Addition of uridines to edited RNAs in trypanosome mitochondria occurs independently of transcription

Journal Article · Thu Jul 05 00:00:00 EDT 1990 · Journal of Biological Chemistry; (USA)

OSTI ID:6643928

Harris, M E; Moore, D R; Hajduk, S L ^[1]

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1. Univ. of Alabama, Birmingham (USA)

RNA editing is a novel RNA processing event of unknown mechanism that results in the introduction of nucleotides not encoded in the DNA into specific RNA molecules. We have examined the post-transcriptional addition of nucleotides into the mitochondrial RNA of Trypanosoma brucei. Utilizing an isolated organelle system we have determined that addition of uridines to edited RNAs does not require ongoing transcription. Trypanosome mitochondria incorporate CTP, ATP, and UTP into RNA in the absence of transcription. GTP is incorporated into RNA only as a result of the transcription process. Post-transcriptional CTP and ATP incorporation can be ascribed to known enzymatic activities. CTP is incorporated into tRNAs as a result of synthesis or turnover of their 3{prime} CCA sequences. ATP is incorporated into the 3{prime} CCA of tRNAs and into mitochondrial messenger RNAs due to polyadenylation. In the absence of transcription, UTP is incorporated into transcripts known to undergo editing, and the degree of UTP incorporation is consistent with the degree of editing occurring in these transcripts. Cytochrome b mRNAs, which contain a single editing site near their 5{prime} ends, are initially transcribed unedited at that site. Post-transcriptional labeling of cytochrome b mRNAs in the organelle with (alpha-32P)UTP results in the addition of uridines near the 5{prime} end of the RNA but not in a 3{prime} region which lacks an editing site. These results indicate that RNA editing is a post-transcriptional process in the mitochondria of trypanosomes.

• OSTI ID: 6643928
• Journal Information: Journal of Biological Chemistry; (USA), Vol. 265:19; ISSN 0021-9258
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
NUCLEOTIDES
BIOLOGICAL LOCALIZATION
RNA
TRANSCRIPTION
ATP
CYTIDINE
CYTOCHROMES
DNA HYBRIDIZATION
ELECTRON MICROSCOPY
MESSENGER-RNA
MITOCHONDRIA
PHOSPHORUS 32
RIBOSOMAL RNA
TRACER TECHNIQUES
TRANSFER RNA
TRYPANOSOMA
URIDINE
ANIMALS
AZINES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CELL CONSTITUENTS
DAYS LIVING RADIOISOTOPES
HETEROCYCLIC COMPOUNDS
HYBRIDIZATION
HYDROXY COMPOUNDS
INVERTEBRATES
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
MASTIGOPHORA
MICROORGANISMS
MICROSCOPY
NUCLEI
NUCLEIC ACIDS
NUCLEOSIDES
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANOIDS
PARASITES
PHOSPHORUS ISOTOPES
PIGMENTS
PROTEINS
PROTOZOA
PYRIMIDINES
RADIOISOTOPES
RIBOSIDES
URACILS
550201* - Biochemistry- Tracer Techniques