Mode of action of the hemin-controlled inhibitor of protein synthesis: studies with factors from rabbit reticulocytes.
Previously [de Haro, C., Datta, A & Ochoa, S. (1978) Proc. Natl. Acad. Sci. USA 75, 243--247] it was shown with initiation factors from Artemia salina embryos that the activity of the initiator methionyl-tRNA binding factor eIF-2 is stimulated by another factor (ESP, for eIF-2 stimulating protein) present, like eIF-2, in ribosomal salt washes. Incubation of eIF-2 with translational inhibitor from rabit reticulocytes, in the presence of ATP, abolished the ESP effect. At physiological concentrations eIF-2 was virtually inactive without ESP. These observations indicated that the translational inhibitor acts by converting eIF-2 to a form that is not stimulated by ESP. The same observations have now been made with eIF-2 and ESP from rabbit reticulocytes but, in this case, the dependence of eIF-2 activity on ESP is much more pronounced than with the A. salina factors. eIF-2 from reticulocytes interacts with ESP from A. salina and conversely.
D000818:Animals; D033364:Decapoda; D006160:Guanosine Triphosphate / Q000378:metabolism; D006427:Hemin / Q000494:pharmacology; D007700:Kinetics; D010448:Peptide Initiation Factors; D011494:Protein Kinases / Q000378:metabolism; D011506:Proteins / Q000378:metabolism*; D012346:RNA, Transfer, Amino Acyl / Q000378:metabolism*; D011817:Rabbits; D012156:Reticulocytes / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism*; D013439:Sulfhydryl Reagents / Q000494:pharmacology
D010448:Peptide Initiation Factors; D011506:Proteins; D012346:RNA, Transfer, Amino Acyl; D013439:Sulfhydryl Reagents; D006427:Hemin; D006160:Guanosine Triphosphate; D011494:Protein Kinases