David Drubin - Harnessing actin dynamics for endocytic trafficking
Channel: Institut des Hautes Études Scientifiques (IHÉS)
Date: 2018-03-26

Clathrin-mediated endocytosis (CME) is the best-studied pathway by which cells selectively internalize molecules from the plasma membrane and surrounding environment. We study this process by live-cell microscopy in yeast and mammalian cells. The yeast studies have revealed a regular sequence of events necessary for endocytic vesicle formation involving some  60  proteins,  which  induce  a  highly  choreographed  series  of  changes  in  membrane geometry, ultimately resulting in scission and vesicle release. To analyze endocytic dynamics in mammalian cells in which endogenous protein stoichiometry is preserved, we have used genome editing for the clathrin light chain A and dynamin-2 genomic loci and generated stem cells expressing fluorescent protein fusions from each locus. These cell lines are being used to study actin assembly at endocytic sites and to make 3D organoids in culture.
Use nano-patterned  substrates,  we  are  actively  studying  roles  for  membrane  curvature  in endocytic  dynamics.
At  the  same  time,  studies  in  yeast  cells  have  recently focused  on discovery of regulatory mechanisms for insuring theproper order and timing of events in the endocytic pathway and how actin assembly at endocytic sites is regulated. Studying the yeast and mammalian systems in parallel is allowing us to translate what is learned from one system to the other.