Regulation of protein synthesis by phosphorylation of eukaryotic initiation factor 2 alpha in intact reticulocytes and reticulocyte lysates.

AUTOR(ES)

Leroux, A

RESUMO

Studies in intact rabbit reticulocytes and reticulocyte lysates provide further evidence of a functional role for the phosphorylation of eukaryotic initiation factor 2 alpha (eIF-2 alpha) in the regulation of initiation of protein synthesis in eukaryotic cells. In intact reticulocytes treated with isonicotinic acid hydrazide to inhibit heme synthesis, the phosphorylation of eIF-2 alpha was significantly greater than in control cells. In heme-deficient reticulocyte lysates and in lysates treated with double-stranded RNA, significant phosphorylation of eIF-2 alpha occurred prior to the onset of inhibition of protein synthesis; a large proportion, however, of the total eIF-2 alpha remained unphosphorylated. These findings indicate that a modest concentration of phosphorylated eIF-2 alpha can suffice to inhibit initiation, and they suggest that one of the factors with which eIF-2 must interact may be rate limiting, especially when eIF-2 alpha is phosphorylated.

Documentos Relacionados

• Regulation of protein synthesis in reticulocyte lysates: phosphorylation of methionyl-tRNAf binding factor by protein kinase activity of translational inhibitor isolated from hemedeficient lysates.
• Protein synthesis in rabbit reticulocytes: characteristics of the protein factor RF that reverses inhibition of protein synthesis in heme-deficient reticulocyte lysates.
• Regulation of double-stranded RNA-activated eukaryotic initiation factor 2α kinase by type 2 protein phosphatase in reticulocyte lysates
• Protein synthesis in rabbit reticulocytes: a study of the mechanism of action of the protein factor RF that reverses protein synthesis inhibition in heme-deficient reticulocyte lysates.
• Role of 3':5'-cyclic-AMP-dependent protein kinase in regulation of protein synthesis in reticulocyte lysates.