SOX6 binds CtBP2 to repress transcription from the Fgf-3 promoter

• Published in: Nucleic acids research Vol. 29; no. 16; pp. 3347 - 3355
• Main Authors: Murakami, Akira, Ishida, Sanami, Thurlow, Jane, Revest, Jean-Michel, Dickson, Clive
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 15.08.2001; Oxford Publishing Limited (England)
• Subjects: Alcohol Oxidoreductases; Amino Acid Motifs; Amino Acid Sequence; Animals; Cell Differentiation; Cell Line; Co-Repressor Proteins; CtBP2 protein; DNA-Binding Proteins; DNA-Binding Proteins - chemistry; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; Ear, Inner; Ear, Inner - embryology; Ear, Inner - metabolism; Enhancer Elements, Genetic; Enhancer Elements, Genetic - genetics; Fgf-3 gene; Fibroblast Growth Factor 3; Fibroblast Growth Factors; Fibroblast Growth Factors - analysis; Fibroblast Growth Factors - genetics; Gene Expression Regulation, Developmental; Gene Silencing; High Mobility Group Proteins; High Mobility Group Proteins - chemistry; High Mobility Group Proteins - genetics; High Mobility Group Proteins - metabolism; Life Sciences; Mice; Molecular Sequence Data; Mutation; Mutation - genetics; Organ Specificity; Phosphoproteins; Phosphoproteins - chemistry; Phosphoproteins - genetics; Phosphoproteins - metabolism; Precipitin Tests; Promoter Regions, Genetic; Promoter Regions, Genetic - genetics; Protein Binding; Proto-Oncogene Proteins; Proto-Oncogene Proteins - analysis; Proto-Oncogene Proteins - genetics; Repressor Proteins; Repressor Proteins - chemistry; Repressor Proteins - genetics; Repressor Proteins - metabolism; Response Elements; Response Elements - genetics; RNA, Messenger; RNA, Messenger - biosynthesis; RNA, Messenger - genetics; RNA, Messenger - metabolism; Sequence Alignment; SOX6 protein; SOXD Transcription Factors; Transcription Factors; Transcription, Genetic; Transcription, Genetic - genetics; Two-Hybrid System Techniques
• ISSN: 0305-1048; 1362-4962; 1362-4962
• DOI: 10.1093/nar/29.16.3347

Fgf-3 is expressed in a complex pattern during mouse development. Previously, an essential regulatory element PS4A was identified in the promoter region, and shown to bind at least three factors. To identify the transcription factor(s), we used a yeast one-hybrid screen and obtained a novel Sox6 cDNA (SOX6D). When introduced into cells it strongly repressed activity from both an Fgf-3 reporter gene as well as an artificial promoter containing three PS4A elements. In situ hybridisation analysis showed that Sox6 and Fgf-3 are co-expressed in the otic vesicle of E9.5 mouse embryos in a mutually exclusive pattern, consistent with a repression of Fgf-3 transcription by SOX6. To characterise additional factor(s) involved in Fgf-3 gene repression, a yeast two-hybrid screen was used with the N‐terminal portion of SOX6D. Mouse CtBP2 cDNA clones were isolated and shown to bind SOX6 in yeast and mammalian cells. Furthermore, mutational analysis of SOX6 showed that binding to CtBP2, and its responsiveness to this co-repressor, were dependent on a short amino acid sequence motif PLNLSS. Co-expression studies in NIH3T3 cells showed that SOX6 and CtBP2 co-operate to repress activity from the Fgf-3 promoter through the enhancer element PS4A. These results show that SOX6 can recruit CtBP2 to repress transcription from the Fgf-3 promoter.