Protein prenylation involves the covalent attachment of Cl5 farnesyl or C20 geranylgeranyl (GG) isoprenoids to cysteine resrdues located at or near the COOH-terminus of various proteins. The majority of cellular proteins that are known to undergo this modtfrcation are small guanosme triphosphate phosphohydrolases (GTPases) belonging to the Ras, Rho/Rat, and Rab families. Each of these proteins require one or more COOH-terminal prenyl groups for proper subcellular localization and function (1 ).
