Cell cycle control and ribosomes synthesis
Project leader: Simon Lebaron
Ribosome production is one the most energy consuming process in the cell and is therefore tightly linked to other essential cellular processes such as growth and cell cycle. Indeed, under favorable growth conditions, a large amount of ribosomes is produced to sustain protein production. To the contrary, when cells are stressed, due either to genetic mutations or lack of nutrients, ribosome synthesis is halted and cell cycle is impeded even before any effect on translation can be detected. This indicates the existence of direct connections that control both ribosome synthesis and cell cycle at the same time, an essential mechanism to maintain cell integrity and to adapt to environmental changes.
One of the key factors that participate to such regulation in mammals is the 5S RNP, constituted by the association of 5S rRNA to ribosomal proteins RPL5 and RPL11. But the repertoire of the different factors involved in this regulation as well as their precise molecular function are still unknown. This project aims at deciphering the function of the 5S particles in cell cycle regulation. We address this questions using human cell lines and in yeast S. cerevisiae as a model organisms. Our work combines molecular, cellular and protepmic analyses with structural approaches by cryo-electron microscopy. This project is performed in collaboration with Nick Watkins’ group (University of Newcastle) and with Julien Marcoux (IPBS, Toulouse).