The α-subunit of the mammalian guanine nucleotide-exchange factor eIF-2B is essential for catalytic activity in vitro

Bridget L. Craddock, Christopher G. Proud

Research output: Contribution to journalArticlepeer-review

15 Citations (Scopus)


Eukaryotic initiation factor (eIF)-2B, the guanine nucleotide exchange factor for eIF-2, consists of five distinct subunits in both mammals and the yeast Saccharomyces cerevisiae. The exchange reaction mediated by eIF-2B can be regulated by phosphorylation of eIF-2 on its α-subunit. This represents a key control point in the initiation of translation. The functions of the individual subunits of the eIF-2B complex remain unclear. Mutational analysis in Saccharomyces cerevisiae suggested that the smallest subunit (the α) is dispensable for exchange, but required for the inhibition of eIF-2B by eIF-2(αP). Here we present evidence that, in mammalian cells, eIF-2Bα is essential for the activity of the complex, since preparations of eIF-2B lacking this subunit are not active in nucleotide exchange in vitro, although the complex still contains the β, γ, δ and ε subunits.

Original languageEnglish
Pages (from-to)843-847
Number of pages5
JournalBiochemical and Biophysical Research Communications
Issue number3
Publication statusPublished or Issued - 27 Mar 1996
Externally publishedYes

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology

Cite this