PREX1

Phosphatidylinositol 3,4,5-trisphosphate-dependent Rac exchanger 1 protein is a is_associated_with::protein that in humans is encoded by the PREX1 is_associated_with::gene.

Function
The protein encoded by this gene acts as a is_associated_with::guanine nucleotide exchange factor for the RHO family of small GTP-binding proteins (RACs). It has been shown to bind to and activate is_associated_with::RAC1 by exchanging bound GDP for free GTP. The encoded protein, which is found mainly in the is_associated_with::cytoplasm, is activated by phosphatidylinositol-3,4,5-trisphosphate and the beta-gamma subunits of is_associated_with::heterotrimeric G proteins.

Clinical significance
The protein has been implicated in the spread of is_associated_with::melanoma skin cancer.