title: The molecular genetics of the mouse I beta-1,6-N-acetylglucosaminyltransferase locus.
abstract: The I antigen and its precursor, the i antigen, are carbohydrate structures and are found on the surface of most mammalian cells. Conversion of the i to the I structure requires I beta-1,6-N-acetylglucosaminyltransferase activity. The present investigation demonstrates a novel transcript form expressed from the mouse I locus and elucidates the molecular genetics and the genomic organization of the mouse I locus. The mouse I locus was demonstrated to express three transcript forms, one newly identified and two previously reported, which have a different exon 1 but identical exons 2 and 3. The three transcripts were shown to express differentially in various mouse tissues, and all their protein products demonstrated GlcNAc-transferring activity in enzyme function assay. The molecular genetics proposed for the mouse I locus shows that it is homologous to the human I locus. It has been established recently that a defect in the human I locus may lead to the development of congenital cataracts. It was demonstrated that the mouse and the human I transcripts expressed in the epithelium cells of the mouse and human lens, respectively, are homologous forms.
authors.affiliation: Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan.
authors.forename: Yuh-Ching
authors.initials: YC
authors.lastname: Twu
authors.forename: Ming-Lun
authors.initials: ML
authors.lastname: Chou
authors.forename: Lung-Chih
authors.initials: LC
authors.lastname: Yu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D018076:DNA, Complementary / Q000235:genetics; D005091:Exons; D015870:Gene Expression; D006801:Humans; D051379:Mice; D008967:Molecular Biology; D008969:Molecular Sequence Data; D017351:N-Acetylglucosaminyltransferases / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D014018:Tissue Distribution
chemical_list: D018076:DNA, Complementary; D012333:RNA, Messenger; C106501:N-acetylglucosaminyltransferase IGnT; D017351:N-Acetylglucosaminyltransferases