Cell size homeostasis and sister chromatid asymmetry in unconventional cell cycles
Dr Nicolas TALAREK
IGMM, Montpellier, France
lundi 19 mars 2018 - 15h00
- Salle de réunion 4004, IGBMC
Invité(e) par Equipe G. Charvin
Cell cycle regulation has been studied for decades and is well characterized in optimal conditions of growth. However, we now realize that cell cycles are wired differently and display some peculiarities when cells grow in more physiological conditions (i.e. poor nutrients, exit from quiescence). Following this idea and using budding yeast as a model system, we have i) identified the Greatwall pathway and the phosphatase PP2A-B55 as key players in cell size homeostasis by coordinating growth and division when cells reprogram their metabolism by growing on poor nutrients; (ii) observed kinetochore asymmetry and non-random segregation of chromatids in yeast cells exiting post-meiotic quiescence. We therefore have in our hands a model to decipher the mechanisms responsible for the asymmetric segregation of cell fate determinants in self-renewing and differentiating adult stem cells. We believe that studying cells that alternate between states of quiescence and proliferation will unravel the fundamental processes used to generate cellular diversity.