Rho GTPase activating protein 31
The ARHGAP31 gene provides instructions for making a protein classified as a Rho GTPase activating protein (GAP). GAPs turn off (inactivate) proteins called GTPases, which play an important role in chemical signaling within cells. Often referred to as molecular switches, GTPases can be turned on and off. They are turned on (active) when they are attached (bound) to a molecule called GTP and are turned off when they are bound to another molecule called GDP. The ARHGAP31 protein inactivates GTPases known as Cdc42 and Rac1 by stimulating a reaction that turns the attached GTP into GDP. When active, Cdc42 and Rac1 transmit signals that are critical for various aspects of embryonic development. The ARHGAP31 protein appears to regulate these GTPases specifically during development of the limbs, skull, and heart.
At least three mutations in the ARHGAP31 gene are known to cause Adams-Oliver syndrome, a condition characterized by areas of missing skin (aplasia cutis congenita), usually on the scalp, and malformations of the hands and feet. These mutations lead to production of an abnormally short ARHGAP31 protein that is more active than normal. The increased GAP activity leads to a reduction in Cdc42 and Rac1 signaling, which impairs proper development of the skin on the top of the head and the bones in the hands and feet.
- Cdc42 GTPase-activating protein
- rho GTPase-activating protein 31