Roy, Kevin R.
Kevin is a first year trainee and is in the Molecular Biology IDP. His research mentor is Dr. Guillaume Chanfreau. He received a B.S. degree in 2009 from UCLA.
Mentor: Dr. Guillaume Chanfreau
Statement: Mitochondrial (Mt) RNA processing is poorly understood relative to nuclear and cytosolic RNA processing. Many mitochondrial transcripts are synthesized as polycistronic precursors which require extensive processing. The processing pathways which produce the mature Mt rRNAs, tRNAs, and mRNAs remain to be fully identified. I am investigating the roles of a putative double-stranded RNA endonuclease (Mt RNAse III) and the mitochondrial 3'-5' exonuclease (Mt degradosome) in yeast mitochondrial RNA metabolism. I have shown that deletion of the Mt RNase III results in accumulation of precursors to the Mt small subunit RNA, suggestive of processing defects. I have also demonstrated that deletion of the Mt degradosome results in complete absence of mature Mt tRNA(Leu), with accumulation of tRNA(Leu) precursors, but with no effect on other Mt tRNAs. This suggests that the Mt degradosome is required for the production of specific Mt tRNAs, in contrast to the current dogma. I will exhaustively examine Mt RNA processing upon inactivation of these Mt RNA processing factors, and will perform in vitro cleavage experiments to verify the activity of these nucleases on their specific substrates. Because many factors in Mt RNA processing are widely conserved, deciphering yeast Mt RNA processing pathways has implications for Mt gene expression in higher eukaryotes.
