phosphatidylinositol N-acetylglucosaminyltransferase subunit A and similar proteins
This family is most closely related to the GT4 family of glycosyltransferases. Phosphatidylinositol glycan-class A (PIG-A), an X-linked gene in humans, is necessary for the synthesis of N-acetylglucosaminyl-phosphatidylinositol, a very early intermediate in glycosyl phosphatidylinositol (GPI)-anchor biosynthesis. The GPI-anchor is an important cellular structure that facilitates the attachment of many proteins to cell surfaces. Somatic mutations in PIG-A have been associated with Paroxysmal Nocturnal Hemoglobinuria (PNH), an acquired hematological disorder.