A novel member of the glycosyltransferase family, beta 3 Gn-T2, highly downregulated in invasive human bladder transitional cell carcinomas.
Differential display reverse transcription (DDRT)-polymerase chain reaction (PCR) was used to compare the transcriptomes of invasive and noninvasive fresh human bladder transitional cell carcinomas. A differentially expressed novel gene sharing structural similarity with the human beta 3-galactosyltransferase family, beta-1,3-N-acetylglucosaminyltransferase-T2 (beta 3Gn-T2), was identified. The full-length beta 3Gn-T2 cDNA, containing a complete open reading frame of 1193 bp, was cloned and sequenced. beta 3Gn-T2 exhibited 29-41% homology to the multigene beta 3-galactosyltransferase family. Expression of the full-length beta 3Gn-T2 cDNA in an in vitro coupled transcription/translation assay yielded a primary translation product with an apparent Mr of 46 kDa, which is in agreement with the predicted 397-amino-acid protein encoded by beta 3Gn-T2. Multiple peptide alignment showed several sequence motifs corresponding to putative catalytic domains that are conserved throughout all members of the beta 3-galactosyltransferase family, namely, a type II transmembrane domain, a conserved DxD motif, an N-glycosylation site, and five conserved cysteins. By RT-PCR strong downregulation of beta 3Gn-T2 expression was noted in invasive human bladder transitional cell carcinomas (16 fresh biopsy samples: grade III, T2-T4) compared with their noninvasive counterparts (15 fresh biopsies: grade II, Ta), suggesting that beta 3Gn-T2 may be involved in cancer progression.
Gromova
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Institute of Cancer Biology, Danish Cancer Society, Copenhagen, Denmark.
Gromov
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Celis
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D000595:Amino Acid Sequence; D001483:Base Sequence; D002295:Carcinoma, Transitional Cell / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D018076:DNA, Complementary / Q000032:analysis / Q000235:genetics; D015536:Down-Regulation; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008969:Molecular Sequence Data; D017351:N-Acetylglucosaminyltransferases / Q000235:genetics / Q000378:metabolism*; D009361:Neoplasm Invasiveness / Q000235:genetics; D016415:Sequence Alignment; D001749:Urinary Bladder Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology
D018076:DNA, Complementary; D017351:N-Acetylglucosaminyltransferases; C428132:B3GNT2 protein, human