Conserved Protein Domain Family

cd12444: RRM1_CPEBs 
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RNA recognition motif 1 (RRM1) found in cytoplasmic polyadenylation element-binding protein CPEB-1, CPEB-2, CPEB-3, CPEB-4 and similar protiens
This subfamily corresponds to the RRM1 of the CPEB family of proteins that bind to defined groups of mRNAs and act as either translational repressors or activators to regulate their translation. CPEB proteins are well conserved in both, vertebrates and invertebrates. Based on sequence similarity, RNA-binding specificity, and functional regulation of translation, the CPEB proteins have been classified into two subfamilies. The first subfamily includes CPEB-1 and related proteins. CPEB-1 is an RNA-binding protein that interacts with the cytoplasmic polyadenylation element (CPE), a short U-rich motif in the 3' untranslated regions (UTRs) of certain mRNAs. It functions as a translational regulator that plays a major role in the control of maternal CPE-containing mRNA in oocytes, as well as of subsynaptic CPE-containing mRNA in neurons. Once phosphorylated and recruiting the polyadenylation complex, CPEB-1 may function as a translational activator stimulating polyadenylation and translation. Otherwise, it may function as a translational inhibitor when dephosphorylated and bind to a protein such as maskin or neuroguidin, which blocks translation initiation through interfering with the assembly of eIF-4E and eIF-4G. Although CPEB-1 is mainly located in cytoplasm, it can shuttle between nucleus and cytoplasm. The second subfamily includes CPEB-2, CPEB-3, CPEB-4, and related protiens. Due to high sequence similarity, members in this subfamily may share similar expression patterns and functions. CPEB-2 is an RNA-binding protein that is abundantly expressed in testis and localized in cytoplasm in transfected HeLa cells. It preferentially binds to poly(U) RNA oligomers and may regulate the translation of stored mRNAs during spermiogenesis. CPEB-2 impedes target RNA translation at elongation; it directly interacts with the elongation factor, eEF2, to reduce eEF2/ribosome-activated GTP hydrolysis in vitro and inhibit peptide elongation of CPEB2-bound RNA in vivo. CPEB-3 is a sequence-specific translational regulatory protein that regulates translation in a polyadenylation-independent manner. It functions as a translational repressor that governs the synthesis of the AMPA receptor GluR2 through binding GluR2 mRNA. It also represses translation of a reporter RNA in transfected neurons and stimulates translation in response to NMDA. CPEB-4 is an RNA-binding protein that mediates meiotic mRNA cytoplasmic polyadenylation and translation. It is essential for neuron survival and present on the endoplasmic reticulum (ER). It is accumulated in the nucleus upon ischemia or the depletion of ER calcium. CPEB-4 is overexpressed in a large variety of tumors and is associated with many mRNAs in cancer cells. All CPEB proteins are nucleus-cytoplasm shuttling proteins. They contain an N-terminal unstructured region, followed by two RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains), and a Zn-finger motif. CPEB-2, -3, and -4 have conserved nuclear export signals that are not present in CPEB-1.
PSSM-Id: 409878
Aligned: 49 rows
Threshold Bit Score: 95.3655
Created: 13-Sep-2011
Updated: 25-Oct-2021
Aligned Rows:
PubMed ReferencesClick to see Conserved Features Help

Sequence Alignment
Format: Row Display: Color Bits: Type Selection:
Q7Z5Q1       332 RKVFVGGLPPDiDEDEITASFrrFGPLVVDWPHKaesksyfppkGYAFLLFQeESSVQALIDACieedgklylcvsspti 411 human
Q9VSR3       447 RKVFVGGLPPDiDEDEITTSFrrFGPLVVDWPHKaesksyfppkGYAFLLFQdESSVQQLIDSCitdedklylcvsspti 526 fruit fly
Q17RY0       472 RKVFVGGLPPDiDEDEITASFrrFGPLIVDWPHKaesksyfppkGYAFLLFQdESSVQALIDACieedgklylcvsspti 551 human
Q28CH2       375 RKVFVGGLPPDiDEDEITASFrrFGPLVVDWPHKaesksyfppkGYAFLLFQeESSVQALIDACleedgklylcvsspti 454 western clawed ...
NP_001184215 447 RKVFVGGLPPDiDEDEITASFrrFGPLIVDWPHKaesksyfppkGYAFLLFQdESSVQALIDACieedgklylcvsspti 526 African clawed ...
XP_414678    454 RKVFVGGLPPDiDEDEITASFrrFGPLIVDWPHKaesksyfppkGYAFLLFQdESSVQALIDACieedgklylcvsspti 533 chicken
Q7SXN4       378 RKVFVGGLPPDiDEDEITASFrrFGHLFVDWPHKaesksyfppkGYAFLLFQdESSVQALIDACmeedgklylcvsspti 457 zebrafish
XP_014347587  96 RKVFVGGLPPDiDEDEITASFrrFGPLVVDWPHKaesksyfppkGYAFLLFQeESSVQALIDACieedgklylcvsspti 175 coelacanth
2DNL_A        89 KDKPVQIRPWNL 100 human
Q7Z5Q1       412 KDKPVQIRPWNL 423 human
Q9VSR3       527 KDKAVQIRPWRL 538 fruit fly
Q17RY0       552 KDKPVQIRPWNL 563 human
Q28CH2       455 KDKPVQIRPWNL 466 western clawed frog
NP_001184215 527 KDKPVQIRPWNL 538 African clawed frog
XP_414678    534 KDKPVQIRPWNL 545 chicken
Q7SXN4       458 KDKPVQIRPWNL 469 zebrafish
2MKI_A        93 KDKPVQIRPWNL 104 human
XP_014347587 176 KDKPVQIRPWNL 187 coelacanth
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