title: Effect of temperature on ppp(A2'p)nA binding protein activities in rabbit reticulocyte lysates and other mammalian extracts.
abstract: Lysates of rabbit reticulocytes and other mammalian cells are known to contain an activity which binds with high specificity ppp(A2'p)3A,3'-[32P]pCp. The binding activity shows a marked dependence on preincubation of lysates at different temperatures (4 degrees C - 45 degrees C). For example, binding was increased 50% by preincubation of rabbit reticulocyte lysates at 37 degrees C for 60 minutes. An identical preincubation of mouse brain extracts results in a greater than 90% loss of binding activity. Fractionation of rabbit reticulocyte lysates into the postribosomal supernatant (PRS) and the ribosomal salt wash (RSW), followed by heparin-agarose column chromatography, showed that with the PRS fraction, most of the binding activity is eluted with 600 mM KCl. With the RSW fraction, more than 50% of the binding activity is eluted with 250 mM KCl. These data suggest that multiple ppp(A2'p)nA binding protein activities exist in mammalian cells.
mesh_terms: D000227:Adenine Nucleotides / Q000378:metabolism*; D000818:Animals; D002478:Cells, Cultured; D004722:Endoribonucleases / Q000378:metabolism*; D005260:Female; D006801:Humans; D007668:Kidney / Q000378:metabolism; D007700:Kinetics; D008099:Liver / Q000378:metabolism; D008168:Lung / Q000378:metabolism; D051379:Mice; D009206:Myocardium / Q000378:metabolism; D009841:Oligonucleotides / Q000378:metabolism*; D009843:Oligoribonucleotides / Q000378:metabolism*; D009928:Organ Specificity; D010920:Placenta / Q000378:metabolism; D011247:Pregnancy; D012156:Reticulocytes / Q000378:metabolism*; D012260:Ribonucleases / Q000378:metabolism*; D013045:Species Specificity; D013696:Temperature
chemical_list: D000227:Adenine Nucleotides; D009841:Oligonucleotides; D009843:Oligoribonucleotides; C023505:2',5'-oligoadenylate; D004722:Endoribonucleases; D012260:Ribonucleases; C034663:ppp(A2'p)nA-dependent endoribonuclease protein, mouse