Invited by Sébastien Léon, Isabelle Sagot (Institut de Biochimie et Génétique Cellulaires – IBGC, Bordeaux) will give an IJM Seminar entitled:
The cell biology of quiescent yeast
Cells perpetually face the decision to proliferate or to enter a non-dividing state. Quiescence, a state defined as a reversible arrest of proliferation, is the most common cellular situation found on earth, as it concerns all kind of cells, from microbes to human stem cells. Quiescent cells not only have to survive and face age but they must also preserve their ability to re-enter the cell cycle in a tightly regulated manner, and give rise to a healthy progeny. Therefore quiescence is at the heart of crucial biological issues including development, aging and evolution. Yet, astonishingly little is known about the molecular determinants that orchestrate quiescence establishment and exit.
We are using both single cell eukaryotes and mammalian models to study the cell biology of quiescence. In the past years, we have shown that upon quiescence entry, cells assemble specific structures that display original properties, including actin and microtubule hyper-stable arrangements. Our project is to study these structures and use them as tools to address central questions such as: how do quiescent cells survive and what are the cascade of molecular switches that tightly control the transitions between quiescence and proliferation.