There are four forms in mammals:
- EIF2AK1: heme-regulated inhibitor kinase (HRI)
- EIF2AK2: the double-stranded RNA-dependent kinase (PKR)
- EIF2AK3: PEK/PERK
- EIF2AK4: 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 in response to various cellular stress response's.
- 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.
- eIF-2 Kinase at the US National Library of Medicine Medical Subject Headings (MeSH)