RHOBTB3 (Rho-related BTB domain containing 3)

RHOBTB3 is one of the three members of the RhoBTB family. All RhoBTB proteins are characterized by a GTPase domain followed by a proline-rich region, a tandem of two BTB domains and a C-terminal putative RING finger domain. In RHOBTB3 the GTPase domain has ATPase activity. RHOBTB3 is a putative tumour suppressor gene. Expression of RHOBTB3 has been found significantly decreased in the breast, kidney, uterus, lung, and ovary tumors and in human renal carcinomas. The mechanism of RHOBTB3 protein as a tumor suppressor may be related to its function as an adaptor of cullin 3-dependent ubiquitin ligases. RHOBTB3 targets cyclin E for degradation and facilitates entry into the G2 phase of the cell cycle. RHOBTB3 also builds a multiprotein complex that maintains HIFα (hypoxia inducible factor α) levels low by promoting its hydroxylation, ubiquitination and degradation