Localisation, function and composition of primary Ca(2+) spark discharge region in isolated smooth muscle cells from guinea-pig mesenteric arteries.
AuthorsPucovský V, Bolton TB
JournalCell Calcium
PubMed ID16297446
'Smooth muscle cells (SMCs) contain numerous calcium release domains, grouped into regions discharging as a single unit. Laser scanning confocal microscopy, voltage clamp and immunocytochemistry of single SMCs from small mesenteric arteries of guinea-pig were used to study the localisation, function and macromolecular composition of such calcium discharge regions (CDRs). ... 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
Calmodulin modulates initiation but not termination of spontaneous Ca2+ sparks in frog skeletal muscle.
AuthorsRodney GG, Schneider MF
JournalBiophys J
PubMed ID12885639
Calmodulin is a ubiquitous Ca(2+) sensing protein that binds to and modulates the sarcoplasmic reticulum Ca(2+) release channel, ryanodine receptor (RYR). Here we assessed the effects of calmodulin on the local Ca(2+) release properties of RYR in permeabilized frog skeletal muscle fibers. Fluorescently labeled recombinant calmodulin in the internal solution ... More
Dynamic imaging of endoplasmic reticulum Ca2+ concentration in insulin-secreting MIN6 Cells using recombinant targeted cameleons: roles of sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA)-2 and ryanodine receptors.
AuthorsVaradi A, Rutter GA
JournalDiabetes
PubMed ID11815480
The endoplasmic reticulum (ER) plays a pivotal role in the regulation of cytosolic Ca(2+) concentrations ([Ca(2+)](cyt)) and hence in insulin secretion from pancreatic beta-cells. However, the molecular mechanisms involved in both the uptake and release of Ca(2+) from the ER are only partially defined in these cells, and the presence ... More
Functional expression of recombinant type 1 ryanodine receptor in insect cells.
AuthorsAntaramián A, Butanda-Ochoa A, Vázquez-Martínez O, Díaz-Muñoz M, Vaca L
JournalCell Calcium
PubMed ID11396983
We have investigated the biochemical properties of the rabbit ryanodine receptor type 1 (RyR1) from skeletal muscle functionally expressed in insect sf 21 cells infected with recombinant baculovirus. Equilibrium [3H]ryanodine binding assays applied to total membrane fractions from sf 21 cells expressing recombinant RyR1 showed a non-hyperbolic saturation curve (Hill ... More
Direct visualization of sarcoplasmic reticulum regions discharging Ca(2+)sparks in vascular myocytes.
AuthorsGordienko DV, Greenwood IA, Bolton TB
JournalCell Calcium
PubMed ID11133352
Localized Ca(2+)-release events, Ca(2+)sparks, have been suggested to be the 'elementary building blocks' of the calcium signalling system in all types of muscles. In striated muscles these occur at regular intervals along the fibre corresponding to the sarcomeric structures which do not exist in smooth muscle. We showed previously that ... More