PubMed:8449405
Annnotations
{"target":"https://pubannotation.org/docs/sourcedb/PubMed/sourceid/8449405","sourcedb":"PubMed","sourceid":"8449405","source_url":"https://www.ncbi.nlm.nih.gov/pubmed/8449405","text":"Expression of the developmental I antigen by a cloned human cDNA encoding a member of a beta-1,6-N-acetylglucosaminyltransferase gene family.\nThe blood group i/I antigens were the first identified alloantigens that display a dramatic change during human development. The i and I antigens are determined by linear and branched poly-N-acetyllactosaminoglycans, respectively. In human erythrocytes during embryonic development, the fetal (i) antigen is replaced by the adult (I) antigen as a result of the appearance of a beta-1,6-N-acetylglucosaminyltransferase, the I-branching enzyme. Here, we report the cDNA cloning and expression of this branching enzyme that converts linear into branched poly-N-acetyllactosaminoglycans, thus introducing the I antigen in transfected cells. The cDNA sequence predicts a protein with type II membrane topology as has been found for all other mammalian glycosyltransferases cloned to date. The Chinese hamster ovary cells that stably express the isolated cDNA acquire I-branched structures as evidenced by the structural analysis of glycopeptides from these cells. Comparison of the amino acid sequence with those of other glycosyltransferases revealed that this I-branching enzyme and another beta-1,6-N-acetylglucosaminyltransferase that forms a branch in O-glycans are strongly homologous in the center of their putative catalytic domains. Moreover, the genes encoding these two beta-1,6-N-acetylglucosaminyltransferases were found to be located at the same locus on chromosome 9, band q21. These results indicate that the I-branching enzyme represents a member of a beta-1,6-N-acetylglucosaminyltransferase gene family of which expression is controlled by developmental programs.","tracks":[{"project":"glycogenes","denotations":[{"id":"PD-GlycoGenes20190927-B_T1","span":{"begin":158,"end":161},"obj":"https://acgg.asia/db/ggdb/info/gg111"},{"id":"PD-GlycoGenes20190927-B_T2","span":{"begin":826,"end":828},"obj":"https://acgg.asia/db/ggdb/info/gg111"},{"id":"PD-GlycoGenes20190927-B_T3","span":{"begin":850,"end":853},"obj":"https://acgg.asia/db/ggdb/info/gg135"}],"attributes":[{"subj":"PD-GlycoGenes20190927-B_T1","pred":"source","obj":"glycogenes"},{"subj":"PD-GlycoGenes20190927-B_T2","pred":"source","obj":"glycogenes"},{"subj":"PD-GlycoGenes20190927-B_T3","pred":"source","obj":"glycogenes"}]}],"config":{"attribute types":[{"pred":"source","value type":"selection","values":[{"id":"glycogenes","color":"#93ecab","default":true}]}]}}