Extraction of active RhoGTPases by RhoGDI regulates spatiotemporal patterning of RhoGTPases

• Published in: eLife 2019-10, Vol.8
• Main Authors: Golding, Adriana E, Visco, Ilaria, Bieling, Peter, Bement, William M
• Format: Article
• Language: English
• Subjects: Animals; Biochemistry and Chemical Biology; Cdc42; cdc42 GTP-Binding Protein - metabolism; Cell Biology; Cell Extracts; Cell Membrane - metabolism; Cytokinesis; Epithelial Cells - metabolism; Epithelial Cells - pathology; Exocytosis; Guanosine diphosphate; Guanosine triphosphate; Lipid bilayers; Mutant Proteins - metabolism; Proteins; Rho; rho GTP-Binding Proteins - metabolism; rho-Specific Guanine Nucleotide Dissociation Inhibitors - metabolism; RhoGDI; RhoGTPase; Visualization; Wound Healing; Xenopus laevis - metabolism
• ISSN: 2050-084X; 2050-084X
• DOI: 10.7554/eLife.50471

The RhoGTPases are characterized as membrane-associated molecular switches that cycle between active, GTP-bound and inactive, GDP-bound states. However, 90-95% of RhoGTPases are maintained in a soluble form by RhoGDI, which is generally viewed as a passive shuttle for inactive RhoGTPases. Our current understanding of RhoGTPase:RhoGDI dynamics has been limited by two experimental challenges: direct visualization of the RhoGTPases in vivo and reconstitution of the cycle in vitro. We developed methods to directly image vertebrate RhoGTPases in vivo or on lipid bilayers in vitro. Using these methods, we identified pools of active and inactive RhoGTPase associated with the membrane, found that RhoGDI can extract both inactive and active RhoGTPases, and found that extraction of active RhoGTPase contributes to their spatial regulation around cell wounds. These results indicate that RhoGDI directly contributes to the spatiotemporal patterning of RhoGTPases by removing active RhoGTPases from the plasma membrane.