Myosin II isoforms promote internalization of spatially distinct clathrin-independent endocytosis cargoes through modulation of cortical tension downstream of ROCK2

Mol Biol Cell. 2021 Feb 1;32(3):226-236. doi: 10.1091/mbc.E20-07-0480. Epub 2020 Dec 16.

Abstract

Although the actomyosin cytoskeleton has been implicated in clathrin-mediated endocytosis, a clear requirement for actomyosin in clathrin-independent endocytosis (CIE) has not been demonstrated. We discovered that the Rho-associated kinase ROCK2 is required for CIE of MHCI and CD59 through promotion of myosin II activity. Myosin IIA promoted internalization of MHCI and myosin IIB drove CD59 uptake in both HeLa and polarized Caco2 intestinal epithelial cells. In Caco2 cells, myosin IIA localized to the basal cortex and apical brush border and mediated MHCI internalization from the basolateral domain, while myosin IIB localized at the basal cortex and apical cell-cell junctions and promoted CD59 uptake from the apical membrane. Atomic force microscopy demonstrated that myosin IIB mediated apical epithelial tension in Caco2 cells. Thus, specific cargoes are internalized by ROCK2-mediated activation of myosin II isoforms to mediate spatial regulation of CIE, possibly by modulation of local cortical tension.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural

MeSH terms

  • Actin Cytoskeleton / metabolism
  • Actomyosin / metabolism
  • Adherens Junctions / physiology
  • CD59 Antigens / metabolism
  • Caco-2 Cells
  • Cadherins / metabolism
  • Clathrin / metabolism
  • Cytoskeletal Proteins / physiology
  • Cytoskeleton / metabolism
  • Endocytosis / physiology*
  • Epithelial Cells / cytology
  • HeLa Cells
  • Histocompatibility Antigens Class I / metabolism
  • Humans
  • Myosin Type II / metabolism*
  • Myosin Type II / physiology
  • Nonmuscle Myosin Type IIA / metabolism
  • Nonmuscle Myosin Type IIB / metabolism
  • Protein Isoforms / metabolism
  • rho-Associated Kinases / metabolism*
  • rho-Associated Kinases / physiology

Substances

  • CD59 Antigens
  • Cadherins
  • Clathrin
  • Cytoskeletal Proteins
  • Histocompatibility Antigens Class I
  • Protein Isoforms
  • CD59 protein, human
  • Actomyosin
  • ROCK2 protein, human
  • rho-Associated Kinases
  • Myosin Type II
  • Nonmuscle Myosin Type IIA
  • Nonmuscle Myosin Type IIB