Regulation of eukaryotic initiation factor 4E (eIF4E) phosphorylation by mitogen-activated protein kinase occurs through modulation of Mnk1-eIF4G interaction.

ABSTRACT: The m(7)G cap binding protein eukaryotic initiation factor 4E (eIF4E) is a rate-limiting determinant of protein synthesis. Elevated eIF4E levels, commonly associated with neoplasia, promote oncogenesis, and phosphorylation of eIF4E at Ser209 is critical for its tumorigenic potential. eIF4E phosphorylation is catalyzed by mitogen-activated protein kinase (MAPK)-interacting serine/threonine kinase (Mnk), a substrate of Erk1/2 and p38 MAPKs. Interaction with the scaffolding protein eIF4G, which also binds eIF4E, brings Mnk and its substrate into physical proximity. Thus, Mnk-eIF4G interaction is important for eIF4E phosphorylation. Through coimmunoprecipitation assays, we showed that MAPK-mediated phosphorylation of the Mnk1 active site controls eIF4G binding. Utilizing a naturally occurring

SUBMITTER: Shveygert M 

PROVIDER: S-EPMC2953056 | biostudies-literature | 2010 Nov

REPOSITORIES: biostudies-literature