Rheb is a member of the Ras superfamily small GTPases that plays important roles in the regulation of protein synthesis and growth in response to nutrient and growth factors. This protein is vital in regulation of growth and cell cycle progression due to its role in the insulin/TOR/S6K signaling pathway. The protein has GTPase activity and shuttles between a GDP-bound form and a GTP-bound form, and farnesylation of the protein is required for this activity.
