Analyzing Rho GTPase-Dependent Processes During Cell Polarization in Brown Algae

2018 ◽  
pp. 401-410 ◽  
Author(s):  
Whitney Hable
Keyword(s):  
Brown Algae ◽  
Rho Gtpase ◽  
Cell Polarization ◽  
Dependent Processes

scholarly journals Post-Translational Modification and Subcellular Compartmentalization: Emerging Concepts on the Regulation and Physiopathological Relevance of RhoGTPases

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1990
Author(s):  
Inmaculada Navarro-Lérida ◽  
Miguel Sánchez-Álvarez ◽  
Miguel Ángel del Pozo
Keyword(s):  
Rho Gtpases ◽  
Rho Gtpase ◽  
Protein Complexes ◽  
Specific Protein ◽  
Cell Polarization ◽  
Small Gtpase ◽  
Post Translational Modification ◽  
Functional Regulation ◽  
Subcellular Compartmentalization ◽  
Cellular Compartments

Cells and tissues are continuously exposed to both chemical and physical stimuli and dynamically adapt and respond to this variety of external cues to ensure cellular homeostasis, regulated development and tissue-specific differentiation. Alterations of these pathways promote disease progression—a prominent example being cancer. Rho GTPases are key regulators of the remodeling of cytoskeleton and cell membranes and their coordination and integration with different biological processes, including cell polarization and motility, as well as other signaling networks such as growth signaling and proliferation. Apart from the control of GTP–GDP cycling, Rho GTPase activity is spatially and temporally regulated by post-translation modifications (PTMs) and their assembly onto specific protein complexes, which determine their controlled activity at distinct cellular compartments. Although Rho GTPases were traditionally conceived as targeted from the cytosol to the plasma membrane to exert their activity, recent research demonstrates that active pools of different Rho GTPases also localize to endomembranes and the nucleus. In this review, we discuss how PTM-driven modulation of Rho GTPases provides a versatile mechanism for their compartmentalization and functional regulation. Understanding how the subcellular sorting of active small GTPase pools occurs and what its functional significance is could reveal novel therapeutic opportunities.

scholarly journals Impaired Rho GTPase activation abrogates cell polarization and migration in macrophages with defective lipolysis

2011 ◽  
Vol 68 (23) ◽  
pp. 3933-3947 ◽  
Author(s):  
Elma Aflaki ◽  
Nariman A. B. Balenga ◽  
Petra Luschnig-Schratl ◽  
Heimo Wolinski ◽  
Silvia Povoden ◽  
...  
Keyword(s):  
Rho Gtpase ◽  
Cell Polarization ◽  
Gtpase Activation ◽  
And Migration

Chondroitin sulfate and cytoplasmic domain-dependent membrane targeting of the NG2 proteoglycan promotes retraction fiber formation and cell polarization

2001 ◽  
Vol 114 (12) ◽  
pp. 2315-2325 ◽  
Author(s):  
William B. Stallcup ◽  
Kimberlee Dahlin-Huppe
Keyword(s):  
Chondroitin Sulfate ◽  
Rho Gtpase ◽  
Cytoplasmic Domain ◽  
Structural Features ◽  
Cell Polarization ◽  
Fiber Formation ◽  
Structural Elements ◽  
Motile Cells ◽  
Chondroitin Sulfate Chain ◽  
Ng2 Proteoglycan

Targeting of the NG2 proteoglycan to cellular retraction fibers was studied by expressing mutant NG2 molecules lacking specific structural elements of the proteoglycan. Both the cytoplasmic domain and the chondroitin sulfate chain of NG2 appear to have roles in sorting NG2 to subcellular microdomains destined to become retraction fibers. Neither of these structural features alone is sufficient to allow optimal targeting of NG2 to retraction fibers, but together they promote efficient localization of the proteoglycan to these sites. This pattern of NG2 sorting seems to be necessary for optimal retraction fiber formation, as cells expressing poorly targeted NG2 mutants are noticeably deficient in their ability to extend retraction fibers. Furthermore, retraction fiber formation correlates strongly with the tendency of cells to assume a polarized morphology with NG2-positive retraction fibers at one pole of the cell and actin-rich lamellipodia at the other. This polarization can be triggered either through engagement of NG2 by the substratum or by exposure to lysophosphatidic acid, a potent activator of the rho GTPase. These results suggest a possible role for NG2 in regulating rho-dependent mechanisms in the trailing processes of motile cells.

scholarly journals Cdc42 regulates neutrophil migration via crosstalk between WASp, CD11b, and microtubules

Blood ◽  
2012 ◽  
Vol 120 (17) ◽  
pp. 3563-3574 ◽  
Author(s):  
Sachin Kumar ◽  
Juying Xu ◽  
Charles Perkins ◽  
Fukun Guo ◽  
Scott Snapper ◽  
...  
Keyword(s):  
Rho Gtpase ◽  
Neutrophil Migration ◽  
Cell Polarization ◽  
Membrane Domains ◽  
Long Distance ◽  
Cellular Defense ◽  
Persistent Cell ◽  
Proper Balance ◽  
Detergent Resistant Membrane ◽  
Standing Question

Abstract Chemotaxis promotes neutrophil participation in cellular defense by enabling neutrophil migration to infected tissue and is controlled by persistent cell polarization. One long-standing question of neutrophil polarity has been how the pseudopod and the uropod are coordinated. In our previous report, we suggested that Rho GTPase Cdc42 controls neutrophil polarity through CD11b signaling at the uropod, albeit through an unknown mechanism. Here, we show that Cdc42 controls polarity, unexpectedly, via its effector WASp. Cdc42 controls WASp activation and its distant localization to the uropod. At the uropod, WASp regulates the reorganization of CD11b integrin into detergent resistant membrane domains; in turn, CD11b recruits the microtubule end binding protein EB1 to capture and stabilize microtubules at the uropod. This organization is necessary to maintain neutrophil polarity during migration and is critical for neutrophil emigration into inflamed lungs. These results suggest unrecognized mechanism of neutrophil polarity in which WASp mediates long-distance control of the uropod by Cdc42 to maintain a proper balance between the pseudopod and the uropod. Our study reveals a new function for WASp in the control of neutrophil polarity via crosstalk between CD11b and microtubules.

A mechanochemical model for rho GTPase mediated cell polarization

2020 ◽  
Vol 504 ◽  
pp. 110386 ◽  
Author(s):  
Kai H. Kopfer ◽  
Willi Jäger ◽  
Franziska Matthäus
Keyword(s):  
Rho Gtpase ◽  
Cell Polarization ◽  
Mechanochemical Model

Cell motility: can Rho GTPases and microtubules point the way?

2001 ◽  
Vol 114 (21) ◽  
pp. 3795-3803 ◽  
Author(s):  
Torsten Wittmann ◽  
Clare M. Waterman-Storer
Keyword(s):  
Actin Cytoskeleton ◽  
Cell Motility ◽  
Rho Gtpases ◽  
Molecular Mechanisms ◽  
Rho Gtpase ◽  
Cell Types ◽  
Small Gtpases ◽  
Cell Polarization ◽  
Microtubule Cytoskeleton ◽  
Filament Bundles

Migrating cells display a characteristic polarization of the actin cytoskeleton. Actin filaments polymerise in the protruding front of the cell whereas actin filament bundles contract in the cell body, which results in retraction of the cell’s rear. The dynamic organization of the actin cytoskeleton provides the force for cell motility and is regulated by small GTPases of the Rho family, in particular Rac1, RhoA and Cdc42. Although the microtubule cytoskeleton is also polarized in a migrating cell, and microtubules are essential for the directed migration of many cell types, their role in cell motility is not well understood at a molecular level. Here, we discuss the potential molecular mechanisms for interplay of microtubules, actin and Rho GTPase signalling in cell polarization and motility. Recent evidence suggests that microtubules locally modulate the activity of Rho GTPases and, conversely, Rho GTPases might be responsible for the initial polarization of the microtubule cytoskeleton. Thus, microtubules might be part of a positive feedback mechanism that maintains the stable polarization of a directionally migrating cell.

Role of Cdc42 dynamics in the control of fission yeast cell polarization

2013 ◽  
Vol 41 (6) ◽  
pp. 1745-1749 ◽  
Author(s):  
Maitreyi Das ◽  
Fulvia Verde
Keyword(s):  
Cell Fate ◽  
Rho Gtpase ◽  
Cellular Level ◽  
Cell Polarization ◽  
Cell Fate Determination ◽  
Cell Morphogenesis ◽  
Oscillatory Dynamics ◽  
Cellular Processes ◽  
Polarized Cell Growth

Cell polarization is fundamental to many cellular processes, including cell differentiation, cell motility and cell fate determination. A key regulatory enzyme in the control of cell morphogenesis is the conserved Rho GTPase Cdc42, which breaks symmetry via self-amplifying positive-feedback mechanisms. Additional mechanisms of control, including competition between different sites of polarized cell growth and time-delayed negative feedback, define a cellular-level system that promotes Cdc42 oscillatory dynamics and modulates activated Cdc42 intracellular distribution.

Rho-GTPase-regulated vesicle trafficking in plant cell polarity

2014 ◽  
Vol 42 (1) ◽  
pp. 212-218 ◽  
Author(s):  
Xu Chen ◽  
Jiří Friml
Keyword(s):  
Cell Polarity ◽  
Plant Cell ◽  
Rho Gtpase ◽  
Vesicle Trafficking ◽  
Large Family ◽  
Small Gtpases ◽  
Cell Polarization ◽  
Cellular Mechanisms ◽  
Pavement Cells ◽  
Cytoskeleton Organization

ROPs (Rho of plants) belong to a large family of plant-specific Rho-like small GTPases that function as essential molecular switches to control diverse cellular processes including cytoskeleton organization, cell polarization, cytokinesis, cell differentiation and vesicle trafficking. Although the machineries of vesicle trafficking and cell polarity in plants have been individually well addressed, how ROPs co-ordinate those processes is still largely unclear. Recent progress has been made towards an understanding of the co-ordination of ROP signalling and trafficking of PIN (PINFORMED) transporters for the plant hormone auxin in both root and leaf pavement cells. PIN transporters constantly shuttle between the endosomal compartments and the polar plasma membrane domains, therefore the modulation of PIN-dependent auxin transport between cells is a main developmental output of ROP-regulated vesicle trafficking. The present review focuses on these cellular mechanisms, especially the integration of ROP-based vesicle trafficking and plant cell polarity.

scholarly journals Turnover Regulation of the Rho GTPase Cdc42 by Heat Shock Protein Chaperones and the MAPK Pathway Scaffold Bem4

2021 ◽  
Author(s):  
Paul J Cullen ◽  
Beatriz Gonzalez
Keyword(s):  
Heat Shock ◽  
Cell Polarity ◽  
Rho Gtpases ◽  
Rho Gtpase ◽  
Mapk Pathway ◽  
Cell Types ◽  
Cell Polarization ◽  
Extrinsic Cues ◽  
Dependent Cell ◽  
Map Kinase Pathway

All cells maintain an axis of polarity that directs the orientation of growth. Cell polarity can be reorganized during development and in response to extrinsic cues to produce new cell types. Rho GTPases are central regulators of cell polarity and signal-dependent cell differentiation. We show here that one of the best understood Rho GTPases, the highly conserved yeast Cdc42p, is turned over by members of the Heat Shock family of Proteins (HSPs). The Hsp40p chaperone, Ydj1p, was required for turnover of Cdc42p by the NEDD4 E3 ubiquitin ligase, Rsp5p, in the proteosome. Cdc42p turnover was regulated by HSPs at high temperatures, and in aging cells where the protein formed aggregates, implicating HSPs in Rho GTPase quality control. We also show that Cdc42pQ61L, which mimics the active (GTP-bound) conformation of the protein, was turned over at elevated levels by Ydj1p and Rsp5p. A turnover-defective version of Cdc42pQ61L led to multibudding phenotypes, implicating Cdc42 turnover in singularity in cell polarization. Cdc42p turnover also impacted MAP kinase pathway specificity. A pathway-specific scaffold, Bem4p, stabilized Cdc42p levels, which biased Cdc42p function in one MAPK pathway over another. Turnover regulation of Rho GTPases by HSPs and scaffolds provides new dimensions to the regulation of cell polarity and signal-dependent morphogenesis.

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