Myosin IIA drives membrane bleb retraction

Mol Biol Cell. 2019 Apr 15;30(9):1051-1059. doi: 10.1091/mbc.E18-11-0752. Epub 2019 Feb 20.

Abstract

Membrane blebs are specialized cellular protrusions that play diverse roles in processes such as cell division and cell migration. Blebbing can be divided into three distinct phases: bleb nucleation, bleb growth, and bleb retraction. Following nucleation and bleb growth, the actin cortex, comprising actin, cross-linking proteins, and nonmuscle myosin II (MII), begins to reassemble on the membrane. MII then drives the final phase, bleb retraction, which results in reintegration of the bleb into the cellular cortex. There are three MII paralogues with distinct biophysical properties expressed in mammalian cells: MIIA, MIIB, and MIIC. Here we show that MIIA specifically drives bleb retraction during cytokinesis. The motor domain and regulation of the nonhelical tailpiece of MIIA both contribute to its ability to drive bleb retraction. These experiments have also revealed a relationship between faster turnover of MIIA at the cortex and its ability to drive bleb retraction.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / metabolism
  • Animals
  • Blister / metabolism*
  • COS Cells
  • Cell Membrane / metabolism
  • Cell Membrane Structures / metabolism
  • Cell Movement / physiology
  • Cell Surface Extensions / metabolism
  • Chlorocebus aethiops
  • Cytokinesis / physiology
  • Cytoplasm / metabolism
  • Cytoskeletal Proteins / metabolism
  • HeLa Cells
  • Humans
  • Myosin Type II / metabolism
  • Nerve Tissue Proteins / metabolism
  • Nonmuscle Myosin Type IIA / metabolism
  • Nonmuscle Myosin Type IIA / physiology*
  • Nonmuscle Myosin Type IIB / metabolism

Substances

  • Actins
  • Cytoskeletal Proteins
  • HAP1 protein, human
  • Nerve Tissue Proteins
  • Myosin Type II
  • Nonmuscle Myosin Type IIA
  • Nonmuscle Myosin Type IIB