scholarly journals Sla1p Is a Functionally Modular Component of the Yeast Cortical Actin Cytoskeleton Required for Correct Localization of Both Rho1p-GTPase and Sla2p, a Protein with Talin Homology

1999 ◽  
Vol 10 (4) ◽  
pp. 1061-1075 ◽  
Author(s):  
Kathryn R. Ayscough ◽  
Jennifer J. Eby ◽  
Thomas Lila ◽  
Hilary Dewar ◽  
Keith G. Kozminski ◽  
...  
Keyword(s):  
Cell Walls ◽  
Binding Protein ◽  
Actin Binding ◽  
Actin Assembly ◽  
Cortical Actin ◽  
Actin Binding Protein ◽  
Actin Patch ◽  
Mutant Forms ◽  
Modular Component ◽  
Terminal Repeat Region

SLA1 was identified previously in budding yeast in a genetic screen for mutations that caused a requirement for the actin-binding protein Abp1p and was shown to be required for normal cortical actin patch structure and organization. Here, we show that Sla1p, like Abp1p, localizes to cortical actin patches. Furthermore, Sla1p is required for the correct localization of Sla2p, an actin-binding protein with homology to talin implicated in endocytosis, and the Rho1p-GTPase, which is associated with the cell wall biosynthesis enzyme β-1,3-glucan synthase. Mislocalization of Rho1p in sla1 null cells is consistent with our observation that these cells possess aberrantly thick cell walls.  Expression of mutant forms of Sla1p in which specific domains were deleted showed that the phenotypes associated with the full deletion are functionally separable. In particular, a region of Sla1p encompassing the third SH3 domain is important for growth at high temperatures, for the organization of cortical actin patches, and for nucleated actin assembly in a permeabilized yeast cell assay. The apparent redundancy between Sla1p and Abp1p resides in the C-terminal repeat region of Sla1p. A homologue of SLA1 was identified inSchizosaccharomyces pombe. Despite relatively low overall sequence homology, this gene was able to rescue the temperature sensitivity associated with a deletion of SLA1 inSaccharomyces cerevisiae.

Cdc42/Rac1-dependent activation of the p21-activated kinase (PAK) regulates human platelet lamellipodia spreading: implication of the cortical-actin binding protein cortactin

Blood ◽  
2002 ◽  
Vol 100 (13) ◽  
pp. 4462-4469 ◽  
Author(s):  
Catherine Vidal ◽  
Blandine Geny ◽  
Josiane Melle ◽  
Martine Jandrot-Perrus ◽  
Michaëla Fontenay-Roupie
Keyword(s):  
Shape Change ◽  
Binding Protein ◽  
Actin Binding ◽  
Cortical Actin ◽  
Toxin B ◽  
Actin Reorganization ◽  
Actin Binding Protein ◽  
Direct Binding ◽  
P21 Activated Kinase ◽  
The Relationship

Platelet activation by thrombin or thrombin receptor-activating peptide (TRAP) results in extensive actin reorganization that leads to filopodia emission and lamellae spreading concomitantly with activation of the Rho family small G proteins, Cdc42 and Rac1. Evidence has been provided that direct binding of Cdc42-guanosine triphosphate (GTP) and Rac1-GTP to the N-terminal regulatory domain of the p21-activated kinase (PAK) stimulates PAK activation and actin reorganization. In the present study, we have investigated the relationship between shape change and PAK activation. We show that thrombin, TRAP, or monoclonal antibody (MoAb) anti-FcγRIIA IV.3 induces an activation of Cdc42 and Rac1. The GpVI ligand, convulxin (CVX), that forces platelets to lamellae spreading efficiently activates Rac1. Thrombin, TRAP, MoAb IV.3, and CVX stimulate autophosphorylation and kinase activity of PAK. Inhibition of Cdc42 and Rac1 with clostridial toxin B inhibits PAK activation and lamellae spreading. The cortical-actin binding protein, p80/85 cortactin, is constitutively associated with PAK in resting platelets and dissociates from PAK after thrombin stimulation. Inhibition of PAK autophosphorylation by toxin B prevents the dissociation of cortactin. These results suggest that Cdc42/Rac1-dependent activation of PAK may trigger early platelet shape change, at least in part through the regulation of cortactin binding to PAK.

scholarly journals The actin binding protein α-adducin modulates desmosomal turnover and plasticity

2019 ◽  
Author(s):  
Matthias Hiermaier ◽  
Felix Kliewe ◽  
Camilla Schinner ◽  
Chiara Stüdle ◽  
I. Piotr Maly ◽  
...  
Keyword(s):  
Binding Protein ◽  
Intercellular Adhesion ◽  
Cyclic Stretch ◽  
Actin Binding ◽  
Mechanical Stimuli ◽  
Cortical Actin ◽  
Adhesive Properties ◽  
Actin Binding Protein ◽  
Tissue Integrity ◽  
Desmoglein 3

Intercellular adhesion is essential for tissue integrity and homeostasis. Desmosomes are especially abundant in the epidermis and the myocardium, tissues, which are under constantly changing mechanical stresses. Yet, it is largely unclear whether desmosomal adhesion can be rapidly adapted to changing demands and the mechanisms underlying desmosome turnover are only partially understood. We here show that loss of the actin-binding protein α-adducin prevented the ability of cultured keratinocytes or murine epidermis to withstand mechanical stress paralleled with reduced desmosome number. This effect was not caused by decreased levels or impaired adhesive properties of desmosomal molecules but rather by altered desmosome turnover. Mechanistically, reduced cortical actin density in α-adducin knockout keratinocytes resulted in increased mobility of the desmosomal adhesion molecule desmoglein 3 (Dsg3) and impaired interactions with E-cadherin, a crucial step in desmosome formation. Accordingly, loss of α-adducin prevented increased membrane localization of Dsg3 in response to cyclic stretch or shear stress. Our data demonstrate plasticity of desmosomal molecules in response to mechanical stimuli and unravel a mechanism how the actin cytoskeleton indirectly shapes intercellular adhesion by restricting the mobility of desmosomal molecules.

scholarly journals Yeast actin-binding proteins: evidence for a role in morphogenesis.

1988 ◽  
Vol 107 (6) ◽  
pp. 2551-2561 ◽  
Author(s):  
D G Drubin ◽  
K G Miller ◽  
D Botstein
Keyword(s):  
Yeast Cell ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Actin Filaments ◽  
Binding Proteins ◽  
Binding Protein ◽  
Actin Binding ◽  
Cortical Actin ◽  
Actin Binding Protein

Three yeast actin-binding proteins were identified using yeast actin filaments as an affinity matrix. One protein appears to be a yeast myosin heavy chain; it is dissociated from actin filaments by ATP, it is similar in size (200 kD) to other myosins, and antibodies directed against Dictyostelium myosin heavy chain bind to it. Immunofluorescence experiments show that a second actin-binding protein (67 kD) colocalizes in vivo with both cytoplasmic actin cables and cortical actin patches, the only identifiable actin structures in yeast. The cortical actin patches are concentrated at growing surfaces of the yeast cell where they might play a role in membrane and cell wall insertion, and the third actin-binding protein (85 kD) is only detected in association with these structures. This 85-kD protein is therefore a candidate for a determinant of growth sites. The in vivo role of this protein was tested by overproduction; this overproduction causes a reorganization of the actin cytoskeleton which in turn dramatically affects the budding pattern and spatial growth organization of the yeast cell.

scholarly journals Kettin, the large actin‐binding protein with multiple immunoglobulin domains, is essential for sarcomeric actin assembly and larval development in Caenorhabditis elegans

FEBS Journal ◽  
2019 ◽  
Vol 287 (4) ◽  
pp. 659-670 ◽  
Author(s):  
Kanako Ono ◽  
Zhaozhao Qin ◽  
Robert C. Johnsen ◽  
David L. Baillie ◽  
Shoichiro Ono
Keyword(s):  
Caenorhabditis Elegans ◽  
Larval Development ◽  
Binding Protein ◽  
Actin Binding ◽  
Actin Assembly ◽  
Actin Binding Protein

Cortical actin binding protein cortactin mediates ENaC activity via Arp2/3 complex

2011 ◽  
Vol 25 (8) ◽  
pp. 2688-2699 ◽  
Author(s):  
Daria V. Ilatovskaya ◽  
Tengis S. Pavlov ◽  
Vladislav Levchenko ◽  
Yuri A. Negulyaev ◽  
Alexander Staruschenko
Keyword(s):  
Binding Protein ◽  
Actin Binding ◽  
Cortical Actin ◽  
Actin Binding Protein

scholarly journals CLIC4 is regulated by RhoA-mDia2 signaling through Profilin-1 binding to modulate filopodium length

2018 ◽  
Author(s):  
Elisabetta Argenzio ◽  
Katarzyna M. Kedziora ◽  
Leila Nahidiazar ◽  
Tadamoto Isogai ◽  
Anastassis Perrakis ◽  
...  
Keyword(s):  
Actin Polymerization ◽  
Binding Protein ◽  
Feedback Mechanism ◽  
Actin Binding ◽  
Actin Assembly ◽  
Wild Type ◽  
Cortical Actin ◽  
Conserved Residues ◽  
Rhoa Activation ◽  
Necessary And Sufficient

AbstractCLIC4 is a cytosolic protein implicated in diverse actin-based processes, including integrin trafficking, cell adhesion and tubulogenesis. CLIC4 is rapidly recruited to the plasma membrane by G12/13-coupled receptor agonists and then partly co-localizes with β1 integrins. Receptor-mediated CLIC4 translocation depends on actin polymerization, but the mechanism and functional significance of CLIC4 trafficking are unknown. Here we show that RhoA activation by either LPA or EGF is necessary and sufficient for CLIC4 translocation, with a regulatory role for the RhoA effector mDia2, an inducer of actin polymerization. We find that CLIC4 directly interacts with the G-actin-binding protein Profilin-1 via conserved residues that are required for CLIC4 trafficking and lie in a concave surface. Consistently, silencing of Profilin-1 impaired CLIC4 trafficking induced by either LPA or EGF. CLIC4 knockdown promoted the formation of long integrin-dependent filopodia, a phenotype rescued by wild-type CLIC4 but not by trafficking-incompetent CLIC4(C35A). Our results establish CLIC4 as a Profilin-1-binding protein and suggest that CLIC4 translocation provides a feedback mechanism to modulate mDia2/Profilin-1-driven cortical actin assembly and membrane protrusion.

scholarly journals Characterization of Mayven, a Novel Actin-binding Protein Predominantly Expressed in Brain

1999 ◽  
Vol 10 (7) ◽  
pp. 2361-2375 ◽  
Author(s):  
Margaret Soltysik-Espanola ◽  
Rick A. Rogers ◽  
Shuxian Jiang ◽  
Tae-Aug Kim ◽  
Roger Gaedigk ◽  
...  
Keyword(s):  
Hippocampal Neurons ◽  
Binding Protein ◽  
Chromosome 8 ◽  
Actin Binding ◽  
Cortical Actin ◽  
Actin Binding Protein ◽  
C Terminus ◽  
Neuronal Processes ◽  
Microscopic Studies

The cytoskeleton plays an important role in neuronal morphogenesis. We have identified and characterized a novel actin-binding protein, termed Mayven, predominantly expressed in brain. Mayven contains a BTB (broad complex, tramtrack, bric-a-brac)/POZ (poxvirus, zinc finger) domain-like structure in the predicted N terminus and “kelch repeats” in the predicted C-terminal domain. Mayven shares 63% identity (77% similarity) with the Drosophila ring canal (“kelch”) protein. Somatic cell-hybrid analysis indicated that the human Mayven gene is located on chromosome 4q21.2, whereas the murine homolog gene is located on chromosome 8. The BTB/POZ domain of Mayven can self-dimerize in vitro, which might be important for its interaction with other BTB/POZ-containing proteins. Confocal microscopic studies of endogenous Mayven protein revealed a highly dynamic localization pattern of the protein. In U373-MG astrocytoma/glioblastoma cells, Mayven colocalized with actin filaments in stress fibers and in patchy cortical actin-rich regions of the cell margins. In primary rat hippocampal neurons, Mayven is highly expressed in the cell body and in neurite processes. Binding assays and far Western blotting analysis demonstrated association of Mayven with actin. This association is mediated through the “kelch repeats” within the C terminus of Mayven. Depolarization of primary hippocampal neurons with KCl enhanced the association of Mayven with actin. This increased association resulted in dynamic changes in Mayven distribution from uniform to punctate localization along neuronal processes. These results suggest that Mayven functions as an actin-binding protein that may be translocated along axonal processes and might be involved in the dynamic organization of the actin cytoskeleton in brain cells.

Clathrin Hub Expression Dissociates the Actin-Binding Protein Hip1R from Coated Pits and Disrupts Their Alignment with the Actin Cytoskeleton

Traffic ◽  
2001 ◽  
Vol 2 (11) ◽  
pp. 851-858 ◽  
Author(s):  
Elizabeth M. Bennett ◽  
Chih-Ying Chen ◽  
Asa E. Y. Engqvist-Goldstein ◽  
David G. Drubin ◽  
Frances M. Brodsky
Keyword(s):  
Actin Cytoskeleton ◽  
Binding Protein ◽  
Actin Binding ◽  
Coated Pits ◽  
Actin Binding Protein
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