eIF-2-alpha kinase is a kinase enzyme that phosphorylates eIF2α. There are four forms in mammals: [2]
- EIF2AK1: heme-regulated inhibitor kinase (HRI)
- EIF2AK2: the double-stranded RNA-dependent kinase (protein kinase R, PKR)
- EIF2AK3: also known as "PKR-like endoplasmic reticulum kinase" (PEK/PERK)
- EIF2AK4: also known as GCN2
These are all responsible for the phosphorylation of the alpha subunit of eIF-2 at serine 51, one of the best-characterized mechanisms for down-regulating protein synthesis in eukaryotes as a part of cellular stress response.[3]
- ^ Nika J, Rippel S, Hannig EM (January 2001). "Biochemical analysis of the eIF2beta gamma complex reveals a structural function for eIF2alpha in catalyzed nucleotide exchange". J. Biol. Chem. 276 (2): 1051–6. doi:10.1074/jbc.M007398200. PMID 11042214.
- ^ "Gene group | HUGO Gene Nomenclature Committee". www.genenames.org.
- ^ Berlanga, JJ; Santoyo, J; De Haro, C (October 1999). "Characterization of a mammalian homolog of the GCN2 eukaryotic initiation factor 2alpha kinase". European Journal of Biochemistry. 265 (2): 754–62. doi:10.1046/j.1432-1327.1999.00780.x. PMID 10504407.