Intracellular ADP Modulates the Ca Release-activated Ca Current in a Temperature- and Ca -dependent Way

Divergence of Ca selectivity and equilibrium Ca blockade in a Ca release-activated Ca channel

Ca is a multifunctional signaling messenger crucial for diverse biological processes. Among the various ways by which cellular Ca signals are generated, storeoperated Ca release-activated Ca (CRAC) channels are recognized as a widespread mechanism for regulating transcription, motility, and proliferation in many cells (Feske, 2009; Hogan et al., 2010; Lewis, 2011). CRAC channels produce sustain...

Store-Operated Ca Release-Activated Ca Channels Regulate PAR2-Activated Ca Signaling and Cytokine Production in Airway Epithelial Cells

Intracellular Ca release in skinned smooth muscle

The release of internal Ca from saponin-treated skinned smooth muscle of guinea pig taenia caecum was studied. The amount of Ca released was estimated by the area under the contraction curve during treatment with 25 mM caffeine in the presence of 0.1 mM EGTA. The magnitude of the caffeine response in skinned muscle, after loading with 10(-6) M Ca for 3 min, was similar to that in the depolarize...

Myofilament Ca sensitization increases cytosolic Ca binding affinity, alters intracellular Ca homeostasis, and causes pause-dependent Ca-triggered arrhythmia.

RATIONALE Ca binding to the troponin complex represents a major portion of cytosolic Ca buffering. Troponin mutations that increase myofilament Ca sensitivity are associated with familial hypertrophic cardiomyopathy and confer a high risk for sudden death. In mice, Ca sensitization causes ventricular arrhythmias, but the underlying mechanisms remain unclear. OBJECTIVE To test the hypothesis t...

Stochastic spreading of intracellular Ca(2+) release.

We study the spreading of calcium-induced calcium release with the stochastic DeYoung-Keizer-model of the inositol 1,4,5-trisphosphate receptor channel. The model shows a transition from isolated release events to steadily propagating waves with increasing IP3 concentration. A state--stochastic backfiring--was found in the regime of steady propagation. The model can be reduced by an adiabatic e...