title: Transcriptional regulation of the human neutral ceramidase gene.
abstract: Ceramidases play a critical role in generating sphingosine-1-phosphate by hydrolyzing ceramide into sphingosine, a substrate for sphingosine kinase. In order to elucidate its transcriptional regulation, we identify here a putative promoter region in the 5'-UTR of the human neutral CDase (nCDase) gene. Using human genomic DNA, we cloned a 3000 bp region upstream of the translational start site of the nCDase gene. Luciferase reporter analyses demonstrated that this 3000 bp region had promoter activity, with the strongest induction occurring within the first 200 bp. Computational analysis revealed the 200 bp essential promoter region contained several well-characterized promoter elements, lacked a conical TATA box, but did contain a reverse oriented CCAAT box, a feature common to housekeeping genes. Electrophoretic mobility shift assays demonstrated that the identified candidate transcriptional response elements (TRE) bind their respective transcription factors, including NF-Y, AP-2, Oct-1, and GATA. Mutagenic analyses of the TRE revealed that these sites regulated promoter activity and mutating an individual site decreased promoter reporter activity by up to 50%. Together, our findings suggest that regulation of nCDase expression involves coordinated TATA-less transcriptional activity.
authors.affiliation: Department of Pharmacology, Penn State College of Medicine, Hershey, PA 17033, USA.
authors.forename: Sean M
authors.initials: SM
authors.lastname: O'Neill
authors.forename: Jong K
authors.initials: JK
authors.lastname: Yun
authors.forename: Todd E
authors.initials: TE
authors.lastname: Fox
authors.forename: Mark
authors.initials: M
authors.lastname: Kester
mesh_terms: D020121:5' Untranslated Regions; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic; D057809:HEK293 Cells; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D055576:Neutral Ceramidase / Q000235:genetics*; D011401:Promoter Regions, Genetic; D020218:Response Elements; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity
chemical_list: D020121:5' Untranslated Regions; D017931:DNA Primers; C526744:ASAH2 protein, human; D055576:Neutral Ceramidase