Regulation of protein synthesis in rabbit reticulocyte lysates: effect of of Ca2+, Mg2+, and Mn2+ on self-phosphorylation and heterophosphorylation catalyzed by the heme-regulated and double-stranded-RNA-activated protein kinases.
The influence of divalent cations Mg2+, Mn2+, and Ca2+ on the cyclic-AMP-independent protein kinases of the heme-regulated and double-stranded-RNA-activated translational inhibitory protein kinases on self-phosphorylation and heterophosphorylation of the substrate (the 38 000-dalton subunit of initiation factor eIF-2) has been examined. Results show that Mg2+, Mn2+, and Ca2+ affect the activities of these enzymes in the following fashion. Mg2+ supports both self-phosphorylation and heterophosphorylation efficiently. Mn2+ on the other hand supports self-phosphorylation but to a lesser degree the heterophosphorylation. Ca2+ promotes neither self-phosphorylation nor heterophosphorylation.
D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D015852:Eukaryotic Initiation Factor-2; D006418:Heme / Q000494:pharmacology*; D008274:Magnesium / Q000494:pharmacology*; D008345:Manganese / Q000494:pharmacology*; D008970:Molecular Weight; D010448:Peptide Initiation Factors / Q000378:metabolism; D010748:Phosphopeptides / Q000032:analysis; D010766:Phosphorylation; D014176:Protein Biosynthesis / Q000187:drug effects*; D011494:Protein Kinases / Q000097:blood*; D011506:Proteins / Q000378:metabolism; D012330:RNA, Double-Stranded / Q000235:genetics; D011817:Rabbits; D012156:Reticulocytes / Q000378:metabolism*
D015852:Eukaryotic Initiation Factor-2; D010448:Peptide Initiation Factors; D010748:Phosphopeptides; D011506:Proteins; D012330:RNA, Double-Stranded; D006418:Heme; D008345:Manganese; D011494:Protein Kinases; D008274:Magnesium; D002118:Calcium