Sci. STKE, 7 January 2003
Calcium High Frequency Filter for Ca2+
Transient changes in intracellular Ca2+ regulate numerous cellular functions including gene expression. Some Ca2+-mediated changes in gene expression are elicited by increases in cytosolic Ca2+ concentration ([Ca2+]c), whereas others require an increase in nuclear Ca2+ concentration ([Ca2+]n). Chamero et al. expressed targeted aequorins in the cytoplasm and nuclei of bovine adrenal chromaffin cells, PC12 cells, and GH3 cells to measure [Ca2+]c and [Ca2+]n and to study the spread of Ca2+ from the cytoplasm to the nucleus following various stimuli. The authors found that stimuli that produced sustained increases in [Ca2+]c, either through Ca2+ entry or through release from intracellular stores, produced similar changes in [Ca2+]n, whereas brief oscillations in [Ca2+]c visualized in individual GH3 cells were dampened during propagation to the nucleus. These data suggest that a kinetic filter limits the effects of high frequency changes in [Ca2+]i on [Ca2+]n but allows sustained Ca2+ signals through. Such a filter could provide a mechanism whereby Ca2+ signals are encoded; this would allow for the differential regulation of processes that depend on increases in either [Ca2+]c or [Ca2+]n.
Citation: High Frequency Filter for Ca2+. Sci. STKE 2003, tw3 (2003).
Science Signaling. ISSN 1937-9145 (online), 1945-0877 (print). Pre-2008: Science's STKE. ISSN 1525-8882