Membrane blebbing during apoptosis results from caspase-mediated activation of ROCK I

Nat Cell Biol. 2001 Apr;3(4):339-45. doi: 10.1038/35070009.

Abstract

The execution phase of apoptosis is characterized by marked changes in cell morphology that include contraction and membrane blebbing. The actin-myosin system has been proposed to be the source of contractile force that drives bleb formation, although the biochemical pathway that promotes actin-myosin contractility during apoptosis has not been identified. Here we show that the Rho effector protein ROCK I, which contributes to phosphorylation of myosin light-chains, myosin ATPase activity and coupling of actin-myosin filaments to the plasma membrane, is cleaved during apoptosis to generate a truncated active form. The activity of ROCK proteins is both necessary and sufficient for formation of membrane blebs and for re-localization of fragmented DNA into blebs and apoptotic bodies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3T3 Cells
  • Animals
  • Apoptosis*
  • Caspase Inhibitors
  • Caspases / metabolism*
  • Cell Membrane / pathology
  • DNA / metabolism
  • DNA Fragmentation
  • Enzyme Activation
  • Humans
  • Intracellular Signaling Peptides and Proteins
  • Mice
  • Protein-Serine-Threonine Kinases / genetics
  • Protein-Serine-Threonine Kinases / metabolism*
  • Recombinant Fusion Proteins / genetics
  • Tumor Cells, Cultured
  • rho-Associated Kinases

Substances

  • Caspase Inhibitors
  • Intracellular Signaling Peptides and Proteins
  • Recombinant Fusion Proteins
  • DNA
  • Protein-Serine-Threonine Kinases
  • rho-Associated Kinases
  • Caspases