title: CpG methylation plays a vital role in determining tissue- and cell-specific expression of the human cell-death-inducing DFF45-like effector A gene through the regulation of Sp1/Sp3 binding.
abstract: Cell-death-inducing DFF45-like effector A (CIDE-A) belongs to a family of proapoptotic proteins, the expression of which is highly restricted in human tissues and cells. Here, the core region of the human CIDE-A promoter was characterized. Surprisingly, two Sp1/Sp3-binding sites, rather than tissue-specific transcription factors, were found to be required for the promoter activity. Although the ubiquitously expressed Sp1 and Sp3 were crucial, they alone could not adequately regulate the specific expression of CIDE-A. We found that the expression of CIDE-A was further regulated by CpG methylation of the promoter region. By performing bisulfite sequencing, we observed dense CpG methylation of the promoter region in tissues and cells with low or no expression of CIDE-A but not in tissues with high level of CIDE-A expression. In vitro methylation of this region showed significantly reduced transcriptional activity. Treatment of CIDE-A-negative cells with 5-aza-2'-deoxycytidine demethylated the CpG sites; this opened the closed chromatin conformation and markedly enhanced the binding affinity of Sp1/Sp3 to the promoter in vivo, thereby restoring CIDE-A expression. These data indicated that CpG methylation plays a crucial role in establishing and maintaining tissue- and cell-specific transcription of the CIDE-A gene through the regulation of Sp1/Sp3 binding.
authors.affiliation: State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Li
authors.forename: Liang
authors.initials: L
authors.lastname: Da
authors.forename: Hong
authors.initials: H
authors.lastname: Tang
authors.forename: Tsaiping
authors.initials: T
authors.lastname: Li
authors.forename: Mujun
authors.initials: M
authors.lastname: Zhao
mesh_terms: D051017:Apoptosis Regulatory Proteins / Q000235:genetics*; D001374:Azacitidine / Q000031:analogs & derivatives / Q000494:pharmacology; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D045744:Cell Line, Tumor; D002843:Chromatin / Q000187:drug effects; D018899:CpG Islands; D019175:DNA Methylation; D000077209:Decitabine; D005091:Exons; D015870:Gene Expression / Q000187:drug effects; D005786:Gene Expression Regulation; D006801:Humans; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D034622:RNA Interference; D016329:Sp1 Transcription Factor / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D051705:Sp3 Transcription Factor / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D014018:Tissue Distribution
chemical_list: D051017:Apoptosis Regulatory Proteins; C502539:CIDEA protein, human; D002843:Chromatin; C497121:SP3 protein, human; D016329:Sp1 Transcription Factor; D051705:Sp3 Transcription Factor; D000077209:Decitabine; D001374:Azacitidine