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
Ca2+ entry via AMPA-type glutamate receptors triggers Ca2+-induced Ca2+ release from ryanodine receptors in rat spiral ganglion neurons.
TL;DR: Functional coupling between somatic AMPA-type glutamate receptors and intracellular Ca(2+) stores via RyR-dependent CICR in primary auditory neurons is demonstrated.
Journal ArticleDOI
Thapsigargin inhibits a potassium conductance and stimulates calcium influx in the intact rat lens
TL;DR: Data indicate that thapsigargin induces both a decrease in K- conductance and an increase in Ca2+ conductance, which probably result from release of stored Ca2- and subsequent activation of store‐operated Ca2‐ channels (capacitative Ca2+, entry).
Journal ArticleDOI
Effect of nitric oxide on calcium-induced calcium release in coronary arterial smooth muscle.
TL;DR: It is suggested that CICR is functioning in CASMCs and participates in the vasoconstriction in response to caffeine-induced Ca(2+) release and that inhibition of C ICR is of importance in mediating the vasodilator response of coronary arteries to NO.
Journal ArticleDOI
Factors determining the recruitment of inositol trisphosphate receptor channels during calcium puffs.
George D. Dickinson,Ian Parker +1 more
TL;DR: It is found that any given channel in a cluster has a mean probability of ∼66% of opening following opening of an initial "trigger" channel, and the probability of puff triggering thus increases steeply with increasing number of channels in a clusters (cluster size).
Journal ArticleDOI
Limbic system-associated membrane protein (LAMP) induces neurite outgrowth and intracellular Ca2+ increase in primary fetal neurons.
TL;DR: It is shown that LAMP can induce several types of calcium (Ca2+) signals, and appears to function primarily through homophilic interactions and acts in part by modulating intracellular Ca2+ levels during neurite outgrowth by increasing the Ca2- influx through L-type calcium channels, but has additional effects on intrACEllular Ca1+ signaling at later developmental stages.
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.