Letter abstract


Nature Cell Biology 11, 71 - 77 (2008)
Published online: 7 December 2008 | doi:10.1038/ncb1814

Regulation of cytokinesis by Rho GTPase flux

Ann L. Miller1 & William M. Bement1,2

Top

In animal cells, cytokinesis is powered by a contractile ring of actin filaments (F-actin) and myosin-2. Formation of the contractile ring is dependent on the small GTPase RhoA1, 2, which is activated in a precise zone at the cell equator3. It has long been assumed that cytokinesis and other Rho-dependent processes are controlled in a sequential manner, whereby Rho activation by guanine nucleotide exchange factors (GEFs) initiates a particular event, and Rho inactivation by GTPase activating proteins (GAPs) terminates that event. MgcRacGAP is a conserved cytokinesis regulator thought to be required only at the end of cytokinesis4, 5. Here we show that GAP activity of MgcRacGAP is necessary early during cytokinesis for the formation and maintenance of the Rho activity zone. Disruption of GAP activity by point mutation results in poorly focused Rho activity zones, whereas complete removal of the GAP domain results in unfocused zones that show lateral instability and/or rapid side-to-side oscillations. We propose that the GAP domain of MgcRacGAP has two unexpected roles throughout cytokinesis: first, it transiently anchors active Rho, and second, it promotes local Rho inactivation, resulting in the constant flux of Rho through the GTPase cycle.

Top
  1. Department of Zoology, University of Wisconsin Madison, Madison, WI 53706, USA.
  2. Laboratory of Molecular Biology, University of Wisconsin Madison, Madison, WI 53706, USA.

Correspondence to: Ann L. Miller1 almiller1@wisc.edu



MORE ARTICLES LIKE THIS

These links to content published by NPG are automatically generated.

NEWS AND VIEWS

Cytokinesis: mind the GAP

Nature Cell Biology News and Views (01 Feb 2009)


Extra navigation

Subscribe to Nature Cell Biology

Subscribe

Open Innovation Challenges

naturejobs