Belonging to the glycosyltransferase 14 family, GCNT2 (glucosaminyl (N-acetyl) transferase 2, I-branching enzyme (I blood group)), also known as II, N-acetylglucosaminyltransferase, IGNT, CCAT, ULG3, GCNT5, GCNT2C or NACGT1, is a 400 amino acid glycosyltransferase that localizes to the Golgi apparatus. Other members of the glycosyltransferase 14 family include GCNT1, GCNT3, GCNT4, GCNT6 and GCNT7. A single-pass type II membrane protein, GCNT2 functions as a branching enzyme known as beta-1,6-N-acetylglucosaminyltransferase, which converts fetal i antigen to adult I antigen in erythrocytes during embryonic development. With expression levels increasing significantly during oncogenesis and development, GCNT2 is found at highest levels in adult prostate and fetal brain, and is found at low levels in heart, small intestine, colon, brain, pancreas and kidney.
In the adult, highly expressed in prostate and to a lesser extent in small intestine and colon. Barely detected in heart, brain, kidney and pancreas. No expression in placenta, lung, liver, skeletal muscle, spleen, thymus, testis, ovary and peripheral blood leukocytes. In fetus, highly expressed in brain and to a lesser extent in lung and kidney. Barely detected in liver.
相似性
Belongs to the glycosyltransferase 14 family.
功能
GCNT2 is the I-branching enzyme, a beta-1,6-N-acetylglucosaminyltransferase that converts linear into branched poly-N-acetyllactosaminoglycans and is responsible for the conversion of fetal i antigen to adult I antigen in erythrocytes during embryonic development. Mutations in this gene have been associated with adult i blood group phenotype. Alternatively spliced transcript variants encoding 3 different isoforms have been described.