Physical Sciences and Mathematics Commons^™

Regulation Of Protein Synthesis In Rabbit Reticulocyte Lysates By The Heme-Regulated Protein Kinase: Inhibition Of Interaction Of Met-TrnaFMet Binding Factor With Another Initiation Factor In Formation Of Met-TrnaFMet.4os Ribosomal Subunit Complexes, R. S. Ranu, I. M. London, A. Das, A. Dasgupta, A. Majumdar, R. Ralston, R. Roy, N. K. Gupta

Chemistry Department: Faculty Publications

Protein synthesis in reticulocytes and their lysates is regulated by heme. In heme deficiency a heme-regulated translational inhibitor (HRI) that blocks initiation of polypeptide chains is activated. HRI is a protein kinase (ATP: protein phosphotransferase, EC 2.7.1.37) that specifically phosphorylates the 38,000-dalton subunit of the Met-tRNA_f^Met indin factor (IF), which forms a ternary complex with Met- tRNA_f^Met and GTP, a finding that suggests that the inhibition by HRI involves the phosphorylation of IF. We have investigated the effect of HRI in the partial reactions of protein chain initiation in which the IF-promoted binding of Met-tRNA_{f …}