Overview:

RHEB is a member of the small GTPase superfamily and encodes a lipid-anchored, cell membrane protein with five repeats of the RAS-related GTP-binding region. RHEB is vital in the regulation of growth and cell cycle progression. RHEB has GTPase activity and shuttles between a GDP-bound form and a GTP-bound form. Drosophila RHEB is a direct target of Tsc2 GTPase-activating protein (GAP) activity both in vivo and in vitro. Point mutations in the Drosophila RHEB gene inhibits cell growth while overexpression promotes cell growth. RHEB functions downstream of Tsc1 and Tsc2 in the mTOR signaling pathway.

References:

1. Stocker, H. et al: Rheb is an essential regulator of S6K in controlling cell growth in Drosophila. Nature Cell Biol. 5: 559-565, 2003. 2. Zhang, Y. et al: Rheb is a direct target of the tuberous sclerosis tumour suppressor proteins. Nature Cell Biol. 5: 578-581, 2003.