The Importance of the 45 S Ribosomal Small Subunit-related Complex for Mitochondrial Translation in Trypanosoma brucei

0420980 - BC 2014 RIV US eng J - Článek v odborném periodiku
Ridlon, L. - Škodová, I. - Pan, S. - Lukeš, Julius - Maslov, D. A.
The Importance of the 45 S Ribosomal Small Subunit-related Complex for Mitochondrial Translation in Trypanosoma brucei.
Journal of Biological Chemistry. Roč. 288, č. 46 (2013), s. 32963-32978. ISSN 0021-9258. E-ISSN 1083-351X
Grant CEP: GA ČR(CZ) GAP305/11/2179; GA MŠMT LH12104
Institucionální podpora: RVO:60077344
Klíčová slova: Leish * Mitochondria * Protein Synthesis * Ribonuclear Protein (RNP) * Trypanosoma brucei * Trypanosome
Kód oboru RIV: EB - Genetika a molekulární biologie
Impakt faktor: 4.600, rok: 2013

The mitochondrial 45 S SSU* complex in Trypanosoma brucei contains the 9 S SSU ribosomal RNA, a set of SSU ribosomal proteins, several pentatricopeptide repeat (PPR) proteins, and proteins not typically found in ribosomes, including rhodanese domain protein (Rhod) and a 200-kDa coiled-coil protein. To investigate the function of this complex, PPR29, Rhod, 200-kDa protein, and mitochondrial ribosomal protein S17 were knocked down by RNAi in procyclic T. brucei. A growth retardation phenotype, a reduction in the amount of the 45 S SSU* complexes, and the preferential inhibition of synthesis of the cytochrome c oxidase subunit I over apocytochrome b were observed as early as day 2 postinduction of RNAi. On the contrary, the down-regulation of mitochondrial ribosomal protein L3 drastically reduced the amount of the large subunit and indiscriminately inhibited mitochondrial translation. The relative amounts of translation-competent, long poly(AU)-tailed cytochrome c oxidase subunit I and edited apocytochrome b mRNAs were selectively reduced by ablation of the 45 S SSU* complex. The formation of the 80 S translation complexes, identified by association of the long-tailed mRNAs with the mitoribosomes, was also disrupted. On the other hand, the relative amount of long-tailed edited RPS12 mRNA was not substantially affected, and there was no noticeable effect on the RPS12 translation complexes. In bloodstream trypanosomes, the amount of the 45 S complexes was drastically reduced compared with procyclics. We propose that the 45 S SSU* complex represents a factor required for normal mitochondrial translation that may have selective effects on different mRNAs.
Trvalý link: http://hdl.handle.net/11104/0227493