Nuclear myosin I regulates cell membrane tension

• DOI: 10.1038/srep30864
• Publication Date: 2016-08-02T09:28:32Z
• Authors: Tomáš Venit; Alžběta Kalendová; Martin Petr; Rastislav Dzijak; Lukáš Pastorek; Jana Rohožková; Jakub Malohlava; Pavel Hozák
• Keywords: Cell Nucleus; Mice, Knockout; 0303 health sciences; Cell Membrane; Fibroblasts; Article; Exocytosis; Actin Cytoskeleton; Mice; Myosin Type I; 03 medical and health sciences; Cell Movement; Animals; Humans; Cell Shape; Cells, Cultured; HeLa Cells; Skin

AbstractPlasma membrane tension is an important feature that determines the cell shape and influences processes such as cell motility, spreading, endocytosis and exocytosis. Unconventional class 1 myosins are potent regulators of plasma membrane tension because they physically link the plasma membrane with adjacent cytoskeleton. We identified nuclear myosin 1 (NM1) - a putative nuclear isoform of myosin 1c (Myo1c) - as a new player in the field. Although having specific nuclear functions, NM1 localizes predominantly to the plasma membrane. Deletion of NM1 causes more than a 50% increase in the elasticity of the plasma membrane around the actin cytoskeleton as measured by atomic force microscopy. This higher elasticity of NM1 knock-out cells leads to 25% higher resistance to short-term hypotonic environment and rapid cell swelling. In contrast, overexpression of NM1 in wild type cells leads to an additional 30% reduction of their survival. We have shown that NM1 has a direct functional role in the cytoplasm as a dynamic linker between the cell membrane and the underlying cytoskeleton, regulating the degree of effective plasma membrane tension.