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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Langevin, population density and moment-based modeling of local and global aspects of intercellular calcium signaling
TL;DR: This dissertation presents a Ca2+ release site modeling approach based on a Langevin description of stochastic Ca2-m ediated inactivation of open channels, and shows how Langevin equations in a whole cell model involving a large number of release sites may be replaced by a single Fokker-Planck equation, yielding an extremely compact and efficient local/global whole cell models.
Book ChapterDOI
Control of Mitochondrial Metabolism by Calcium-Dependent Hormones
TL;DR: It is shown that mitochondria are able to integrate oscillating Ca2+ signals into a graded metabolic output and hormone-induced oscillations in [Ca2+]m elicit sustained increases in NADH.
Journal ArticleDOI
Ca2+ signalling system initiated by endoplasmic reticulum stress stimulates PERK activation.
Constanza Feliziani,Macarena Fernadez,Gonzalo Quassollo,Deborah M. Holstein,Sebastián M Bairo,James C. Paton,Adrienne W. Paton,Juan de Batista,James D. Lechleiter,Mariana Bollo +9 more
TL;DR: In this article , the authors reveal the existence of a Ca 2+ signal mechanism by which stressor-mediated Ca 2 + release regulates ER stress by tethering a genetically encoded ca 2+ indicator (GCamP6) to the ER membrane.
Journal ArticleDOI
A Tale of two receptors.
Ielyaas Cloete,Juliana C. Corrêa-Velloso,Paula J. Bartlett,Vivien Kirk,Andrew P. Thomas,James Sneyd +5 more
TL;DR: In this article, a new model of Ca2+ oscillations in hepatocytes based on these experiments was proposed to investigate the mechanisms controlling P2Y-activated Ca2+, which accounts for Ca2 + regulation of the IP3 receptor (IP3R), the positive feedback from Ca 2+ on phospholipase C (PLC), and the p2Y receptor phosphorylation by protein kinase C(PKC).
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.
Journal ArticleDOI
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.
Journal ArticleDOI
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.