RhoGAP_nadrin: RhoGAP (GTPase-activator protein [GAP] for Rho-like small GTPases) domain of Nadrin-like proteins. Nadrin, also named Rich-1, has been shown to be involved in the regulation of Ca2+-dependent exocytosis in neurons and recently has been implicated in tight junction maintenance in mammalian epithelium. Small GTPases cluster into distinct families, and all act as molecular switches, active in their GTP-bound form but inactive when GDP-bound. The Rho family of GTPases activates effectors involved in a wide variety of developmental processes, including regulation of cytoskeleton formation, cell proliferation and the JNK signaling pathway. GTPases generally have a low intrinsic GTPase hydrolytic activity but there are family-specific groups of GAPs that enhance the rate of GTP hydrolysis by several orders of magnitude.