title: A ribonuclease activity is activated by heparin or by digestion with proteinase K in mitochondrial extracts of Leishmania tarentolae.
abstract: A ribonuclease activity in a 100,000 x g supernatant of a Triton lysate of a mitochondrial-kinetoplast fraction from Leishmania tarentolae is activated by incubation with heparin or by predigestion of the lysate with proteinase k or pronase. In vitro-transcribed pre-edited cytochrome b mRNA is cleaved at several sites. With time, complete degradation of the RNA occurs. All cleavages occurred within putative single-stranded regions of the RNA. No cleavage was observed with 9 S rRNA. The presence of a nonspecific nucleotide or nucleoside slows the rate of cleavage. The cleavage activity is inhibited by sodium dodecyl sulfate or phenol/chloroform extraction, is retained by a 10-kDa cutoff filter, and passes through a 30-kDa filter. Micrococcal nuclease inhibits the proteinase-induced activity but not the heparin-induced activity.
authors.affiliation: Department of Biology, University of California, Los Angeles 90024.
authors.forename: A M
authors.initials: AM
authors.lastname: Simpson
authors.forename: N
authors.initials: N
authors.lastname: Bakalara
authors.forename: L
authors.initials: L
authors.lastname: Simpson
mesh_terms: D000818:Animals; D001483:Base Sequence; D003573:Cytochrome b Group / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D019286:Endopeptidase K; D004789:Enzyme Activation; D006493:Heparin / Q000494:pharmacology*; D007891:Leishmania / Q000201:enzymology*; D008928:Mitochondria / Q000201:enzymology*; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012335:RNA, Ribosomal / Q000235:genetics / Q000378:metabolism; D012260:Ribonucleases / Q000378:metabolism*; D012697:Serine Endopeptidases / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D003573:Cytochrome b Group; D012333:RNA, Messenger; D012335:RNA, Ribosomal; D006493:Heparin; D012260:Ribonucleases; D012697:Serine Endopeptidases; D019286:Endopeptidase K