Format

Send to

Choose Destination
FEBS Lett. 1998 Jan 9;421(2):125-30.

Regulation of eukaryotic initiation factor eIF2B: glycogen synthase kinase-3 phosphorylates a conserved serine which undergoes dephosphorylation in response to insulin.

Author information

1
Department of Biosciences, University of Kent at Canterbury, UK.

Abstract

Eukaryotic initiation factor eIF2B catalyses a key regulatory step in mRNA translation. eIF2B and total protein synthesis are acutely activated by insulin, and this requires phosphatidylinositol 3-kinase (PI 3-kinase). The epsilon-subunit of eIF2B is phosphorylated by glycogen synthase kinase-3 (GSK-3), which is inactivated by insulin in a PI 3-kinase-dependent manner. Here we identify the phosphorylation site in eIF2Bepsilon as Ser540 and show that treatment of eIF2B with GSK-3 inhibits its activity. Ser540 is phosphorylated in intact cells and undergoes dephosphorylation in response to insulin. This is blocked by PI 3-kinase inhibitors. Insulin-induced dephosphorylation of this inhibitory site in eIF2B seems likely to be important in the overall activation of translation by this hormone.

PMID:
9468292
DOI:
10.1016/s0014-5793(97)01548-2
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Wiley
Loading ...
Support Center