FBS Colloquia No.389Ubiquitin Biology Laboratory

On the Mechanisms that Prevent the Loss of Mitochondrial Genetic Information

In eukaryotic cells, genomic DNA—the carrier of genetic information—is compartmentalized either within the nucleus or mitochondria. Nuclear genomic DNA (nDNA) is physically separated from the cytoplasm, making it relatively less susceptible to various cytoplasmic events. For example, when cells experience amino acid starvation, autophagy is induced, targeting cytoplasmic components for degradation. However, nDNA, enclosed by the nuclear envelope, is generally protected from such autophagic degradation. In contrast, mitochondrial genomic DNA (mtDNA), located within mitochondria that exist in the cytoplasm, is not as well protected as nDNA. Mitochondria can be targeted by autophagy (mitophagy), but whether mtDNA is degraded along with other mitochondrial components or selectively protected during this process has remained unclear. In this seminar, I will present recent findings on the phenomenon in which mtDNA is selectively protected during periods of intense mitochondrial degradation.