Mitf–PU.1 interactions with the tartrate-resistant acid phosphatase gene promoter during osteoclast differentiation

• Published in: Bone (New York, N.Y.) N.Y.), 2004-02, Vol.34 (2), p.237-245
• Main Authors: Partington, G.A, Fuller, K, Chambers, T.J, Pondel, M
• Format: Article
• Language: English
• Subjects: Acid Phosphatase - genetics; Animals; Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; Biological and medical sciences; Cell Differentiation - physiology; Cells, Cultured; Diseases of the osteoarticular system; DNA-Binding Proteins - metabolism; Electrophoretic Mobility Shift Assay; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation; Isoenzymes - genetics; Medical sciences; Mice; Microphthalmia-Associated Transcription Factor; Mitf; Osteoclasts; Osteoclasts - metabolism; Promoter Regions, Genetic; Proto-Oncogene Proteins - metabolism; Tartrate-Resistant Acid Phosphatase; Trans-Activators - metabolism; Transcription Factors - metabolism; TRAP; Traumas. Diseases due to physical agents; Vertebrates: anatomy and physiology, studies on body, several organs or systems
• ISSN: 8756-3282; 1873-2763
• DOI: 10.1016/j.bone.2003.11.010

It has been postulated that the transcription factors micropthalmia associated factor (Mitf) and PU.1 interact with the tartrate-resistant acid phosphatase (TRAP) gene promoter and activate TRAP gene expression in osteoclasts. However, studies on the interaction of these factors with the TRAP promoter employing nuclear extracts from osteoclasts and osteoclast precursors have not been reported. We therefore treated murine mononuclear phagocyte cells with various cytokines to generate cultures of osteoclasts and macrophagic cells with high or low potential to form osteoclasts. The presence of Mitf and PU.1 in nuclear extracts from these cultures and the ability of these factors to bind to the TRAP promoter was then assessed. We demonstrate that Mitf and a related factor, TFE3, are present in nuclear extracts from all cultures and bind the TRAP promoter. While PU.1 is present in nuclear extracts from all cultures, it does not significantly interact with a putative binding site in the TRAP promoter. These results suggest Mitf and PU.1 interactions with the TRAP promoter are not responsible for the specific activation of TRAP gene expression in osteoclasts.