GAPVD1

GTPase activating protein and VPS9 domains 1, also known as GAPVD1, Gapex-5 and RME-6 is a is_associated_with::protein which in humans is encoded by the GAPVD1 is_associated_with::gene.

Function
GAPVD1 is Rab GTPase is_associated_with::guanine nucleotide exchange factor essential for activation of is_associated_with::RAB5A during engulfment of apoptotic cells. GAPVD1 is also involved in the degradation of the is_associated_with::epidermal growth factor receptor. Gapex-5 mediated activation of Rab5 has been implicated in the insulin stimulated formation of plasma membrane phosphatidylinositol-3-phosphate.

Structure
Based on sequence homology, mammalian Gapex-5 has been shown to have an amino-terminal Ras GAP domain, a central polyproline (SH3 binding) region and a carboxy-terminal Rab GEF domain. The RabGEF domain has been suggested to activate Rab5 and Rab31.