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
More filters
Journal ArticleDOI
Cooperative activation of IP3 receptors by sequential binding of IP3 and Ca2+ safeguards against spontaneous activity
TL;DR: It is proposed that the closed conformation of the IP3 receptor is very stable and therefore minimally susceptible to spontaneous activation; at least three (probably four) IP3 molecules may be required to provide enough binding energy to drive the receptor into a stable open conformation.
Journal ArticleDOI
Phospholipid signalling in the nucleus. Een DAG uit het leven van de inositide signalering in de nucleus.
TL;DR: This work discusses at length data related to the sources and possible consequences of nuclear DAG production as this lipid appears to be increasingly central to a number of general physiological functions.
Journal ArticleDOI
Coordination of Ca2+ signalling by NAADP.
TL;DR: Recent studies in intact cells have demonstrated functional coupling ('channel chatter') between Ca2+ release pathways mediated by NAADP, inositol trisphosphate and cyclic ADP-ribose, probably an important determinant in shaping cytosolic Ca 2+ signals.
Journal ArticleDOI
The Role of Mitochondria for Ca2+ Refilling of the Endoplasmic Reticulum
TL;DR: Data point to different contribution of mitochondria in the process of ER Ca2+ refilling based on the presence or absence of IP3, which represents the turning point for the dependence or autonomy of ERCa2- refilling from trans-mitochondrial Ca2- flux.
Journal ArticleDOI
Pharmacological analysis of intracellular Ca2+ signalling: problems and pitfalls
Colin W. Taylor,Lisa M. Broad +1 more
TL;DR: Taylor and Broad as mentioned in this paper summarized the more serious problems associated with some of the commonly used drugs, and described specific situations in which the multiple effects of drugs on Ca2(+)-signalling pathways have confused analysis of these pathways.
References
More filters
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.
Journal ArticleDOI
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.
Journal ArticleDOI
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.