scholarly journals Polarized Exocytosis

2017 ◽  
Vol 9 (12) ◽  
pp. a027870 ◽  
Author(s):  
Jingwen Zeng ◽  
Shanshan Feng ◽  
Bin Wu ◽  
Wei Guo
Keyword(s):  
Polarized Exocytosis

scholarly journals The Sterol-Binding Protein Kes1/Osh4p Is a Regulator of Polarized Exocytosis

Traffic ◽  
2011 ◽  
Vol 12 (11) ◽  
pp. 1521-1536 ◽  
Author(s):  
Gabriel Alfaro ◽  
Jesper Johansen ◽  
Shubha A. Dighe ◽  
Giselle Duamel ◽  
Keith G. Kozminski ◽  
...  
Keyword(s):  
Binding Protein ◽  
Sterol Binding ◽  
Polarized Exocytosis

scholarly journals Cell patterning by secretion-induced plasma membrane flows

2020 ◽  
Author(s):  
Veneta Gerganova ◽  
Iker Lamas ◽  
David M. Rutkowski ◽  
Aleksandar Vještica ◽  
Daniela Gallo Castro ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Negative Feedback ◽  
Reaction Diffusion ◽  
Cell Patterning ◽  
Yeast Cells ◽  
Membrane Insertion ◽  
Gtpase Activating Proteins ◽  
Associated Proteins ◽  
Bulk Membrane ◽  
Polarized Exocytosis

AbstractCells self-organize using reaction-diffusion and fluid-flow principles. Whether bulk membrane flows contribute to cell patterning has not been established. Here, using mathematical modelling, optogenetics and synthetic probes, we show that polarized exocytosis causes lateral membrane flows away from regions of membrane insertion. Plasma membrane-associated proteins with sufficiently low diffusion and/or detachment rates couple to the flows and deplete from areas of exocytosis. In rod-shaped fission yeast cells, zones of Cdc42 GTPase activity driving polarized exocytosis are limited by GTPase activating proteins (GAPs). We show that membrane flows pattern the GAP Rga4 distribution and coupling of a synthetic GAP to membrane flows is sufficient to establish the rod shape. Thus, membrane flows induced by Cdc42-dependent exocytosis form a negative feedback restricting the zone of Cdc42 activity.One Sentence SummaryExocytosis causes bulk membrane flows that drag associated proteins and form a negative feedback restricting the exocytic site.

scholarly journals GIV/Girdin and Exo70 Constitute the Core of the Mammalian Polarized Exocytic Machinery

2019 ◽  
Author(s):  
Cristina Rohena ◽  
Navin Rajapakse ◽  
I-Chung Lo ◽  
Peter Novick ◽  
Debashis Sahoo ◽  
...  
Keyword(s):  
Matrix Metalloproteases ◽  
Regulatory Control ◽  
List Type ◽  
Linear Motif ◽  
Linear Interaction ◽  
Spatial Control ◽  
Disease States ◽  
Cargo Proteins ◽  
And Migration ◽  
Polarized Exocytosis

SUMMARYPolarized exocytosis is a fundamental process by which membrane and cargo proteins are delivered to the plasma membrane with precise spatial control; it is essential for cell growth, morphogenesis, and migration. Although the need for the octameric exocyst complex is conserved from yeast to humans, what imparts spatial control is known only in yeast, i.e., a polarity scaffold without mammalian homolog, called Bem1p. We demonstrate that polarity scaffold GIV/Girdin fulfills the key criteria and functions of its yeast counterpart Bem1p. Both Bem1p and GIV bind yeast and mammalian Exo70 proteins via similar short-linear interaction motifs, but each preferentially binds its evolutionary counterpart. In cells where this GIV•Exo-70 interaction is selectively disrupted, delivery of the metalloprotease MT1-MMP to podosomes, collagen degradation and haptotaxis through basement membrane matrix were impaired. GIV’s interacting partners reveal other components of polarized exocytosis in mammals. Findings not only expose how GIV “upgrades” the exocytic process in mammals, but also how the ability to regulate exocytosis shapes GIV’s ability to fuel metastasis.GRAPHIC ABSTRACTGraphic Abstract: Schematic comparing the components of polarized exocytosis, i.e., the major polarity scaffold in yeast (Bem1p; left) and humans (Girdin; right) and the various cellular components and signaling mechanisms that are known to converge on them.The eTOC blurbPolarized exocytosis is a precision-controlled process that is enhanced in disease states, e.g., cancer invasion; what imparts polarity was unknown. Authors reveal how the process underwent an evolutionary upgrade from yeast to humans by pinpointing GIV/Girdin as the polarity scaffold which orchestrates the exocytosis of matrix metalloproteases during cell invasion.HIGHLIGHTSGIV (human) and Bem1p (yeast) bind Exo70; are required for exocytosisGIV binds and aids PM localization Exo70 via a conserved short linear motifBinding facilitates MT1-MMP delivery to podosomes, ECM degradation, invasionRegulatory control over polarized exocytosis is upgraded during evolution

Shigella flexneri subverts host polarized exocytosis to enhance cell‐to‐cell spread

2021 ◽  
Author(s):  
Thilina U.B. Herath ◽  
Arpita Roy ◽  
Antonella Gianfelice ◽  
Keith Ireton
Keyword(s):  
Shigella Flexneri ◽  
Cell Spread ◽  
Polarized Exocytosis

scholarly journals Polarized Exocytosis Induces Compensatory Endocytosis by Sec4p-Regulated Cortical Actin Polymerization

PLoS Biology ◽  
2016 ◽  
Vol 14 (8) ◽  
pp. e1002534 ◽  
Author(s):  
Jesper Johansen ◽  
Gabriel Alfaro ◽  
Christopher T. Beh
Keyword(s):  
Actin Polymerization ◽  
Cortical Actin ◽  
Polarized Exocytosis

scholarly journals Time-gated confocal microscopy reveals accumulation of exocyst subunits at the plant-pathogen interface

2019 ◽  
Author(s):  
Elysa J R Overdijk ◽  
Han Tang ◽  
Jan Willem Borst ◽  
Francine Govers ◽  
Tijs Ketelaar
Keyword(s):  
Plasma Membrane ◽  
Confocal Microscopy ◽  
Plant Development ◽  
Plant Pathogen ◽  
Protein Complex ◽  
Physcomitrella Patens ◽  
Phytophthora Capsici ◽  
Pathogen Invasion ◽  
Pathogen Attack ◽  
Polarized Exocytosis

Abstract Polarized exocytosis is essential for plant development and defence. The exocyst, an octameric protein complex that tethers exocytotic vesicles to the plasma membrane, targets exocytosis. Upon pathogen attack, secreted materials form papillae to halt pathogen penetration. To determine if the exocyst is directly involved in targeting exocytosis to infection sites, information about its localization is instrumental. Here, we investigated exocyst subunit localization in the moss Physcomitrella patens upon pathogen attack and infection by Phytophthora capsici. Time-gated confocal microscopy was used to eliminate autofluorescence of deposited material around infection sites allowing the visualization of the subcellular localization of exocyst subunits and of v-SNARE Vamp72A1-labeled exocytotic vesicles during infection. This showed that exocyst subunits Sec3a, Sec5b, Sec5d and Sec6 accumulated at sites of attempted pathogen penetration. Upon pathogen invasion, the exocyst subunits accumulated on the membrane surrounding papilla-like structures and hyphal encasements. Vamp72A1-labeled vesicles were found to localize in the cytoplasm around infection sites. The re-localization of exocyst subunits to infection sites suggests that the exocyst is directly involved in facilitating polarized exocytosis during pathogenesis.

scholarly journals The Exo70 Subunit of the Exocyst Is an Effector for Both Cdc42 and Rho3 Function in Polarized Exocytosis

2010 ◽  
Vol 21 (3) ◽  
pp. 430-442 ◽  
Author(s):  
Hao Wu ◽  
Courtney Turner ◽  
Jimmy Gardner ◽  
Brenda Temple ◽  
Patrick Brennwald
Keyword(s):  
Rho Gtpases ◽  
Rho Gtpase ◽  
Biochemical Properties ◽  
Loss Of Function ◽  
Gain Of Function ◽  
Present Evidence ◽  
Spatial Regulation ◽  
Exocyst Complex ◽  
Polarized Exocytosis

The Rho3 and Cdc42 members of the Rho GTPase family are important regulators of exocytosis in yeast. However, the precise mechanism by which they regulate this process is controversial. Here, we present evidence that the Exo70 component of the exocyst complex is a direct effector of both Rho3 and Cdc42. We identify gain-of-function mutants in EXO70 that potently suppress mutants in RHO3 and CDC42 defective for exocytic function. We show that Exo70 has the biochemical properties expected of a direct effector for both Rho3 and Cdc42. Surprisingly, we find that C-terminal prenylation of these GTPases both promotes the interaction and influences the sites of binding within Exo70. Finally, we demonstrate that the phenotypes associated with novel loss-of-function mutants in EXO70, are entirely consistent with Exo70 as an effector for both Rho3 and Cdc42 function in secretion. These data suggest that interaction with the Exo70 component of the exocyst is a key event in spatial regulation of exocytosis by Rho GTPases.

scholarly journals The exocyst complex in polarized exocytosis

2009 ◽  
Vol 21 (4) ◽  
pp. 537-542 ◽  
Author(s):  
Bing He ◽  
Wei Guo
Keyword(s):  
Exocyst Complex ◽  
Polarized Exocytosis
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