catalytic activity:UDP-N-acetyl-D-glucosamine + 1-phosphatidyl-1D-myo-inositol = UDP + 6-(N-acetyl-alpha-D-glucosaminyl)-1-phosphatidyl-1D-myo-inositol.,disease:Defects in PIGA are the cause of paroxysmal nocturnal hemoglobinuria (PNH) [MIM:311770]. PNH is an acquired hemolytic blood disorder characterized by chronic hemolysis with hemoglobinuria, increased tendency to venous thrombosis, and variable degrees of bone marrow failure Biosynthesis of the GPI anchor is deficient in patients with PNH leading to deficient surface expression of GPI-anchored proteins such as DAF or CD59 which play roles in the protection of red cells from the action of complement.,function:Necessary for the synthesis of N-acetylglucosaminyl-phosphatidylinositol, the very early intermediate in GPI-anchor biosynthesis.,online information:Phosphatidylinositol N-acetylglucosaminyltransferase subunit A,pathway:Glycolipid biosynthesis; glycosylphosphatidylinositol-anchor biosynthesis.,similarity:Belongs to the glycosyltransferase 1 family.,subunit:Associates with PIGC, PIGH, PIGP, PIGQ and DPM2. The latter is not essential for activity. Interacts directly with PIGY.,
Endoplasmic reticulum membrane; Single-pass membrane protein.
Brain,Kidney,