Coordination of protein and organelle homeostasis with cell size
Dr Kurt SCHMOLLER
Intitute of functional epigenetics, Helmholtz Zentrum, Germany
Monday, September 16th 2019 - 2 p.m.
- Meeting room 3013, ICS
Hosted by Manuel MENDOZA
Size is a fundamental property of cells that is intricately linked to most intracellular processes. If cell size changes due to cell growth, during development and differentiation, or in response to changes in nutrient conditions, cells adjust the size of many organelles, including the nucleus, mitochondria, and the mitotic spindle. At the same time, cells coordinate the proteome composition with cell size: In general, the cell-size-dependent abundance of the limiting biosynthetic machinery couples protein amounts to cell size. While well suited for proteins that need to be maintained at constant concentration, this mechanism imposes a problem for DNA-binding proteins, which are required at a constant DNA-to-protein stoichiometry. Despite the fundamental importance for numerous biological processes, the regulatory mechanisms by which cell size governs biosynthetic processes and organelle homeostasis are poorly understood. We use budding yeast as a model to reveal how cells can coordinate mitochondria homeostasis and the size of the contractile ring with cell size. Moreover, we use histone biogenesis as a model to unravel how cells can couple the amount of DNA-binding proteins to DNA content, even though total protein synthesis increases with cell size instead.