Eukaryotic Translation Initiation Factor 2 Alpha Kinase 4 (EIF2aK4)

EIF2AK4 belongs to a family of kinases that phosphorylate the alpha subunit of eukaryotic translation initiation factor-2 (EIF2S1) to downregulate protein synthesis in response to varied cellular stresses. The deduced 1,648-amino acid protein has a calculated molecular mass of 186.4 kD. Gcn2 contains all 12 conserved catalytic subdomains of eukaryotic serine/threonine protein kinases. The N-terminal half of Gcn2 contains a degenerate kinase domain, followed by a central catalytic domain with a large insert typical of EIF2-alpha kinases. The C-terminal half of Gcn2 contains 3 motifs conserved among class II aminoacyl-tRNA synthetases. Gcn2 expression in all mouse tissues examined, with highest levels in liver and brain. Western blot analysis detected Gcn2 in mouse liver extracts at an apparent molecular mass of about 190 kD.