Specific phosphorylation of pig liver initiation factor eIF-2 by the N-ethylmaleimide-treated hemin-controlled translational inhibitor.
The specific phosphorylation of pig liver initiation factor 2(eIF-2) by the N-ethylmaleimide (NEM)-treated hemin-controlled translational inhibitor (HCI) from rabbit reticulocytes was investigated. The inhibitor phosphorylated the serine residue of the alpha subunit of eIF-2 (eIF-2 alpha) and 1 mol of phosphate was incorporated into 1 mol of eIF-2 alpha by the inhibitor on maximal phosphorylation, even when eIF-2 was pretreated with alkaline phosphatase prior to phosphorylation. The 32P-labeled eIF-2 alpha was subjected to tryptic digestion and the tryptic digest was analyzed by two-dimensional peptide mapping on a cellulose thin-layer sheet. After 94 h digestion, the autoradiograph of the peptide map showed a single 32P-labeled band with a molecular weight of approximately 1,200. These findings suggest that one specific serine residue of pig liver eIF-2 alpha was phosphorylated by the NEM-treated HCI.
D000818:Animals; D004789:Enzyme Activation / Q000187:drug effects; D005033:Ethylmaleimide / Q000494:pharmacology; D015852:Eukaryotic Initiation Factor-2; D006427:Hemin / Q000502:physiology; D008099:Liver / Q000378:metabolism; D008970:Molecular Weight; D010448:Peptide Initiation Factors / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D012694:Serine / Q000378:metabolism; D013552:Swine; D019892:eIF-2 Kinase
D015852:Eukaryotic Initiation Factor-2; D010448:Peptide Initiation Factors; D011506:Proteins; D012694:Serine; D006427:Hemin; D011494:Protein Kinases; D019892:eIF-2 Kinase; D005033:Ethylmaleimide