1. The Krüppel-like transcriptional factors Zf9 and GKLF coactivate the human keratin 4 promoter and physically interact
- Author
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Anil K. Rustgi, Oliver G. Opitz, Scott L. Friedman, Jun-ichi Okano, Timothy D. Jenkins, and Hiroshi Nakagawa
- Subjects
Transcriptional Activation ,Kruppel-Like Transcription Factors ,Biophysics ,Transfection ,Biochemistry ,Cell Line ,Kruppel-Like Factor 4 ,03 medical and health sciences ,Esophagus ,0302 clinical medicine ,Structural Biology ,Proto-Oncogene Proteins ,Gene expression ,Kruppel-Like Factor 6 ,Tumor Cells, Cultured ,Genetics ,Humans ,RNA, Messenger ,Promoter Regions, Genetic ,Molecular Biology ,Transcription factor ,Sequence Deletion ,030304 developmental biology ,Regulation of gene expression ,0303 health sciences ,Reporter gene ,biology ,Zf9/KLF6 ,Epithelial Cells ,Keratin 4 promoter ,Cell Biology ,Immunohistochemistry ,Precipitin Tests ,DNA-Binding Proteins ,Gene Expression Regulation, Neoplastic ,Molecular Weight ,Repressor Proteins ,KLF6 ,Keratin 4 ,KLF4 ,030220 oncology & carcinogenesis ,Trans-Activators ,biology.protein ,Cancer research ,Keratins ,Gut-enriched Krüppel-like factor (GKLF/KLF4) ,Protein Binding ,Transcription Factors - Abstract
Zf9/CPBP/KLF6 is a widely expressed member of the Krüppel-like family of transcriptional factors which regulates gene expression in hepatic stellate cells. Because of its ubiquitous expression including in the esophagus, we have explored its function in the esophageal squamous epithelium, a model system to study cellular proliferation and differentiation. Reverse transcription-PCR (RT-PCR) and Western blot analyses revealed that Zf9 was highly expressed in human esophageal squamous cancer cell lines. Additionally, Zf9 localizes to the esophageal squamous epithelium by immunohistochemistry. Using transient transfection, Zf9 transactivates the human keratin 4 (K4) promoter reporter gene construct in a subset of the esophageal cancer cell lines through indirect mechanisms. Co-transfection of Zf9 and GKLF/KLF4, which is also a member of the Krüppel-like factors and expressed in the esophageal squamous epithelium, leads to coactivation in an additive fashion. Furthermore, we demonstrate that there is a physical interaction between GKLF and Zf9, a novel finding for Krüppel-like family members.
- Published
- 2000
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