title: Characterization of the poly(ADP-ribose) polymerase associated with free cytoplasmic mRNA-protein particles.
abstract: Poly(ADP-ribose) polymerase associated with free cytoplasmic messenger ribonucleoprotein particles (mRNP) has been characterized in mouse plasmacytoma. This cytoplasmic enzyme undergoes auto-ADP-ribosylation and has a similar molecular weight and common antigenic sites with the chromatin bound poly(ADP-ribose) polymerase in spite of its DNA independency. The free mRNP poly(ADP-ribose) polymerase is released from the particle only by high saline concentrations (0.7 M KCl) and the dissociated enzyme expresses a higher activity. The treatment of free mRNP by RNase A stimulates the poly(ADP-ribose) polymerase activity. Partial destruction of mRNP by high saline concentration or mRNA digestion unmasks new protein sites for ADP-ribosylation. In view of the changes that occur in the free mRNP structure to permit mRNA translation, a possible role of poly(ADP-ribosylation) as an important post-synthetic modification of some of the mRNP proteins is discussed.
mesh_terms: D000818:Animals; D001345:Autoradiography; D003593:Cytoplasm / Q000201:enzymology / Q000378:metabolism*; D004247:DNA / Q000502:physiology; D003850:Deoxyribonuclease I / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C / Q000378:metabolism; D008970:Molecular Weight; D009363:Neoplasm Proteins / Q000378:metabolism; D010954:Plasmacytoma / Q000201:enzymology / Q000378:metabolism; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism*; D011189:Potassium Chloride / Q000494:pharmacology; D014176:Protein Biosynthesis; D012259:Ribonuclease, Pancreatic / Q000378:metabolism; D012261:Ribonucleoproteins / Q000378:metabolism*
chemical_list: D009363:Neoplasm Proteins; D012261:Ribonucleoproteins; C026452:messenger ribonucleoprotein; D011189:Potassium Chloride; D004247:DNA; D011065:Poly(ADP-ribose) Polymerases; D003850:Deoxyribonuclease I; D012259:Ribonuclease, Pancreatic