title: RhoGTPase-binding proteins, the exocyst complex and polarized vesicle trafficking.
abstract: Cell polarity, the asymmetric distribution of proteins and lipids, is essential for a variety of cellular functions. One mechanism orchestrating cell polarity is polarized vesicle trafficking; whereby cargo loaded secretory vesicles are specifically transported to predetermined areas of the cell. The evolutionarily conserved exocyst complex and its small GTPase regulators play crucial roles in spatiotemporal control of polarized vesicle trafficking. In studies on neuronal membrane remodeling and synaptic plasticity, conserved mechanisms of exocyst regulation and cargo recycling during polarized vesicle trafficking are beginning to emerge as well. Recently, our lab demonstrated that RhoGTPase-binding proteins in both yeast (Bem3) and mammals (Ocrl1) are also required for the efficient traffic of secretory vesicles to sites of polarized growth and signaling. Together with our studies, we highlight the evolutionary conservation of the basic elements essential for polarized vesicle traffic across different cellular functions and model systems. In conclusion, we emphasize that studies on RhoGTPase-binding proteins in these processes should be included in the next level of investigation, for a more complete understanding of their hitherto unknown roles in polarized membrane traffic and exocyst regulation.
authors.affiliation: National Center for Biological Sciences; Bangalore; Karnataka, India.
authors.forename: Debarati
authors.initials: D
authors.lastname: Mukherjee
authors.affiliation: Department of Biological Sciences; Purdue University; West Lafayette, IN USA.
authors.forename: Arpita
authors.initials: A
authors.lastname: Sen
authors.affiliation: Department of Biological Sciences; Purdue University; West Lafayette, IN USA.
authors.forename: R Claudio
authors.initials: RC
authors.lastname: Aguilar
mesh_terms: D000818:Animals; D016764:Cell Polarity; D002923:Cilia / Q000378:metabolism; D020690:GTPase-Activating Proteins / Q000378:metabolism*; D006801:Humans; D009473:Neuronal Plasticity; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D022142:Secretory Vesicles / Q000502:physiology*
chemical_list: C084220:BEM3 protein, S cerevisiae; D020690:GTPase-Activating Proteins; D029701:Saccharomyces cerevisiae Proteins; D010744:Phosphoric Monoester Hydrolases
keywords: Bem3; Ocrl1; exocyst; polarized secretion; primary cilium; recycling endosome; synaptic plasticity