Abstract
A substantial amount of cytochrome oxidase subunit III (COIII) mRNA continues to be synthesized de novo in Trypanosoma brucei in the presence of actinomycin D, presumably by a DNA-independent transcription process. We describe the identification of negative-strand COIII RNA molecules, characterization of their termini, and the detection of RNA-dependent RNA polymerase activity. Three lines of evidence for the existence of negative-strand COIII RNA are presented: (i) hybridization with oligonucleotide probes with the same polarity as mRNA after preliminary enrichment for putative negative-strand RNA by affinity purification; (ii) cloning and sequencing of negative-strand complements for the unedited, edited, and partially edited COIII RNA; and (iii) exact correspondence of the terminal sequences of the putative negative-strand RNA molecules to the ends of COIII RNA. The presence of negative-strand complements of COIII RNA is consistent with the notion that a significant amount of mRNA in T. brucei is synthesized by an RNA-dependent RNA polymerase with negative-strand RNA as an intermediate template.
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- Abraham J. M., Feagin J. E., Stuart K. Characterization of cytochrome c oxidase III transcripts that are edited only in the 3' region. Cell. 1988 Oct 21;55(2):267–272. doi: 10.1016/0092-8674(88)90049-9. [DOI] [PubMed] [Google Scholar]
- Bhat G. J., Koslowsky D. J., Feagin J. E., Smiley B. L., Stuart K. An extensively edited mitochondrial transcript in kinetoplastids encodes a protein homologous to ATPase subunit 6. Cell. 1990 Jun 1;61(5):885–894. doi: 10.1016/0092-8674(90)90199-o. [DOI] [PubMed] [Google Scholar]
- Blum B., Bakalara N., Simpson L. A model for RNA editing in kinetoplastid mitochondria: "guide" RNA molecules transcribed from maxicircle DNA provide the edited information. Cell. 1990 Jan 26;60(2):189–198. doi: 10.1016/0092-8674(90)90735-w. [DOI] [PubMed] [Google Scholar]
- Blum B., Simpson L. Guide RNAs in kinetoplastid mitochondria have a nonencoded 3' oligo(U) tail involved in recognition of the preedited region. Cell. 1990 Jul 27;62(2):391–397. doi: 10.1016/0092-8674(90)90375-o. [DOI] [PubMed] [Google Scholar]
- Borst P. Discontinuous transcription and antigenic variation in trypanosomes. Annu Rev Biochem. 1986;55:701–732. doi: 10.1146/annurev.bi.55.070186.003413. [DOI] [PubMed] [Google Scholar]
- Feagin J. E., Abraham J. M., Stuart K. Extensive editing of the cytochrome c oxidase III transcript in Trypanosoma brucei. Cell. 1988 May 6;53(3):413–422. doi: 10.1016/0092-8674(88)90161-4. [DOI] [PubMed] [Google Scholar]
- Grady L. J., Campbell W. P. Amplification of large RNAs (greater than 1.5 kb) by polymerase chain reaction. Biotechniques. 1989 Sep;7(8):798–800. [PubMed] [Google Scholar]
- Laird P. W. Trans splicing in trypanosomes--archaism or adaptation? Trends Genet. 1989 Jul;5(7):204–208. doi: 10.1016/0168-9525(89)90082-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Shaw J. M., Feagin J. E., Stuart K., Simpson L. Editing of kinetoplastid mitochondrial mRNAs by uridine addition and deletion generates conserved amino acid sequences and AUG initiation codons. Cell. 1988 May 6;53(3):401–411. doi: 10.1016/0092-8674(88)90160-2. [DOI] [PubMed] [Google Scholar]
- Stuart K. RNA editing in mitochondrial mRNA of trypanosomatids. Trends Biochem Sci. 1991 Feb;16(2):68–72. doi: 10.1016/0968-0004(91)90027-s. [DOI] [PubMed] [Google Scholar]
- Volloch V., Schweitzer B., Rits S. Uncoupling of the synthesis of edited and unedited COIII RNA in Trypanosoma brucei. Nature. 1990 Feb 1;343(6257):482–484. doi: 10.1038/343482a0. [DOI] [PubMed] [Google Scholar]