Reactome | RHOBTB2 GTPase cycle

RHOBTB2 GTPase cycle

Stable Identifier

R-HSA-9013418

Type

Pathway

Species

Homo sapiens

Locations in the PathwayBrowser

Expand all

General

SBML | | PDF

SVG | | PPTX | SBGN

Click the image above or here to open this pathway in the Pathway Browser

RHOBTB2 is an atypical member of the RHO GTPase family that is predicted not to cycle between a GTP-bound form and a GDP-bound form (Berthold et al. 2008). RHOBTB family proteins, in contrast to other RHO GTPases, possess other conserved domains in addition to the GTPase domain. The GTPase domain at the N terminus is followed by a proline rich region, a tandem of two BTB (broad complex, tramtrack, bric à brac) domains, and a conserved C terminal BACK (BTB and C terminal Kelch) domain (Berthold et al. 2008, Ji and Rivero 2016). RHOBTB proteins can form homo- and heterodimers, but the role of dimerization in RHOBTB function is not known (Berthold et al. 2008, Ji and Rivero 2016). RHOBTB2 is usually expressed weakly (Berthold et al. 2008), at a lower level than RHOBTB1 (Ji and Rivero 2016). Relatively high levels of RHOBTB2 can be detected in neural and cardiac tissues (Berthold et al. 2016). RHOBTB2 is involved in COP9 signalosome-regulated and CUL3-dependent protein ubiquitination (Berthold et al. 2008; Ji and Rivero 2016). RHOBTB2 suppresses cellular proliferation and promotes apoptosis (Ji and Rivero 2016). RHOBTB2 takes part in vesicle transport (Ji and Rivero 2016). RHOBTB2 was initially discovered as the gene homozygously deleted in breast cancer and was named DBC2 (deleted in breast cancer 2) (Berthold et al. 2008). RHOBTB2 level is decreased in many tumor types and it is proposed to act as a tumor suppressor. Genomic deletions and a small number of pathogenic mutations in RHOBTB2 have been reported in cancer (Berthold et al. 2008; Ji and Rivero 2016). Mutations of RHOBTB2 that result in impaired interaction with CUL3 have been found to cause epileptic encephalopathy (Belal et al. 2018).

Literature References

PubMed ID	Title	Journal	Year
18298893	Rho GTPases of the RhoBTB subfamily and tumorigenesis Berthold, J, Schenkova, K, Rivero, F	Acta Pharmacol. Sin.	2008
27314390	Atypical Rho GTPases of the RhoBTB Subfamily: Roles in Vesicle Trafficking and Tumorigenesis Ji, W, Rivero, F	Cells	2016
29768694	De novo variants in RHOBTB2, an atypical Rho GTPase gene, cause epileptic encephalopathy Belal, H, Nakashima, M, Matsumoto, H, Yokochi, K, Taniguchi-Ikeda, M, Aoto, K, Amin, MB, Maruyama, A, Nagase, H, Mizuguchi, T, Miyatake, S, Miyake, N, Iijima, K, Nonoyama, S, Matsumoto, N, Saitsu, H	Hum Mutat	2018