An inositol 1,4,5-trisphosphate receptor-gated intracellular Ca(2+) store is involved in regulating sperm hyperactivated motility.
AuthorsHo HC, Suarez SS
JournalBiol Reprod
PubMed ID11673282
'Hyperactivated motility, a swimming pattern displayed by mammalian sperm in the oviduct around the time of ovulation, is essential to fertilization. Ca(2+) has been shown to be crucial for the initiation and maintenance of hyperactivated motility. Nevertheless, how Ca(2+) reaches the axoneme in the core of the flagellum to switch ... More
NAADP controls cross-talk between distinct Ca2+ stores in the heart.
AuthorsMacgregor A, Yamasaki M, Rakovic S, Sanders L, Parkesh R, Churchill GC, Galione A, Terrar DA
JournalJ Biol Chem
PubMed ID17387177
'In cardiac muscle the sarcoplasmic reticulum (SR) plays a key role in the control of contraction, releasing Ca(2+) in response to Ca(2+) influx across the sarcolemma via voltage-gated Ca(2+) channels. Here we report evidence for an additional distinct Ca(2+) store and for actions of nicotinic acid adenine dinucleotide phosphate (NAADP) ... More
Nucleoplasmic Ca(2+)loading is regulated by mobilization of perinuclear Ca(2+).
AuthorsAbrenica B, Gilchrist JS
JournalCell Calcium
PubMed ID10970769
'Regulation of nucleoplasmic calcium (Ca(2+)) concentration may occur by the mobilization of perinuclear luminal Ca(2+)pools involving specific Ca(2+)pumps and channels of both inner and outer perinuclear membranes. To determine the role of perinuclear luminal Ca(2+), we examined freshly cultured 10 day-old embryonic chick ventricular cardiomyocytes. We obtained evidence suggesting the ... More
cAMP-dependent mobilization of intracellular Ca2+ stores by activation of ryanodine receptors in pancreatic beta-cells. A Ca2+ signaling system stimulated by the insulinotropic hormone glucagon-like peptide-1-(7-37).
AuthorsHolz GG, Leech CA, Heller RS, Castonguay M, Habener JF
JournalJ Biol Chem
PubMed ID10318832
'Glucagon-like peptide-1 (GLP-1) is an intestinally derived insulinotropic hormone currently under investigation for use as a novel therapeutic agent in the treatment of type 2 diabetes mellitus. In vitro studies of pancreatic islets of Langerhans demonstrated that GLP-1 interacts with specific beta-cell G protein-coupled receptors, thereby facilitating insulin exocytosis by ... More
Ryanodine and inositol trisphosphate receptors are differentially distributed and expressed in rat parotid gland.
AuthorsZhang X, Wen J, Bidasee KR, Besch HR, Wojcikiewicz RJ, Lee B, Rubin RP
JournalBiochem J
PubMed ID10333498
'The present study examines the cellular distribution of the ryanodine receptor/channel (RyR) and inositol 1,4,5-trisphosphate receptor (InsP3R) subtypes in parotid acini. Using fluorescently labelled 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene-3-propionic acid glycyl-ryanodine (BODIPYtrade mark-ryanodine) and confocal microscopy, RyRs were localized primarily to the perinuclear region (basal pole) of the acinar cell. Ryanodine, Ruthenium Red, cAMP ... More
Origin sites of calcium release and calcium oscillations in frog sympathetic neurons.
AuthorsMcDonough SI, Cseresnyés Z, Schneider MF
JournalJ Neurosci
PubMed ID11124983
'In many neurons, Ca(2+) signaling depends on efflux of Ca(2+) from intracellular stores into the cytoplasm via caffeine-sensitive ryanodine receptors (RyRs) of the endoplasmic reticulum. We have used high-speed confocal microscopy to image depolarization- and caffeine-evoked increases in cytoplasmic Ca(2+) levels in individual cultured frog sympathetic neurons. Although caffeine-evoked Ca(2+) ... More
New aspects of nuclear calcium signalling.
AuthorsGerasimenko O, Gerasimenko J
JournalJ Cell Sci
PubMed ID15226390
Nuclear calcium signalling has been a controversial battlefield for many years and the question of how permeable the nuclear pore complexes (NPCs) are to Ca2+ has been the subject of a particularly hot dispute. Recent data from isolated nuclei suggest that the NPCs are open even after depletion of the ... More
Homogeneous Ca2+ stores in rat adrenal chromaffin cells.
AuthorsInoue M, Sakamoto Y, Fujishiro N, Imanaga I, Ozaki S, Prestwich GD, Warashina A
JournalCell Calcium
PubMed ID12526884
The localization and function of Ca(2+) stores in isolated chromaffin cells of rat adrenal medulla were investigated using confocal laser microscopy and amperometry. Binding sites for BODIPY-inositol 1,4,5-trisphosphate (IP(3)), -ryanodine (Ry), and -thapsigargin (Thap) were both perinuclear and at the cell periphery. The endoplasmic reticulum (ER), which was identified by ... More
Requirement of ryanodine receptor subtypes 1 and 2 for Ca(2+)-induced Ca(2+) release in vascular myocytes.
AuthorsCoussin F, Macrez N, Morel JL, Mironneau J
JournalJ Biol Chem
PubMed ID10734110
While the roles of subtypes 1 and 2 of the ryanodine receptors (RYRs) have been studied in cellular systems expressing specifically one or the other of these subtypes (i.e. skeletal and cardiac muscle), the function of these receptors has not been evaluated in smooth muscles. We have previously reported RYR-mediated ... More
Functional properties of ryanodine receptors in hippocampal neurons change during early differentiation in culture.
AuthorsSukhareva M, Smith SV, Maric D, Barker JL
JournalJ Neurophysiol
PubMed ID12205130
6-((4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-propionyl)amino)hexanoic acid ryanodine (BODIPY-ryanodine) binding and Ca(2+) imaging were used to study the properties of ryanodine receptors (RyRs) and cytoplasmic Ca(2+) (Ca) changes in neurons cultured from the embryonic rat hippocampus during the earliest stages of differentiation. Baseline Ca levels declined from 164 +/- 5 (SD) nM at early stages ... More
Functional triads consisting of ryanodine receptors, Ca(2+) channels, and Ca(2+)-activated K(+) channels in bullfrog sympathetic neurons. Plastic modulation of action potential.
AuthorsAkita T, Kuba K
JournalJ Gen Physiol
PubMed ID11055998
Fluorescent ryanodine revealed the distribution of ryanodine receptors in the submembrane cytoplasm (less than a few micrometers) of cultured bullfrog sympathetic ganglion cells. Rises in cytosolic Ca(2+) ([Ca(2+)](i)) elicited by single or repetitive action potentials (APs) propagated at a high speed (150 microm/s) in constant amplitude and rate of rise ... More
Nucleoplasmic calcium regulation in rabbit aortic vascular smooth muscle cells.
AuthorsAbrenica B, Pierce GN, Gilchrist JS
JournalCan J Physiol Pharmacol
PubMed ID12733828
In this study, we investigated whether nucleoplasmic free Ca2+ in aortic vascular smooth muscle cells (VSMCs) might be independently regulated from cytosolic free Ca2+. Understanding mechanisms and pathways responsible for this regulation is especially relevant given the role of a numerous intranuclear Ca2+-sensitive proteins in transcriptional regulation, apoptosis and cell ... More
Submaximal stimulation of porcine endothelial cells causes focal Ca2+ elevation beneath the cell membrane.
AuthorsGraier WF, Paltauf-Doburzynska J, Hill BJ, Fleischhacker E, Hoebel BG, Kostner GM, Sturek M
JournalJ Physiol
PubMed ID9481676
1. Endothelial cell activation is correlated with increased cytosolic Ca2+ concentration, often monitored with cytoplasmic Ca2+ dyes, such as fura-2 and Calcium Green-1. We tested the hypothesis that during weak stimulation of porcine coronary artery endothelial cells, focal, subplasmalemmal Ca2+ elevations occur which are controlled by cell membrane Na(+)-Ca2+ exchange ... More
C(a2+)-dependent glutamate release involves two classes of endoplasmic reticulum Ca(2+) stores in astrocytes.
AuthorsHua X, Malarkey EB, Sunjara V, Rosenwald SE, Li WH, Parpura V
JournalJ Neurosci Res
PubMed ID15048932
Astrocytes can modulate synaptic transmission by releasing glutamate in a Ca(2+)-dependent manner. Although the internal Ca(2+) stores have been implicated as the predominant source of Ca(2+) necessary for this glutamate release, the contribution of different classes of these stores is still not well defined. To address this issue, we cultured ... More