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 ε-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 eIF2Bε as Ser540 and show that treatment of eIF2B with GSK-3 inhibits its activity. Set540 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.
Original language | English |
---|---|
Pages (from-to) | 125-130 |
Number of pages | 6 |
Journal | FEBS Letters |
Volume | 421 |
Issue number | 2 |
DOIs | |
Publication status | Published or Issued - 9 Jan 1998 |
Keywords
- Eukaryotic initiation factor
- Glycogen synthase kinase-3
- Insulin
- Phosphorylation
ASJC Scopus subject areas
- Biophysics
- Structural Biology
- Biochemistry
- Molecular Biology
- Genetics
- Cell Biology