Glycoprotein alpha-galactosyltransferase 1 (GGTA1)

Glycoprotein alpha-galactosyltransferase 1 (GGTA1) encodes the enzyme alpha-1,3-galactosyltransferase in most mammals except humans, apes, and Old World monkeys. In these latter species, the gene is mutated and encodes a truncated, enzymatically inactive protein lacking the C-terminal catalytic domain. The active enzyme in non-primate mammals catalyzes the synthesis of the alpha-Gal (Galα1-3Gal) epitope, a glycan structure not found on human cells. Humans produce natural anti–alpha-Gal antibodies, which can mediate hyperacute immune rejection of xenotransplanted organs from non-primate mammals expressing GGTA1. Aberrant expression of GGTA1 protein in humans, where it is normally inactive, can be associated with autoimmune disorders and certain germ cell tumors[1][2][4]. Thus, GGTA1 is not a direct therapeutic target in humans but is of major relevance in xenotransplant immunology and related research. Key clarifications: - In humans, GGTA1 is non-enzymatic (not an active therapeutic target)[1][4]. - GGTA1 is often referenced in the context of xenotransplantation barriers (due to the alpha-Gal epitope). - Some aliases listed refer to pseudogenes or inactive proteins, not active drug targets. - Not directly drugged or used in approved therapies; main relevance is as an immunological barrier in transplantation.

Other names

Inactive N-acetyllactosaminide alpha-1,3-galactosyltransferaseGGTA1PGGTAGLYT2a1/3GTPpseudogeneglycoprotein alpha-galactosyltransferase 1 pseudogene