title: TbMP81 is required for RNA editing in Trypanosoma brucei.
abstract: Most mitochondrial mRNAs are edited in Trypano soma brucei by a series of steps that are catalyzed by a multienzyme complex that is in its initial stages of characterization. RNA interference (RNAi)-mediated repression of the expression of TbMP81, a zinc finger protein component of the complex, inhibited growth of bloodstream and insect forms, and blocked in vivo RNA editing. This repression preferentially inhibited insertion editing compared with deletion editing in vitro. It resulted in reduced specific endoribonucleolytic cleavage and a greater reduction of U addition and associated RNA ligation activities than U removal and associated RNA ligation activities. The repressed cells retained 20S editing complexes with several demonstrable proteins and adenylatable TbMP52 RNA ligase, but adenlyatable TbMP48 was not detected. Elimination of TbMP48 by RNAi repression did not inhibit cell growth or in vivo editing in either bloodstream or procyclic forms. These results indicate that TbMP81 is required for RNA editing and suggest that the editing complex is functionally partitioned.
authors.affiliation: Zentrum für Molekulare Biologie, Heidelberg, Germany.
authors.forename: Maciej
authors.initials: M
authors.lastname: Drozdz
authors.forename: Setareh S
authors.initials: SS
authors.lastname: Palazzo
authors.forename: Reza
authors.initials: R
authors.lastname: Salavati
authors.forename: Jeff
authors.initials: J
authors.lastname: O'Rear
authors.forename: Christine
authors.initials: C
authors.lastname: Clayton
authors.forename: Kenneth
authors.initials: K
authors.lastname: Stuart
mesh_terms: D000818:Animals; D004722:Endoribonucleases / Q000378:metabolism; D016254:Mutagenesis, Insertional; D015800:Protozoan Proteins; D017393:RNA Editing; D016053:RNA, Protozoan / Q000502:physiology*; D012261:Ribonucleoproteins / Q000235:genetics / Q000378:metabolism*; D014346:Trypanosoma brucei brucei / Q000254:growth & development / Q000378:metabolism; D016335:Zinc Fingers
chemical_list: D015800:Protozoan Proteins; D016053:RNA, Protozoan; D012261:Ribonucleoproteins; C437997:TbMP81 protein, Trypanosoma brucei; D004722:Endoribonucleases