Elementary and global aspects of calcium signalling.
TLDR
Using Ca2+ imaging techniques, the opening of individual channels has now been visualized and models have been proposed to explain how these elementary events are coordinated to generate the global Ca 2+ signals that regulate cellular activity.Abstract:
Calcium is a ubiquitous second messenger used to regulate a wide range of cellular processes. This role in signalling has to be conducted against the rigid homeostatic mechanisms that ensure that the resting level of Ca2+ is kept low (i.e. between 20 and 100 nmol l-1) in order to avoid the cytotoxic effects of a prolonged elevation of [Ca2+]. Cells have evolved a sophisticated signalling system based on the generation of brief pulses of Ca2+ which enables this ion to be used as a messenger, thus avoiding its toxic effects. Such Ca2+ spikes usually result from the coordinated release of Ca2+ from internal stores using either inositol 1,4,5-trisphosphate or ryanodine receptors. Using Ca2+ imaging techniques, the opening of individual channels has now been visualized and models have been proposed to explain how these elementary events are coordinated to generate the global Ca2+ signals that regulate cellular activity.read more
Citations
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Molecular basis of spatio-temporal dynamics in inositol 1,4,5-trisphosphate-mediated Ca2+ signalling.
TL;DR: Subtypes of IP3 receptors that have distinct functional properties and contribute to the diversity of Ca2+ signalling patterns are described, highlighting the potential importance of the spatio-temporal information of any signalling molecule.
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Potassium-Efflux Channels in Extensor and Flexor Cells of the Motor Organ of Samanea saman Are Not Identical. Effects of Cytosolic Calcium
Menachem Moshelion,Nava Moran +1 more
TL;DR: Detailed analysis revealed that in flexors millimolar [Ca(2+)](cyt) decreased the maximum number of open channels, but simultaneously increased K(D) channel opening probability by negatively shifting the half-maximum-activation voltage by 40 to 50 mV, practically cancelled-out.
Journal ArticleDOI
Statistical properties and information content of calcium oscillations.
Alexander Skupin,Martin Falcke +1 more
TL;DR: The stochastic data is analyzed and it is shown how internal properties can be determined from global observations of spontaneous and stimulated oscillations.
Journal ArticleDOI
Modelling the transition from simple to complex Ca2+oscillations in pancreatic acinar cells
TL;DR: The model predicts that calcium-dependent production and degradation of IP3 is a key mechanism for complex calcium oscillations in pancreatic acinar cells.
Journal ArticleDOI
Mechanisms of histamine-induced intracellular Ca2+ release and extracellular Ca2+ entry in MG63 human osteosarcoma cells
Kam Chung Lee,Li-Ling Tseng,Yu-Chih Chen,Jun-Wen Wang,Cheng-Hsien Lu,Jin-Shiung Cheng,Jue-Long Wang,Yuk-Keung Lo,Chung-Ren Jan +8 more
TL;DR: Together, this study shows that histamine increased in ([Ca2+](i)) in osteosarcoma cells by stimulating H2 histamine receptors.
References
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Journal ArticleDOI
Inositol trisphosphate and calcium signalling
TL;DR: Inositol trisphosphate is a second messenger that controls many cellular processes by generating internal calcium signals through receptors whose molecular and physiological properties closely resemble the calcium-mobilizing ryanodine receptors of muscle.
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Inositol trisphosphate, a novel second messenger in cellular signal transduction.
TL;DR: Diacylglycerol operates within the plane of the membrane to activate protein kinase C, whereas inositol trisphosphate is released into the cytoplasm to function as a second messenger for mobilizing intracellular calcium.
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A model for receptor-regulated calcium entry
TL;DR: A capacitative model is proposed for the mechanism by which activation of surface membrane receptors causes sustained Ca2+ entry into cells from the extracellular space, which allows forCa2+ release and Ca2-mobilization to be controlled by a single messenger, inositol (1,4,5) trisphosphate.
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Release of Ca2+ from a nonmitochondrial intracellular store in pancreatic acinar cells by inositol-1,4,5-trisphosphate.
TL;DR: It is reported here that micromolar concentrations of Ins1,4,5P3 release Ca2+ from a nonmitochondrial intracellular Ca2- store in pancreatic acinar cells, and the results strongly suggest that this is the same Ca1+ store that is released by acetylcholine.
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Calcium sparks: elementary events underlying excitation-contraction coupling in heart muscle
TL;DR: The calcium spark is the consequence of elementary events underlying excitation-contraction coupling and provides an explanation for both spontaneous and triggered changes in the intracellular calcium concentration in the mammalian heart.