Eukaryotic Translation Initiation Factor 2A (EIF2A)

EIF2A is a 65-kD protein that catalyzes the formation of puromycin-sensitive 80S preinitiation complexes. deduced 585-amino acid protein has a calculated molecular mass of 65.1 kD. Human EIF2A shares 28% amino acid identity with the S. cerevisiae protein. Eif2a/Eif4e double mutants showed a severe growth defect, disorganized actin cytoskeleton, and elevated actin levels, suggesting that these factors have a role in cell morphology. Expression of Eif2a downregulated Ure2 internal ribosome entry site (IRES) activity in yeast cells. Human EIF2A could partially suppress Ure2 IRES activity in yeast cells. Compared with the yeast protein, human EIF2A showed reduced association with 80S ribosomes and was instead predominantly associated with 40S ribosomes in yeast cells.