title: Regulation of translation in rabbit reticulocytes and mouse L-cells; comparison of the effects of temperature.
abstract: Various parameters of protein synthesis were analyzed in rabbit reticulocytes exposed to various temperatures for up to five hours. Between 10 degrees C and 40 degrees C total protein synthesis exhibited two different apparent activation energies (36 kcal/mole, 10-24 degrees C; 22 kcal/mole, 24-40 degrees C), as did protein elongation and release (35 kcal/mole, 10-25 degrees C; 12 kcal/mole, 25-40 degrees C). However, the level of polysomes remained essentially unchanged between 0 degrees C and 42 degrees C which implies that the activation energy for polypeptide initiation is quite similar to that for elongation and is also biphasic. This situation is different from that in cultured mouse L-cells where the polysome level is dependent on temperatures. Nevertheless, reticulocytes and L-cells appear to be similar in their temperature dependence of initiation and in their rate of elongation (5-6 amino acids/second at 36 degrees C.
mesh_terms: D000818:Animals; D007700:Kinetics; D007739:L Cells / Q000378:metabolism*; D007930:Leucine / Q000378:metabolism; D051379:Mice; D011132:Polyribosomes / Q000378:metabolism; D014176:Protein Biosynthesis; D051381:Rats; D012156:Reticulocytes / Q000378:metabolism*
chemical_list: D007930:Leucine