Rho/Rac

Rho/Rac proteins belong to the Ras superfamily of small GTPases. They are G proteins and GTPases involved in intracellular signal transduction.

Subfamilies
There are six subfamilies: Rho, Rac, Cdc42, Rnd, RhoBTB, and ThoT/Miro.

Functions
Rho/Rac proteins are involved in a wide variety of cellular functions such as cell polarity, vesicular trafficking, the cell cycle and transcriptomal dynamics. GEFs activate Rho/Rac proteins by promoting the exchange of GDP for GTP whileGAPs catalyze the hydrolysis of the bound GTPs and inactivate Rho/Rac proteins.

Regulations
Since Rho/Rac proteins are crucial in many cellular functions, they are regulated in a number of ways such as activation and inactivation by GEFs and GAPS as well as the regulation of their protein expression levels and subcellular localization.

Many Rho/Rac GTPases are specific to cell types. Stimulus such as UV irradiation, growth factors , and cytokines.