RNA recognition motif 2 (RRM2) found in terminal EAR1-like proteins; This subgroup corresponds to the RRM2 of terminal EAR1-like proteins, including terminal EAR1-like protein 1 and 2 (TEL1 and TEL2) found in land plants. They may play a role in the regulation of leaf initiation. The terminal EAR1-like proteins are putative RNA-binding proteins carrying three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and TEL characteristic motifs that allow sequence and putative functional discrimination between the terminal EAR1-like proteins and Mei2-like proteins.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 11072029 182 QGSLVIMNLEPTVSSSTLRHIFQVYGEVKQVRETPCKREQRFVEFFDVRDAAKALRVMNGKVISGKPMVIQ 252
Cdd:cd12527   1 QGSLVILNLLPAVSSFTLREIFQVYGDVKDVRETPLKPSQRFVEFFDVRDAARALHEMNGKEIFGKRLVIE 71

RNA recognition motif 2 (RRM2) found in terminal EAR1-like proteins; This subgroup corresponds to the RRM2 of terminal EAR1-like proteins, including terminal EAR1-like protein 1 and 2 (TEL1 and TEL2) found in land plants. They may play a role in the regulation of leaf initiation. The terminal EAR1-like proteins are putative RNA-binding proteins carrying three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and TEL characteristic motifs that allow sequence and putative functional discrimination between the terminal EAR1-like proteins and Mei2-like proteins.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 11072029 182 QGSLVIMNLEPTVSSSTLRHIFQVYGEVKQVRETPCKREQRFVEFFDVRDAAKALRVMNGKVISGKPMVIQ 252
Cdd:cd12527   1 QGSLVILNLLPAVSSFTLREIFQVYGDVKDVRETPLKPSQRFVEFFDVRDAARALHEMNGKEIFGKRLVIE 71

RNA recognition motif 2;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 11072029   336 RTTVMIKNIPNKYTQKLLLKMLDTHCKdcnqsvikegnktpmSSYDFVYLPIDFSNKSNVGYGFVNMTSPEAVWRLYKSF 415
Cdd:pfam04059   1 RTTLMIKNIPNKYTQKMLLAAIDEKNK---------------GTYDFLYLPIDFKNKCNVGYAFINMIEPQSIIPFGKAF 65

                          90       100       110
                  ....*....|....*....|....*....|...
gi 11072029   416 HNQHWRDFtTTRKICEVTYARIQGLESLREHFK 448
Cdd:pfam04059  66 NGKKWEKF-NSEKVASLAYARIQGKDALIAHFQ 97

polyadenylate binding protein, human types 1, 2, 3, 4 family; These eukaryotic proteins recognize the poly-A of mRNA and consists of four tandem RNA recognition domains at the N-terminus (rrm: pfam00076) followed by a PABP-specific domain (pfam00658) at the C-terminus. The protein is involved in the transport of mRNA's from the nucleus to the cytoplasm. There are four paralogs in Homo sapiens which are expressed in testis, platelets, broadly expressed and of unknown tissue range.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 11072029    86 QVPATVTETSLRRDMELFGEVRGVQMERAHEG-IVIFHFYNLINSQ---RAFNEIRYRHMQQQEQQQHFHFTTARGLVSG 161
Cdd:TIGR01628 185 NLDPSVNEDKLRELFAKFGEITSAAVMKDGSGrSRGFAFVNFEKHEdaaKAVEEMNGKKIGLAKEGKKLYVGRAQKRAER 264

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 11072029   162 HSLWAHfVFPQLNAVPEGNNQGS-LVIMNLEPTVSSSTLRHIFQVYGEVKQVR----ETPCKREQRFVEFFDVRDAAKAL 236
Cdd:TIGR01628 265 EAELRR-KFEELQQERKMKAQGVnLYVKNLDDTVTDEKLRELFSECGEITSAKvmldEKGVSRGFGFVCFSNPEEANRAV 343

                         170
                  ....*....|....*
gi 11072029   237 RVMNGKVISGKPMVI 251
Cdd:TIGR01628 344 TEMHGRMLGGKPLYV 358

RNA recognition motif (RRM) domain [Translation, ribosomal structure and biogenesis];

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 11072029 189 NLEPTVSSSTLRHIFQVYGEVKQV-----RETpcKREQR--FVEFFDVRDAAKALRVMNGKVISGKPMVIQFSRP 256
Cdd:COG0724   8 NLPYSVTEEDLRELFSEYGEVTSVklitdRET--GRSRGfgFVEMPDDEEAQAAIEALNGAELMGRTLKVNEARP 80

RNA recognition motif 2 (RRM2) found in terminal EAR1-like proteins; This subgroup corresponds to the RRM2 of terminal EAR1-like proteins, including terminal EAR1-like protein 1 and 2 (TEL1 and TEL2) found in land plants. They may play a role in the regulation of leaf initiation. The terminal EAR1-like proteins are putative RNA-binding proteins carrying three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and TEL characteristic motifs that allow sequence and putative functional discrimination between the terminal EAR1-like proteins and Mei2-like proteins.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 11072029 182 QGSLVIMNLEPTVSSSTLRHIFQVYGEVKQVRETPCKREQRFVEFFDVRDAAKALRVMNGKVISGKPMVIQ 252
Cdd:cd12527   1 QGSLVILNLLPAVSSFTLREIFQVYGDVKDVRETPLKPSQRFVEFFDVRDAARALHEMNGKEIFGKRLVIE 71

RNA recognition motif 3 (RRM3) found in Mei2-like proteins and terminal EAR1-like proteins; This subfamily corresponds to the RRM3 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.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 11072029 339 VMIKNIPNKYTQKLLLKMLDTHCKDcnqsvikegnktpmSSYDFVYLPIDFSNKSNVGYGFVNMTSPEAVWRLYKSFHNQ 418
Cdd:cd12277   1 VMLRNIPNKYTQEMLLQEIDEHGKG--------------GAYDFFYLPLDFKTKCNVGYAFINFINPEAAERFYKAFNGK 66

                        90       100
                ....*....|....*....|.
gi 11072029 419 HWRDFtTTRKICEVTYARIQG 439
Cdd:cd12277  67 KWKNF-PSKKVCDISYARLQG 86

RNA recognition motif 2;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 11072029   336 RTTVMIKNIPNKYTQKLLLKMLDTHCKdcnqsvikegnktpmSSYDFVYLPIDFSNKSNVGYGFVNMTSPEAVWRLYKSF 415
Cdd:pfam04059   1 RTTLMIKNIPNKYTQKMLLAAIDEKNK---------------GTYDFLYLPIDFKNKCNVGYAFINMIEPQSIIPFGKAF 65

                          90       100       110
                  ....*....|....*....|....*....|...
gi 11072029   416 HNQHWRDFtTTRKICEVTYARIQGLESLREHFK 448
Cdd:pfam04059  66 NGKKWEKF-NSEKVASLAYARIQGKDALIAHFQ 97

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.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 11072029 182 QGSLVIMNLEPTVSSSTLRHIFQVYGEVKQVRETPCKREQRFVEFFDVRDAAKALRVMNGKVISGKPMVIQ 252
Cdd:cd12276   1 QGTLLVFNLDAPVSNDELKSLFSKFGEIKEIRPTPDKPSQKFVEFYDVRDAEAALDGLNGRELLGGKLKVA 71

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.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 11072029  79 TRAVMLLQVPATVTETSLRRDMELFGEVRGVQMERAHEGIVIFHFYNLINSQRAFNEIRYRHM 141
Cdd:cd12275   1 SRSLFVINVPRDVTESTLRRLFEVYGDVRGVQTERISEGIVTVHFYDIRDAKRAVRELCGRHM 63

RNA recognition motif;

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 11072029    184 SLVIMNLEPTVSSSTLRHIFQVYGEVKQVRETPCKREQR-----FVEFFDVRDAAKALRVMNGKVISGKPMVI 251
Cdd:smart00360   1 TLFVGNLPPDTTEEELRELFSKFGKVESVRLVRDKETGKskgfaFVEFESEEDAEKALEALNGKELDGRPLKV 73

RNA recognition motif 1 (RRM1) found in plant Mei2-like proteins; This subgroup corresponds to the RRM1 of Mei2-like proteins that represent an ancient eukaryotic RNA-binding proteins family. Their 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. Members in this family contain three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). The C-terminal RRM (RRM3) is unique to Mei2-like proteins and it is highly conserved between plants and fungi. Up to date, the intracellular localization, RNA target(s), cellular interactions and phosphorylation states of Mei2-like proteins in plants remain unclear.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 11072029 185 LVIMNLEPTVSSSTLRHIFQVYGEVKQVReTPCKreQR---FVEFFDVRDAAKALRVMNGKVISGKPMVIQFSRP 256
Cdd:cd12524   4 LFVRNINSSVEDEELRALFEQFGEIRTLY-TACK--HRgfiMVSYYDIRAAQSAKRALQGTELGGRKLDIHFSIP 75

polyadenylate binding protein, human types 1, 2, 3, 4 family; These eukaryotic proteins recognize the poly-A of mRNA and consists of four tandem RNA recognition domains at the N-terminus (rrm: pfam00076) followed by a PABP-specific domain (pfam00658) at the C-terminus. The protein is involved in the transport of mRNA's from the nucleus to the cytoplasm. There are four paralogs in Homo sapiens which are expressed in testis, platelets, broadly expressed and of unknown tissue range.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 11072029    86 QVPATVTETSLRRDMELFGEVRGVQMERAHEG-IVIFHFYNLINSQ---RAFNEIRYRHMQQQEQQQHFHFTTARGLVSG 161
Cdd:TIGR01628 185 NLDPSVNEDKLRELFAKFGEITSAAVMKDGSGrSRGFAFVNFEKHEdaaKAVEEMNGKKIGLAKEGKKLYVGRAQKRAER 264

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 11072029   162 HSLWAHfVFPQLNAVPEGNNQGS-LVIMNLEPTVSSSTLRHIFQVYGEVKQVR----ETPCKREQRFVEFFDVRDAAKAL 236
Cdd:TIGR01628 265 EAELRR-KFEELQQERKMKAQGVnLYVKNLDDTVTDEKLRELFSECGEITSAKvmldEKGVSRGFGFVCFSNPEEANRAV 343

                         170
                  ....*....|....*
gi 11072029   237 RVMNGKVISGKPMVI 251
Cdd:TIGR01628 344 TEMHGRMLGGKPLYV 358

RNA recognition motif 3 (RRM3) found in heterogeneous nuclear ribonucleoprotein R (hnRNP R) and similar proteins; This subfamily corresponds to the RRM3 in hnRNP R, hnRNP Q, and APOBEC-1 complementation factor (ACF). hnRNP R is a ubiquitously expressed nuclear RNA-binding protein that specifically bind mRNAs with a preference for poly(U) stretches and has been implicated in mRNA processing and mRNA transport, and also acts as a regulator to modify binding to ribosomes and RNA translation. hnRNP Q is also a ubiquitously expressed nuclear RNA-binding protein. It has been identified as a component of the spliceosome complex, as well as a component of the apobec-1 editosome, and has been implicated in the regulation of specific mRNA transport. ACF is an RNA-binding subunit of a core complex that interacts with apoB mRNA to facilitate C to U RNA editing. It may also act as an apoB mRNA recognition factor and chaperone and play a key role in cell growth and differentiation. This family also includes two functionally unknown RNA-binding proteins, RBM46 and RBM47. All members contain three conserved RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains).

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 11072029 184 SLVIMNLEPTVSSSTLRHIFQVYGEVKQVRETpckREQRFVEFFDVRDAAKALRVMNGKVISGKPMVIQFSRP 256
Cdd:cd12251   3 VLYVRNLMLSTTEEKLRELFSEYGKVERVKKI---KDYAFVHFEERDDAVKAMEEMNGKELEGSEIEVSLAKP 72

RNA recognition motif 1 (RRM1) found in granule-associated RNA binding proteins p40-TIA-1 and TIAR; This subfamily corresponds to the RRM1 of nucleolysin TIA-1 isoform p40 (p40-TIA-1 or TIA-1) and nucleolysin TIA-1-related protein (TIAR), both of which are granule-associated RNA binding proteins involved in inducing apoptosis in cytotoxic lymphocyte (CTL) target cells. TIA-1 and TIAR share high sequence similarity. They are expressed in a wide variety of cell types. TIA-1 can be phosphorylated by a serine/threonine kinase that is activated during Fas-mediated apoptosis.TIAR is mainly localized in the nucleus of hematopoietic and nonhematopoietic cells. It is translocated from the nucleus to the cytoplasm in response to exogenous triggers of apoptosis. Both, TIA-1 and TIAR, bind specifically to poly(A) but not to poly(C) homopolymers. They are composed of three N-terminal highly homologous RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a glutamine-rich C-terminal auxiliary domain containing a lysosome-targeting motif. TIA-1 and TIAR interact with RNAs containing short stretches of uridylates and their RRM2 can mediate the specific binding to uridylate-rich RNAs. The C-terminal auxiliary domain may be responsible for interacting with other proteins. In addition, TIA-1 and TIAR share a potential serine protease-cleavage site (Phe-Val-Arg) localized at the junction between their RNA binding domains and their C-terminal auxiliary domains.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 11072029 185 LVIMNLEPTVSSSTLRHIFQVYGEVKQ---VRETPCKREQRFVEFFDVRDAAKALRVMNGKVISGKPM 249
Cdd:cd12352   1 LYVGNLDRQVTEDLILQLFSQIGPCKSckmITEHGGNDPYCFVEFYEHNHAAAALQAMNGRKILGKEV 68

RNA recognition motif (RRM) domain [Translation, ribosomal structure and biogenesis];

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 11072029 189 NLEPTVSSSTLRHIFQVYGEVKQV-----RETpcKREQR--FVEFFDVRDAAKALRVMNGKVISGKPMVIQFSRP 256
Cdd:COG0724   8 NLPYSVTEEDLRELFSEYGEVTSVklitdRET--GRSRGfgFVEMPDDEEAQAAIEALNGAELMGRTLKVNEARP 80

RNA recognition motif (RRM) found in eukaryotic RNA-binding protein 18 and similar proteins; This subfamily corresponds to the RRM of RBM18, a putative RNA-binding protein containing a well-conserved RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain). The biological role of RBM18 remains unclear.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 11072029 185 LVIMNLEPTVSSSTLRHIFQVYGEVKQV-----RETPCKREQR---FVEFFDVRDAAKALRVMNGKVISGKPMVIQFSR 255
Cdd:cd12355   2 LWIGNLDPRLTEYHLLKLLSKYGKIKKFdflfhKTGPLKGQPRgycFVTFETKEEAEKAIECLNGKLALGKKLVVRWAH 80

RNA recognition motif 1 (RRM1) found in RNA-binding protein 28 (RBM28) and similar proteins; This subfamily corresponds to the RRM1 of RBM28 and Nop4p. RBM28 is a specific nucleolar component of the spliceosomal small nuclear ribonucleoproteins (snRNPs), possibly coordinating their transition through the nucleolus. It specifically associates with U1, U2, U4, U5, and U6 small nuclear RNAs (snRNAs), and may play a role in the maturation of both small nuclear and ribosomal RNAs. RBM28 has four RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and an extremely acidic region between RRM2 and RRM3. The family also includes nucleolar protein 4 (Nop4p or Nop77p) encoded by YPL043W from Saccharomyces cerevisiae. It is an essential nucleolar protein involved in processing and maturation of 27S pre-rRNA and biogenesis of 60S ribosomal subunits. Nop4p also contains four RRMs.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 11072029 184 SLVIMNLEPTVSSSTLRHIFQVYGEVKQ---VRE---TPCkREQRFVEFFDVRDAAKALRVMNGKVISGKPMVIQFSRP 256
Cdd:cd12413   1 TLFVRNLPYDTTDEQLEELFSDVGPVKRcfvVKDkgkDKC-RGFGYVTFALAEDAQRALEEVKGKKFGGRKIKVELAKK 78

RNA recognition motif 2 (RRM2) found in the Spen (split end) protein family; This subfamily corresponds to the RRM2 domain in the Spen (split end) protein family which includes RNA binding motif protein 15 (RBM15), putative RNA binding motif protein 15B (RBM15B), and similar proteins found in Metazoa. RBM15, also termed one-twenty two protein 1 (OTT1), conserved in eukaryotes, is a novel mRNA export factor and component of the NXF1 pathway. It binds to NXF1 and serves as receptor for the RNA export element RTE. It also possess mRNA export activity and can facilitate the access of DEAD-box protein DBP5 to mRNA at the nuclear pore complex (NPC). RNA-binding protein 15B (RBM15B), also termed one twenty-two 3 (OTT3), is a paralog of RBM15 and therefore 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. Members in this family belong to the Spen (split end) protein family, which share 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.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 11072029 184 SLVIMNLEPTVSSSTLRHIFQVYGEVKQVretPCKREQR-------FVEFFDVRDAAKALRVMNGKVISGKPMVIQFSR 255
Cdd:cd12309   4 TLFVGNLEITITEEELRRAFERYGVVEDV---DIKRPPRgqgnayaFVKFLNLDMAHRAKVAMSGQYIGRNQIKIGYGK 79

RNA recognition motif 3 (RRM3) found in vertebrate RNA-binding protein 46 (RBM46); This subgroup corresponds to the RRM3 of RBM46, also termed cancer/testis antigen 68 (CT68), is a putative RNA-binding protein that shows high sequence homology with heterogeneous nuclear ribonucleoprotein R (hnRNP R) and heterogeneous nuclear ribonucleoprotein Q (hnRNP Q). Its biological function remains unclear. Like hnRNP R and hnRNP Q, RBM46 contains two well defined and one degenerated RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains).

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 11072029 185 LVIMNLEPTVSSSTLRHIFQVY--GEVKQVRETpckREQRFVEFFDVRDAAKALRVMNGKVISGKPMVIQFSRP 256
Cdd:cd12496   4 LYVRNLMISTTEETIKAEFNKFkpGVVERVKKL---RDYAFVHFFNREDAVAAMSVMNGKCIDGASIEVTLAKP 74

RNA recognition motif 3 (RRM3) found in vertebrate heterogeneous nuclear ribonucleoprotein R (hnRNP R); This subgroup corresponds to the RRM3 of hnRNP R. a ubiquitously expressed nuclear RNA-binding protein that specifically bind mRNAs with a preference for poly(U) stretches. Upon binding of RNA, hnRNP R forms oligomers, most probably dimers. hnRNP R has been implicated in mRNA processing and mRNA transport, and also acts as a regulator to modify binding to ribosomes and RNA translation. hnRNP R is predominantly located in axons of motor neurons and to a much lower degree in sensory axons. In axons of motor neurons, it also functions as a cytosolic protein and interacts with wild type of survival motor neuron (SMN) proteins directly, further providing a molecular link between SMN and the spliceosome. Moreover, hnRNP R plays an important role in neural differentiation and development, as well as in retinal development and light-elicited cellular activities. hnRNP R contains an acidic auxiliary N-terminal region, followed by two well-defined and one degenerated RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a C-terminal RGG motif; hnRNP R binds RNA through its RRM domains.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 11072029 185 LVIMNLEPTVSSSTLRHIFQVYGEVKQVRETpckREQRFVEFFDvRDAA-KALRVMNGKVISGKPMVIQFSRP 256
Cdd:cd12494   4 LFVRNLATTVTEEILEKTFSQFGKLERVKKL---KDYAFVHFED-RDAAvKAMDEMNGKEVEGEEIEIVLAKP 72

RNA recognition motif 1 (RRM1) found in type I polyadenylate-binding proteins; This subfamily corresponds to the RRM1 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 a 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 mammals, 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 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.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 11072029 184 SLVIMNLEPTVSSSTLRHIFQVYGEVKQVRETPCKREQR-----FVEFFDVRDAAKALRVMNGKVISGKPMVIQFS 254
Cdd:cd12378   1 SLYVGDLHPDVTEAMLYEKFSPAGPVLSIRVCRDAVTRRslgyaYVNFQQPADAERALDTLNFDVIKGKPIRIMWS 76

RNA recognition motif (RRM) found in RNA-binding protein with serine-rich domain 1 (RNPS1) and similar proteins; This subfamily corresponds to the RRM of RNPS1 and its eukaryotic homologs. RNPS1, also termed RNA-binding protein prevalent during the S phase, or SR-related protein LDC2, was originally characterized as a general pre-mRNA splicing activator, which activates both constitutive and alternative splicing of pre-mRNA in vitro.It has been identified as a protein component of the splicing-dependent mRNP complex, or exon-exon junction complex (EJC), and is directly involved in mRNA surveillance. Furthermore, RNPS1 is a splicing regulator whose activator function is controlled in part by CK2 (casein kinase II) protein kinase phosphorylation. It can also function as a squamous-cell carcinoma antigen recognized by T cells-3 (SART3)-binding protein, and is involved in the regulation of mRNA splicing. RNPS1 contains an N-terminal serine-rich (S) domain, a central RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), and the C-terminal arginine/serine/proline-rich (RS/P) domain.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 11072029 185 LVIMNLEPTVSSSTLRHIFQVYGEVKQV-----RETPCKREQRFVEFFDVRDAAKALRVMNGKVISGKPMVIQ 252
Cdd:cd12365   1 LHVGKLTRNVTKDHLKEIFSVYGTVKNVdlpidREPNLPRGYAYVEFESPEDAEKAIKHMDGGQIDGQEVTVE 73

RNA recognition motif 3 (RRM3) found in vertebrate polypyrimidine tract-binding protein 1 (PTB); This subgroup corresponds to the RRM3 of PTB, also known as 58 kDa RNA-binding protein PPTB-1 or heterogeneous nuclear ribonucleoprotein I (hnRNP I), an important negative regulator of alternative splicing in mammalian cells. PTB also functions at several other aspects of mRNA metabolism, including mRNA localization, stabilization, polyadenylation, and translation. PTB contains four RNA recognition motifs (RRM), also known as RBD (RNA binding domain) or RNP (ribonucleoprotein domain). RRM1 and RRM2 are independent from each other and separated by flexible linkers. By contrast, there is an unusual and conserved interdomain interaction between RRM3 and RRM4. It is widely held that only RRMs 3 and 4 are involved in RNA binding and RRM2 mediates PTB homodimer formation. However, new evidence show that the RRMs 1 and 2 also contribute substantially to RNA binding. Moreover, PTB may not always dimerize to repress splicing. It is a monomer in solution.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 11072029 185 LVIMNLEP-TVSSSTLRHIFQVYGEVKQVRETPCKREQRFVEFFDVRDAAKALRVMNGKVISGKPM--------VIQFSR 255
Cdd:cd12695   2 LLVSNLNPeRVTPQCLFILFGVYGDVQRVKILFNKKENALVQMADGNQAQLAMSHLNGQKLHGKPIritlskhqTVQLPR 81

                        90
                ....*....|
gi 11072029 256 PG----GLTK 261
Cdd:cd12695  82 EGqedqGLTK 91

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.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 11072029 184 SLVIMNLEPTVSSSTLRHIFQVYGEVKQV--RETPCKREQRFVEFFDVRDAAKALRVMNGKVISGKPM 249
Cdd:cd12350   4 TLFIGNLEKTTTYGDLRNIFERFGEIIDIdiKKQNGNPQYAFLQYCDIASVVKAIKKMDGEYLGNNRL 71

RNA recognition motif 2 (RRM2) found in splicing regulatory glutamine/lysine-rich protein 1 (SREK1) and similar proteins; This subfamily corresponds to the RRM2 of SREK1, also termed serine/arginine-rich-splicing regulatory protein 86-kDa (SRrp86), or splicing factor arginine/serine-rich 12 (SFRS12), or splicing regulatory protein 508 amino acid (SRrp508). SREK1 belongs to a family of proteins containing regions rich in serine-arginine dipeptides (SR proteins family), which is involved in bridge-complex formation and splicing by mediating protein-protein interactions across either introns or exons. It is a unique SR family member and it may play a crucial role in determining tissue specific patterns of alternative splicing. SREK1 can alter splice site selection by both positively and negatively modulating the activity of other SR proteins. For instance, SREK1 can activate SRp20 and repress SC35 in a dose-dependent manner both in vitro and in vivo. In addition, SREK1 contains two (some contain only one) RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and two serine-arginine (SR)-rich domains (SR domains) separated by an unusual glutamic acid-lysine (EK) rich region. The RRM and SR domains are highly conserved among other members of the SR superfamily. However, the EK domain is unique to SREK1. It plays a modulatory role controlling SR domain function by involvement in the inhibition of both constitutive and alternative splicing and in the selection of splice-site.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 11072029 184 SLVIMNLEPTVSSSTLRHIFQVYGEVKQVR--ETPCKREQR-FVEFFDVRDAAKALRvMNGKVISGKPMVIQFSR 255
Cdd:cd12260   6 TVYVGNLDPSTTADQLLEFFSQAGEVKYVRmaGDETQPTRYaFVEFAEQTSVINALK-LNGKMFGGRPLKVNHSN 79

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.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 11072029 179 GNNqgsLVIMNLEPTVSSSTLRHIFQVYGEV---KQVRETpcKREQR---FVEFFDVRDAAKALRVMNGKVISGKPM 249
Cdd:cd12381   1 GVN---LYVKNLDDTIDDEKLREEFSPFGTItsaKVMTDE--GGRSKgfgFVCFSSPEEATKAVTEMNGRIIGGKPL 72

RNA recognition motif (RRM) found in serine/arginine-rich splicing factor SRSF10, SRSF12 and similar proteins; This subfamily corresponds to the RRM of SRSF10 and SRSF12. SRSF10, also termed 40 kDa SR-repressor protein (SRrp40), or FUS-interacting serine-arginine-rich protein 1 (FUSIP1), or splicing factor SRp38, or splicing factor, arginine/serine-rich 13A (SFRS13A), or TLS-associated protein with Ser-Arg repeats (TASR). It is a serine-arginine (SR) protein that acts as a potent and general splicing repressor when dephosphorylated. It mediates global inhibition of splicing both in M phase of the cell cycle and in response to heat shock. SRSF10 emerges as a modulator of cholesterol homeostasis through the regulation of low-density lipoprotein receptor (LDLR) splicing efficiency. It also regulates cardiac-specific alternative splicing of triadin pre-mRNA and is required for proper Ca2+ handling during embryonic heart development. In contrast, the phosphorylated SRSF10 functions as a sequence-specific splicing activator in the presence of a nuclear cofactor. It activates distal alternative 5' splice site of adenovirus E1A pre-mRNA in vivo. Moreover, SRSF10 strengthens pre-mRNA recognition by U1 and U2 snRNPs. SRSF10 localizes to the nuclear speckles and can shuttle between nucleus and cytoplasm. SRSF12, also termed 35 kDa SR repressor protein (SRrp35), or splicing factor, arginine/serine-rich 13B (SFRS13B), or splicing factor, arginine/serine-rich 19 (SFRS19), is a serine/arginine (SR) protein-like alternative splicing regulator that antagonizes authentic SR proteins in the modulation of alternative 5' splice site choice. For instance, it activates distal alternative 5' splice site of the adenovirus E1A pre-mRNA in vivo. Both, SRSF10 and SRSF12, contain a single N-terminal RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), followed by a C-terminal RS domain rich in serine-arginine dipeptides.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 11072029 184 SLVIMNLEPTVSSSTLRHIFQVYGEVKQVReTPC---KREQR---FVEFFDVRDAAKALRVMNGKVISGKPMVIQFSR 255
Cdd:cd12312   2 SLFVRNVADDTRPDDLRREFGRYGPIVDVY-IPLdfyTRRPRgfaYIQFEDVRDAEDALYYLDRTRFLGREIEIQFAQ 78

RNA recognition motif 3 (RRM3) found in yeast negative growth regulatory protein NGR1 (RBP1), yeast protein NAM8 and similar proteins; This subfamily corresponds to the RRM3 of NGR1 and NAM8. NGR1, also termed RNA-binding protein RBP1, is a putative glucose-repressible protein that binds both RNA and single-stranded DNA (ssDNA) in yeast. It may function in regulating cell growth in early log phase, possibly through its participation in RNA metabolism. NGR1 contains two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), followed by a glutamine-rich stretch that may be involved in transcriptional activity. In addition, NGR1 has an asparagine-rich region near the carboxyl terminus which also harbors a methionine-rich region. The family also includes protein NAM8, which is a putative RNA-binding protein that acts as a suppressor of mitochondrial splicing deficiencies when overexpressed in yeast. It may be a non-essential component of the mitochondrial splicing machinery. Like NGR1, NAM8 contains two RRMs.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*....
gi 11072029 190 LEPTVSSSTLRHIFQVYGEVKQVRETPCKReQRFVEFFDVRDAAKALRVMNGKVISGKP 248
Cdd:cd12346   9 LDPNVTEEDLRVLFGPFGEIVYVKIPPGKG-CGFVQFVNRASAEAAIQKLQGTPIGGSR 66

RNA recognition motif 6 (RRM6) found in RNA-binding protein 19 (RBM19 or RBD-1) and RNA recognition motif 5 (RRM5) found in multiple RNA-binding domain-containing protein 1 (MRD1); This subfamily corresponds to the RRM6 of RBM19 and RRM5 of MRD1. RBM19, also termed RNA-binding domain-1 (RBD-1), is a nucleolar protein conserved in eukaryotes. It is involved in ribosome biogenesis by processing rRNA and is essential for preimplantation development. It has a unique domain organization containing 6 conserved RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains). MRD1 is encoded by a novel yeast gene MRD1 (multiple RNA-binding domain). It is well-conserved in yeast and its homologs exist in all eukaryotes. MRD1 is present in the nucleolus and the nucleoplasm. It interacts with the 35 S precursor rRNA (pre-rRNA) and U3 small nucleolar RNAs (snoRNAs). It is essential for the initial processing at the A0-A2 cleavage sites in the 35 S pre-rRNA. MRD1 contains 5 conserved RRMs, which may play an important structural role in organizing specific rRNA processing events.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 11072029 185 LVIMNLEPTVSSSTLRHIFQVYGEVKQVReTPCKREQR-----FVEFFDVRDAAKALRVMNGKVISGKPMVIQFS 254
Cdd:cd12320   3 LIVKNVPFEATRKEIRELFSPFGQLKSVR-LPKKFDGShrgfaFVEFVTKQEAQNAMEALKSTHLYGRHLVLEYA 76

RNA recognition motif 2 (RRM2) and 4 (RRM4) found in RNA-binding protein MRN1 and similar proteins; This subgroup corresponds to the RRM2 and RRM4 of MRN1, also termed multicopy suppressor of RSC-NHP6 synthetic lethality protein 1, or post-transcriptional regulator of 69 kDa, and is an RNA-binding protein found in yeast. Although its specific biological role remains unclear, MRN1 might be involved in translational regulation. Members in this family contain four copies of conserved RNA recognition motif (RRM), also known as RBD (RNA binding domain) or RNP (ribonucleoprotein domain).

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 11072029  79 TRAVMLLQVPATVTETSLRRDMELFGEVRGVQMERaHEGIVIFHFYNLINSQRAFNEIRYRH 140
Cdd:cd12262   3 SRNVYVGNLDDSLTEEEIRGILEKYGEIESIKILK-EKNCAFVNYLNIANAIKAVQELPIKN 63

RNA recognition motif (RRM) found in cold inducible RNA binding protein (CIRBP), RNA binding motif protein 3 (RBM3) and similar proteins; This subfamily corresponds to the RRM domain of two structurally related heterogenous nuclear ribonucleoproteins, CIRBP (also termed CIRP or A18 hnRNP) and RBM3 (also termed RNPL), both of which belong to a highly conserved cold shock proteins family. The cold shock proteins can be induced after exposure to a moderate cold-shock and other cellular stresses such as UV radiation and hypoxia. CIRBP and RBM3 may function in posttranscriptional regulation of gene expression by binding to different transcripts, thus allowing the cell to response rapidly to environmental signals. However, the kinetics and degree of cold induction are different between CIRBP and RBM3. Tissue distribution of their expression is different. CIRBP and RBM3 may be differentially regulated under physiological and stress conditions and may play distinct roles in cold responses of cells. CIRBP, also termed glycine-rich RNA-binding protein CIRP, is localized in the nucleus and mediates the cold-induced suppression of cell cycle progression. CIRBP also binds DNA and possibly serves as a chaperone that assists in the folding/unfolding, assembly/disassembly and transport of various proteins. RBM3 may enhance global protein synthesis and the formation of active polysomes while reducing the levels of ribonucleoprotein complexes containing microRNAs. RBM3 may also serve to prevent the loss of muscle mass by its ability to decrease cell death. Furthermore, RBM3 may be essential for cell proliferation and mitosis. Both, CIRBP and RBM3, contain an N-terminal RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), that is involved in RNA binding, and C-terminal glycine-rich domain (RGG motif) that probably enhances RNA-binding via protein-protein and/or protein-RNA interactions. Like CIRBP, RBM3 can also bind to both RNA and DNA via its RRM domain.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 11072029 183 GSLVIMNLEPTVSSSTLRHIFQVYGEVKQV-----RETPCKREQRFVEFFDVRDAAKALRVMNGKVISGK 247
Cdd:cd12449   1 GKLFVGGLSFDTNEQSLEEVFSKYGQISEVvvvkdRETQRSRGFGFVTFENPDDAKDAMMAMNGKSLDGR 70

RNA recognition motif 2 (RRM2) found in squamous cell carcinoma antigen recognized by T-cells 3 (SART3) and similar proteins; This subfamily corresponds to the RRM2 of SART3, also termed Tat-interacting protein of 110 kDa (Tip110), is an RNA-binding protein expressed in the nucleus of the majority of proliferating cells, including normal cells and malignant cells, but not in normal tissues except for the testes and fetal liver. It is involved in the regulation of mRNA splicing probably via its complex formation with RNA-binding protein with a serine-rich domain (RNPS1), a pre-mRNA-splicing factor. SART3 has also been identified as a nuclear Tat-interacting protein that regulates Tat transactivation activity through direct interaction and functions as an important cellular factor for HIV-1 gene expression and viral replication. In addition, SART3 is required for U6 snRNP targeting to Cajal bodies. It binds specifically and directly to the U6 snRNA, interacts transiently with the U6 and U4/U6 snRNPs, and promotes the reassembly of U4/U6 snRNPs after splicing in vitro. SART3 contains an N-terminal half-a-tetratricopeptide repeat (HAT)-rich domain, a nuclearlocalization signal (NLS) domain, and two C-terminal RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains).

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 11072029 185 LVIMNLEPTVSSSTLRHIFQVYGEVKQVRETPCK----REQRFVEFFDVRDAAKALRVMNGKVISGKPMVIQFSRP 256
Cdd:cd12392   5 LFVKGLPFSCTKEELEELFKQHGTVKDVRLVTYRngkpKGLAYVEYENEADASQAVLKTDGTEIKDHTISVAISNP 80

RNA recognition motif 1 (RRM1) found in Drosophila sex-lethal (SXL) and similar proteins; This subfamily corresponds to the RRM1 of SXL which governs sexual differentiation and X chromosome dosage compensation in Drosophila melanogaster. 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 also to its own pre-mRNA and promotes female-specific alternative splicing. SXL contains an N-terminal Gly/Asn-rich domain that may be responsible for the protein-protein interaction, and tandem RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), that show high preference to bind single-stranded, uridine-rich target RNA transcripts.

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                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 11072029 185 LVIMNLEPTVSSSTLRHIFQVYGEVKQvretpCK--REQR--------FVEFFDVRDAAKALRVMNGKVISGKPMVIQFS 254
Cdd:cd12649   3 LIVNYLPQDLTDREFRALFRAIGPVNT-----CKivRDKKtgysygfgFVDFTSEEDAQRAIKTLNGLQLQNKRLKVAYA 77

                ....
gi 11072029 255 RPGG 258
Cdd:cd12649  78 RPGG 81

RNA recognition motif (RRM) found in U1 small nuclear ribonucleoprotein 70 kDa (U1-70K) and similar proteins; This subfamily corresponds to the RRM of U1-70K, also termed snRNP70, a key component of the U1 snRNP complex, which is one of the key factors facilitating the splicing of pre-mRNA via interaction at the 5' splice site, and is involved in regulation of polyadenylation of some viral and cellular genes, enhancing or inhibiting efficient poly(A) site usage. U1-70K plays an essential role in targeting the U1 snRNP to the 5' splice site through protein-protein interactions with regulatory RNA-binding splicing factors, such as the RS protein ASF/SF2. Moreover, U1-70K protein can specifically bind to stem-loop I of the U1 small nuclear RNA (U1 snRNA) contained in the U1 snRNP complex. It also mediates the binding of U1C, another U1-specific protein, to the U1 snRNP complex. U1-70K contains a conserved RNA recognition motif (RRM), also termed RBD (RNA binding domain) or RNP (ribonucleoprotein domain), followed by an adjacent glycine-rich region at the N-terminal half, and two serine/arginine-rich (SR) domains at the C-terminal half. The RRM is responsible for the binding of stem-loop I of U1 snRNA molecule. Additionally, the most prominent immunodominant region that can be recognized by auto-antibodies from autoimmune patients may be located within the RRM. The SR domains are involved in protein-protein interaction with SR proteins that mediate 5' splice site recognition. For instance, the first SR domain is necessary and sufficient for ASF/SF2 Binding. The family also includes Drosophila U1-70K that is an essential splicing factor required for viability in flies, but its SR domain is dispensable. The yeast U1-70k doesn't contain easily recognizable SR domains and shows low sequence similarity in the RRM region with other U1-70k proteins and therefore not included in this family. The RRM domain is dispensable for yeast U1-70K function.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 11072029 194 VSSSTLRHIFQVYGEVKQVR-----ETPCKREQRFVEFFDVRDAAKALRVMNGKVISGKPMVIQFSR 255
Cdd:cd12236  13 TTESKLRREFEKYGPIKRVRlvrdkKTGKSRGYAFIEFEHERDMKAAYKHADGKKIDGRRVLVDVER 79