The SCAR/WAVE complex is necessary for proper regulation of traction stresses during amoeboid motility

Bastounis, Effie; Meili, Ruedi; Alonso-Latorre, Baldomero; Álamo, Juan C. del; Lasheras, Juan C.; Firtel, Richard A.

doi:10.1091/mbc.e11-03-0278

Cited by 25 publications

(36 citation statements)

References 44 publications

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“…The Rap1 (directed against amino acids 169-182 of Dictyostelium Rap1) and Pia antibodies (directed against amino acids 138-159 of Dictyostelium Pianissimo) were custom-made by ProSci Incorporated (Poway, CA, USA). Antibodies against PKB and PKBR1, and Lifeact-GFP, GFP-MyoII and PHcrac-GFP constructs were gifts from Rick Firtel (University of California-San Diego, La Jolla, CA) and have been previously described (Bastounis et al, 2011;Jeon et al, 2007a;Meili et al, 1999;Sasaki et al, 2004). The cAR1 antibody was a generous gift from Peter Devreotes (Johns Hopkins, Baltimore, MD) and is described elsewhere (Hereld et al, 1994).…”

Section: Methodsmentioning

confidence: 99%

Protein kinase A regulates the Ras, Rap1 and TORC2 pathways in response to the chemoattractant cAMP in Dictyostelium

Scavello

Petlick

Ramesh

et al. 2017

Journal of Cell Science

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Efficient directed migration requires tight regulation of chemoattractant signal transduction pathways in both space and time, but the mechanisms involved in such regulation are not well understood. Here, we investigated the role of protein kinase A (PKA) in controlling signaling of the chemoattractant cAMP in Dictyostelium discoideum. We found that cells lacking PKA display severe chemotaxis defects, including impaired directional sensing. Although PKA is an important regulator of developmental gene expression, including the cAMP receptor cAR1, our studies using exogenously expressed cAR1 in cells lacking PKA, cells lacking adenylyl cyclase A (ACA) and cells treated with the PKA-selective pharmacological inhibitor H89, suggest that PKA controls chemoattractant signal transduction, in part, through the regulation of RasG, Rap1 and TORC2. As these pathways control the ACAmediated production of intracellular cAMP, they lie upstream of PKA in this chemoattractant signaling network. Consequently, we propose that the PKA-mediated regulation of the upstream RasG, Rap1 and TORC2 signaling pathways is part of a negative feedback mechanism controlling chemoattractant signal transduction during Dictyostelium chemotaxis.

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Section: Methodsmentioning

confidence: 99%

Protein kinase A regulates the Ras, Rap1 and TORC2 pathways in response to the chemoattractant cAMP in Dictyostelium

Scavello

Petlick

Ramesh

et al. 2017

Journal of Cell Science

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“…To move on surfaces, amoeboid cells implement a motility cycle (2)(3)(4), enabled by the coordination of adhesion turnover, Factin polymerization and crosslinking, and motor protein contractility (5). Unlike slower moving cells that form stable integrin-mediated focal adhesions, amoeboid cells such as neutrophils and Dictyostelium cells rely on transient, diffuse adhesions (2).…”

Section: Introductionmentioning

confidence: 99%

Three-Dimensional Balance of Cortical Tension and Axial Contractility Enables Fast Amoeboid Migration

Álvarez-González

Meili

Bastounis

et al. 2015

Biophysical Journal

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Fast amoeboid migration requires cells to apply mechanical forces on their surroundings via transient adhesions. However, the role these forces play in controlling cell migration speed remains largely unknown. We used three-dimensional force microscopy to measure the three-dimensional forces exerted by chemotaxing Dictyostelium cells, and examined wild-type cells as well as mutants with defects in contractility, internal F-actin crosslinking, and cortical integrity. We showed that cells pull on their substrate adhesions using two distinct, yet interconnected mechanisms: axial actomyosin contractility and cortical tension. We found that the migration speed increases when axial contractility overcomes cortical tension to produce the cell shape changes needed for locomotion. We demonstrated that the three-dimensional pulling forces generated by both mechanisms are internally balanced by an increase in cytoplasmic pressure that allows cells to push on their substrate without adhering to it, and which may be relevant for amoeboid migration in complex three-dimensional environments.

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“…For each of the stages, it shows the average traction forces exerted by this cell. To demonstrate the existence of a well-defined motility cycle, the degree of periodicity of the individual records for the length and the strain energy can be determined by fitting the data in a nonlinear, least squares sense with a sine wave and then calculating their cross-correlation [76]. …”

Section: Motility Cycle Definition and Phase Identificationmentioning

confidence: 99%

“…On the other hand, cells lacking the protein PIR121 lose the periodicity in the execution of the motility cycle, while cells lacking the protein SCAR can perform the motility cycle periodically. For scrA - cells the degree of periodicity (DOP) of the cell length evolution, defined as the correlation between the cell length and the best-fitting sine wave, it is similar to that of wild-type cells; whereas that for pirA - cells, is significantly lower [76]. The time evolution of the cell length for pirA - cells is not periodic and exhibits more random and uncoordinated oscillations [76].…”

Section: Motility Cycle Definition and Phase Identificationmentioning

confidence: 99%

“…For scrA - cells the degree of periodicity (DOP) of the cell length evolution, defined as the correlation between the cell length and the best-fitting sine wave, it is similar to that of wild-type cells; whereas that for pirA - cells, is significantly lower [76]. The time evolution of the cell length for pirA - cells is not periodic and exhibits more random and uncoordinated oscillations [76]. Therefore, we concluded that the protein PIR121 of the SCAR/WAVE complex is necessary for the periodic execution of the motility cycle.…”

Section: Motility Cycle Definition and Phase Identificationmentioning

confidence: 99%

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Cytoskeletal Mechanics Regulating Amoeboid Cell Locomotion

Álvarez-González

Bastounis

Meili

et al. 2014

Applied Mechanics Reviews

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Migrating cells exert traction forces when moving. Amoeboid cell migration is a common type of cell migration that appears in many physiological and pathological processes and is performed by a wide variety of cell types. Understanding the coupling of the biochemistry and mechanics underlying the process of migration has the potential to guide the development of pharmacological treatment or genetic manipulations to treat a wide range of diseases. The measurement of the spatiotemporal evolution of the traction forces that produce the movement is an important aspect for the characterization of the locomotion mechanics. There are several methods to calculate the traction forces exerted by the cells. Currently the most commonly used ones are traction force microscopy methods based on the measurement of the deformation induced by the cells on elastic substrate on which they are moving. Amoeboid cells migrate by implementing a motility cycle based on the sequential repetition of four phases. In this paper we review the role that specific cytoskeletal components play in the regulation of the cell migration mechanics. We investigate the role of specific cytoskeletal components regarding the ability of the cells to perform the motility cycle effectively and the generation of traction forces. The actin nucleation in the leading edge of the cell, carried by the ARP2/3 complex activated through the SCAR/WAVE complex, has shown to be fundamental to the execution of the cyclic movement and to the generation of the traction forces. The protein PIR121, a member of the SCAR/WAVE complex, is essential to the proper regulation of the periodic movement and the protein SCAR, also included in the SCAR/WAVE complex, is necessary for the generation of the traction forces during migration. The protein Myosin II, an important F-actin cross-linker and motor protein, is essential to cytoskeletal contractility and to the generation and proper organization of the traction forces during migration.

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The SCAR/WAVE complex is necessary for proper regulation of traction stresses during amoeboid motility

Abstract: A combination of traction force and F-actin measurements shows that cells lacking either of the SCAR/WAVE complex proteins SCAR and PIR121 exhibit an altered cell motility cycle and spatiotemporal distribution of tractions stresses, which correlate in magnitude with F-actin levels.

Cited by 25 publications

References 44 publications

Protein kinase A regulates the Ras, Rap1 and TORC2 pathways in response to the chemoattractant cAMP in Dictyostelium

Protein kinase A regulates the Ras, Rap1 and TORC2 pathways in response to the chemoattractant cAMP in Dictyostelium

Three-Dimensional Balance of Cortical Tension and Axial Contractility Enables Fast Amoeboid Migration

Cytoskeletal Mechanics Regulating Amoeboid Cell Locomotion

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