title: L-Sox5 and Sox6 proteins enhance chondrogenic miR-140 microRNA expression by strengthening dimeric Sox9 activity.
abstract: Sox9 plays a critical role in early chondrocyte initiation and promotion as well as repression of later maturation. Fellow Sox family members L-Sox5 and Sox6 also function as regulators of cartilage development by boosting Sox9 activation of chondrocyte-specific genes such as Col2a1 and Agc1; however, the regulatory mechanism and other target genes are largely unknown. MicroRNAs are a class of short, non-coding RNAs that act as negative regulators of gene expression by promoting target mRNA degradation and/or repressing translation. Analysis of genetically modified mice identified miR-140 as a cartilage-specific microRNA that could be a critical regulator of cartilage development and homeostasis. Recent findings suggest Sox9 promotes miR-140 expression, although the detailed mechanisms are not fully understood. In this study we demonstrate that the proximal upstream region of pri-miR-140 has chondrogenic promoter activity in vivo. We found an L-Sox5/Sox6/Sox9 (Sox trio) response element and detailed binding site in the promoter region. Furthermore, detailed analysis suggests the DNA binding and/or transactivation ability of Sox9 as a homodimer is boosted by L-Sox5 and Sox6. These findings provide new insight into cartilage-specific gene regulation by the Sox trio.
authors.affiliation: Department of Systems Biomedicine, National Research Institute for Child Health and Development, 2-10-1 Okura, Setagaya-ku, Tokyo 157-8535, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yamashita
authors.forename: Shigeru
authors.initials: S
authors.lastname: Miyaki
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Kato
authors.forename: Shigetoshi
authors.initials: S
authors.lastname: Yokoyama
authors.forename: Tempei
authors.initials: T
authors.lastname: Sato
authors.forename: Francisco
authors.initials: F
authors.lastname: Barrionuevo
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Akiyama
authors.forename: Gerd
authors.initials: G
authors.lastname: Scherer
authors.forename: Shuji
authors.initials: S
authors.lastname: Takada
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Asahara
mesh_terms: D000818:Animals; D002356:Cartilage / Q000378:metabolism*; D019902:Chondrocytes / Q000166:cytology; D047369:Chromatin Immunoprecipitation; D019281:Dimerization; D005786:Gene Expression Regulation; D057809:HEK293 Cells; D006609:High Mobility Group Proteins / Q000235:genetics; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D035683:MicroRNAs / Q000378:metabolism*; D016133:Polymerase Chain Reaction / Q000379:methods; D020033:Protein Isoforms; D055758:SOX9 Transcription Factor / Q000378:metabolism*; D055755:SOXD Transcription Factors / Q000378:metabolism*; D015533:Transcriptional Activation; D019076:Transgenes
chemical_list: D006609:High Mobility Group Proteins; C547828:MIRN140 microRNA, mouse; D035683:MicroRNAs; C544302:Mirn140 microRNA, human; D020033:Protein Isoforms; C490301:SOX5 protein, human; C486270:SOX6 protein, human; D055758:SOX9 Transcription Factor; C527932:SOX9 protein, human; D055755:SOXD Transcription Factors; C089186:Sox5 protein, mouse; C095939:Sox6 protein, mouse; C527933:Sox9 protein, mouse