Involvement of upstream stimulatory factors 1 and 2 in RANKL-induced transcription of tartrate-resistant acid phosphatase gene during osteoclast differentiation.

Academic Article

Abstract

  • Tartrate-resistant acid phosphatase (TRAP) plays an important role in bone resorption. TRAP expression in osteoclasts is regulated by receptor activator of NF-kappaB (RANKL), a potent activator of osteoclast differentiation. However, the molecular mechanism underlying the RANKL-induced TRAP expression remains unknown. Here we show that two regions in the mouse TRAP promoter (one at -1858 to -1239 and the other at -1239 to -1039, relative to the translation start site) are implicated in RANKL-induced TRAP transcription in RAW264.7 cells. A detailed characterization of the region at -1239 to -1039 identifies a 12-bp sequence, AGCCACGTGGTG, that specifically binds nuclear proteins from RAW264.7 cells and primary bone marrow macrophages (BMMs) in an electrophoretic mobility shift assay (EMSA). Moreover, the binding is significantly enhanced in EMSA with nuclear extracts from RANKL-treated RAW264.7 cells and BMMs, suggesting that the 12-bp sequence may be involved in RANKL-induced TRAP transcription. Various assays reveal that nuclear proteins binding to the 12-bp sequence are upstream stimulatory factors (USF) 1 and 2. Importantly, mutation of the USF-binding site partially blocks RANKL-induced TRAP transcription in RAW264.7 cells, confirming that USF1 and USF2 are functionally involved in RANKL-induced TRAP transcription. In summary, our data show that USF1 and USF2 play a functional role in RANKL-dependent TRAP expression during osteoclast differentiation.
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    Keywords

  • Acid Phosphatase, Animals, Base Sequence, Carrier Proteins, Cell Differentiation, Cells, Cultured, DNA-Binding Proteins, Gene Expression Regulation, Isoenzymes, Membrane Glycoproteins, Mice, Molecular Sequence Data, NF-kappa B, Osteoclasts, Promoter Regions, Genetic, Protein Binding, RANK Ligand, Receptor Activator of Nuclear Factor-kappa B, Tartrate-Resistant Acid Phosphatase, Transcription Factor AP-1, Transcription Factors, Transcription, Genetic, Upstream Stimulatory Factors
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    Author List

  • Liu Y; Shi Z; Silveira A; Liu J; Sawadogo M; Yang H; Feng X
  • Start Page

  • 20603
  • End Page

  • 20611
  • Volume

  • 278
  • Issue

  • 23