Eukaryotic Translation Initiation Factor 2 Subunit 1 (EIF2S1)

EIF2S1 encoded by this gene is the alpha subunit of the translation initiation factor eIF2 complex which catalyzes the first regulated step of protein synthesis initiation, promoting the binding of the initiator tRNA to 40S ribosomal subunits. Binding occurs as a ternary complex of methionyl-tRNA, eIF2, and GTP. eIF2 is composed of 3 nonidentical subunits, alpha (36 kD, this article), beta (38 kD), and gamma (52 kD). The rate of formation of the ternary complex is modulated by the phosphorylation state of eIF2-alpha. Salubrinal is a selective inhibitor of enzymes that dephosphorylate EIF2-alpha. Salubrinal also blocks EIF2-alpha dephosphorylation by a herpes simplex virus protein and inhibits viral replication. EIF2-alpha phosphorylation is cytoprotective during endoplasmic reticulum stress.