GEF-H1 modulates localized RhoA activation during cytokinesis under the control of mitotic kinases

Dev Cell. 2007 May;12(5):699-712. doi: 10.1016/j.devcel.2007.03.014.

Abstract

Formation of the mitotic cleavage furrow is dependent upon both microtubules and activity of the small GTPase RhoA. GEF-H1 is a microtubule-regulated exchange factor that couples microtubule dynamics to RhoA activation. GEF-H1 localized to the mitotic apparatus in HeLa cells, particularly at the tips of cortical microtubules and the midbody, and perturbation of GEF-H1 function induced mitotic aberrations, including asymmetric furrowing, membrane blebbing, and impaired cytokinesis. The mitotic kinases Aurora A/B and Cdk1/Cyclin B phosphorylate GEF-H1, thereby inhibiting GEF-H1 catalytic activity. Dephosphorylation of GEF-H1 occurs just prior to cytokinesis, accompanied by GEF-H1-dependent GTP loading on RhoA. Using a live cell biosensor, we demonstrate distinct roles for GEF-H1 and Ect2 in regulating Rho activity in the cleavage furrow, with GEF-H1 catalyzing Rho activation in response to Ect2-dependent localization and initiation of cell cleavage. Our results identify a GEF-H1-dependent mechanism to modulate localized RhoA activation during cytokinesis under the control of mitotic kinases.

Publication types

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

MeSH terms

  • Aurora Kinases
  • CDC2 Protein Kinase / metabolism*
  • Cell Membrane / metabolism
  • Cell Survival
  • Cytokinesis*
  • Down-Regulation / genetics
  • Enzyme Activation
  • Guanine Nucleotide Exchange Factors / deficiency
  • Guanine Nucleotide Exchange Factors / genetics
  • Guanine Nucleotide Exchange Factors / metabolism*
  • Guanosine Triphosphate / metabolism
  • HeLa Cells
  • Humans
  • Mitosis*
  • Phosphorylation
  • Protein Binding
  • Protein Transport
  • Protein-Serine-Threonine Kinases / metabolism*
  • Rho Guanine Nucleotide Exchange Factors
  • Subcellular Fractions / metabolism
  • rhoA GTP-Binding Protein / metabolism*

Substances

  • ARHGEF2 protein, human
  • Guanine Nucleotide Exchange Factors
  • Rho Guanine Nucleotide Exchange Factors
  • Guanosine Triphosphate
  • Aurora Kinases
  • Protein-Serine-Threonine Kinases
  • CDC2 Protein Kinase
  • rhoA GTP-Binding Protein