Taurine is present in a variety of tissues and exhibits many important phys
iological functions in the cell. Even though its functions are well documen
ted in many tissues, its actions on bone cells are largely unknown. Conside
ring a recent finding that taurine is present in the bone, we wished to det
ermine if taurine could have any effects on osteoblast cells. Taurine (10 m
M) stimulated alkaline phosphatase activity as well as collagen synthesis.
Taurine also stimulated tyrosine phosphorylation of a number of cellular pr
oteins including a 42-kDa protein. The 42-kDa protein was identified as ext
racellular signal regulated protein kinase 2 (ERK22). A mitogen-activated p
rotein kinase kinase (MEK) inhibitor blocked the taurine-stimulated alkalin
e phosphatase activity and colla gen synthesis. These results suggest that
taurine could regulate osteoblast metabolism via ERK2 activation. (C) 2001
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