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J Biol Chem. 2003 Oct 10;278(41):40088-96. Epub 2003 Jul 21.

Calcineurin directs the reciprocal regulation of calcium entry pathways in nonexcitable cells.

Author information

1
Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, New York 14642, USA.

Abstract

The reciprocal regulation of noncapacitative and capacitative (or store-operated) Ca2+ entry in nonexcitable cells (Mignen, O., Thompson, J. L., and Shuttleworth, T. J. (2001) J. Biol. Chem. 276, 35676-35683) represents a switching between two distinct Ca2+-selective channels: the noncapacitative arachidonate-regulated Ca2+ channels (ARC channels) and the store-operated Ca2+ channels (SOC channels). This switch is directly associated with the change from oscillatory to sustained Ca2+ signals as agonist concentrations increase and involves a Ca2+-dependent inhibition of the ARC channels. Here we show that this process is mediated via a calcineurin-dependent inhibition of the noncapacitative ARC channels. Pharmacological and molecular inhibition of calcineurin activity (using cyclosporin or the FK506 analogue ascomycin, and a transfected C-terminal domain of the calcineurin inhibitory protein CAIN, respectively) results in a complete reversal of the Ca2+-dependent inhibition of the ARC channels. Agonist concentrations that result in oscillatory Ca2+ signals and specifically activate Ca2+ entry through the ARC channels fail to increase calcineurin activity. However, agonist concentrations that activate the store-operated Ca2+ channels and produce prolonged increases in cytosolic Ca2+ concentrations increase calcineurin activity. Thus, calcineurin is the key mediator of the reciprocal regulation of these co-existing channels, allowing each to play a unique and non-overlapping role in Ca2+ signaling.

PMID:
12874277
DOI:
10.1074/jbc.M306365200
[Indexed for MEDLINE]
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