GCNT2 explained

N-acetyllactosaminide beta-1,6-N-acetylglucosaminyl-transferase is an enzyme that in humans is encoded by the GCNT2 gene.^{[1] [2] [3]}

This gene encodes the enzyme responsible for formation of the blood group I antigen. The i and I antigens are distinguished by linear and branched poly-N-acetyllactosaminoglycans, respectively. The encoded protein is the I-branching enzyme, a beta-1,6-N-acetylglucosaminyltransferase 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 different isoforms have been described.

Further reading

• Fukuda M, Fukuda MN, Hakomori S. Sen-itiroh Hakomori . Developmental change and genetic defect in the carbohydrate structure of band 3 glycoprotein of human erythrocyte membrane . J. Biol. Chem. . 254 . 10 . 3700–3 . 1979 . 10.1016/S0021-9258(18)50640-2 . 438154 . free .
• Keats B, Ott J, Conneally M . Report of the committee on linkage and gene order . Cytogenet. Cell Genet. . 51 . 1–4 . 459–502 . 1989 . 2791656 . 10.1159/000132805 .
• Bierhuizen MF, Maemura K, Kudo S, Fukuda M . Genomic organization of core 2 and I branching beta-1,6-N-acetylglucosaminyltransferases. Implication for evolution of the beta-1,6-N-acetylglucosaminyltransferase gene family . Glycobiology . 5 . 4 . 417–25 . 1995 . 7579796 . 10.1093/glycob/5.4.417 .
• Magnet AD, Fukuda M . Expression of the large I antigen forming beta-1,6-N-acetylglucosaminyltransferase in various tissues of adult mice . Glycobiology . 7 . 2 . 285–95 . 1997 . 9134435 . 10.1093/glycob/7.2.285 . free .
• Sasaki K, Kurata-Miura K, Ujita M . Expression cloning of cDNA encoding a human beta-1,3-N-acetylglucosaminyltransferase that is essential for poly-N-acetyllactosamine synthesis . Proc. Natl. Acad. Sci. U.S.A. . 94 . 26 . 14294–9 . 1998 . 9405606 . 10.1073/pnas.94.26.14294 . 24948 . etal. free .
• Olavesen MG, Bentley E, Mason RV . Fine mapping of 39 ESTs on human chromosome 6p23-p25 . Genomics . 46 . 2 . 303–6 . 1998 . 9417921 . 10.1006/geno.1997.5032 . etal.
• Yu LC, Twu YC, Chang CY, Lin M . Molecular basis of the adult i phenotype and the gene responsible for the expression of the human blood group I antigen . Blood . 98 . 13 . 3840–5 . 2002 . 11739194 . 10.1182/blood.V98.13.3840 . free .
• Potter KN, Hobby P, Klijn S . Evidence for involvement of a hydrophobic patch in framework region 1 of human V4-34-encoded Igs in recognition of the red blood cell I antigen . J. Immunol. . 169 . 7 . 3777–82 . 2002 . 12244172 . 10.4049/jimmunol.169.7.3777. etal. free .
• Yu LC, Twu YC, Chou ML . The molecular genetics of the human I locus and molecular background explain the partial association of the adult i phenotype with congenital cataracts . Blood . 101 . 6 . 2081–8 . 2003 . 12424189 . 10.1182/blood-2002-09-2693 . etal. free .
• Inaba N, Hiruma T, Togayachi A . A novel I-branching beta-1,6-N-acetylglucosaminyltransferase involved in human blood group I antigen expression . Blood . 101 . 7 . 2870–6 . 2003 . 12468428 . 10.1182/blood-2002-09-2838 . etal. free .
• Strausberg RL, Feingold EA, Grouse LH . Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences . Proc. Natl. Acad. Sci. U.S.A. . 99 . 26 . 16899–903 . 2003 . 12477932 . 10.1073/pnas.242603899 . 139241 . 2002PNAS...9916899M . etal. free .
• Zhang T, Haws P, Wu Q . Multiple variable first exons: a mechanism for cell- and tissue-specific gene regulation . Genome Res. . 14 . 1 . 79–89 . 2004 . 14672974 . 10.1101/gr.1225204 . 314283 .
• Ota T, Suzuki Y, Nishikawa T . Complete sequencing and characterization of 21,243 full-length human cDNAs . Nat. Genet. . 36 . 1 . 40–5 . 2004 . 14702039 . 10.1038/ng1285 . etal. free .
• Pras E, Raz J, Yahalom V . A nonsense mutation in the glucosaminyl (N-acetyl) transferase 2 gene (GCNT2): association with autosomal recessive congenital cataracts . Invest. Ophthalmol. Vis. Sci. . 45 . 6 . 1940–5 . 2004 . 15161861 . 10.1167/iovs.03-1117 . etal. free .
• Gerhard DS, Wagner L, Feingold EA . The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC) . Genome Res. . 14 . 10B . 2121–7 . 2004 . 15489334 . 10.1101/gr.2596504 . 528928 . etal.

Notes and References

1. Bierhuizen MF, Mattei MG, Fukuda M . Expression of the developmental I antigen by a cloned human cDNA encoding a member of a beta-1,6-N-acetylglucosaminyltransferase gene family . Genes Dev . 7 . 3 . 468–78 . Apr 1993 . 8449405 . 10.1101/gad.7.3.468 . free .
2. Yeh JC, Ong E, Fukuda M . Molecular cloning and expression of a novel beta-1, 6-N-acetylglucosaminyltransferase that forms core 2, core 4, and I branches . J Biol Chem . 274 . 5 . 3215–21 . Mar 1999 . 9915862 . 10.1074/jbc.274.5.3215 . free .
3. Web site: Entrez Gene: GCNT2 glucosaminyl (N-acetyl) transferase 2, I-branching enzyme (I blood group).