Paip2A inhibits translation by competitively binding to the RNA recognition motifs of PABPC1 and promoting its dissociation from the poly(A) tail
Takeru Sagae, Mariko Yokogawa, Ryoichi Sawazaki, Yuichiro Ishii, Nao Hosoda, S. Hoshino, Shunsuke Imai, Ichio Shimada, Masanori Osawa
Abstract
values of 5 and 1 μM were observed for the interactions of isolated RRM3 with poly(A) and Paip2A, respectively. NMR analyses also revealed that Paip2A can bind to the poly(A)-binding interfaces of the RRM2 and RRM3 regions of PABPC1. Based on these results, we propose the following functional mechanism for Paip2A: Paip2A initially binds to the RRM2 region of poly(A)-bound PABPC1, and RRM2-anchored Paip2A effectively displaces the RRM3 region from poly(A), resulting in dissociation of the whole PABPC1 molecule. Together, our findings provide insight into the translation repression effect of Paip2A and may aid in the development of novel anticancer and/or antiviral drugs.