Mitochondria are described as cellular power plants because they generate most of the energy supply within a cell. In addition to supplying energy, mitochondria also are involved in a broad range of other cellular processes including signaling, differentiation, death, control of the cell cycle and growth. The import of nucleus-encoded small RNAs into mitochondria is essential for the replication, transcription and translation of the mitochondrial genome, but the mechanisms that deliver RNA into mitochondria have remained poorly understood. The study in Cell outlined a new role for a protein called polynucleotide phosphorylase (PNPASE) in regulating the import of RNA into mitochondria. Reducing the expression — or output — of PNPASE decreased RNA import, which impaired the processing of mitochondrial genome-encoded RNAs. Reduced RNA processing inhibited the translation of proteins required to maintain the mitochondrial electron transport chain that consumes oxygen during cell respiration to produce energy. With reduced PNPASE, unprocessed mitochondrial-encoded RNAs accumulated, protein translation was inhibited and energy production was compromised, leading to stalled cell growth. The findings from the current study provide a form of gene therapy for mitochondria by compensating for mutations that cause a wide range of diseases, said study co-senior author Koehler. “This opens up new avenues to understand and develop therapies for mitochondrial diseases,” Koehler said. “This has the potential to have a really big impact. We just have to get it to the next step.” Gene therapy is often used to express proteins that can treat the cause of a variety of diseases. In this case, post-doctoral fellow Geng Wang developed a strategy to target and import specific RNA molecules encoded in the nucleus into the mitochondria and, once there, to express proteins needed to repair mitochondrial gene mutations.
Posted on: Fri, 13 Sep 2013 08:13:35 +0000
Trending Topics
Recently Viewed Topics
© 2015