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Polyadenylate-binding protein 1


Known also as: Poly(A)-binding protein 1
Known abbreviations: PABP-1, PAB1, PABP, PABP1, PABPC1, PABPC2, PABPL1

Yeast homolog: PAB1

Protein




Structures









Models
Domains

Secondary structure

Disorder

This protein is highly disordered (48 % of residues are predicted to be disordered)

Top 3 models:
Template: 2ghp, chain A
Method: hhsearch
Fragment: 51-372
Template: 2ghp, chain C
Method: phyre
Fragment: 2-269
Template: 1g9l, chain A
Method: mgenthreader
Fragment: 491-636


This protein has alternative isoforms:
Isoform 1:
Sequence length:636 aa
Molecular weight:70.671 kDa
Isoelectric point:9.81
Sequence:
1........10........20........30........40........50........60........70........80........90........100.......110.......120.......130
MNPSAPSYPMASLYVGDLHPDVTEAMLYEKFSPAGPILSIRVCRDMITRRSLGYAYVNFQQPADAERALDTMNFDVIKGKPVRIMWSQRDPSLRKSGVGNIFIKNLDKSIDNKALYDTFSAFGNILSCKV
VCDENGSKGYGFVHFETQEAAERAIEKMNGMLLNDRKVFVGRFKSRKEREAELGARAKEFTNVYIKNFGEDMDDERLKDLFGKFGPALSVKVMTDESGKSKGFGFVSFERHEDAQKAVDEMNGKELNGKQ
IYVGRAQKKVERQTELKRKFEQMKQDRITRYQGVNLYVKNLDDGIDDERLRKEFSPFGTITSAKVMMEGGRSKGFGFVCFSSPEEATKAVTEMNGRIVATKPLYVALAQRKEERQAHLTNQYMQRMASVR
AVPNPVINPYQPAPPSGYFMAAIPQTQNRAAYYPPSQIAQLRPSPRWTAQGARPHPFQNMPGAIRPAAPRPPFSTMRPASSQVPRVMSTQRVANTSTQTMGPRPAAAAAAATPAVRTVPQYKYAAGVRNP
QQHLNAQPQVTMQQPAVHVQGQEPLTASMLASAPPQEQKQMLGERLFPLIQAMHPTLAGKITGMLLEIDNSELLHMLESPESLRSKVDEAVAVLQAHQAKEAAQKAVNSATGVPTV



Isoform 2:
Sequence length:547 aa
Molecular weight:61.181 kDa
Isoelectric point:9.35
Sequence:
1........10........20........30........40........50........60........70........80........90........100.......110.......120.......130
MNPSAPSYPMASLYVGDLHPDVTEAMLYEKFSPAGPILSIRVCRDMITRRSLGYAYVNFQQPADAERALDTMNFDVIKGKPVRIMWSQRDPSLRKSGVGNIFIKNLDKSIDNKALYDTFSAFGNILSCKV
VCDENGSKGYGFVHFETQEAAERAIEKMNGMLLNDRKVFVGRFKSRKEREAELGARAKEFTNVYIKNFGEDMDDERLKDLFGKFGPALSVKVMTDESGKSKGFGFVSFERHEDAQKAVDEMNGKELNGKQ
IYVGRAQKKVERQTELKRKFEQMKQDRITRYQGVNLYVKNLDDGIDDERLRKEFSPFGTITSAKVMMEGGRSKGFGFVCFSSPEEATKAVTEMNGRIVATKPLYVALAQRKEERQAHLTNQYMQRMASVR
AVPNPVINPYQPAPPSGYFMAAIPQTQNRAAYYPPSQIAQLRPSPRWTAQGARPHPAVHVQGQEPLTASMLASAPPQEQKQMLGERLFPLIQAMHPTLAGKITGMLLEIDNSELLHMLESPESLRSKVDE
AVAVLQAHQAKEAAQKAVNSATGVPTV



Gene location: 8q22.2-q23


Summary
Binds the poly(A) tail of mRNA. The protein shuttles between the nucleus and cytoplasm and binds to the 3' poly(A) tail of eukaryotic messenger RNAs via RNA-recognition motifs. The binding of this protein to poly(A) promotes ribosome recruitment and translation initiation; it is also required for poly(A) shortening which is the first step in mRNA decay. May be involved in cytoplasmic regulatory processes of mRNA metabolism such as pre-mRNA splicing.

Its function in translational initiation regulation can either be enhanced by PAIP1 or repressed by PAIP2. Can probably bind to cytoplasmic RNA sequences other than poly(A) in vivo. Involved in translationally coupled mRNA turnover. Implicated with other RNA-binding proteins in the cytoplasmic deadenylation/translational and decay interplay of the FOS mRNA mediated by the major coding-region determinant of instability (mCRD) domain. Involved in regulation of nonsense-mediated decay (NMD) of mRNAs containing premature stop codons; for the recognition of premature termination codons (PTC) and initiation of NMD a competitive interaction between UPF1 and PABPC1 with the ribosome-bound release factors is proposed.

Component of a multi subunit autoregulatory ribonucleoprotein complex (ARC), at least composed of IGF2BP1, PABPC1 and CSDE1. Interacts with IGF2BP1. Part of a complex associated with the FOS mCRD domain and consisting of HNRPD, SYNCRIP, PAIP1 and CSDE1/UNR. Interacts with the PABPC1-interacting motif-1 (PAM1) and -2 (PAM2) of PAIP1 and PAIP2. Interacts with PAIP1 with a 1:1 stoichiometry and with PAIP2 with a 1:2 stoichiometry. The interaction with CSDE1 is direct and RNA-independent. Found in a mRNP complex with YBX2. Interacts with PAPD4/GLD2. Identified in the spliceosome C complex. Identified in a mRNP complex, at least composed of DHX9, DDX3X, ELAVL1, HNRNPU, IGF2BP1, ILF3, PABPC1, PCBP2, PTBP2, STAU1, STAU2, SYNCRIP and YBX1. Identified in a mRNP granule complex, at least composed of ACTB, ACTN4, DHX9, ERG, HNRNPA1, HNRNPA2B1, HNRNPAB, HNRNPD, HNRNPL, HNRNPR, HNRNPU, HSPA1, HSPA8, IGF2BP1, ILF2, ILF3, NCBP1, NCL, PABPC1, PABPC4, PABPN1, RPLP0, RPS3, RPS3A, RPS4X, RPS8, RPS9, SYNCRIP, TROVE2, YBX1 and untranslated mRNAs. Interacts with IGF2BP1 and NFX1. Interacts with PIWIL1.

Many viruses shutoff host mRNA translational machinery by inhibiting cellular PABPC1 activity using different mechanisms. Picornaviruses, caliciviruses or lentiviruses encode proteases that cleave PABPC1 at several defined sites in the proline-rich linker region between RRMs and the C-terminal domain. Rotaviruses, gammherpesviruses and bunyamwera virus relocalize PABPC1 from the cytoplasm to the nucleus thus altering its function. Many of these viruses translate their mRNA in a PABPC1-independent manner and are unaffected by host PABPC1 inhibition.

Phosphorylated by MAPKAPK2. Methylated by CARM1.

See this protein in other databases:
         

Literature:

Additional computationally mapped references ...


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