PT - JOURNAL ARTICLE AU - Adriana Golding AU - Ilaria Visco AU - Peter Bieling AU - William Bement TI - Extraction of active RhoGTPases by RhoGDI regulates spatiotemporal patterning of RhoGTPases AID - 10.1101/720094 DP - 2019 Jan 01 TA - bioRxiv PG - 720094 4099 - http://biorxiv.org/content/early/2019/08/02/720094.short 4100 - http://biorxiv.org/content/early/2019/08/02/720094.full AB - The RhoGTPases are characterized as membrane-associated molecular switches cycling 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 tools, we identified pools of active and inactive RhoGTPase associated with the membrane, showed that RhoGDI can actively extract both inactive and active RhoGTPases, and that the extraction of active RhoGTPase contributes to their spatial regulation around wounds. In contrast to the textbook model of the RhoGTPase cycle, these results indicate that RhoGDI actively contributes to spatiotemporal patterning by removing active RhoGTPases from the plasma membrane.