVDPSKRLTMSELRNHPWLQGSSSPsSTP 277

                         90       100       110
                 ....*....|....*....|....*....|....
gi 115532264  80 LQTPSILPSSADET---FNETLRAFLHANRDGFH 110
Cdd:cd14092  278 LMTPGVLSSSAAAVstaLRATFDAFHLAFREGFR 311

Protein kinase domain;

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 115532264    1 MLSGQVPFHARSRqesaTEIMQRICRAEFSFtGDAWTNVSADAKNLITGLLTVDPKKRLSMQELTAHMWL 70
Cdd:pfam00069 153 LLTGKPPFPGING----NEIYELIIDQPYAF-PELPSNLSEEAKDLLKKLLKKDPSKRLTATQALQHPWF 217

C-terminal catalytic domain of the Serine/Threonine Kinase, Mitogen and stress-activated kinase; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. MSKs contain an N-terminal kinase domain (NTD) from the AGC family and a C-terminal kinase domain (CTD) from the CAMK family. MSKs are activated by two major signaling cascades, the Ras-MAPK and p38 stress kinase pathways, in response to various stimuli such as growth factors, hormones, neurotransmitters, cellular stress, and pro-inflammatory cytokines. This triggers phosphorylation in the activation loop (A-loop) of the CTD of MSK. The active CTD phosphorylates the hydrophobic motif (HM) in the C-terminal extension of NTD, which facilitates the phosphorylation of the A-loop and activates the NTD, which in turn phosphorylates downstream targets. MSKs are predominantly nuclear proteins. They are widely expressed in many tissues including heart, brain, lung, liver, kidney, and pancreas. There are two isoforms of MSK, called MSK1 and MSK2. The MSK subfamily is part of a larger superfamily that includes the catalytic domains of other STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 115532264   1 MLSGQVPFHARSRQESATEIMQRICRAEFSFTGDAWTNVSADAKNLITGLLTVDPKKRLSMQELTAHMWLKSSASM-DTP 79
Cdd:cd14092  198 MLSGQVPFQSPSRNESAAEIMKRIKSGDFSFDGEEWKNVSSEAKSLIQGLLTVDPSKRLTMSELRNHPWLQGSSSPsSTP 277

                         90       100       110
                 ....*....|....*....|....*....|....
gi 115532264  80 LQTPSILPSSADET---FNETLRAFLHANRDGFH 110
Cdd:cd14092  278 LMTPGVLSSSAAAVstaLRATFDAFHLAFREGFR 311

C-terminal catalytic domain of the Serine/Threonine Kinase, Mitogen and stress-activated kinase 2; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. MSK2 and MSK1 play nonredundant roles in activating histone H3 kinases, which play pivotal roles in compaction of the chromatin fiber. MSK2 is the required H3 kinase in response to stress stimuli and activation of the p38 MAPK pathway. MSK2 also plays a role in the pathogenesis of psoriasis. MSKs contain an N-terminal kinase domain (NTD) from the AGC family and a C-terminal kinase domain (CTD) from the CAMK family, similar to 90 kDa ribosomal protein S6 kinases (RSKs). MSKs are activated by two major signaling cascades, the Ras-MAPK and p38 stress kinase pathways, which trigger phosphorylation in the activation loop (A-loop) of the CTD of MSK. The active CTD phosphorylates the hydrophobic motif (HM) of NTD, which facilitates the phosphorylation of the A-loop and activates the NTD, which in turn phosphorylates downstream targets. The MSK2 subfamily is part of a larger superfamily that includes the catalytic domains of other protein STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 115532264   1 MLSGQVPFHARSRQES---ATEIMQRICRAEFSFTGDAWTNVSADAKNLITGLLTVDPKKRLSMQELTAHMWLKSSASM- 76
Cdd:cd14180  197 MLSGQVPFQSKRGKMFhnhAADIMHKIKEGDFSLEGEAWKGVSEEAKDLVRGLLTVDPAKRLKLSELRESDWLQGGSALs 276

                         90       100       110
                 ....*....|....*....|....*....|
gi 115532264  77 DTPLQTPSILPSSADETFNETLRAFLHANR 106
Cdd:cd14180  277 STPLMTPDVLESSGPAVRTGVNATFMAFNR 306

C-terminal catalytic domain of the Serine/Threonine Kinases, Ribosomal S6 kinases; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. RSKs contain an N-terminal kinase domain (NTD) from the AGC family and a C-terminal kinase domain (CTD) from the CAMK family. They are activated by signaling inputs from extracellular regulated kinase (ERK) and phosphoinositide dependent kinase 1 (PDK1). ERK phosphorylates and activates the CTD of RSK, serving as a docking site for PDK1, which phosphorylates and activates the NTD, which in turn phosphorylates all known RSK substrates. RSKs act as downstream effectors of mitogen-activated protein kinase (MAPK) and play key roles in mitogen-activated cell growth, differentiation, and survival. Mammals possess four RSK isoforms (RSK1-4) from distinct genes. RSK proteins are also referred to as MAP kinase-activated protein kinases (MAPKAPKs), 90 kDa ribosomal protein S6 kinases (p90-RSKs), or p90S6Ks. The RSK subfamily is part of a larger superfamily that includes the catalytic domains of other STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 115532264   1 MLSGQVPFhARSRQESATEIMQRICRAEFSFTGDAWTNVSADAKNLITGLLTVDPKKRLSMQELTAHMWLKS----SASM 76
Cdd:cd14091  191 MLAGYTPF-ASGPNDTPEVILARIGSGKIDLSGGNWDHVSDSAKDLVRKMLHVDPSQRPTAAQVLQHPWIRNrdslPQRQ 269

                         90
                 ....*....|....*...
gi 115532264  77 DTPLQTPSILPSSADETF 94
Cdd:cd14091  270 LTDPQDAALVKGAVAATF 287

Catalytic domain of the Serine/Threonine Kinase, Doublecortin-like kinase (also called Doublecortin-like and CAM kinase-like); STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. DCKL (or DCAMKL) proteins belong to the doublecortin (DCX) family of proteins which are involved in neuronal migration, neurogenesis, and eye receptor development, among others. Family members typically contain tandem doublecortin (DCX) domains at the N-terminus; DCX domains can bind microtubules and serve as protein-interaction platforms. In addition, DCKL proteins contain a C-terminal kinase domain with similarity to CAMKs. They are involved in the regulation of cAMP signaling. Vertebrates contain three DCKL proteins (DCKL1-3); DCKL1 and 2 also contain a serine, threonine, and proline rich domain (SP), while DCKL3 contains only a single DCX domain instead of tandem domains. The DCKL subfamily is part of a larger superfamily that includes the catalytic domains of other STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 115532264   1 MLSGQVPFhaRSRQESATEIMQRICRAEFSFTGDAWTNVSADAKNLITGLLTVDPKKRLSMQELTAHMW 69
Cdd:cd14095  192 LLCGFPPF--RSPDRDQEELFDLILAGEFEFLSPYWDNISDSAKDLISRMLVVDPEKRYSAGQVLDHPW 258

Catalytic domain of the Serine/Threonine kinase, Cell cycle Checkpoint Kinase 2; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. Checkpoint Kinase 2 (Chk2) plays an important role in cellular responses to DNA double-strand breaks and related lesions. It is phosphorylated and activated by ATM kinase, resulting in its dissociation from sites of damage to phosphorylate downstream targets such as BRCA1, p53, cell cycle transcription factor E2F1, the promyelocytic leukemia protein (PML) involved in apoptosis, and CDC25 phosphatases, among others. Mutations in Chk2 is linked to a variety of cancers including familial breast cancer, myelodysplastic syndromes, prostate cancer, lung cancer, and osteosarcomas. Chk2 contains an N-terminal SQ/TQ cluster domain (SCD), a central forkhead-associated (FHA) domain, and a C-terminal catalytic kinase domain. The Chk2 subfamily is part of a larger superfamily that includes the catalytic domains of other protein kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 115532264   1 MLSGQVPFharSRQESATEIMQRICRAEFSFTGDAWTNVSADAKNLITGLLTVDPKKRLSMQELTAHMWL 70
Cdd:cd14084  209 CLSGYPPF---SEEYTQMSLKEQILSGKYTFIPKAWKNVSEEAKDLVKKMLVVDPSRRPSIEEALEHPWL 275

Catalytic domain of AMP-activated protein kinase-like Serine/Threonine Kinases; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. The AMPK-like subfamily is composed of AMPK, MARK, BRSK, NUAK, MELK, SNRK, TSSK, and SIK, among others. LKB1 serves as a master upstream kinase that activates AMPK and most AMPK-like kinases. AMPK, also called SNF1 (sucrose non-fermenting1) in yeasts and SnRK1 (SNF1-related kinase1) in plants, is a heterotrimeric enzyme composed of a catalytic alpha subunit and two regulatory subunits, beta and gamma. It is a stress-activated kinase that serves as master regulator of glucose and lipid metabolism by monitoring carbon and energy supplies, via sensing the cell's AMP:ATP ratio. MARKs phosphorylate tau and related microtubule-associated proteins (MAPs), and regulates microtubule-based intracellular transport. They are involved in embryogenesis, epithelial cell polarization, cell signaling, and neuronal differentiation. BRSKs play important roles in establishing neuronal polarity. TSSK proteins are almost exclusively expressed postmeiotically in the testis and play important roles in spermatogenesis and/or spermiogenesis. The AMPK-like subfamily is part of a larger superfamily that includes the catalytic domains of other STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 115532264   1 MLSGQVPFHARSrqESATEimQRICRAEFSFtgdaWTNVSADAKNLITGLLTVDPKKRLSMQELTAHMW 69
Cdd:cd14003  192 MLTGYLPFDDDN--DSKLF--RKILKGKYPI----PSHLSPDARDLIRRMLVVDPSKRITIEEILNHPW 252

Catalytic domain of the Serine/Threonine Kinase, Phosphorylase kinase Gamma subunit; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. Phosphorylase kinase (PhK) catalyzes the phosphorylation of inactive phosphorylase b to form the active phosphorylase a. It coordinates hormonal, metabolic, and neuronal signals to initiate the breakdown of glycogen stores, which enables the maintenance of blood-glucose homeostasis during fasting, and is also used as a source of energy for muscle contraction. PhK is one of the largest and most complex protein kinases, composed of a heterotetramer containing four molecules each of four subunit types: one catalytic (gamma) and three regulatory (alpha, beta, and delta). Each subunit has tissue-specific isoforms or splice variants. Vertebrates contain two isoforms of the gamma subunit (gamma 1 and gamma 2). The gamma subunit, when isolated, is constitutively active and does not require phosphorylation of the A-loop for activity. The regulatory subunits restrain this kinase activity until signals are received to relieve this inhibition. For example, the kinase is activated in response to hormonal stimulation, after autophosphorylation or phosphorylation by cAMP-dependent kinase of the alpha and beta subunits. The high-affinity binding of ADP to the beta subunit also stimulates kinase activity, whereas calcium relieves inhibition by binding to the delta (calmodulin) subunit. The PhKG subfamily is part of a larger superfamily that includes the catalytic domains of other STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 115532264   1 MLSGQVPFHARsRQEsateIMQR-ICRAEFSFTGDAWTNVSADAKNLITGLLTVDPKKRLSMQELTAHMWL 70
Cdd:cd14093  207 LLAGCPPFWHR-KQM----VMLRnIMEGKYEFGSPEWDDISDTAKDLISKLLVVDPKKRLTAEEALEHPFF 272

Catalytic domain of the Serine/Threonine kinase, Mitogen-activated protein kinase-activated protein kinase 5; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. MAPK-activated protein kinase 5 (MAPKAP5 or MK5) is also called PRAK (p38-regulated/activated protein kinase). It contains a catalytic kinase domain followed by a C-terminal autoinhibitory region that contains nuclear localization (NLS) and nuclear export (NES) signals with a p38 MAPK docking motif that overlaps the NLS. MK5 is a ubiquitous protein that is implicated in neuronal morphogenesis, cell migration, and tumor angiogenesis. It interacts with PKA, which induces cytoplasmic translocation of MK5. Its substrates includes p53, ERK3/4, Hsp27, and cytosolic phospholipase A2 (cPLA2). The MAPKAPK subfamily is part of a larger superfamily that includes the catalytic domains of other protein STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 115532264   1 MLSGQVPFHARSRQESATEIMQR-ICRAEFSFTGDAWTNVSADAKNLITGLLTVDPKKRLSMQELTAHMWL 70
Cdd:cd14171  219 MLCGYPPFYSEHPSRTITKDMKRkIMTGSYEFPEEEWSQISEMAKDIVRKLLCVDPEERMTIEEVLHHPWL 289

Catalytic domain of the Serine/Threonine kinases, Mitogen-activated protein kinase-activated protein kinases; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. This subfamily is composed of the MAPK-activated protein kinases MK2, MK3, MK5 (also called PRAK for p38-regulated/activated protein kinase), and related proteins. These proteins contain a catalytic kinase domain followed by a C-terminal autoinhibitory region that contains nuclear localization (NLS) and nuclear export (NES) signals with a p38 MAPK docking motif that overlaps the NLS. In addition, MK2 and MK3 contain an N-terminal proline-rich region that can bind to SH3 domains. MK2 and MK3 are bonafide substrates for the MAPK p38, while MK5 plays a functional role in the p38 MAPK pathway although their direct interaction has been difficult to detect. MK2 and MK3 are closely related and show, thus far, indistinguishable substrate specificity, while MK5 shows a distinct spectrum of substrates. MK2 and MK3 are mainly involved in the regulation of gene expression and they participate in diverse cellular processes such as endocytosis, cytokine production, cytoskeletal reorganization, cell migration, cell cycle control and chromatin remodeling. They are implicated in inflammation and cance and their substrates include mRNA-AU-rich-element (ARE)-binding proteins (TTP and hnRNP A0), Hsp proteins (Hsp27 and Hsp25) and RSK, among others. MK2/3 are both expressed ubiquitously but MK2 is expressed at significantly higher levels. MK5 is a ubiquitous protein that is implicated in neuronal morphogenesis, cell migration, and tumor angiogenesis. It interacts with PKA, which induces cytoplasmic translocation of MK5. Its substrates includes p53, ERK3/4, Hsp27, and cytosolic phospholipase A2 (cPLA2). The MAPKAPK subfamily is part of a larger superfamily that includes the catalytic domains of other protein STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 115532264   1 MLSGQVPFHARSRQESATEIMQRICRAEFSFTGDAWTNVSADAKNLITGLLTVDPKKRLSMQELTAHMW 69
Cdd:cd14089  195 LLCGYPPFYSNHGLAISPGMKKRIRNGQYEFPNPEWSNVSEEAKDLIRGLLKTDPSERLTIEEVMNHPW 263

C-terminal catalytic domain of the Serine/Threonine Kinase, Ribosomal S6 kinase 4 (also called Ribosomal protein S6 kinase alpha-6 or 90kDa ribosomal protein S6 kinase 6); STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. RSK4 is also called S6K-alpha-6, RPS6KA6, p90RSK6 or pp90RSK4. RSK4 is a substrate of ERK and is a modulator of p53-dependent proliferation arrest in human cells. Deletion of the RSK4 gene, RPS6KA6, frequently occurs in patients of X-linked deafness type 3, mental retardation and choroideremia. Studies of RSK4 in cancer cells and tissues suggest that it may be oncogenic or tumor suppressive depending on many factors. RSK4 is one of four RSK isoforms (RSK1-4) from distinct genes present in vertebrates. RSKs contain an N-terminal kinase domain (NTD) from the AGC family and a C-terminal kinase domain (CTD) from the CAMK family. They are activated by signaling inputs from extracellular regulated kinase (ERK) and phosphoinositide dependent kinase 1 (PDK1). ERK phosphorylates and activates the CTD of RSK, serving as a docking site for PDK1, which phosphorylates and activates the NTD, which in turn phosphorylates all known RSK substrates. RSKs act as downstream effectors of mitogen-activated protein kinase (MAPK) and play key roles in mitogen-activated cell growth, differentiation, and survival. The RSK4 subfamily is part of a larger superfamily that includes the catalytic domains of other STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 115532264   1 MLSGQVPFhARSRQESATEIMQRICRAEFSFTGDAWTNVSADAKNLITGLLTVDPKKRLSMQELTAHMWL 70
Cdd:cd14177  195 MLAGYTPF-ANGPNDTPEEILLRIGSGKFSLSGGNWDTVSDAAKDLLSHMLHVDPHQRYTAEQVLKHSWI 263

Protein kinase domain;

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 115532264    1 MLSGQVPFHARSRqesaTEIMQRICRAEFSFtGDAWTNVSADAKNLITGLLTVDPKKRLSMQELTAHMWL 70
Cdd:pfam00069 153 LLTGKPPFPGING----NEIYELIIDQPYAF-PELPSNLSEEAKDLLKKLLKKDPSKRLTATQALQHPWF 217

Pseudokinase domain, first repeat, of the Giant Serine/Threonine Kinase Uncoordinated protein 89; The pseudokinase domain shows similarity to protein kinases but lacks crucial residues for catalytic activity. The nematode Unc-89 gene, through alternative promoter use and splicing, encodes at least six major isoforms (Unc-89A to Unc-89F) of giant muscle proteins that are homologs for the vetebrate obscurin. In flies, five isoforms of Unc-89 have been detected: four in the muscles of adult flies (two in the indirect flight muscle and two in other muscles) and another isoform in the larva. Unc-89 in nematodes is required for normal muscle cell architecture. In flies, it is necessary for the development of a symmetrical sarcomere in the flight muscles. Unc-89 proteins contain several adhesion and signaling domains including multiple copies of the immunoglobulin (Ig) domain, as well as fibronectin type III (FN3), SH3, RhoGEF, and PH domains. The nematode Unc-89 isoforms D, C, D, and F contain two kinase domain with B and F having two complete kinase domains while the first repeat of C and D are partial domains. Homology modeling suggests that the first kinase repeat of Unc-89 may be catalytically inactive, a pseudokinase, while the second kinase repeat may be active. The pseudokinase domain may function as a regulatory domain or a protein interaction domain. The Unc-89 subfamily is part of a larger superfamily that includes the catalytic domains of other protein STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 115532264   1 MLSGQVPFHARSRQESATEIMQricrAEFSFTGDAWTNVSADAKNLITGLLTVDPKKRLSMQELTAHMWL 70
Cdd:cd14109  190 LLGGISPFLGDNDRETLTNVRS----GKWSFDSSPLGNISDDARDFIKKLLVYIPESRLTVDEALNHPWF 255

Catalytic domain of Serine/Threonine Kinase 33; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. STK33 is highly expressed in the testis and is present in low levels in most tissues. It may be involved in spermatogenesis and organ ontogenesis. It interacts with and phosphorylates vimentin and may be involved in regulating intermediate filament cytoskeletal dynamics. Its role in promoting the cell viability of KRAS-dependent cancer cells is under debate; some studies have found STK33 to promote cancer cell viability, while other studies have found it to be non-essential. KRAS is the most commonly mutated human oncogene, thus, studies on the role of STK33 in KRAS mutant cancer cells are important. The STK33 subfamily is part of a larger superfamily that includes the catalytic domains of other STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 115532264   1 MLSGQVPFHARSRQEsateIMQRICRAEFSFTGDAWTNVSADAKNLITGLLTVDPKKRLSMQELTAHMWL 70
Cdd:cd14097  201 LLCGEPPFVAKSEEK----LFEEIRKGDLTFTQSVWQSVSDAAKNVLQQLLKVDPAHRMTASELLDNPWI 266

Catalytic domain of the Serine/Threonine kinase, Calcium/calmodulin-dependent protein kinase Type I beta; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. CaMKs are multifunctional calcium and calmodulin (CaM) stimulated STKs involved in cell cycle regulation. The CaMK family includes CaMKI, CaMKII, CaMKIV, and CaMK kinase (CaMKK). In vertebrates, there are four CaMKI proteins encoded by different genes (alpha, beta, gamma, and delta), each producing at least one variant. CaMKs contain an N-terminal catalytic domain and a C-terminal regulatory domain that harbors a CaM binding site. CaMKI proteins are monomeric and they play pivotal roles in the nervous system, including long-term potentiation, dendritic arborization, neurite outgrowth, and the formation of spines, synapses, and axons. In addition, they may be involved in osteoclast differentiation and bone resorption. The CaMKI-beta subfamily is part of a larger superfamily that includes the catalytic domains of other protein kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 115532264   1 MLSGQVPFHarsrQESATEIMQRICRAEFSFTGDAWTNVSADAKNLITGLLTVDPKKRLSMQELTAHMWLKSSASMD 77
Cdd:cd14169  195 LLCGYPPFY----DENDSELFNQILKAEYEFDSPYWDDISESAKDFIRHLLERDPEKRFTCEQALQHPWISGDTALD 267

Catalytic domain of the Serine/Threonine Kinase, Death-associated protein kinase-Related Apoptosis-inducing protein Kinase; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. DRAKs, also called STK17, were named based on their similarity (around 50% identity) to the kinase domain of DAPKs. They contain an N-terminal kinase domain and a C-terminal regulatory domain. Vertebrates contain two subfamily members, DRAK1 and DRAK2. Both DRAKs are localized to the nucleus, autophosphorylate themselves, and phosphorylate myosin light chain as a substrate. They may play a role in apoptotic signaling. The DRAK subfamily is part of a larger superfamily that includes the catalytic domains of other protein STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 115532264   1 MLSGQVPFHARSRQESATEIMQriCRAEFSftGDAWTNVSADAKNLITGLLTVDPKKRLSMQELTAHMWL 70
Cdd:cd14106  203 LLTGHSPFGGDDKQETFLNISQ--CNLDFP--EELFKDVSPLAIDFIKRLLVKDPEKRLTAKECLEHPWL 268

Catalytic domain of the Serine/Threonine kinases, Mitogen-activated protein kinase signal-integrating kinases; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. MAPK signal-integrating kinases (Mnks) are MAPK-activated protein kinases and is comprised by a group of four proteins, produced by alternative splicing from two genes (Mnk1 and Mnk2). The isoforms of Mnk1 (1a/1b) and Mnk2 (2a/2b) differ at their C-termini, with the a-form having a longer C-terminus containing a MAPK-binding region. All Mnks contain a catalytic kinase domain and a polybasic region at the N-terminus which binds importin and the eukaryotic initiation factor eIF4G. The best characterized Mnk substrate is eIF4G, whose phosphorylation may promote the export of certain mRNAs from the nucleus. Mnk also phosphorylate substrates that bind to AU-rich elements that regulate mRNA stability and translation. Mnks have also been implicated in tyrosine kinase receptor signaling, inflammation, and cell prolieration or survival. The Mnk subfamily is part of a larger superfamily that includes the catalytic domains of other protein STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 115532264   1 MLSGQVPFHAR-------SRQESATE----IMQRICRAEFSFTGDAWTNVSADAKNLITGLLTVDPKKRLSMQELTAHMW 69
Cdd:cd14090  209 MLCGYPPFYGRcgedcgwDRGEACQDcqelLFHSIQEGEYEFPEKEWSHISAEAKDLISHLLVRDASQRYTAEQVLQHPW 288

Catalytic kinase domain of Myosin Light Chain Kinase-like Serine/Threonine Kinases; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. This family is composed of MLCKs and related MLCK-like kinase domains from giant STKs such as titin, obscurin, SPEG, Unc-89, Trio, kalirin, and Twitchin. Also included in this family are Death-Associated Protein Kinases (DAPKs) and Death-associated protein kinase-Related Apoptosis-inducing protein Kinase (DRAKs). MLCK phosphorylates myosin regulatory light chain and controls the contraction of all muscle types. Titin, obscurin, Twitchin, and SPEG are muscle proteins involved in the contractile apparatus. The giant STKs are multidomain proteins containing immunoglobulin (Ig), fibronectin type III (FN3), SH3, RhoGEF, PH and kinase domains. Titin, obscurin, Twitchin, and SPEG contain many Ig domain repeats at the N-terminus, while Trio and Kalirin contain spectrin-like repeats. The MLCK-like family is part of a larger superfamily that includes the catalytic domains of other protein STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 115532264   1 MLSGQVPFHArsrqESATEIMQRICRAEFSFTGDAWTNVSADAKNLITGLLTVDPKKRLSMQELTAHMW 69
Cdd:cd14006  183 LLSGLSPFLG----EDDQETLANISACRVDFSEEYFSSVSQEAKDFIRKLLVKEPRKRPTAQEALQHPW 247

Catalytic domain of the Serine/Threonine Kinase, Phosphoinositide-dependent kinase 1; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. PDK1 carries an N-terminal catalytic domain and a C-terminal pleckstrin homology (PH) domain that binds phosphoinositides. It phosphorylates the activation loop of AGC kinases that are regulated by PI3K such as PKB, SGK, and PKC, among others, and is crucial for their activation. Thus, it contributes in regulating many processes including metabolism, growth, proliferation, and survival. PDK1 also has the ability to autophosphorylate and is constitutively active in mammalian cells. It is essential for normal embryo development and is important in regulating cell volume. The PDK1 subfamily is part of a larger superfamily that includes the catalytic domains of other STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 115532264   1 MLSGQVPFHArsrqESATEIMQRICRAEFSFTgdawTNVSADAKNLITGLLTVDPKKRL------SMQELTAHMW 69
Cdd:cd05581  211 MLTGKPPFRG----SNEYLTFQKIVKLEYEFP----ENFPPDAKDLIQKLLVLDPSKRLgvnengGYDELKAHPF 277

Catalytic domain of the Serine/Threonine kinase, Mitogen-activated protein kinase-activated protein kinase 3; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. MAPK-activated protein kinase 3 (MAPKAP3 or MK3) contains an N-terminal proline-rich region that can bind to SH3 domains, a catalytic kinase domain followed by a C-terminal autoinhibitory region that contains nuclear localization (NLS) and nuclear export (NES) signals with a p38 MAPK docking motif that overlaps the NLS. MK3 is a bonafide substrate for the MAPK p38. It is closely related to MK2 and thus far, MK2/3 show indistinguishable substrate specificity. They are mainly involved in the regulation of gene expression and they participate in diverse cellular processes such as endocytosis, cytokine production, cytoskeletal reorganization, cell migration, cell cycle control and chromatin remodeling. They are implicated in inflammation and cance and their substrates include mRNA-AU-rich-element (ARE)-binding proteins (TTP and hnRNP A0), Hsp proteins (Hsp27 and Hsp25) and RSK, among others. MK2/3 are both expressed ubiquitously but MK2 is expressed at significantly higher levels. MK3 activity is only significant when MK2 is absent. The MK3 subfamily is part of a larger superfamily that includes the catalytic domains of other protein STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 115532264   1 MLSGQVPFHARSRQESATEIMQRICRAEFSFTGDAWTNVSADAKNLITGLLTVDPKKRLSMQELTAHMWL 70
Cdd:cd14172  198 LLCGFPPFYSNTGQAISPGMKRRIRMGQYGFPNPEWAEVSEEAKQLIRHLLKTDPTERMTITQFMNHPWI 267

Catalytic domain of the Serine/Threonine kinases, Liver Kinase B1, Calmodulin Dependent Protein Kinase Kinase, and similar proteins; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. Both LKB1 and CaMKKs can phosphorylate and activate AMP-activated protein kinase (AMPK). LKB1, also called STK11, serves as a master upstream kinase that activates AMPK and most AMPK-like kinases. LKB1 and AMPK are part of an energy-sensing pathway that links cell energy to metabolism and cell growth. They play critical roles in the establishment and maintenance of cell polarity, cell proliferation, cytoskeletal organization, as well as T-cell metabolism, including T-cell development, homeostasis, and effector function. CaMKKs are upstream kinases of the CaM kinase cascade that phosphorylate and activate CaMKI and CamKIV. They may also phosphorylate other substrates including PKB and AMPK. Vertebrates contain two CaMKKs, CaMKK1 (or alpha) and CaMKK2 (or beta). CaMKK1 is involved in the regulation of glucose uptake in skeletal muscles. CaMKK2 is involved in regulating energy balance, glucose metabolism, adiposity, hematopoiesis, inflammation, and cancer. The LKB1/CaMKK subfamily is part of a larger superfamily that includes the catalytic domains of other STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 115532264   1 MLSGQVPFHARSRQESATEImqRICRAEFSFTGDawtnVSADAKNLITGLLTVDPKKRLSMQELTAHMWL 70
Cdd:cd14008  204 LVFGRLPFNGDNILELYEAI--QNQNDEFPIPPE----LSPELKDLLRRMLEKDPEKRITLKEIKEHPWV 267

Catalytic domain of the Serine/Threonine kinase, Calcium/calmodulin-dependent protein kinase Type I gamma; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. CaMKs are multifunctional calcium and calmodulin (CaM) stimulated STKs involved in cell cycle regulation. The CaMK family includes CaMKI, CaMKII, CaMKIV, and CaMK kinase (CaMKK). In vertebrates, there are four CaMKI proteins encoded by different genes (alpha, beta, gamma, and delta), each producing at least one variant. CaMKs contain an N-terminal catalytic domain and a C-terminal regulatory domain that harbors a CaM binding site. CaMKI proteins are monomeric and they play pivotal roles in the nervous system, including long-term potentiation, dendritic arborization, neurite outgrowth, and the formation of spines, synapses, and axons. In addition, they may be involved in osteoclast differentiation and bone resorption. The CaMKI-gamma subfamily is part of a larger superfamily that includes the catalytic domains of other protein kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 115532264   1 MLSGQVPFHarsrQESATEIMQRICRAEFSFTGDAWTNVSADAKNLITGLLTVDPKKRLSMQELTAHMWLKSSASM 76
Cdd:cd14166  194 LLCGYPPFY----EETESRLFEKIKEGYYEFESPFWDDISESAKDFIRHLLEKNPSKRYTCEKALSHPWIIGNTAL 265

Catalytic domain of the Serine/Threonine kinase, Liver Kinase B1; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. LKB1, also called STK11, was first identified as a tumor suppressor responsible for Peutz-Jeghers syndrome, a disorder that leads to an increased risk of spontaneous epithelial cancer. It serves as a master upstream kinase that activates AMP-activated protein kinase (AMPK) and most AMPK-like kinases. LKB1 and AMPK are part of an energy-sensing pathway that links cell energy to metabolism and cell growth. They play critical roles in the establishment and maintenance of cell polarity, cell proliferation, cytoskeletal organization, as well as T-cell metabolism, including T-cell development, homeostasis, and effector function. To be activated, LKB1 requires the adaptor proteins STe20-Related ADaptor (STRAD) and mouse protein 25 (MO25). The LKB1 subfamily is part of a larger superfamily that includes the catalytic domains of other STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 115532264   1 MLSGQVPFHarsrQESATEIMQRICRAEFSFTgdawTNVSADAKNLITGLLTVDPKKRLSMQELTAHMWL 70
Cdd:cd14119  194 MTTGKYPFE----GDNIYKLFENIGKGEYTIP----DDVDPDLQDLLRGMLEKDPEKRFTIEQIRQHPWF 255

Catalytic domain of the Serine/Threonine kinase, Calcium/calmodulin-dependent protein kinase Type II; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. CaMKs are multifunctional calcium and calmodulin (CaM) stimulated STKs involved in cell cycle regulation. There are several types of CaMKs including CaMKI, CaMKII, and CaMKIV. CaMKs contain an N-terminal catalytic domain followed by a regulatory domain that harbors a CaM binding site. In addition, CaMKII contains a C-terminal association domain that facilitates oligomerization. There are four CaMKII proteins (alpha, beta, gamma, delta) encoded by different genes; each gene undergoes alternative splicing to produce more than 30 isoforms. CaMKII-alpha and -beta are enriched in neurons while CaMKII-gamma and -delta are predominant in myocardium. CaMKII is a signaling molecule that translates upstream calcium and reactive oxygen species (ROS) signals into downstream responses that play important roles in synaptic function and cardiovascular physiology. It is a major component of the postsynaptic density and is critical in regulating synaptic plasticity including long-term potentiation. It is critical in regulating ion channels and proteins involved in myocardial excitation-contraction and excitation-transcription coupling. Excessive CaMKII activity promotes processes that contribute to heart failure and arrhythmias. The CaMKII subfamily is part of a larger superfamily that includes the catalytic domains of other protein kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 115532264   1 MLSGQVPFHARSRQEsateIMQRICRAEFSFTGDAWTNVSADAKNLITGLLTVDPKKRLSMQELTAHMWLK 71
Cdd:cd14086  196 LLVGYPPFWDEDQHR----LYAQIKAGAYDYPSPEWDTVTPEAKDLINQMLTVNPAKRITAAEALKHPWIC 262

Catalytic domain of the Serine/Threonine kinase, Calcium/calmodulin-dependent protein kinase Type I alpha; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. CaMKs are multifunctional calcium and calmodulin (CaM) stimulated STKs involved in cell cycle regulation. The CaMK family includes CaMKI, CaMKII, CaMKIV, and CaMK kinase (CaMKK). In vertebrates, there are four CaMKI proteins encoded by different genes (alpha, beta, gamma, and delta), each producing at least one variant. CaMKs contain an N-terminal catalytic domain and a C-terminal regulatory domain that harbors a CaM binding site. CaMKI proteins are monomeric and they play pivotal roles in the nervous system, including long-term potentiation, dendritic arborization, neurite outgrowth, and the formation of spines, synapses, and axons. In addition, they may be involved in osteoclast differentiation and bone resorption. The CaMKI-alpha subfamily is part of a larger superfamily that includes the catalytic domains of other protein kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 115532264   1 MLSGQVPFHarsrQESATEIMQRICRAEFSFTGDAWTNVSADAKNLITGLLTVDPKKRLSMQELTAHMWL 70
Cdd:cd14167  196 LLCGYPPFY----DENDAKLFEQILKAEYEFDSPYWDDISDSAKDFIQHLMEKDPEKRFTCEQALQHPWI 261

Catalytic domain of an Uncharacterized group of Serine/Threonine kinases with similarity to Calcium/calmodulin-dependent protein kinases; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. This subfamily is composed of uncharacterized STKs with similarity to CaMKs, which are multifunctional calcium and calmodulin (CaM) stimulated STKs involved in cell cycle regulation. The CaMK family includes CaMKI, CaMKII, CaMKIV, and CaMK kinase (CaMKK). CaMKs contain an N-terminal catalytic domain followed by a regulatory domain that harbors a CaM binding site. This uncharacterized subfamily is part of a larger superfamily that includes the catalytic domains of other protein kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 115532264   1 MLSGQVPFHARSRQESA----TEIMQRICRAEFSFTGDAWTNVSADAKNLITGLLTVDPKKRLSMQELTAHMWL 70
Cdd:cd14088  192 LLSGNPPFYDEAEEDDYenhdKNLFRKILAGDYEFDSPYWDDISQAAKDLVTRLMEVEQDQRITAEEAISHEWI 265

C-terminal kinase domain of the Large Serine/Threonine Kinase and Rho Guanine Nucleotide Exchange Factor, Triple functional domain protein; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. Triple functional domain protein (Trio), also called PTPRF-interacting protein, is a large multidomain protein containing a series of spectrin-like repeats, two each of RhoGEF and SH3 domains, an immunoglobulin-like (Ig) domain and a C-terminal kinase. Trio plays important roles in neuronal cell migration and axon guidance. It was originally identified as an interacting partner of the of the receptor-like tyrosine phosphatase (RPTP) LAR (leukocyte-antigen-related protein), a family of receptors that function in the signaling to the actin cytoskeleton during development. Trio functions as a GEF for Rac1, RhoG, and RhoA, and is involved in the regulation of lamellipodia formation, mediating Rac1-dependent cell spreading and migration. The Trio subfamily is part of a larger superfamily that includes the catalytic domains of other protein STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 115532264   1 MLSGQVPFharsRQESATEIMQRICRAEFSFTGDAWTNVSADAKNLITGLLTVDPKKRLSMQELTAHMWL 70
Cdd:cd14113  198 LLSGVSPF----LDESVEETCLNICRLDFSFPDDYFKGVSQKAKDFVCFLLQMDPAKRPSAALCLQEQWL 263

Catalytic domain of the Serine/Threonine Kinase, Death-Associated Protein Kinase; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. DAPKs mediate cell death and act as tumor suppressors. They are necessary to induce cell death and their overexpression leads to death-associated changes including membrane blebbing, cell rounding, and formation of autophagic vesicles. Vertebrates contain three subfamily members with different domain architecture, localization, and function. DAPK1 is the prototypical member of the subfamily and is also simply referred to as DAPK. DAPK2 is also called DAPK-related protein 1 (DRP-1), while DAPK3 has also been named DAP-like kinase (DLK) and zipper-interacting protein kinase (ZIPk). These proteins are ubiquitously expressed in adult tissues, are capable of cross talk with each other, and may act synergistically in regulating cell death. The DAPK subfamily is part of a larger superfamily that includes the catalytic domains of other protein STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 115532264   1 MLSGQVPFHARSRQESATEIMqricRAEFSFTGDAWTNVSADAKNLITGLLTVDPKKRLSMQELTAHMWL 70
Cdd:cd14105  204 LLSGASPFLGDTKQETLANIT----AVNYDFDDEYFSNTSELAKDFIRQLLVKDPRKRMTIQESLRHPWI 269

The catalytic domain of the Giant Serine/Threonine Kinases, Twitchin and Projectin; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. This subfamily is composed of Caenorhabditis elegans and Aplysia californica Twitchin, Drosophila melanogaster Projectin, and similar proteins. These are very large muscle proteins containing multiple immunoglobulin (Ig)-like and fibronectin type III (FN3) domains and a single kinase domain near the C-terminus. Twitchin and Projectin are both associated with thick filaments. Twitchin is localized in the outer parts of A-bands and is involved in regulating muscle contraction. It interacts with the myofibrillar proteins myosin and actin in a phosphorylation-dependent manner, and may be involved in regulating the myosin cross-bridge cycle. The kinase activity of Twitchen is activated by Ca2+ and the Ca2+ binding protein S100A1. Projectin is associated with the end of thick filaments and is a component of flight muscle connecting filaments. The kinase domain of Projectin may play roles in autophosphorylation and transphosphorylation, which impact the formation of myosin filaments. The Twitchin-like subfamily is part of a larger superfamily that includes the catalytic domains of other protein STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 115532264   1 MLSGQVPFHArsrqESATEIMQRICRAEFSFTGDAWTNVSADAKNLITGLLTVDPKKRLSMQELTAHMWL 70
Cdd:cd14114  194 LLSGLSPFAG----ENDDETLRNVKSCDWNFDDSAFSGISEEAKDFIRKLLLADPNKRMTIHQALEHPWL 259

Catalytic domain of the Serine/Threonine Kinase, Yank1; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. This subfamily contains uncharacterized STKs with similarity to the human protein designated as Yank1 or STK32A. The Yank1 subfamily is part of a larger superfamily that includes the catalytic domains of other STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 115532264   1 MLSGQVPFHARSRqESATEIMQRICRAEFSFTgDAWtnvSADAKNLITGLLTVDPKKRLS-MQELTAHMWL 70
Cdd:cd05578  192 MLRGKRPYEIHSR-TSIEEIRAKFETASVLYP-AGW---SEEAIDLINKLLERDPQKRLGdLSDLKNHPYF 257

Catalytic domain of the Serine/Threonine Kinases, Chlamydomonas reinhardtii CNK2 and similar proteins; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. Chlamydomonas reinhardtii CNK2 has both cilliary and cell cycle functions. It influences flagellar length through promoting flagellar disassembly, and it regulates cell size, through influencing the size threshold at which cells commit to mitosis. This subfamily belongs to the (NIMA)-related kinase (Nek) family, which includes seven different Chlamydomonas Neks (CNKs 1-6 and Fa2). This subfamily includes CNK1, and -2. The Nek family is part of a larger superfamily that includes the catalytic domains of other STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 115532264   1 MLSGQVPFHARSRQEsateIMQRICRAEFSFTGdawTNVSADAKNLITGLLTVDPKKRLSMQELTAH 67
Cdd:cd08530  194 MATFRPPFEARTMQE----LRYKVCRGKFPPIP---PVYSQDLQQIIRSLLQVNPKKRPSCDKLLQS 253

N-terminal catalytic domain of the Serine/Threonine Kinase, Mitogen and stress-activated kinase; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. MSKs contain an N-terminal kinase domain (NTD) from the AGC family and a C-terminal kinase domain (CTD) from the CAMK family. MSKs are activated by two major signaling cascades, the Ras-MAPK and p38 stress kinase pathways, in response to various stimuli such as growth factors, hormones, neurotransmitters, cellular stress, and pro-inflammatory cytokines. This triggers phosphorylation in the activation loop (A-loop) of the CTD of MSK. The active CTD phosphorylates the hydrophobic motif (HM) in the C-terminal extension of NTD, which facilitates the phosphorylation of the A-loop and activates the NTD, which in turn phosphorylates downstream targets. MSKs are predominantly nuclear proteins. They are widely expressed in many tissues including heart, brain, lung, liver, kidney, and pancreas. There are two isoforms of MSK, called MSK1 and MSK2. The MSK subfamily is part of a larger superfamily that includes the catalytic domains of other STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 115532264   1 MLSGQVPFHARSRQESATEIMQRICRAEFSFTgdawTNVSADAKNLITGLLTVDPKKRL-----SMQELTAHMWLKS 72
Cdd:cd05583  195 LLTGASPFTVDGERNSQSEISKRILKSHPPIP----KTFSAEAKDFILKLLEKDPKKRLgagprGAHEIKEHPFFKG 267

Catalytic domain of Myotonic Dystrophy protein kinase (DMPK)-like Serine/Threonine Kinases; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. The DMPK-like subfamily is composed of DMPK and DMPK-related cell division control protein 42 (Cdc42) binding kinase (MRCK). DMPK is expressed in skeletal and cardiac muscles, and in central nervous tissues. The functional role of DMPK is not fully understood. It may play a role in the signal transduction and homeostasis of calcium. The DMPK gene is implicated in myotonic dystrophy 1 (DM1), an inherited multisystemic disorder with symptoms that include muscle hyperexcitability, progressive muscle weakness and wasting, cataract development, testicular atrophy, and cardiac conduction defects. The genetic basis for DM1 is the mutational expansion of a CTG repeat in the 3'-UTR of DMPK. MRCK is activated via interaction with the small GTPase Cdc42. MRCK/Cdc42 signaling mediates myosin-dependent cell motility. Three isoforms of MRCK are known, named alpha, beta and gamma. MRCKgamma is expressed in heart and skeletal muscles, unlike MRCKalpha and MRCKbeta, which are expressed ubiquitously. The DMPK-like subfamily is part of a larger superfamily that includes the catalytic domains of other STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 115532264   1 MLSGQVPFHARSRQESATEIMQRicRAEFSFTGDAwTNVSADAKNLITGLLTvDPKKRL---SMQELTAHMWLKSSASMD 77
Cdd:cd05597  201 MLYGETPFYAESLVETYGKIMNH--KEHFSFPDDE-DDVSEEAKDLIRRLIC-SRERRLgqnGIDDFKKHPFFEGIDWDN 276

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|....*..
gi 115532264  78 TPLQTPSILP--SSADETFN-----------ETLRAFLHANRDGFHL 111
Cdd:cd05597  277 IRDSTPPYIPevTSPTDTSNfdvddddlrhtDSLPPPSNAAFSGLHL 323

Catalytic domain of the Serine/Threonine Kinase, Protein Kinase C; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. PKCs are classified into three groups (classical, atypical, and novel) depending on their mode of activation and the structural characteristics of their regulatory domain. PKCs undergo three phosphorylations in order to take mature forms. In addition, classical PKCs depend on calcium, DAG (1,2-diacylglycerol), and in most cases, phosphatidylserine (PS) for activation. Novel PKCs are calcium-independent, but require DAG and PS for activity, while atypical PKCs only require PS. PKCs phosphorylate and modify the activities of a wide variety of cellular proteins including receptors, enzymes, cytoskeletal proteins, transcription factors, and other kinases. They play a central role in signal transduction pathways that regulate cell migration and polarity, proliferation, differentiation, and apoptosis. Also included in this subfamily are the PKC-like proteins, called PKNs. The PKC subfamily is part of a larger superfamily that includes the catalytic domains of other STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*....
gi 115532264   1 MLSGQVPFHARSRQESATEIMQRicraEFSFTgdawTNVSADAKNLITGLLTVDPKKRL 59
Cdd:cd05570  189 MLAGQSPFEGDDEDELFEAILND----EVLYP----RWLSREAVSILKGLLTKDPARRL 239

Catalytic domain of the Serine/Threonine Kinase, G protein-coupled Receptor Kinase 5; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. GRK5 is widely expressed in many tissues. It associates with the membrane though an N-terminal PIP2 binding domain and also binds phospholipids via its C-terminus. GRK5 deficiency is associated with early Alzheimer's disease in humans and mouse models. GRK5 also plays a crucial role in the pathogenesis of sporadic Parkinson's disease. It participates in the regulation and desensitization of PDGFRbeta, a receptor tyrosine kinase involved in a variety of downstream cellular effects including cell growth, chemotaxis, apoptosis, and angiogenesis. GRK5 also regulates Toll-like receptor 4, which is involved in innate and adaptive immunity. GRKs phosphorylate and regulate G protein-coupled receptors (GPCRs), the largest superfamily of cell surface receptors which regulate some part of nearly all physiological functions. Phosphorylated GPCRs bind to arrestins, which prevents further G protein signaling despite the presence of activating ligand. The GRK5 subfamily is part of a larger superfamily that includes the catalytic domains of other STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 115532264   1 MLSGQVPFHARSRQESATEIMQRICRAEFSFTgdawTNVSADAKNLITGLLTVDPKKRLSMQE 63
Cdd:cd05632  196 MIEGQSPFRGRKEKVKREEVDRRVLETEEVYS----AKFSEEAKSICKMLLTKDPKQRLGCQE 254

Catalytic domain of the Serine/Threonine Kinase, Myosin Light Chain Kinase 3; STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. MLCK3 (or MYLK3) phosphorylates myosin regulatory light chain 2 and controls the contraction of cardiac muscles. It is expressed specifically in both the atrium and ventricle of the heart and its expression is regulated by the cardiac protein Nkx2-5. MLCK3 plays an important role in cardiogenesis by regulating the assembly of cardiac sarcomeres, the repeating contractile unit of striated muscle. MLCK3 contains a single kinase domain near the C-terminus and a unique N-terminal half, and unlike MLCK1/2, it does not appear to be regulated by Ca2+/calmodulin. The MLCK3 subfamily is part of a larger superfamily that includes the catalytic domains of other protein STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 115532264   1 MLSGQVPFHArsrqESATEIMQRICRAEFSFTGDAWTNVSADAKNLITGLLTVDPKKRLSMQELTAHMWL 70
Cdd:cd14192  196 LLSGLSPFLG----ETDAETMNNIVNCKWDFDAEAFENLSEEAKDFISRLLVKEKSCRMSATQCLKHEWL 261