RNA recognition motif;

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                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 1069336961  821 IYIRNLSNSISANELKRRFEVFGEITECCVLS-----KSRGekCGFITYRDSEHA--ALSLQKGASLRKRT 884
Cdd:smart00360   2 LFVGNLPPDTTEEELRELFSKFGKVESVRLVRdketgKSKG--FAFVEFESEEDAekALEALNGKELDGRP 70

RNA recognition motif. (a.k.a. RRM, RBD, or RNP domain); The RRM motif is probably diagnostic of an RNA binding protein. RRMs are found in a variety of RNA binding proteins, including various hnRNP proteins, proteins implicated in regulation of alternative splicing, and protein components of snRNPs. The motif also appears in a few single stranded DNA binding proteins. The RRM structure consists of four strands and two helices arranged in an alpha/beta sandwich, with a third helix present during RNA binding in some cases The C-terminal beta strand (4th strand) and final helix are hard to align and have been omitted in the SEED alignment The LA proteins have an N terminal rrm which is included in the seed. There is a second region towards the C terminus that has some features characteriztic of a rrm but does not appear to have the important structural core of a rrm. The LA proteins are one of the main autoantigens in Systemic lupus erythematosus (SLE), an autoimmune disease.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 1069336961 821 IYIRNLSNSISANELKRRFEVFGEITECCVLSKSRGE--KCGFITYRDSEHAALSLQK--GASLRKRT 884
Cdd:pfam00076   1 LFVGNLPPDTTEEDLKDLFSKFGPIKSIRLVRDETGRskGFAFVEFEDEEDAEKAIEAlnGKELGGRE 68

RNA recognition motif (RRM) found in the peroxisome proliferator-activated receptor gamma coactivator 1A (PGC-1alpha) family of regulated coactivators; This subfamily corresponds to the RRM of PGC-1alpha, PGC-1beta, and PGC-1-related coactivator (PRC), which serve as mediators between environmental or endogenous signals and the transcriptional machinery governing mitochondrial biogenesis. They play an important integrative role in the control of respiratory gene expression through interacting with a number of transcription factors, such as NRF-1, NRF-2, ERR, CREB and YY1. All family members are multi-domain proteins containing the N-terminal activation domain, an LXXLL coactivator signature, a tetrapeptide motif (DHDY) responsible for HCF binding, and an RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain). In contrast to PGC-1alpha and PRC, PGC-1beta possesses two glutamic/aspartic acid-rich acidic domains, but lacks most of the arginine/serine (SR)-rich domain that is responsible for the regulation of RNA processing.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1069336961 817 EGRMIYIRNLSNSISANELKRRFEVFGEITECCVLSKSRGEKCGFITYRDSEHAALSLQKGASLRKRTEPPFQLSYGGLR 896
Cdd:cd12357     1 ERRVVYVGKLEQDTTRSELRRRFEVFGEIEECTVHFRERGDKYGFVTYRYSEDAFLALENGHDLRKRNEPMFDLSFGGRR 80

                          90
                  ....*....|.
gi 1069336961 897 HFFWTKYTDLD 907
Cdd:cd12357    81 AFCKSSYADLD 91

RNA recognition motif (RRM) found in peroxisome proliferator-activated receptor gamma coactivator-related protein 1 (PRC) and similar proteins; This subgroup corresponds to the RRM of PRC, also termed PGC-1-related coactivator, one of the members of PGC-1 transcriptional coactivators family, including peroxisome proliferator-activated receptor gamma coactivators PGC-1alpha and PGC-1beta. Unlike PGC-1alpha and PGC-1beta, PRC is ubiquitous and more abundantly expressed in proliferating cells than in growth-arrested cells. PRC has been implicated in the regulation of several metabolic pathways, mitochondrial biogenesis, and cell growth. It functions as a growth-regulated transcriptional cofactor activating many nuclear genes specifying mitochondrial respiratory function. PRC directly interacts with nuclear transcriptional factors implicated in respiratory chain expression including nuclear respiratory factors 1 and 2 (NRF-1 and NRF-2), CREB (cAMP-response element-binding protein), and estrogen-related receptor alpha (ERRalpha). It interacts indirectly with the NRF-2beta subunit through host cell factor (HCF), a cellular protein involved in herpes simplex virus (HSV) infection and cell cycle regulation. Furthermore, like PGC-1alpha and PGC-1beta, PRC can transactivate a number of NRF-dependent nuclear genes required for mitochondrial respiratory function, including those encoding cytochrome c, 5-aminolevulinate synthase, Tfam, and TFB1M, and TFB2M. Further research indicates that PRC may also act as a sensor of metabolic stress that orchestrates a redox-sensitive program of inflammatory gene expression. PRC is a multi-domain protein containing an N-terminal activation domain, an LXXLL coactivator signature, a central proline-rich region, a tetrapeptide motif (DHDY) responsible for HCF binding, a C-terminal arginine/serine-rich (SR) domain, and an RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain).

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1069336961 817 EGRMIYIRNLSNSISANELKRRFEVFGEITECCVLSKSRGEKCGFITYRDSEHAALSLQKGASLRKRTEPPFQLSYGGLR 896
Cdd:cd12624     1 ERRVVYIGKIRGRMTRSELKDRFSVFGEIEECTIHFREEGDNYGFVTYRYTEDAFAAIENGHKLRRPDELPFDLCFGGRR 80

                          90
                  ....*....|.
gi 1069336961 897 HFFWTKYTDLD 907
Cdd:cd12624    81 QFCKSSYADLD 91

RNA recognition motif;

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                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 1069336961  821 IYIRNLSNSISANELKRRFEVFGEITECCVLS-----KSRGekCGFITYRDSEHA--ALSLQKGASLRKRT 884
Cdd:smart00360   2 LFVGNLPPDTTEEELRELFSKFGKVESVRLVRdketgKSKG--FAFVEFESEEDAekALEALNGKELDGRP 70

RNA recognition motif 3 (RRM3) found found in type I polyadenylate-binding proteins; This subfamily corresponds to the RRM3 of type I poly(A)-binding proteins (PABPs), highly conserved proteins that bind to the poly(A) tail present at the 3' ends of most eukaryotic mRNAs. They have been implicated in the regulation of poly(A) tail length during the polyadenylation reaction, translation initiation, mRNA stabilization by influencing the rate of deadenylation and inhibition of mRNA decapping. The family represents type I polyadenylate-binding proteins (PABPs), including polyadenylate-binding protein 1 (PABP-1 or PABPC1), polyadenylate-binding protein 3 (PABP-3 or PABPC3), polyadenylate-binding protein 4 (PABP-4 or APP-1 or iPABP), polyadenylate-binding protein 5 (PABP-5 or PABPC5), polyadenylate-binding protein 1-like (PABP-1-like or PABPC1L), polyadenylate-binding protein 1-like 2 (PABPC1L2 or RBM32), polyadenylate-binding protein 4-like (PABP-4-like or PABPC4L), yeast polyadenylate-binding protein, cytoplasmic and nuclear (PABP or ACBP-67), and similar proteins. PABP-1 is an ubiquitously expressed multifunctional protein that may play a role in 3' end formation of mRNA, translation initiation, mRNA stabilization, protection of poly(A) from nuclease activity, mRNA deadenylation, inhibition of mRNA decapping, and mRNP maturation. Although PABP-1 is thought to be a cytoplasmic protein, it is also found in the nucleus. PABP-1 may be involved in nucleocytoplasmic trafficking and utilization of mRNP particles. PABP-1 contains four copies of RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), a less well conserved linker region, and a proline-rich C-terminal conserved domain (CTD). PABP-3 is a testis-specific poly(A)-binding protein specifically expressed in round spermatids. It is mainly found in mammalian and may play an important role in the testis-specific regulation of mRNA homeostasis. PABP-3 shows significant sequence similarity to PABP-1. However, it binds to poly(A) with a lower affinity than PABP-1. PABP-1 possesses an A-rich sequence in its 5'-UTR and allows binding of PABP and blockage of translation of its own mRNA. In contrast, PABP-3 lacks the A-rich sequence in its 5'-UTR. PABP-4 is an inducible poly(A)-binding protein (iPABP) that is primarily localized to the cytoplasm. It shows significant sequence similarity to PABP-1 as well. The RNA binding properties of PABP-1 and PABP-4 appear to be identical. PABP-5 is encoded by PABPC5 gene within the X-specific subinterval, and expressed in fetal brain and in a range of adult tissues in mammalian, such as ovary and testis. It may play an important role in germ cell development. Moreover, unlike other PABPs, PABP-5 contains only four RRMs, but lacks both the linker region and the CTD. PABP-1-like and PABP-1-like 2 are the orthologs of PABP-1. PABP-4-like is the ortholog of PABP-5. Their cellular functions remain unclear. The family also includes the yeast PABP, a conserved poly(A) binding protein containing poly(A) tails that can be attached to the 3'-ends of mRNAs. The yeast PABP and its homologs may play important roles in the initiation of translation and in mRNA decay. Like vertebrate PABP-1, the yeast PABP contains four RRMs, a linker region, and a proline-rich CTD as well. The first two RRMs are mainly responsible for specific binding to poly(A). The proline-rich region may be involved in protein-protein interactions.

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                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1069336961 821 IYIRNLSNSISANELKRRFEVFGEITECCVL----SKSRGekCGFITYRDSEHAA 871
Cdd:cd12380     4 VYVKNFGEDVDDDELKELFEKYGKITSAKVMkddsGKSKG--FGFVNFENHEAAQ 56

RNA recognition motif. (a.k.a. RRM, RBD, or RNP domain); The RRM motif is probably diagnostic of an RNA binding protein. RRMs are found in a variety of RNA binding proteins, including various hnRNP proteins, proteins implicated in regulation of alternative splicing, and protein components of snRNPs. The motif also appears in a few single stranded DNA binding proteins. The RRM structure consists of four strands and two helices arranged in an alpha/beta sandwich, with a third helix present during RNA binding in some cases The C-terminal beta strand (4th strand) and final helix are hard to align and have been omitted in the SEED alignment The LA proteins have an N terminal rrm which is included in the seed. There is a second region towards the C terminus that has some features characteriztic of a rrm but does not appear to have the important structural core of a rrm. The LA proteins are one of the main autoantigens in Systemic lupus erythematosus (SLE), an autoimmune disease.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 1069336961 821 IYIRNLSNSISANELKRRFEVFGEITECCVLSKSRGE--KCGFITYRDSEHAALSLQK--GASLRKRT 884
Cdd:pfam00076   1 LFVGNLPPDTTEEDLKDLFSKFGPIKSIRLVRDETGRskGFAFVEFEDEEDAEKAIEAlnGKELGGRE 68

RNA recognition motif 1 (RRM1) found in the U1A/U2B"/SNF protein family; This subfamily corresponds to the RRM1 of U1A/U2B"/SNF protein family which contains Drosophila sex determination protein SNF and its two mammalian counterparts, U1 small nuclear ribonucleoprotein A (U1 snRNP A or U1-A or U1A) and U2 small nuclear ribonucleoprotein B" (U2 snRNP B" or U2B"), all of which consist of two RNA recognition motifs (RRMs), connected by a variable, flexible linker. SNF is an RNA-binding protein found in the U1 and U2 snRNPs of Drosophila where it is essential in sex determination and possesses a novel dual RNA binding specificity. SNF binds with high affinity to both Drosophila U1 snRNA stem-loop II (SLII) and U2 snRNA stem-loop IV (SLIV). It can also bind to poly(U) RNA tracts flanking the alternatively spliced Sex-lethal (Sxl) exon, as does Drosophila Sex-lethal protein (SXL). U1A is an RNA-binding protein associated with the U1 snRNP, a small RNA-protein complex involved in pre-mRNA splicing. U1A binds with high affinity and specificity to stem-loop II (SLII) of U1 snRNA. It is predominantly a nuclear protein that shuttles between the nucleus and the cytoplasm independently of interactions with U1 snRNA. Moreover, U1A may be involved in RNA 3'-end processing, specifically cleavage, splicing and polyadenylation, through interacting with a large number of non-snRNP proteins. U2B", initially identified to bind to stem-loop IV (SLIV) at the 3' end of U2 snRNA, is a unique protein that comprises of the U2 snRNP. Additional research indicates U2B" binds to U1 snRNA stem-loop II (SLII) as well and shows no preference for SLIV or SLII on the basis of binding affinity. Moreover, U2B" does not require an auxiliary protein for binding to RNA, and its nuclear transport is independent of U2 snRNA binding.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 1069336961 821 IYIRNLSNSISANELKRR----FEVFGEITECCVLS--KSRGEkcGFITYRDSEHAALSLQ 875
Cdd:cd12246     2 LYINNLNEKIKKDELKRSlyalFSQFGPVLDIVASKslKMRGQ--AFVVFKDVESATNALR 60

RNA recognition motif 3 in fungal pre-messenger RNA splicing protein 24 (Prp24) and similar proteins; This subfamily corresponds to the RRM3 of Prp24, also termed U4/U6 snRNA-associated-splicing factor PRP24 (U4/U6 snRNP), an RNA-binding protein with four well conserved RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). It facilitates U6 RNA base-pairing with U4 RNA during spliceosome assembly. Prp24 specifically binds free U6 RNA primarily with RRMs 1 and 2 and facilitates pairing of U6 RNA bases with U4 RNA bases. Additionally, it may also be involved in dissociation of the U4/U6 complex during spliceosome activation.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1069336961 819 RMIYIRNLSNSISANELKRRFEVFGEITEcCVLSKSRGEK-------CGFITYRDSEHAALSLQK-GASLRKR 883
Cdd:cd12298     1 REIRVRNLDFELDEEALRGIFEKFGEIES-INIPKKQKNRkgrhnngFAFVTFEDADSAESALQLnGTLLDNR 72

RNA recognition motif 2 (RRM2) found in Mei2-like proteins and terminal EAR1-like proteins; This subfamily corresponds to the RRM2 of Mei2-like proteins from plant and fungi, terminal EAR1-like proteins from plant, and other eukaryotic homologs. Mei2-like proteins represent an ancient eukaryotic RNA-binding proteins family whose corresponding Mei2-like genes appear to have arisen early in eukaryote evolution, been lost from some lineages such as Saccharomyces cerevisiae and metazoans, and diversified in the plant lineage. The plant Mei2-like genes may function in cell fate specification during development, rather than as stimulators of meiosis. In the fission yeast Schizosaccharomyces pombe, the Mei2 protein is an essential component of the switch from mitotic to meiotic growth. S. pombe Mei2 stimulates meiosis in the nucleus upon binding a specific non-coding RNA. The terminal EAR1-like protein 1 and 2 (TEL1 and TEL2) are mainly found in land plants. They may play a role in the regulation of leaf initiation. All members in this family are putative RNA-binding proteins carrying three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). In addition to the RRMs, the terminal EAR1-like proteins also contain TEL characteristic motifs that allow sequence and putative functional discrimination between them and Mei2-like proteins.

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                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1069336961 820 MIYIRNLSNSISANELKRRFEVFGEITEccVLSKSRGEKCGFITYRDSEHAALSLQ 875
Cdd:cd12276     3 TLLVFNLDAPVSNDELKSLFSKFGEIKE--IRPTPDKPSQKFVEFYDVRDAEAALD 56

RNA recognition motif (RRM) found in U2-associated protein SR140 and similar proteins; This subgroup corresponds to the RRM of SR140 (also termed U2 snRNP-associated SURP motif-containing protein orU2SURP, or 140 kDa Ser/Arg-rich domain protein) which is a putative splicing factor mainly found in higher eukaryotes. Although it is initially identified as one of the 17S U2 snRNP-associated proteins, the molecular and physiological function of SR140 remains unclear. SR140 contains an N-terminal RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), a SWAP/SURP domain that is found in a number of pre-mRNA splicing factors in the middle region, and a C-terminal arginine/serine-rich domain (RS domain).

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 1069336961 821 IYIRNLSNSISANELKRRFEVFGEITECCVL------SKSRGEKCGFITY---RDSEHAALSLQ 875
Cdd:cd12223     4 LYVGNLPPSVTEEVLLREFGRFGPLASVKIMwprteeERRRNRNCGFVAFmsrADAERAMRELN 67

RNA recognition motif 4 (RRM4) found in type I polyadenylate-binding proteins; This subfamily corresponds to the RRM4 of type I poly(A)-binding proteins (PABPs), highly conserved proteins that bind to the poly(A) tail present at the 3' ends of most eukaryotic mRNAs. They have been implicated in theThe CD corresponds to the RRM. regulation of poly(A) tail length during the polyadenylation reaction, translation initiation, mRNA stabilization by influencing the rate of deadenylation and inhibition of mRNA decapping. The family represents type I polyadenylate-binding proteins (PABPs), including polyadenylate-binding protein 1 (PABP-1 or PABPC1), polyadenylate-binding protein 3 (PABP-3 or PABPC3), polyadenylate-binding protein 4 (PABP-4 or APP-1 or iPABP), polyadenylate-binding protein 5 (PABP-5 or PABPC5), polyadenylate-binding protein 1-like (PABP-1-like or PABPC1L), polyadenylate-binding protein 1-like 2 (PABPC1L2 or RBM32), polyadenylate-binding protein 4-like (PABP-4-like or PABPC4L), yeast polyadenylate-binding protein, cytoplasmic and nuclear (PABP or ACBP-67), and similar proteins. PABP-1 is an ubiquitously expressed multifunctional protein that may play a role in 3' end formation of mRNA, translation initiation, mRNA stabilization, protection of poly(A) from nuclease activity, mRNA deadenylation, inhibition of mRNA decapping, and mRNP maturation. Although PABP-1 is thought to be a cytoplasmic protein, it is also found in the nucleus. PABP-1 may be involved in nucleocytoplasmic trafficking and utilization of mRNP particles. PABP-1 contains four copies of RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), a less well conserved linker region, and a proline-rich C-terminal conserved domain (CTD). PABP-3 is a testis-specific poly(A)-binding protein specifically expressed in round spermatids. It is mainly found in mammalian and may play an important role in the testis-specific regulation of mRNA homeostasis. PABP-3 shows significant sequence similarity to PABP-1. However, it binds to poly(A) with a lower affinity than PABP-1. Moreover, PABP-1 possesses an A-rich sequence in its 5'-UTR and allows binding of PABP and blockage of translation of its own mRNA. In contrast, PABP-3 lacks the A-rich sequence in its 5'-UTR. PABP-4 is an inducible poly(A)-binding protein (iPABP) that is primarily localized to the cytoplasm. It shows significant sequence similarity to PABP-1 as well. The RNA binding properties of PABP-1 and PABP-4 appear to be identical. PABP-5 is encoded by PABPC5 gene within the X-specific subinterval, and expressed in fetal brain and in a range of adult tissues in mammalian, such as ovary and testis. It may play an important role in germ cell development. Moreover, unlike other PABPs, PABP-5 contains only four RRMs, but lacks both the linker region and the CTD. PABP-1-like and PABP-1-like 2 are the orthologs of PABP-1. PABP-4-like is the ortholog of PABP-5. Their cellular functions remain unclear. The family also includes the yeast PABP, a conserved poly(A) binding protein containing poly(A) tails that can be attached to the 3'-ends of mRNAs. The yeast PABP and its homologs may play important roles in the initiation of translation and in mRNA decay. Like vertebrate PABP-1, the yeast PABP contains four RRMs, a linker region, and a proline-rich CTD as well. The first two RRMs are mainly responsible for specific binding to poly(A). The proline-rich region may be involved in protein-protein interactions.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 1069336961 821 IYIRNLSNSISANELKRRFEVFGEITECCVLS----KSRGekCGFITYRDSEHAALSLQK 876
Cdd:cd12381     4 LYVKNLDDTIDDEKLREEFSPFGTITSAKVMTdeggRSKG--FGFVCFSSPEEATKAVTE 61

RNA recognition motif 1 (RRM1) found in RNA-binding protein Musashi homolog Musashi-1, Musashi-2 and similar proteins; This subfamily corresponds to the RRM1 in Musashi-1 and Musashi-2. Musashi-1 (also termed Msi1) is a neural RNA-binding protein putatively expressed in central nervous system (CNS) stem cells and neural progenitor cells, and associated with asymmetric divisions in neural progenitor cells. It is evolutionarily conserved from invertebrates to vertebrates. Musashi-1 is a homolog of Drosophila Musashi and Xenopus laevis nervous system-specific RNP protein-1 (Nrp-1). It has been implicated in the maintenance of the stem-cell state, differentiation, and tumorigenesis. It translationally regulates the expression of a mammalian numb gene by binding to the 3'-untranslated region of mRNA of Numb, encoding a membrane-associated inhibitor of Notch signaling, and further influences neural development. Moreover, Musashi-1 represses translation by interacting with the poly(A)-binding protein and competes for binding of the eukaryotic initiation factor-4G (eIF-4G). Musashi-2 (also termed Msi2) has been identified as a regulator of the hematopoietic stem cell (HSC) compartment and of leukemic stem cells after transplantation of cells with loss and gain of function of the gene. It influences proliferation and differentiation of HSCs and myeloid progenitors, and further modulates normal hematopoiesis and promotes aggressive myeloid leukemia. Both, Musashi-1 and Musashi-2, contain two conserved N-terminal tandem RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), along with other domains of unknown function.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1069336961 821 IYIRNLSNSISANELKRRFEVFGEITECCVL-----SKSRGekCGFITYRDSEHAALSLQKGA 878
Cdd:cd12576     2 MFIGGLSWQTTPEGLREYFSKFGEITECMVMrdpttKRSRG--FGFVTFSDPASVDKVLAQGP 62

RNA recognition motif 2 (RRM2) found in CUGBP Elav-like family member CELF-3, CELF-4, CELF-5, CELF-6 and similar proteins; This subgroup corresponds to the RRM2 of CELF-3, CELF-4, CELF-5, and CELF-6, all of which belong to the CUGBP1 and ETR-3-like factors (CELF) or BRUNOL (Bruno-like) family of RNA-binding proteins that display dual nuclear and cytoplasmic localizations and have been implicated in the regulation of pre-mRNA splicing and in the control of mRNA translation and deadenylation. CELF-3, expressed in brain and testis only, is also known as bruno-like protein 1 (BRUNOL-1), or CAG repeat protein 4, or CUG-BP- and ETR-3-like factor 3, or embryonic lethal abnormal vision (ELAV)-type RNA-binding protein 1 (ETR-1), or expanded repeat domain protein CAG/CTG 4, or trinucleotide repeat-containing gene 4 protein (TNRC4). It plays an important role in the pathogenesis of tauopathies. CELF-3 contains three highly conserved RNA recognition motifs (RRMs), also known as RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains): two consecutive RRMs (RRM1 and RRM2) situated in the N-terminal region followed by a linker region and the third RRM (RRM3) close to the C-terminus of the protein. The effect of CELF-3 on tau splicing is mediated mainly by the RNA-binding activity of RRM2. The divergent linker region might mediate the interaction of CELF-3 with other proteins regulating its activity or involved in target recognition. CELF-4, being highly expressed throughout the brain and in glandular tissues, moderately expressed in heart, skeletal muscle, and liver, is also known as bruno-like protein 4 (BRUNOL-4), or CUG-BP- and ETR-3-like factor 4. Like CELF-3, CELF-4 also contain three highly conserved RRMs. The splicing activation or repression activity of CELF-4 on some specific substrates is mediated by its RRM1/RRM2. On the other hand, both RRM1 and RRM2 of CELF-4 can activate cardiac troponin T (cTNT) exon 5 inclusion. CELF-5, expressed in brain, is also known as bruno-like protein 5 (BRUNOL-5), or CUG-BP- and ETR-3-like factor 5. Although its biological role remains unclear, CELF-5 shares same domain architecture with CELF-3. CELF-6, being strongly expressed in kidney, brain, and testis, is also known as bruno-like protein 6 (BRUNOL-6), or CUG-BP- and ETR-3-like factor 6. It activates exon inclusion of a cardiac troponin T minigene in transient transfection assays in a muscle-specific splicing enhancer (MSE)-dependent manner and can activate inclusion via multiple copies of a single element, MSE2. CELF-6 also promotes skipping of exon 11 of insulin receptor, a known target of CELF activity that is expressed in kidney. In addition to three highly conserved RRMs, CELF-6 also possesses numerous potential phosphorylation sites, a potential nuclear localization signal (NLS) at the C terminus, and an alanine-rich region within the divergent linker region.

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                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1069336961 819 RMIYIRNLSNSISANELKRRFEVFGEITECCVL----SKSRGekCGFITYRDSEHA 870
Cdd:cd12635     2 RKLFVGMLGKQQSEDDVRRLFEPFGSIEECTILrgpdGNSKG--CAFVKFSSHAEA 55

RNA recognition motif 1 (RRM1) found in the p54nrb/PSF/PSP1 family; This subfamily corresponds to the RRM1 of the p54nrb/PSF/PSP1 family, including 54 kDa nuclear RNA- and DNA-binding protein (p54nrb or NonO or NMT55), polypyrimidine tract-binding protein (PTB)-associated-splicing factor (PSF or POMp100), paraspeckle protein 1 (PSP1 or PSPC1), which are ubiquitously expressed and are conserved in vertebrates. p54nrb is a multi-functional protein involved in numerous nuclear processes including transcriptional regulation, splicing, DNA unwinding, nuclear retention of hyperedited double-stranded RNA, viral RNA processing, control of cell proliferation, and circadian rhythm maintenance. PSF is also a multi-functional protein that binds RNA, single-stranded DNA (ssDNA), double-stranded DNA (dsDNA) and many factors, and mediates diverse activities in the cell. PSP1 is a novel nucleolar factor that accumulates within a new nucleoplasmic compartment, termed paraspeckles, and diffusely distributes in the nucleoplasm. The cellular function of PSP1 remains unknown currently. This subfamily also includes some p54nrb/PSF/PSP1 homologs from invertebrate species, such as the Drosophila melanogaster gene no-ontransient A (nonA) encoding puff-specific protein Bj6 (also termed NONA) and Chironomus tentans hrp65 gene encoding protein Hrp65. D. melanogaster NONA is involved in eye development and behavior, and may play a role in circadian rhythm maintenance, similar to vertebrate p54nrb. C. tentans Hrp65 is a component of nuclear fibers associated with ribonucleoprotein particles in transit from the gene to the nuclear pore. All family members contain a DBHS domain (for Drosophila behavior, human splicing), which comprises two conserved RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a charged protein-protein interaction module. PSF has an additional large N-terminal domain that differentiates it from other family members.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1069336961 821 IYIRNLSNSISANELKRRFEVFGEITEcCVLSKSRGekCGFITYRDSEHA-----AL--SLQKGASLRKR 883
Cdd:cd12332     4 LFVGNLPNDITEEEFKELFQKYGEVSE-VFLNKGKG--FGFIRLDTRANAeaakaELdgTPRKGRQLRVR 70

RNA recognition motif 1 (RRM1) found in heterogeneous nuclear ribonucleoprotein hnRNP A and hnRNP D subfamilies and similar proteins; This subfamily corresponds to the RRM1 in the hnRNP A subfamily which includes hnRNP A0, hnRNP A1, hnRNP A2/B1, hnRNP A3 and similar proteins. hnRNP A0 is a low abundance hnRNP protein that has been implicated in mRNA stability in mammalian cells. hnRNP A1 is an abundant eukaryotic nuclear RNA-binding protein that may modulate splice site selection in pre-mRNA splicing. hnRNP A2/B1 is an RNA trafficking response element-binding protein that interacts with the hnRNP A2 response element (A2RE). hnRNP A3 is also a RNA trafficking response element-binding protein that participates in the trafficking of A2RE-containing RNA. The hnRNP A subfamily is characterized by two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), followed by a long glycine-rich region at the C-terminus. The hnRNP D subfamily includes hnRNP D0, hnRNP A/B, hnRNP DL and similar proteins. hnRNP D0 is a UUAG-specific nuclear RNA binding protein that may be involved in pre-mRNA splicing and telomere elongation. hnRNP A/B is an RNA unwinding protein with a high affinity for G- followed by U-rich regions. hnRNP A/B has also been identified as an APOBEC1-binding protein that interacts with apolipoprotein B (apoB) mRNA transcripts around the editing site and thus, plays an important role in apoB mRNA editing. hnRNP DL (or hnRNP D-like) is a dual functional protein that possesses DNA- and RNA-binding properties. It has been implicated in mRNA biogenesis at the transcriptional and post-transcriptional levels. All members in this subfamily contain two putative RRMs and a glycine- and tyrosine-rich C-terminus. The family also contains DAZAP1 (Deleted in azoospermia-associated protein 1), RNA-binding protein Musashi homolog Musashi-1, Musashi-2 and similar proteins. They all harbor two RRMs.

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gi 1069336961 821 IYIRNLSNSISANELKRRFEVFGEITECCVLS-----KSRGekCGFITYRDSEHAALSLQKG 877
Cdd:cd12325     1 LFVGGLSWETTEESLREYFSKYGEVVDCVVMKdpatgRSRG--FGFVTFKDPSSVDAVLAAR 60

RNA recognition motif 3 (RRM3) found in SMART/HDAC1-associated repressor protein (SHARP) and similar proteins; This subfamily corresponds to the RRM3 of SHARP, also termed Msx2-interacting protein (MINT), or SPEN homolog, an estrogen-inducible transcriptional repressor that interacts directly with the nuclear receptor corepressor SMRT, histone deacetylases (HDACs) and components of the NuRD complex. SHARP recruits HDAC activity and binds to the steroid receptor RNA coactivator SRA through four conserved N-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), further suppressing SRA-potentiated steroid receptor transcription activity. Thus, SHARP has the capacity to modulate both liganded and nonliganded nuclear receptors. SHARP also has been identified as a component of transcriptional repression complexes in Notch/RBP-Jkappa signaling pathways. In addition to the N-terminal RRMs, SHARP possesses a C-terminal SPOC domain (Spen paralog and ortholog C-terminal domain), which is highly conserved among Spen proteins.

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gi 1069336961 819 RMIYIRNLSNSISANELKRRFEVFGEITECCVLSKSRGEKCGFITYRD 866
Cdd:cd12350     3 RTLFIGNLEKTTTYGDLRNIFERFGEIIDIDIKKQNGNPQYAFLQYCD 50

RNA recognition motif 2 (RRM2) found in vertebrate RNA-binding protein RBM23, RBM39 and similar proteins; This subfamily corresponds to the RRM2 of RBM39 (also termed HCC1), a nuclear autoantigen that contains an N-terminal arginine/serine rich (RS) motif and three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). An octapeptide sequence called the RS-ERK motif is repeated six times in the RS region of RBM39. Although the cellular function of RBM23 remains unclear, it shows high sequence homology to RBM39 and contains two RRMs. It may possibly function as a pre-mRNA splicing factor.

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gi 1069336961 821 IYIRNLSNSISANELKRRFEVFGEItECCVLSK------SRGEkcGFITYRDSEHAALSLQK 876
Cdd:cd12284     1 LYVGSLHFNITEDMLRGIFEPFGKI-EFVQLQKdpetgrSKGY--GFIQFRDAEDAKKALEQ 59

RNA recognition motif 2 (RRM2) found in Drosophila melanogaster Bruno protein and similar proteins; This subgroup corresponds to the RRM2 of Bruno, a Drosophila RNA recognition motif (RRM)-containing protein that plays a central role in regulation of Oskar (Osk) expression. It mediates repression by binding to regulatory Bruno response elements (BREs) in the Osk mRNA 3' UTR. The full-length Bruno protein contains three RRMs, two located in the N-terminal half of the protein and the third near the C-terminus, separated by a linker region.

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gi 1069336961 819 RMIYIRNLSNSISANELKRRFEVFGEITECCVL----SKSRGekCGFITYRDSEHA 870
Cdd:cd12636     2 RKLFVGMLSKKCNESDVRIMFSPYGSIEECTVLrdqnGKSRG--CAFVTFTSRQCA 55

RNA recognition motif 1 (RRM1) found in heterogeneous nuclear ribonucleoprotein A subfamily; This subfamily corresponds to the RRM1 in hnRNP A0, hnRNP A1, hnRNP A2/B1, hnRNP A3 and similar proteins. hnRNP A0 is a low abundance hnRNP protein that has been implicated in mRNA stability in mammalian cells. It has been identified as the substrate for MAPKAP-K2 and may be involved in the lipopolysaccharide (LPS)-induced post-transcriptional regulation of tumor necrosis factor-alpha (TNF-alpha), cyclooxygenase 2 (COX-2) and macrophage inflammatory protein 2 (MIP-2). hnRNP A1 is an abundant eukaryotic nuclear RNA-binding protein that may modulate splice site selection in pre-mRNA splicing. hnRNP A2/B1 is an RNA trafficking response element-binding protein that interacts with the hnRNP A2 response element (A2RE). Many mRNAs, such as myelin basic protein (MBP), myelin-associated oligodendrocytic basic protein (MOBP), carboxyanhydrase II (CAII), microtubule-associated protein tau, and amyloid precursor protein (APP) are trafficked by hnRNP A2/B1. hnRNP A3 is also a RNA trafficking response element-binding protein that participates in the trafficking of A2RE-containing RNA. The hnRNP A subfamily is characterized by two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), followed by a long glycine-rich region at the C-terminus.

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gi 1069336961 821 IYIRNLSNSISANELKRRFEVFGEITECCVL-----SKSRGekCGFITYRDSE 868
Cdd:cd12578     2 LFIGGLSYETTDDSLRNHFEQWGEITDVVVMkdpatKRSRG--FGFVTYSSAS 52

RNA recognition motif 1 (RRM1) found in Mei2-like proteins and terminal EAR1-like proteins; This subfamily corresponds to the RRM1 of Mei2-like proteins from plant and fungi, terminal EAR1-like proteins from plant, and other eukaryotic homologs. Mei2-like proteins represent an ancient eukaryotic RNA-binding protein family whose corresponding Mei2-like genes appear to have arisen early in eukaryote evolution, been lost from some lineages such as Saccharomyces cerevisiae and metazoans, and diversified in the plant lineage. The plant Mei2-like genes may function in cell fate specification during development, rather than as stimulators of meiosis. In the fission yeast Schizosaccharomyces pombe, the Mei2 protein is an essential component of the switch from mitotic to meiotic growth. S. pombe Mei2 stimulates meiosis in the nucleus upon binding a specific non-coding RNA. The terminal EAR1-like protein 1 and 2 (TEL1 and TEL2) are mainly found in land plants. They may play a role in the regulation of leaf initiation. All members in this family are putative RNA-binding proteins carrying three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). In addition to the RRMs, the terminal EAR1-like proteins also contain TEL characteristic motifs that allow sequence and putative functional discrimination between them and Mei2-like proteins.

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gi 1069336961 819 RMIYIRNLSNSISANELKRRFEVFGEITECCVLSKSRG-EKCGFITYRDSEHAALSLQkGASLRKRT 884
Cdd:cd12275     2 RSLFVINVPRDVTESTLRRLFEVYGDVRGVQTERISEGiVTVHFYDIRDAKRAVRELC-GRHMQQQA 67

RNA recognition motif 2 (RRM2) found in putative RNA binding motif protein 15B (RBM15B) from vertebrate; This subgroup corresponds to the RRM2 of RBM15B, also termed one twenty-two 3 (OTT3), a paralog of RNA binding motif protein 15 (RBM15), also known as One-twenty two protein 1 (OTT1). Like RBM15, RBM15B has post-transcriptional regulatory activity. It is a nuclear protein sharing with RBM15 the association with the splicing factor compartment and the nuclear envelope as well as the binding to mRNA export factors NXF1 and Aly/REF. RBM15B belongs to the Spen (split end) protein family, which shares a domain architecture comprising of three N-terminal RNA recognition motifs (RRMs), also known as RBD (RNA binding domain) or RNP (ribonucleoprotein domain), and a C-terminal SPOC (Spen paralog and ortholog C-terminal) domain.

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gi 1069336961 819 RMIYIRNLSNSISANELKRRFEVFGEITECCVLSKSRGE--KCGFITYR--DSEHAALSLQKGASLRKRtepPFQLSYG 893
Cdd:cd12556     9 RNLFIGNLDHNVSEVELRRAFEKYGIIEEVVIKRPARGQggAYAFLKFQnlDMAHRAKVAMSGRVIGRN---PIKIGYG 84

RNA recognition motif 1 (RRM1) found in the Hu proteins family, Drosophila sex-lethal (SXL), and similar proteins; This subfamily corresponds to the RRM1 of Hu proteins and SXL. The Hu proteins family represents a group of RNA-binding proteins involved in diverse biological processes. Since the Hu proteins share high homology with the Drosophila embryonic lethal abnormal vision (ELAV) protein, the Hu family is sometimes referred to as the ELAV family. Drosophila ELAV is exclusively expressed in neurons and is required for the correct differentiation and survival of neurons in flies. The neuronal members of the Hu family include Hu-antigen B (HuB or ELAV-2 or Hel-N1), Hu-antigen C (HuC or ELAV-3 or PLE21), and Hu-antigen D (HuD or ELAV-4), which play important roles in neuronal differentiation, plasticity and memory. HuB is also expressed in gonads. Hu-antigen R (HuR or ELAV-1 or HuA) is ubiquitously expressed Hu family member. It has a variety of biological functions mostly related to the regulation of cellular response to DNA damage and other types of stress. Hu proteins perform their cytoplasmic and nuclear molecular functions by coordinately regulating functionally related mRNAs. In the cytoplasm, Hu proteins recognize and bind to AU-rich RNA elements (AREs) in the 3' untranslated regions (UTRs) of certain target mRNAs, such as GAP-43, vascular epithelial growth factor (VEGF), the glucose transporter GLUT1, eotaxin and c-fos, and stabilize those ARE-containing mRNAs. They also bind and regulate the translation of some target mRNAs, such as neurofilament M, GLUT1, and p27. In the nucleus, Hu proteins function as regulators of polyadenylation and alternative splicing. Each Hu protein contains three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). RRM1 and RRM2 may cooperate in binding to an ARE. RRM3 may help to maintain the stability of the RNA-protein complex, and might also bind to poly(A) tails or be involved in protein-protein interactions. This family also includes the sex-lethal protein (SXL) from Drosophila melanogaster. SXL governs sexual differentiation and X chromosome dosage compensation in flies. It induces female-specific alternative splicing of the transformer (tra) pre-mRNA by binding to the tra uridine-rich polypyrimidine tract at the non-sex-specific 3' splice site during the sex-determination process. SXL binds to its own pre-mRNA and promotes female-specific alternative splicing. It contains an N-terminal Gly/Asn-rich domain that may be responsible for the protein-protein interaction, and tandem RRMs that show high preference to bind single-stranded, uridine-rich target RNA transcripts.

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gi 1069336961 826 LSNSISANELKRRFEVFGEITEC-CVLSKSRGEKC--GFITYRDSEHAALSLQ 875
Cdd:cd12375     7 LPQSMTQEELRSLFGAIGPIESCkLVRDKITGQSLgyGFVNYRDPNDARKAIN 59

RNA recognition motif (RRM) found in nucleolar protein 8 (NOL8) and similar proteins; This model corresponds to the RRM of NOL8 (also termed Nop132) encoded by a novel NOL8 gene that is up-regulated in the majority of diffuse-type, but not intestinal-type, gastric cancers. Thus, NOL8 may be a good molecular target for treatment of diffuse-type gastric cancer. Also, NOL8 is a phosphorylated protein that contains an N-terminal RNA recognition motif (RRM), also known as RBD (RNA binding domain) or RNP (ribonucleoprotein domain), suggesting NOL8 is likely to function as a novel RNA-binding protein. It may be involved in regulation of gene expression at the post-transcriptional level or in ribosome biogenesis in cancer cells.

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gi 1069336961 821 IYIRNLSNSISANELKRRFEVFGEITeCCVLSKSRGEKC---GFITYRDSEhaaLSLQK 876
Cdd:cd12226     2 LFVGGLSPSITEDDLERRFSRFGTVS-DVEIIRKKDAPDrgfAYIDLRTSE---AALQK 56