mtDNA Copy Number Regulation

"How is the number of mitochondrial DNA molecules controlled and coordinated with cellular growth and metabolic demand?"

Image showing the result of a colony blot from a screen in S. cerevisiae for a screen for mutants involved in mtDNA copy number regulation. Image taken by Aylin Göke

Each cell contains multiple copies of mitochondrial DNA, and maintaining the correct number of genomes is essential for proper mitochondrial function. Too few copies can limit energy production, while uncontrolled expansion can disrupt mitochondrial organization and cellular homeostasis. Our work explores the molecular mechanisms that regulate mtDNA copy number and nucleoid composition. In particular, we study how mitochondrial proteins coordinate genome replication, nucleoid architecture, and cellular physiology to maintain appropriate mtDNA abundance across different growth conditions.

Focus Projects

Documentation for specific projects in this area is currently being finalized.

Key Publications

Nucleic Acids Res. 2026

Mrx6 binds the Lon protease Pim1 N-terminal domain to confer selective substrate specificity and regulate mtDNA copy number

Schrott, S., Marafelli, I., Gerle, C., Bibinger, S., Bertgen, L., Marino, G., Schwenkert, S., Rathberger, R., Herrmann, J., Osman, C.
Full Paper
Nat. Struct. Mol. Biol. 2023

Regulation with cell size ensures mitochondrial DNA homeostasis during cell growth

Seel, A., Padovani, F., Mayer, M., Finster, A., Bureik, D., Thoma, F., Osman, C., Klecker, T., Schmoller, K.
Full Paper
Nucleic Acids Res. 2023

Two mitochondrial HMG-box proteins, Cim1 and Abf2, antagonistically regulate mtDNA copy number in Saccharomyces cerevisiae

Schrott, S., Osman, C.
Full Paper
Mol. Biol. Cell 2020

Mrx6 regulates mitochondrial DNA copy number in Saccharomyces cerevisiae by engaging the evolutionarily conserved Lon protease Pim1

Göke, A., Schrott, S., Mizrak, A., Belyy, V., Osman, C., Walter, P.
Full Paper
Proc. Natl. Acad. Sci. U.S.A. 2015

Integrity of the yeast mitochondrial genome, but not its distribution and inheritance, relies on mitochondrial fission and fusion

Osman, C., Noriega, T., Okreglak, V., Walter, P.
Full Paper
Back to Research Pillars