Multiple assay systems to analyze the dynamics of mitochondrial nucleoids in living mammalian cells

Mitochondria, which play a critical role in energy production by oxidative respiration, are highly dynamic organelles and their double membranes undergo frequent events of fusion fission. Mitochondria believed to be derived from the endosymbiosis proteobacteria, thus mitochondria still contain own DNA, mitochondrial DNA (mtDNA). Several copies mtDNA form nucleoid with DNA-binding proteins. Recently, morphology distribution membrane were reported cooperatively regulated during movement. However, molecular mechanism is unclear, because involved molecules poorly understood, suitable techniques analyze have not been fully developed. To solve these issues, we examined dynamics two approaches. First, constructed new probe perform live imaging using domain transcriptional factor A (TFAM) photo-convertible fluorescent protein Kikume Green-Red (KikGR). Nucleoids visualized stably for long period probe. Second, searched regulatory factors small interfering RNA screening HeLa cells identified subset MARCH family ubiquitin ligases that affect morphology. The probe, this study, would useful reveal novel mechanisms regulation. should concerned regulation activity its quality control, associated dynamics. • Under microscopy, observed as dot-like structures, nucleoids. dynamically move along living cells. We sensitive photoconvertible siRNA revealed proteins