Dynamic regulation of the translation initiation helicase complex by mitogenic signal transduction to eukaryotic translation initiation factor 4G.

Journal Article (Journal Article)

Eukaryotic translation initiation factor 4F (eIF4F), comprising the cap-binding protein eIF4E, the helicase eIF4A, and the central scaffold eIF4G, is a convergence node for a complex signaling network that controls protein synthesis. Together with eIF3 and eIF4A/4B, eIF4G recruits ribosomal subunits to mRNAs and facilitates 5' untranslated region unwinding. Mammalian eIF4G contains three HEAT domains and unstructured regions involved in protein-protein interactions. Despite detailed eIF4G structure data, the mechanisms controlling initiation scaffold formation remain obscure. We found a new, highly regulated eIF4B/-3 binding site within the HEAT-1/-2 interdomain linker, harboring two phosphorylation sites that we identified as substrates for Erk1/2 and casein kinase 2. Phorbol ester-induced sequential phosphorylation of both sites detached HEAT-2 from the complex with eIF4A/-4B/-3 and stimulated the association of HEAT-3 with the mitogen-activated protein kinase signal integrating kinase Mnk1. Our results provide a mechanistic link between intracellular signal transduction and dynamic initiation complex formation coordinated by flexible eIF4G structure.

Full Text

Duke Authors

Cited Authors

  • Dobrikov, MI; Dobrikova, EY; Gromeier, M

Published Date

  • March 2013

Published In

Volume / Issue

  • 33 / 5

Start / End Page

  • 937 - 946

PubMed ID

  • 23263986

Pubmed Central ID

  • PMC3623071

Electronic International Standard Serial Number (EISSN)

  • 1098-5549

Digital Object Identifier (DOI)

  • 10.1128/MCB.01441-12

Language

  • eng

Conference Location

  • United States