RAP2B, Member Of RAS Oncogene Family (RAP2B)

This intronless gene belongs to a family of RAS-related genes. The proteins encoded by these genes share approximately 50% amino acid identity with the classical RAS proteins and have numerous structural features in common. The most striking difference between the RAP and RAS proteins resides in their 61st amino acid: glutamine in RAS is replaced by threonine in RAP proteins. Evidence suggests that this protein may be polyisoprenylated and palmitoylated. RAB2B was detergent soluble in resting platelets, but a significant amount of RAP2B was associated with the cytoskeleton in platelets aggregated with thrombin, a thromboxane analog, or a Ca(2+)-ATPase inhibitor. Translocation of RAP2B to the cytoskeleton was strictly dependent on platelet aggregation.