DLC-1

Deleted in Liver Cancer 1 (DLC1) is also known as rho GTPase-activating protein 7 (ARHGAP7) and StAR-related lipid transfer protein 12 (STARD12). DLC1 gene is deleted in the primary tumor of hepatocellular carcinoma. It maps to 8p22-p21.3, a region frequently deleted in solid tumors. It is suggested that this gene is a candidate tumor suppressor gene for human liver cancer, as well as for prostate, lung, colorectal, and breast cancers. The DLC1 protein contains four major functional domains: an N-terminal sterile ¦Á motif (SAM), a serine-rich (SR) region, a Rho-GAP domain, and a C-terminal steroidogenic acute regulatory protein related lipid-transfer (START) domain. DLC1 is localized to focal adhesions located at the periphery of cells. The main function of DLC1 is its Rho-GAP activity: its ability to enhance activated GTP-bound Rho-GTPases' (specifically, RhoA and Cdc42) intrinsic ability to convert their GTP into GDP, thus rendering them inactive. RhoGTPases are members of the Ras superfamily, and are involved in actin cytoskeleton organization and cell adhesion.