anti-eIF-2α (pS51) (human), Rabbit Monoclonal (RM298)

Eukaryotic Initiation Factor 2 (eIF2) is a eukaryotic initiation factor. It is required for most forms of eukaryotic translation initiation. eIF2 mediates the binding of tRNAiMet to the ribosome in a GTP-dependent manner. eIF2 is a heterotrimer consisting of an alpha (also called subunit 1, EIF2S1), a beta (subunit 2, EIF2S2), and a gamma (subunit 3, EIF2S3) subunit. eIF2 activity is regulated by a mechanism involving both guanine nucleotide exchange and phosphorylation. Phosphorylation takes place at the α-subunit, which is a target for a number of serine kinases that phosphorylate serine 51. Those kinases act as a result of stress such as amino acid deprivation (GCN2), ER stress (PERK), the presence of dsRNA (PKR) heme deficiency (HRI), or interferon. Once phosphorylated, eIF2 shows increased affinity for its Guanine nucleotide exchange factor eIF2B. Increased concentrations of inactive (phosphorylated) eIF2 were found in patients suffering from neurodegenerative diseases such as Alzheimer’s, Parkinson’s, and Huntington’s disease. EIF2a (Eukaryotic translation initiation factor 2A) is a heterotrimer composed of three subunits (alpha, beta and gamma). This translation initiation factor drives binding of initiator methionyl-tRNA to the 40S ribosome to form the 43S pre-initiation complex. The polypeptide can be phosphorylated by related protein kinases activated in response to stress. Phosphorylated eIF2α prevents the recycling of the eIF2-bound GDP to GTP by the guanine nucleotide exchange factor (GEF) eIF2B.