Phosphatidylinositol glycan anchor biosynthesis class N protein (PIGN)

Phosphatidylinositol glycan anchor biosynthesis class N protein (PIGN) is an enzyme located in the endoplasmic reticulum that catalyzes the transfer of phosphoethanolamine (EtNP) from phosphatidylethanolamine (PE) to the first mannose residue during glycosylphosphatidylinositol (GPI) anchor biosynthesis[1][2][3][5][7]. The GPI anchor is a glycolipid that tethers proteins to the cell membrane, enabling functions such as cell adhesion, signaling, immunity, and neurogenesis[1][2][3][5]. Loss-of-function mutations in the PIGN gene lead to multiple congenital disorders, primarily affecting neurological development, muscle tone, and organ formation, including Fryns syndrome and MCAHS1[1][2][3]. These disorders are characterized by reduced cell surface expression of GPI-anchored proteins, severe congenital anomalies, and early lethality in the most affected cases[1][2][3][5]. No known drugs directly target PIGN, and the protein’s essential biosynthetic role poses therapeutic challenges and safety concerns if disrupted[2][3][5].

Other names

GPI ethanolamine phosphate transferase 1PIGNMCD4GPI-ETIPIG-NMCAHSMCAHS1MCD4 homologphosphatidylinositol-glycan biosynthesis class N protein