S100 beta stimulates calcium fluxes in glial and neuronal cells.
The glial-derived protein S100 beta can act as a mitogen or a neurotrophic factor, stimulating proliferation of glial cells or differentiation of immature neurons. We report here that dimeric S100 beta evokes increases in intracellular free calcium concentrations ([Ca2+]i) in both glial cells and neuronal cells. The [Ca2+]i increase exhibited a rapid transient component which was not affected by removal of extracellular calcium and a sustained component which appeared to require influx of extracellular calcium through Ni(2+)-sensitive channels. S100 beta also stimulated hydrolysis of phosphoinositides, suggesting a mobilization of calcium from intracellular stores. These data suggest that although the final biological responses of neuronal and glial cells to S100 beta are different, transduction of the S100 beta signal in both cell types involves changes in [Ca2+]i.
Barger
S W
SW
Department of Cell Biology, Vanderbilt University, Nashville, Tennessee 37232.
Van Eldik
L J
LJ
D000818:Animals; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000494:pharmacology; D002417:Cattle; D002460:Cell Line; D002478:Cells, Cultured; D002642:Chick Embryo; D003001:Cloning, Molecular; D005813:Genes, Synthetic; D005910:Glioma; D007700:Kinetics; D009414:Nerve Growth Factors; D009447:Neuroblastoma; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D010716:Phosphatidylinositols / Q000378:metabolism; D051381:Rats; D011994:Recombinant Proteins / Q000494:pharmacology; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000494:pharmacology*
D002135:Calcium-Binding Proteins; D009414:Nerve Growth Factors; D010716:Phosphatidylinositols; D011994:Recombinant Proteins; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; D002118:Calcium