Post-transcriptional regulation of mitochondrial gene expression (#74)
Mitochondria play a key role in energy production that is essential for cell health and function. Human mitochondria contain a small and compact genome that is transcribed as long polycistronic transcripts that encompass each strand of the genome, which are processed into mature mRNAs, tRNAs and rRNAs within the mitochondrial matrix. Recently we provided the first comprehensive map of the human mitochondrial transcriptome by near-exhaustive deep sequencing of long and small RNA fractions from purified mitochondria. We have identified previously undescribed transcripts, including small RNA and long non-coding RNAs encoded by the mitochondrial genome. Furthermore despite their common polycistronic origin, we observed wide variation between individual tRNAs, mRNAs, and rRNA amounts, indicating the importance of RNA-binding proteins in the regulation of mitochondrial gene expression. We have investigated the roles of a new class of RNA-binding proteins and found that they are all localized to mitochondria where they regulate mitochondrial gene expression. These RNA-binding proteins have diverse roles in RNA metabolism and protein synthesis that are important for mitochondrial function and cell health.