Caldesmon controls stress fiber force-balance through dynamic cross-linking of myosin II and actin-tropomyosin filaments

Shrikant B. Kokate, Katarzyna Ciuba, Vivien D. Tran, Reena Kumari, Sari Tojkander, Ulrike Engel, Konstantin Kogan, Sanjay Kumar, Pekka Lappalainen

    Research output: Contribution to journalArticleScientificpeer-review

    10 Citations (Scopus)
    13 Downloads (Pure)

    Abstract

    Contractile actomyosin bundles are key force-producing and mechanosensing elements in muscle and non-muscle tissues. Whereas the organization of muscle myofibrils and mechanism regulating their contractility are relatively well-established, the principles by which myosin-II activity and force-balance are regulated in non-muscle cells have remained elusive. We show that Caldesmon, an important component of smooth muscle and non-muscle cell actomyosin bundles, is an elongated protein that functions as a dynamic cross-linker between myosin-II and tropomyosin-actin filaments. Depletion of Caldesmon results in aberrant lateral movement of myosin-II filaments along actin bundles, leading to irregular myosin distribution within stress fibers. This manifests as defects in stress fiber network organization and contractility, and accompanied problems in cell morphogenesis, migration, invasion, and mechanosensing. These results identify Caldesmon as critical factor that ensures regular myosin-II spacing within non-muscle cell actomyosin bundles, and reveal how stress fiber networks are controlled through dynamic cross-linking of tropomyosin-actin and myosin filaments.

    Original languageEnglish
    Article number6032
    Number of pages20
    JournalNature Communications
    Volume13
    DOIs
    Publication statusPublished - Oct 2022
    Publication typeA1 Journal article-refereed

    Publication forum classification

    • Publication forum level 3

    ASJC Scopus subject areas

    • General Chemistry
    • General Biochemistry,Genetics and Molecular Biology
    • General
    • General Physics and Astronomy

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