Bundling of actin filaments by alpha-actinin depends on its molecular length.

Meyer, R.; Aebi, Ueli

doi:10.1083/jcb.110.6.2013

Cited by 261 publications

(229 citation statements)

References 35 publications

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“…Also, under the conditions used, the actin was saturated by a -actinin when the molar ratio for a -actinin/G-actin in the incubation mixture was 0.25-0.30. These results agree with the data reported in the literature (15,16).…”

Section: Resultssupporting

confidence: 83%

“…Sometimes cross-bridges connecting actin laments and a -actinin molecules can be seen on the micrographs (Fig. 3C) (16). Actin bundles obtained in the presence of both ABPs were of intermediate width (Fig.…”

Section: Resultsmentioning

confidence: 95%

“…2), and binding of calponin does not induce signi cant dissociation of a -actinin from either bundled or single actin laments (Fig.1A, B). Interaction of a -actinin with actin leads to formation of ladderlike structures (16), in which widely separated actin laments are cross-linked by a -actinin-forming rungs of the ladder (Fig. 4A).…”

Section: Discussionmentioning

confidence: 99%

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Simultaneous Interaction of Actin With a‐Actinin and Calponin

Panasenko

Gusev

2000

IUBMB Life

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SummaryInteraction of calponin and ®-actinin with actin was analyzed by means of cosedimentation and electron microscopy. G-actin was polymerized in the presence of calponin, ®-actinin, or both of these actin-binding proteins (ABPs). The single and bundled actin laments were separated, and the stoichiometry of ABPs and actin in both types of laments was determined. Binding of calponin to the single or bundled actin laments was not dependent on the presence of ®-actinin and did not displace ®-actinin from actin. In the presence of calponin, however, less ®-actinin was bound to the bundled actin laments, and the binding of ®-actinin was accompanied by a partial decrease in the calponin/actin stoichiometry in the bundles of actin laments. Calponin had no in uence on the binding of ®-actinin to the single actin laments. The structure of actin bundles formed in the presence of the two ABPs differed from that formed in the presence of either one singly. We conclude that calponin and ®-actinin can coexist on actin and that nearly each actin monomer can bind one of these ABPs. IUBMB Life, 49: 277 -282, 2000

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Section: Resultssupporting

confidence: 83%

Section: Resultsmentioning

confidence: 95%

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Simultaneous Interaction of Actin With a‐Actinin and Calponin

Panasenko

Gusev

2000

IUBMB Life

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“…Indeed, it appears that these two proteins typically mediate the formation of distinct types of actin filament bundles. In particular, fimbrins, with their two closely spaced actin-binding domains, appear to form very tightly packed bundles, whereas ␣-actinins, whose actinbinding domains are at the opposite ends of the long homodimers, appear to form looser bundles (Meyer and Aebi, 1990;Drenckhahn et al, 1991;Alberts et al, 1994;Hö fer and Drenckhahn, 1996;Djinovic-Carugo et al, 1999;Bartles, 2000). In contrast to the bundles formed by typical ␣-actinins, those formed by the putative Ain1p homodimers would presumably be more tightly packed and hence more similar to the bundles formed by fimbrins.…”

Section: Evolution and Functional Relationships Of Actinbundling Protmentioning

confidence: 99%

Roles of a Fimbrin and an α-Actinin-like Protein in Fission Yeast Cell Polarization and Cytokinesis

Bähler

Pringle

2001

MBoC

144

183

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Eukaryotic cells contain many actin-interacting proteins, including the ␣-actinins and the fimbrins, both of which have actin cross-linking activity in vitro. We report here the identification and characterization of both an ␣-actinin-like protein (Ain1p) and a fimbrin (Fim1p) in the fission yeast Schizosaccharomyces pombe. Ain1p localizes to the actomyosin-containing medial ring in an F-actindependent manner, and the Ain1p ring contracts during cytokinesis. ain1 deletion cells have no obvious defects under normal growth conditions but display severe cytokinesis defects, associated with defects in medial-ring and septum formation, under certain stress conditions. Overexpression of Ain1p also causes cytokinesis defects, and the ain1 deletion shows synthetic effects with other mutations known to affect medial-ring positioning and/or organization. Fim1p localizes both to the cortical actin patches and to the medial ring in an F-actin-dependent manner, and several lines of evidence suggest that Fim1p is involved in polarization of the actin cytoskeleton. Although a fim1 deletion strain has no detectable defect in cytokinesis, overexpression of Fim1p causes a lethal cytokinesis defect associated with a failure to form the medial ring and concentrate actin patches at the cell middle. Moreover, an ain1 fim1 double mutant has a synthetical-lethal defect in medial-ring assembly and cell division. Thus, Ain1p and Fim1p appear to have an overlapping and essential function in fission yeast cytokinesis. In addition, protein-localization and mutant-phenotype data suggest that Fim1p, but not Ain1p, plays important roles in mating and in spore formation. INTRODUCTIONThe actin cytoskeleton is involved in many processes in eukaryotic cells, including the polarization of cell growth and cytokinesis. These many roles involve the interaction of actin with a wide variety of actin-binding proteins, including proteins that can cross-link actin filaments into isotropic gels or bundles. Many actin cross-linking proteins have been purified and studied in vitro, but their functions in vivo remain poorly understood (reviewed by Matsudaira, 1994a;Otto, 1994;Furukawa and Fechheimer, 1997;Ayscough, 1998;Bartles, 2000).Among the actin cross-linking proteins, one of the best characterized is ␣-actinin. It was first isolated from rabbit skeletal muscle (Ebashi and Ebashi, 1965) and has subsequently been identified in both muscle and nonmuscle cells from a variety of animals, in Acanthamoeba, and in Dictyostelium (Furukawa and Fechheimer, 1997;Critchley and Flood, 1999). ␣-Actinin forms a homodimer of antiparallel polypeptides (Critchley and Flood, 1999;Djinovic-Carugo et al., 1999), with the actin-binding domain of each polypeptide close to the NH 2 terminus, followed by four spectrin-like repeats and two COOH-terminal EF-hand motifs. Skeletal muscle isoforms are localized to the Z-disk and are not regulated by Ca 2ϩ , whereas nonmuscle isoforms are localized to focal adhesions, stress fibers, and other structures and are typically regulated by C...

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“…Crosslinker lengths vary considerably. For example, a-actinin, which binds actin filaments in a parallel or antiparallel orientation, is~35 nm in length (8), whereas filamin is 160-190 nm long (9). To actively contract the actin network, myosin II monomers (a functional monomer includes two heavy chains, two essential light chains, and two regulatory light chains) assemble into functional bipolar filaments that are~300 nm in length (10).…”

mentioning

confidence: 99%

Mechanochemical Signaling Directs Cell-Shape Change

Schiffhauer

Robinson

2017

Biophysical Journal

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For specialized cell function, as well as active cell behaviors such as division, migration, and tissue development, cells must undergo dynamic changes in shape. To complete these processes, cells integrate chemical and mechanical signals to direct force production. This mechanochemical integration allows for the rapid production and adaptation of leading-edge machinery in migrating cells, the invasion of one cell into another during cell-cell fusion, and the force-feedback loops that ensure robust cytokinesis. A quantitative understanding of cell mechanics coupled with protein dynamics has allowed us to account for furrow ingression during cytokinesis, a model cell-shape-change process. At the core of cell-shape changes is the ability of the cell's machinery to sense mechanical forces and tune the force-generating machinery as needed. Force-sensitive cytoskeletal proteins, including myosin II motors and actin cross-linkers such as a-actinin and filamin, accumulate in response to internally generated and externally imposed mechanical stresses, endowing the cell with the ability to discern and respond to mechanical cues. The physical theory behind how these proteins display mechanosensitive accumulation has allowed us to predict paralogspecific behaviors of different cross-linking proteins and identify a zone of optimal actin-binding affinity that allows for mechanical stress-induced protein accumulation. These molecular mechanisms coupled with the mechanical feedback systems ensure robust shape changes, but if they go awry, they are poised to promote disease states such as cancer cell metastasis and loss of tissue integrity.The concept ''form begets function begets form'' provides an excellent foundation for understanding the behavior of biological systems. Even specialized cells, the smallest unit of complex living systems, perform all of the necessary functions of an organism by assuming distinct shapes, mechanical properties, and physical behaviors. Different cell types use a common set of cytoskeletal elements to provide precise physical support for their distinct functions. For example, red blood cells and neurons have very different shapes that allow them to perform their specific roles. However, they both utilize alternating patterns of actin and spectrin to form cortices with appropriate viscous and elastic properties, albeit in different structural arrangements. Perturbations to this structural network cause a breakdown in the mechanical properties, or the form, of these cells, which inhibits cell function (1,2).Fascinatingly, the physical properties of cells are both determined and acted upon by the cytoskeletal apparatus. Cells are capable of modifying their own physical properties and driving changes in cell shape in response to internal and external chemical and mechanical stimuli. These modifications occur through the remodeling of the cell cortex, the network of cytoskeletal proteins directly under the plasma membrane. Much progress has been made recently in deciphering how chemical signa...

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Bundling of actin filaments by alpha-actinin depends on its molecular length.

Cited by 261 publications

References 35 publications

Simultaneous Interaction of Actin With a‐Actinin and Calponin

Simultaneous Interaction of Actin With a‐Actinin and Calponin

Roles of a Fimbrin and an α-Actinin-like Protein in Fission Yeast Cell Polarization and Cytokinesis

Mechanochemical Signaling Directs Cell-Shape Change

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