title: Functional and sequence analysis of human neuroglobin gene promoter region.
abstract: Neuroglobin (Ngb), a recently found oxygen-binding protein belonging to the vertebrate globin family, is mainly expressed in neurons of brains and eyes. Current studies have revealed diverse potential functions of Ngb and it was found to be able to reduce the severity of stroke and Alzheimer's disease, implying its importance in brains. However, the mechanism of Ngb regulation of transcription has not been elucidated yet. In this study, we analyzed the 5'-flanking region of human neuroglobin gene (NGB) and identified a transcription start site (TSS) located at -306bp relative to the translation start site ATG. We characterized the proximal promoter of NGB and found two GC-boxes located at -16 and +30bp relative to the TSS which are bound by transcription factor Sp1 and Sp3. Mutation of either GC-box led to a significant reduction in NGB promoter activity, while overexpression of Sp1 and Sp3 resulted in activation of the promoter. However, two putative NRSE sites (-359 and -127bp relative to the TSS) apparently showed no influence on NGB tissue-specific expression. Treatment of two non-neuronal cell lines HeLa and BEAS-2B with 5-aza-2'-deoxycytidine remarkably induced NGB expression, suggesting a potential role of DNA methylation in regulating NGB tissue-specific expression.
authors.affiliation: School of Biological Sciences, The University of Hong Kong, Hong Kong SAR.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Zhipeng
authors.initials: Z
authors.lastname: Tian
authors.forename: Sha
authors.initials: S
authors.lastname: Sha
authors.forename: Lydia Yuk Luen
authors.initials: LY
authors.lastname: Cheng
authors.forename: Sjaak
authors.initials: S
authors.lastname: Philipsen
authors.forename: Kian-Cheng
authors.initials: KC
authors.lastname: Tan-Un
mesh_terms: D024506:5' Flanking Region / Q000235:genetics; D001374:Azacitidine / Q000031:analogs & derivatives / Q000494:pharmacology; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002460:Cell Line; D045744:Cell Line, Tumor; D047369:Chromatin Immunoprecipitation; D000077209:Decitabine; D024202:Electrophoretic Mobility Shift Assay; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D005914:Globins / Q000235:genetics* / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009419:Nerve Tissue Proteins / Q000235:genetics* / Q000378:metabolism; D000078787:Neuroglobin; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011485:Protein Binding; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016329:Sp1 Transcription Factor / Q000378:metabolism; D051705:Sp3 Transcription Factor / Q000378:metabolism; D024363:Transcription Initiation Site
chemical_list: D004791:Enzyme Inhibitors; D009419:Nerve Tissue Proteins; D000078787:Neuroglobin; D016329:Sp1 Transcription Factor; D051705:Sp3 Transcription Factor; D000077209:Decitabine; D005914:Globins; D008156:Luciferases; D001374:Azacitidine