The actomyosin cytoskeleton is responsible for most force-driven processes in cells and tissues. How it assembles into the necessary structures at the right time and place is an important question. Here, we focus on molecular mechanisms of actomyosin regulation recently elucidated in animal models, and highlight several common principles that emerge. The architecture of the actomyosin network - an important determinant of its function - results from actin polymerization, crosslinking and turnover, localized myosin activation, and contractility-driven self-organization. Spatiotemporal regulation is achieved by tissue-specific expression and subcellular localization of Rho GTPase regulators. Subcellular anchor points of actomyosin structures control the outcome of their contraction, and molecular feedback mechanisms dictate whether they are transient, cyclic, or persistent.
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http://dx.doi.org/10.1016/j.tcb.2018.09.006 | DOI Listing |
J Virol
January 2025
Microbiology and Immunology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA.
Measles virus (MeV) is a highly contagious respiratory virus transmitted via aerosols. To understand how MeV exits the airways of an infected host, we use unpassaged primary cultures of human airway epithelial cells (HAE). MeV typically remains cell-associated in HAE and forms foci of infection, termed infectious centers, by directly spreading cell-to-cell.
View Article and Find Full Text PDFBiol Open
January 2025
Department of Pulmonary Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
Epithelial cell cohesion and barrier function critically depend on α-catenin, an actin-binding protein and essential constituent of cadherin-catenin-based adherens junctions. α-catenin undergoes actomyosin force-dependent unfolding of both actin-binding and middle domains to strongly engage actin filaments and its various effectors; this mechanosensitivity is critical for adherens junction function. We previously showed that α-catenin is highly phosphorylated in an unstructured region that links the mechanosensitive middle and actin-binding domains (known as the P-linker region), but the cellular processes that promote α-catenin phosphorylation have remained elusive.
View Article and Find Full Text PDFCommun Biol
January 2025
Freie Universität Berlin, Institute for Chemistry and Biochemistry, Thielallee 63, 14195, Berlin, Germany.
Blood vessel formation relies on biochemical and mechanical signals, particularly during sprouting angiogenesis when endothelial tip cells (TCs) guide sprouting through filopodia formation. The contribution of BMP receptors in defining tip-cell characteristics is poorly understood. Our study combines genetic, biochemical, and molecular methods together with 3D traction force microscopy, which reveals an essential role of BMPR2 for actin-driven filopodia formation and mechanical properties of endothelial cells (ECs).
View Article and Find Full Text PDFTropomyosin is an actin-binding protein that plays roles ranging from regulating muscle contraction to controlling cytokinesis and cell migration. The simple nematode provides a useful model for studying the core functions of tropomyosin in an animal, having a relatively simple anatomy, and a single tropomyosin gene, , that produces seven isoforms. Three higher molecular weight isoforms (LEV-11A, D, O) regulate contraction of body wall and other muscles, but comparatively less is known of the functions of four lower molecular weight isoforms (LEV-11C, E, T, U).
View Article and Find Full Text PDFDev Biol
December 2024
Department of Dermatology, Duke University Medical Center, Durham, NC, 27710, USA; Department of Cell Biology, Duke University Medical Center, Durham, NC, 27710, USA. Electronic address:
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