Polyadenylate-binding protein-interacting protein 1 (PAIP1)

PAIP1 is an RNA-binding protein that acts as a coactivator for translation initiation of poly(A)-containing mRNAs by interacting with poly(A)-binding protein (PABP) and the cap-binding complex eIF4A[1][6]. It competes with PAIP2 for binding to PABPC1 and forms multiprotein complexes that help stabilize the closed-loop mRNA structure, which is crucial for efficient translation[2][4][6]. PAIP1 also interacts with multiple translation initiation factors, including eIF3 and eIF4G, and regulates protein biosynthesis and mRNA turnover[2][4][6]. In Drosophila and mammalian cells, loss or knockdown of PAIP1 leads to impaired translation, apoptosis, and activation of the integrated stress response[3]. PAIP1 has been implicated in viral protein synthesis, particularly in the context of SARS-CoV infection[6]. Its role in translation termination and readthrough at premature stop codons has also been documented, mainly through interaction with release factors and stabilization of post-termination complexes[4]. There are multiple isoforms of PAIP1 produced through alternative splicing[2][6].

Other names

Poly(A)-binding protein-interacting protein 1PABP-interacting protein 1PAIP-1polyadenylate-binding protein-interacting protein 1PABC1-interacting protein 1