NEPhos_Phosphoregulation of ESCRT-III during nuclear envelope reformation

The nuclear envelope (NE) is a double membrane barrier which encloses the genome of eukaryotic cells, physically shielding the genetic material from the cytoplasmic environment. This creates a selective barrier that regulates the trafficking of proteins between the two compartments. During each mitosis, the NE is dismantled in prophase to allow the proper segregation of the duplicated chromosomes and then reassembled around the two nascent nuclei in late anaphase/telophase. Even though the circuitry of kinases/ phosphatase initiating and sustaining mitosis is well defined, how the latter mitotic events are fine-tuned to achieve a complete and timely NE sealing are still ill-understood. I will use a combination of genetic, proteomic, cellular biology and imaging approaches to shed light on how the ESCRT-III machinery is regulated by phosphorylation/dephosphorylation events and protein-protein interactions at sites of NE reformation during mitotic exit. Understanding the mechanistical aspects guiding nuclear reassembly will allow a better understanding of how mitotic exit events are coordinated in space and time to ensure a timely and functional nucleocytoplasmic compartmentalisation at every cell cycle. Moreover, NE defects are a known cause of disease, as chromatin exposure to the cytoplasmic milieu poses a threat to genome stability. Since ESCRT-III deregulation can lead to an impairment of NE integrity and eventually to a loss of nuclear compartmentalisation, a deeper understanding of how ESCRT-III proteins act in space and time could reveal not only new insights in the cellular mechanisms underlying pathology but also new therapeutical approaches.