Phase partitioning initiates Rab protein membrane domain formation and promote vesicle tethering

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.04.17.537227v1?rss=1 Authors: Jimenez, A. J., Perez, F. Abstract: Cellular processes are regulated by the formation of specific membrane domains with different lipid and protein compositions. Small GTPases play a role in symmetry breaking and compartmentalization, with early endosomes presenting Rab5-enriched domains that regulate vesicle tethering and fusion. Rabaptin5, which binds activated Rab5 and forms dimers, is essential for endosome fusion and promotes Rab5 recruitment to membranes. Liquid-liquid phase separation (LLPS) is a mechanism for the biogenesis and maintenance of membrane-less organelles and intracellular organization. We show that several partners of Rab proteins, such as Rabaptin5, have phase-separation properties. In particular, Rabaptin5 form condensates close to membranes, while promoting the enrichment of several Rabs involved in early steps of endocytosis. We propose that phase separation of Rab partners ensures efficient recruitment of their respective Rabs and domain formation and maintenance. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC