Partial purification and characterization of a translational inhibitor from Friend leukemia cells.
A translational inhibitor has been isolated from unstimulated Friend leukemia cells. The inhibitor is a heat-labile, sulfhydryl reagent-insensitive protein with a molecular weight of approximately 214,000. It inhibits protein synthesis at a step of peptide chain initiation by preventing initiation factor-dependent binding of methionyl-tRNAf to 40 S ribosomal subunits. However, it does not interfere with the formation of the ribosome-independent ternary complex between the initiation factor IF-E2, methionyl-tRNAf, and GTP. The inhibitor preparation contains protein kinase activity which phosphorylates the smallest subunit of IF-E2. There appears to be a functional similarity between this inhibitor from Friend leukemia cells and the hemin-controlled repressor from reticulocytes.
D000818:Animals; D005622:Friend murine leukemia virus; D007700:Kinetics; D007942:Leukemia, Experimental / Q000032:analysis*; D008715:Methionine; D008970:Molecular Weight; D009363:Neoplasm Proteins / Q000302:isolation & purification*; D010442:Peptide Chain Initiation, Translational; D010448:Peptide Initiation Factors; D014176:Protein Biosynthesis / Q000187:drug effects; D011494:Protein Kinases / Q000378:metabolism; D012343:RNA, Transfer / Q000378:metabolism; D011817:Rabbits; D012156:Reticulocytes / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism
D009363:Neoplasm Proteins; D010448:Peptide Initiation Factors; D012343:RNA, Transfer; D008715:Methionine; D011494:Protein Kinases