PABPC1

Description

The PABPC1 (poly(A) binding protein cytoplasmic 1) is a protein-coding gene located on chromosome 8.

Polyadenylate-binding protein 1 is a protein that in humans is encoded by the PABPC1 gene. The protein PABP1 binds mRNA and facilitates a variety of functions such as transport into and out of the nucleus, degradation, translation, and stability. There are two separate PABP1 proteins, one which is located in the nucleus (PABPN1) and the other which is found in the cytoplasm (PABPC1). The location of PABP1 affects the role of that protein and its function with RNA.

== Function == The poly(A)-binding protein (PAB or PABP), which is found complexed to the 3' poly(A) tail of eukaryotic mRNA, is required for poly(A) lengthening and the termination of translation. In humans, the PABPs comprise a small nuclear isoform and a conserved gene family of other poly(A)-binding proteins.[supplied by OMIM] PABPC1 is usually diffused within the cytoplasm and concentrated at sites of high mRNA concentration such as stress granules, processing bodies, and locations of high translational activity. PABPC1 is also associated with nonsense-mediated mRNA decay (NMD). PABPC1 binds to the poly(A) tail and interact with eIF4G, which stabilizes the circularization of mRNAs. This structure is required for the prevention of mRNA degradation via NMD. In the nucleus PABP1 binds to the poly(A) tails of pre-mRNAs to facilitate stability, export, transport, and degradation. PABP1 binding is also required for nuclear-mediated degradation. PABPC1 contains four RNA-recognition motifs (RRMs).

PABPC1 binds to the poly(A) tail of mRNA, including its own transcript, and regulates mRNA metabolism, such as pre-mRNA splicing and mRNA stability. Its role in translational initiation regulation can be enhanced by PAIP1 or repressed by PAIP2. PABPC1 can bind to cytoplasmic RNA sequences other than poly(A) and binds to N6-methyladenosine (m6A)-containing mRNAs, contributing to MYC stability by binding to m6A-containing MYC mRNAs. It is involved in translationally coupled mRNA turnover and participates in the cytoplasmic deadenylation/translational and decay interplay of the FOS mRNA mediated by the major coding-region determinant of instability (mCRD) domain. PABPC1 plays a role in the regulation of nonsense-mediated decay (NMD) of mRNAs containing premature stop codons. It is proposed that PABPC1 and UPF1 compete with the ribosome-bound release factors for the recognition of premature termination codons (PTC) and initiation of NMD. PABPC1, by binding to long poly(A) tails, may protect them from uridylation by ZCCHC6/ZCCHC11, contributing to mRNA stability.

PABPC1 is also known as PAB1, PABP, PABP1, PABPC2, PABPL1.

Associated Diseases

WES Whole Exome Sequencing