description
The active eIF2:GTP complex may be formed by direct binding of GTP to free eIF2 or by GDP-GTP exchange on the eIF2:GDP:eIF2B complex. The eIF2:GDP complex binds eIF2B forming an eIF2:GDP:eIF2B intermediate complex. eIF2B is a guanine nucleotide releasing factor required to cause GDP release so that a new GTP molecule can bind and activate eIF2. Phosphorylated eIF2:GDP sequesters all eIF2B as an inactive complex, and thus, reuse of eIF2 is inhibited as a consequence of the tight bond it forms with eIF2B, which prevents nucleotide exchange. Therefore, in the absence of free eIF2B, excess eIF2 remains in its inactive GDP-bound form and protein synthesis slows dramatically
external resources
NCBI:1268687
REACTOME:R-HSA-72731
PUBMED:7063012
genes
EIF2S1
,
EIF2B1
,
EIF2S3
,
EIF2B4
,
EIF2B3
,
EIF2B2
,
EIF2B5
,
EIF2S2
,
