Published ahead of print on October 30, 2003, doi:10.1165/rcmb.2003-0202OC
© 2004 American Thoracic Society DOI: 10.1165/rcmb.2003-0202OC Mucin BiosynthesisBovine C2GnT-M Gene, Tissue-Specific Expression, and Herpes Virus-4 HomologueDepartment of Biochemistry and Molecular Biology, College of Medicine, and Eppley Institute for Research in Cancer and Allied Diseases, Nebraska Medical Center, Omaha; and Department of Veterinary and Biomedical Sciences, University of Nebraska, Lincoln, Nebraska Address correspondence to: Pi-Wan Cheng, Ph.D., Department of Biochemistry and Molecular Biology, 984525 Nebraska Medical Center, Omaha, NE 68198-4525. E-mail: pcheng{at}unmc.edu Mucin glycans are the major determinant of mucin functions. Mucin glycan branch structures, which increase structural heterogeneity and thus functional potential, are extended from ß6 N-acetylglucosaminides formed by ß6 N-acetylglucosaminyltransferases (ß6GnT). Core 2 ß6GnT-M (C2GnT-M) is the only branching enzyme that can synthesize all known mucin ß6 N-acetylglucosaminides. We report the cloning of four different bovine (b) C2GnT-M transcripts that are different only at 5'-untranslated regions. Two bC2GnT-M transcripts are found exclusively in tracheal epithelium and testis, whereas the other two are found in all other mucus-secreting tissues. The bC2GnT-M gene contains four exons spanning 5.3 kb, and the entire open reading frame is in one exon. The bC2GnT-M ORF has 95, 83, and 75% sequence identity to those of bovine herpes virus type 4 (BHV-4), human, and rat C2GnT-Ms, respectively. The homology between bovine and BHV-4 C2GnT-M genes is in the region between 170 nucleotides upstream from ATG start codon and 114 nucleotides downstream from TGA stop codon of the viral gene. Localized at the nonconserved region of the viral genome, the BHV-4 C2GnT-M gene is the only known viral C2GnT-M gene. The results suggest that BHV-4 acquired its C2GnT-M gene from the bovine gene. The mechanism of the viral acquisition of bC2GnT-M gene and the roles of the C2GnT-M gene in the survival and pathogenesis of this virus remain to be elucidated.
Abbreviations: ß6-N-acetylglucosaminyltransferases, ß6GnT • bovine herpes virus type 4, BHV-4 • bovine serum albumin, BSA • core 2 ß6 N-acetylglucosaminyltransferase, C2GnT • C2GnT thymus type, C2GnT-3 • C2GnT leukocyte type, C2GnT-L • C2GnT mucus-type, C2GnT-M • galactose, Gal • N-acetylgalactosamine, GalNAc • glyceraldehyde-3-phosphate dehydrogenase, GAPDH • N-acetylglucosamine, GlcNAc • blood group I ß6 N-acetylglucosaminyltransferase, IGnT • blood group i ß3 N-acetylglucosaminyltransferase, iGnT • lipopolysaccharide, LPS • long unique genome region, LUR • mannoside ßN-acetylglucosaminyltransferases, MGAT • open reading frame, ORF • reverse transcription-polymerase chain reaction, RT-PCR • sodium dodecyl sulfate, SDS • short interspersed element, SINE • standard saline citrate, SSC • Tris-buffered saline, TBS This article has been cited by other articles:
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