title: A novel cis-element that enhances connective tissue growth factor gene expression in chondrocytic cells.
abstract: To clarify the chondrocyte-specific regulatory mechanism of connective tissue growth factor (ctgf) gene expression, we analyzed the functionality and DNA-protein interaction of the CTGF promoter. Comparative luciferase assay of the CTGF promoter deletion mutants among HCS-2/8 chondrocytic cells and fibroblastic cells revealed that a 110-bp region in the promoter was crucial for the HCS-2/8-specific transcriptional enhancement. Subsequent competitive gel shift assay revealed that transcription factors in HCS-2/8 nuclei bound to a 60-bp portion in the corresponding region. Relative luciferase activity from a CTGF promoter with mutant TGF-beta response element (TbRE) was 16.9% lower than that from an intact promoter. On the other hand, relative luciferase activity from a CTGF promoter with 4bp point mutations at 30bp upstream of the TbRE was 47.7% lower than that from the intact one. The binding activity of HCS-2/8 nuclear factor(s) to the sequence over the 4-bp was remarkably higher than that of any nuclear extract from other types of cells. Therefore, we entitled the sequence 'TRENDIC', a transcription enhancer dominant in chondrocytes, which stands for a novel enhancer for chondrocyte-specific CTGF gene expression.
authors.affiliation: Department of Biochemistry and Molecular Dentistry, Okayama University Graduate School of Medicine and Dentistry, 2-5-1 Shikata-cho 700-8525, Okayama, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Eguchi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kubota
authors.forename: Seiji
authors.initials: S
authors.lastname: Kondo
authors.forename: Takuo
authors.initials: T
authors.lastname: Kuboki
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Yatani
authors.forename: Masaharu
authors.initials: M
authors.lastname: Takigawa
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D019902:Chondrocytes / Q000378:metabolism*; D055513:Connective Tissue Growth Factor; D004247:DNA; D004742:Enhancer Elements, Genetic; D005786:Gene Expression Regulation / Q000502:physiology*; D006133:Growth Substances / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D017874:Immediate-Early Proteins / Q000235:genetics* / Q000378:metabolism; D036341:Intercellular Signaling Peptides and Proteins; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D014157:Transcription Factors / Q000378:metabolism
chemical_list: C526317:CCN2 protein, human; D006133:Growth Substances; D017874:Immediate-Early Proteins; D036341:Intercellular Signaling Peptides and Proteins; D014157:Transcription Factors; D055513:Connective Tissue Growth Factor; D004247:DNA