 The binding of GTP to the GTPase results in the release of the GEF, which can then activate a new GTPase.Thus, GEFs both destabilize the GTPase interaction with GDP and stabilize the nucleotide-free GTPase until a GTP molecule binds to it.GAPs (GTPase-activating protein) act antagonistically to inactivate GTPases by increasing their intrinsic rate of GTP hydrolysis.