RRC ID 39896
Author Fujita T, Izumo N, Fukuyama R, Meguro T, Nakamuta H, Kohno T, Koida M.
Title Phosphate provides an extracellular signal that drives nuclear export of Runx2/Cbfa1 in bone cells.
Journal Biochem Biophys Res Commun
Abstract Inorganic phosphate (Pi) supplement is generally used to accelerate mineralization of cultured bone cells but the mechanism of action is totally unknown. How the action is related with the transactivation of Runx2/Cbfa1,a master gene product of bone formation,was examined. Clonal bone cells (osteoblastic MC3T3-E1, chondrocytic ATDC5 and osteocytic MLO-Y4) on preculture in ascorbate-containing medium constantly expressed and accumulated Cbfa1 in the nuclei, and subsequent increase of Pi concentration to 3 or 10 mM was found to invariably induce nuclear export (not import) of Cbfa1 which was completed in a few hours. In addition, Pi was found to lower the expression of osteocalcin. Leptomycin B completely inhibited Pi-induced nuclear export, suggesting that CRM1/exportin 1 is involved in Pi-induced nuclear export. The result suggests that bone cells are equipped with a novel Pi sensing mechanism which is functionally linked to a nuclear export system of Cbfa1.
Volume 280(1)
Pages 348-52
Published 2001-1-12
DOI 10.1006/bbrc.2000.4108
PII S0006-291X(00)94108-1
PMID 11162521
MeSH 3T3 Cells Animals Carrier Proteins / metabolism Cell Nucleus / drug effects Cell Nucleus / metabolism* Core Binding Factor Alpha 1 Subunit Fatty Acids, Unsaturated / pharmacology Karyopherins* Kinetics Mice Neoplasm Proteins* Nuclear Proteins / metabolism Osteoblasts / cytology Osteoblasts / physiology* Osteocytes / cytology Osteocytes / physiology* Osteogenesis / physiology* Phosphates / metabolism* Protein Transport / drug effects Receptors, Cytoplasmic and Nuclear* Signal Transduction / physiology* Transcription Factors / metabolism*
IF 2.705
Times Cited 58
Human and Animal Cells