Vascular non-inflammatory molecule 2, also known as glycosyl-phosphatidyl inositol-anchored protein GPI-80, Vanin-2, Protein FOAP-4 and VNN2, is a cell membrane protein which belongs to the CN hydrolase family and Vanin subfamily. VNN2 is widely expressed with higher expression in spleen and blood. VNN2 is a member of the vanin family of proteins which share extensive sequence similarity with each other, and also with biotinidase. The family includes secreted and membrane-associated proteins, a few of which have been reported to participate in hematopoietic cell trafficking. No biotinidase activity has been demonstrated for any of the vanin proteins, however, they possess pantetheinase activity, which may play a role in oxidative-stress response. VNN2 is an amidohydrolase that hydrolyzes specifically one of the carboamide linkages in D-pantetheine thus recycling pantothenic acid (vitamin B5) and releasing cysteamine. It is involved in the thymus homing of bone marrow cells. VNN2 plays a role in transendothelial migration of neutrophils and may regulate beta-2 integrin-mediated cell adhesion, migration and motility of neutrophil.
