RAP2C, Member Of RAS Oncogene Family (RAP2C)

Binding of GTP to recombinant purified Rap2C was Mg(2+)-dependent. When expressed in eukaryotic cells, Rap2C localized at the plasma membrane, as dictated by the presence of a CAAX motif at the C-terminus. Rap2C represented the predominant Rap2 protein expressed in circulating mononuclear leukocytes, but was not present in platelets. Importantly, Rap2C was found to be expressed in human megakaryocytes, suggesting that the protein may be down-regulated during platelets generation. Rap2C is a new member of the Rap2 subfamily of proteins, able to bind guanine nucleotides with peculiar properties, and differently expressed by various hematopoietic subsets. This new protein may therefore contribute to the still poorly clarified cellular events regulated by this subfamily of GTP-binding proteins.