Pharmacology of Capacitative Calcium Entry

  1. James W. Putney Jr., Ph.D.
  1. Laboratory of Signal Transduction National Institute of Environmental Health Sciences/NIH, PO Box 12233 Research Triangle Park, NC 27709
  1. E-mail putney{at}niehs.nih.gov; fax 919-541-7879.

Abstract

The versatility of Ca2+ as a messenger in multiple signaling events requires that the concentration of calcium ions within the cytoplasm be highly regulated. In particular, the release of calcium from intracellular stores must often be linked to calcium influx across the cell membrane. Capacitative calcium entry, whereby the depletion of intracellular Ca2+ stores induces the influx of extracellular calcium, is a crucial element of concerted calcium signaling. Investigations into the phenomenon are contributing to a new appreciation for the organized cytoplasmic framework that supports calcium signaling.

Graphic The endoplasmic reticulum (stained red above) is an important source of the calcium ions that pour into the cytosol in response to extracellular stimuli. The mechanism by which release of calcium ions from intracellular stores is coordinated with ion influx across the plasma membrane is referred to as capacitative calcium entry. Research into this mechanism will likely result in new pharmacological approaches to cell signaling.

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