Xenbase Image ID: 123806

Figure 4. Rho activity zones in MgcRacGAP ΔGAP-expressing cells oscillatea, z-stack cross-section kymographs of the region where the Rho activity zone is forming for control, WT Mgc-, Mgc R384A-, or Mgc ΔGAP-expressing cells. Appearance of the Rho activity zone is marked with an arrowhead, and the furrow is marked with an arrow. Asterisks indicate places where the Rho activity zone splits. b, Kymographs made along the lines shown in the first frame of c and d. Yellow dots indicate F-actin oscillations. c–d, Control (c) or Mgc ΔGAP-expressing cells (d) were co-injected with EMTB-3XGFP to monitor microtubules (green) and mChe-UtrCH to monitor F-actin (red) and imaged during cytokinesis. Frames from time-lapse movies are shown. Yellow dots in d are fiduciary marks to help visualize the F-actin oscillations. Scale bars, 20 μm. e, Model showing that equatorial accumulation of Ect2 and MgcRacGAP leads to focused activation of Rho, which in turn leads to focused activation of Rho effectors. Our results are consistent with the GTPase flux model, suggesting that Ect2 locally activates Rho, while MgcRacGAP counterbalances Ect2 by locally inactivating Rho, keeping Rho in a constant state of flux through the GTPase cycle and maintaining a focused Rho activity zone at the cell equator. Image published in: Miller AL and Bement WM (2009) Image downloaded from an Open Access article in PubMed Central. Image reproduced on Xenbase with permission of the publisher and the copyright holder. Larger Image Printer Friendly View

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