title: Transcriptional regulation of N-acetylglucosaminyltransferase V by the src oncogene.
abstract: Transformation of baby hamster kidney fibroblasts by the Rous sarcoma virus causes a significant increase in the GlcNAcbeta(1, 6)Man-branched oligosaccharides by elevating the activity and mRNA transcript levels encoding N-acetylglucosaminyltransferase V (GlcNAc-T V). Elevated activity and mRNA levels could be inhibited by blocking cell proliferation with herbimycin A, demonstrating that Src kinase activity can regulate GlcNAc-T V expression. 5' RACE analysis was used to identify a 3-kilobase 5'-untranslated region from GlcNAc-T V mRNA and locate a transcriptional start site in a 25-kilobase pair GlcNAc-T V human genomic clone. A 6-kilobase pair fragment of the 5' region of the gene contained AP-1 and PEA3/Ets binding elements and, when co-transfected with a src expression plasmid into HepG2 cells, conferred src-stimulated transcriptional enhancement upon a luciferase reporter gene. This stimulation by src could be antagonized by co-transfection with a dominant-negative mutant of the Raf kinase, suggesting the involvement of Ets transcription factors in the regulation of GlcNAc-T V gene expression. The src-responsive element was localized by 5' deletion analysis to a 250-base pair region containing two overlapping Ets sites. src stimulation of transcription from this region was inhibited by co-transfection with a dominant-negative mutant of Ets-2, demonstrating that the effects of the src kinase on GlcNAc-T V expression are dependent on Ets.
authors.affiliation: Department of Biochemistry and Molecular Biology and Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, 30602, USA.
authors.forename: P
authors.initials: P
authors.lastname: Buckhaults
authors.forename: L
authors.initials: L
authors.lastname: Chen
authors.forename: N
authors.initials: N
authors.lastname: Fregien
authors.forename: M
authors.initials: M
authors.lastname: Pierce
mesh_terms: D000818:Animals; D001483:Base Sequence; D016227:Benzoquinones; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000502:physiology; D006224:Cricetinae; D015971:Gene Expression Regulation, Enzymologic; D016391:Genes, src; D047029:Lactams, Macrocyclic; D008969:Molecular Sequence Data; D017351:N-Acetylglucosaminyltransferases / Q000235:genetics*; D014176:Protein Biosynthesis; D011809:Quinones / Q000494:pharmacology; D017828:Rifabutin / Q000031:analogs & derivatives; D014158:Transcription, Genetic
chemical_list: D016227:Benzoquinones; D047029:Lactams, Macrocyclic; D011809:Quinones; D017828:Rifabutin; C020754:herbimycin; D017351:N-Acetylglucosaminyltransferases; C037649:N-acetyllactosaminide beta-1,6-N-acetylglucosaminyltransferase; D017871:Calcium-Calmodulin-Dependent Protein Kinases