Poly A Binding Protein Interacting Protein 1 (PAIP1)

PAIP1 encoded by this gene interacts with poly(A)-binding protein and with the cap-binding complex eIF4A. It is involved in translational initiation and protein biosynthesis. Overexpression of this gene in COS7 cells stimulates translation. Alternative splicing occurs at this locus and three transcript variants encoding three distinct isoforms have been identified.

Sequence analysis of the deduced 480-amino acid PAIP1 protein predicted that it shares 39% amino acid similarity with the central portion of eIF4G, which contains an eIF4A-binding region. PAIP1 also contains a proline-rich N terminus. SDS-PAGE analysis determined that PAIP1 is expressed as a 70-kD protein.in HeLa extracts, the C terminus of PAIP1 interacts with PABC1, and PAIP1 interacts with eIF4A but not eIF4G complexes.