PABPC1
Domain
The RNA-binding domains RRM1 and RRM2 and the C-terminus (last 138 amino acids) regions interact with the PABPC1-interacting motif-1 (PAM1) and -2 (PAM2) of PAIP1, respectively.
The RNA-binding domains RRM2 and RRM3 and the C-terminus (last 138 amino acids) regions interact with the PABPC1-interacting motif-1 (PAM1) and -2 (PAM2) of PAIP2, respectively.
Function
Binds the poly(A) tail of mRNA, including that of its own transcript, and regulates processes of mRNA metabolism such as pre-mRNA splicing and mRNA stability (PubMed:11051545, PubMed:17212783, PubMed:25480299). Its function in translational initiation regulation can either be enhanced by PAIP1 or repressed by PAIP2 (PubMed:11051545, PubMed:20573744). Can probably bind to cytoplasmic RNA sequences other than poly(A) in vivo. Binds to N6-methyladenosine (m6A)-containing mRNAs and contributes to MYC stability by binding to m6A-containing MYC mRNAs (PubMed:32245947). Involved in translationally coupled mRNA turnover (PubMed:11051545). 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 (PubMed:11051545). 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 (PubMed:18447585). By binding to long poly(A) tails, may protect them from uridylation by ZCCHC6/ZCCHC11 and hence contribute to mRNA stability (PubMed:25480299).
(Microbial infection) Positively regulates the replication of dengue virus (DENV).
Post-translational modifications
Phosphorylated by MAPKAPK2.
Methylated by CARM1. Arg-493 is dimethylated, probably to asymmetric dimethylarginine.
Sequence Similarities
Belongs to the polyadenylate-binding protein type-1 family.
Tissue Specificity
Ubiquitous.
Cellular localization
- Cytoplasm
- Cytoplasm
- Stress granule
- Nucleus
- Cell projection
- Lamellipodium
- Localized in cytoplasmic mRNP granules containing untranslated mRNAs (PubMed:17289661). Shuttles between the cytoplasm and the nucleus (PubMed:9582337). During stress and in the absence of DDX3X, localizes to the nucleus (PubMed:21883093). At the leading edge of migrating fibroblasts, colocalizes with DDX3X (PubMed:28733330). Relocalizes to cytoplasmic stress granules upon cellular stress where it colocalizes with ENDOV (PubMed:27573237). In case of HRSV infection, localizes in cytoplasmic inclusion bodies substructures called inclusion bodies associated granules (IBAGs) (PubMed:31649314).
Alternative names
PAB1, PABP, PABP1, PABPC2, PABPC1, Polyadenylate-binding protein 1, PABP-1, Poly(A)-binding protein 1