Release of Ca2+ from a non-mitochondrial store site in peritoneal macrophages treated with saponin by inositol 1,4,5-trisphosphate

Hirata, Masato; Suematsu, Eiichi; Hashimoto, Toshihiko; Hamachi, Toshihiro; Koga, Tomohiro

doi:10.1042/bj2230229

Cited by 166 publications

(48 citation statements)

References 20 publications

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“…Compared with the IP3R-labelled ER domain, the 3F3A ER domain shows increased dissociation from mitochondria in RAS-transformed NIH-3T3 cells relative to nontransformed NIH-3T3 cells. IP3R gating occurs at a [Ca 2+ ] cyt of 200-300 nM (Bezprozvanny et al, 1991;Hirata et al, 1984;Iino, 1990). This is slightly higher than reported here for mitochondrial dissociation of the 3F3A SER domain (100-200 nM) but sufficient for increased clustering of IP3R in the ER adjacent to mitochondria (Shuai and Jung, 2003;Wilson et al, 1998).…”

Section: Regulation Of Ser Tubule-mitochondria Interactioncontrasting

confidence: 40%

Reversible interactions between smooth domains of the endoplasmic reticulum and mitochondria are regulated by physiological cytosolic Ca2+ levels

Goetz

Genty

St-Pierre

et al. 2007

Journal of Cell Science

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The 3F3A monoclonal antibody to autocrine motility factor receptor (AMFR) labels mitochondria-associated smooth endoplasmic reticulum (ER) tubules. siRNA down-regulation of AMFR expression reduces mitochondria-associated 3F3A labelling. The 3F3A-labelled ER domain does not overlap with reticulon-labelled ER tubules, the nuclear membrane or perinuclear ER markers and only partially overlaps with the translocon component Sec61α. Upon overexpression of FLAG-tagged AMFR, 3F3A labelling is mitochondria associated, excluded from the perinuclear ER and co-distributes with reticulon. 3F3A labelling therefore defines a distinct mitochondria-associated ER domain. Elevation of free cytosolic Ca2+ levels with ionomycin promotes dissociation of 3F3A-labelled tubules from mitochondria and, judged by electron microscopy, disrupts close contacts (<50 nm) between smooth ER tubules and mitochondria. The ER tubule-mitochondria association is similarly disrupted upon thapsigargin-induced release of ER Ca2+ stores or purinergic receptor stimulation by ATP. The inositol (1,4,5)-trisphosphate [Ins(1,4,5)P3] receptor (IP3R) colocalises to 3F3A-labelled mitochondria-associated ER tubules, and conditions that induce ER tubule-mitochondria dissociation disrupt continuity between 3F3A- and IP3R-labelled ER domains. RAS-transformed NIH-3T3 cells have increased basal cytosolic Ca2+ levels and show dissociation of the 3F3A-labelled, but not IP3R-labelled, ER from mitochondria. Our data indicate that regulation of the ER-mitochondria association by free cytosolic Ca2+ is a characteristic of smooth ER domains and that multiple mechanisms regulate the interaction between these organelles.

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Section: Regulation Of Ser Tubule-mitochondria Interactioncontrasting

confidence: 40%

Reversible interactions between smooth domains of the endoplasmic reticulum and mitochondria are regulated by physiological cytosolic Ca2+ levels

Goetz

Genty

St-Pierre

et al. 2007

Journal of Cell Science

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“…Indeed, the notion that IP 3 mediates Ca 2+ release in the heart is not new, and has been established by studies spanning the last two decades. The very earliest studies on cardiac IP 3 signaling found evidence for functional IP 3 Rs capable of releasing Ca 2+ from the SR [47][48][49][50][51]. However, compared with Ca 2+ -induced Ca 2+ release through RyRs, though, the IP 3 -induced Ca 2+ release was slow and small.…”

Section: The Dilemma Of Cardiac Ip 3 Receptors: Lost In An Ocean Of Rmentioning

confidence: 99%

Emerging roles of inositol 1,4,5-trisphosphate signaling in cardiac myocytes

Kockskämper

Zima

Roderick

et al. 2008

Journal of Molecular and Cellular Cardiology

169

149

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Inositol 1,4,5-trisphosphate (IP 3 ) is a ubiquitous intracellular messenger regulating diverse functions in almost all mammalian cell types. It is generated by membrane receptors that couple to phospholipase C (PLC), an enzyme which liberates IP 3 from phosphatidylinositol 4,5-bisphosphate (PIP 2 ). The major action of IP 3 , which is hydrophilic and thus translocates from the membrane into the cytoplasm, is to induce Ca 2+ release from endogenous stores through IP 3 receptors (IP 3 Rs). Cardiac excitation-contraction coupling relies largely on ryanodine receptor (RyR)-induced Ca 2+ release from the sarcoplasmic reticulum. Myocytes express a significantly larger number of RyRs compared to IP 3 Rs (∼100:1), and furthermore they experience substantial fluxes of Ca 2+ with each heartbeat. Therefore, the role of IP 3 and IP 3 -mediated Ca 2+ signaling in cardiac myocytes has long been enigmatic. Recent evidence, however, indicates that despite their paucity cardiac IP 3 Rs may play crucial roles in regulating diverse cardiac functions. Strategic localization of IP 3 Rs in cytoplasmic compartments and the nucleus enables them to participate in subsarcolemmal, bulk cytoplasmic and nuclear Ca 2+ signaling in embryonic stem cell-derived and neonatal cardiomyocytes, and in adult cardiac myocytes from the atria and ventricles. Intriguingly, expression of both IP 3 Rs and membrane receptors that couple to PLC/IP 3 signaling is altered in cardiac disease such as atrial fibrillation or heart failure, suggesting the involvement of IP 3 signaling in the pathology of these diseases. Thus, IP 3 exerts important physiological and pathological functions in the heart, ranging from the regulation of pacemaking, excitation-contraction and excitation-transcription coupling to the initiation and/or progression of arrhythmias, hypertrophy and heart failure. KeywordsInositol 1,4,5-trisphosphate; Cardiac myocyte; Calcium; Inotropy; Arrhythmias; Nucleus; Hypertrophy © 2008 Elsevier Inc. All rights reserved. * Corresponding author. E-mail address: jens.kockskaemper@meduni-graz.at (J. Kockskämper).. NIH Public Access NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript The discovery of IP 3A quarter of a century ago it was shown that D-myo inositol 1,4,5-trisphosphate (IP 3 ) releases Ca 2+ from a non-mitochondrial internal Ca 2+ store [1]. Since this hallmark discovery, IP 3 has emerged as a ubiquitous intracellular messenger, releasing Ca 2+ from stores through activation of IP 3 receptors (IP 3 Rs) in almost all eukaryotic cells. The major IP 3 -sensitive intracellular Ca 2+ store is the endoplasmic reticulum. However, IP 3 has also been shown to release Ca 2+ stored in other compartments, such as the Golgi and the nuclear envelope [2]. In addition, IP 3 Rs are present on the plasma membrane of some cell types, where they can gate Ca 2+ influx [3]. A crucial role for IP 3 -dependent Ca 2+ release has been demonstrated in many mammalian cell types, ranging from tiny platelets, where it initiates blood clottin...

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“…

(2,14,25). IP3 may be phosphorylated to form other inositol phosphates (19) or hydrolyzed in a 3-step dephosphorylation into inositol and Pi by specific phosphatases (3).

Although very little is known about signal transduction in higher plant cells, calcium has become recognized as a key regulator of plant metabolism (11,12,18,23,26).

…”

mentioning

confidence: 99%

myo-Inositol Trisphosphate Mobilizes Calcium from Fusogenic Carrot (Daucus carota L.) Protoplasts

Rincón¹,

Boss²

1987

Plant Physiol.

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(2,14,25). IP3 may be phosphorylated to form other inositol phosphates (19) or hydrolyzed in a 3-step dephosphorylation into inositol and Pi by specific phosphatases (3).Although very little is known about signal transduction in higher plant cells, calcium has become recognized as a key regulator of plant metabolism (11,12,18,23,26). It activates protein kinases (13), and plays a critical role in cell division (12), secretion (7), protoplast fusion (10), and tropic responses (22,23). All of these physiological responses appear to be preceded by an increase of cytosolic free Ca2' concentration, but it is not clear whether the increase in cytosolic Ca24 concentration is due to an increase in Ca2`influx across the plasma membrane or to an increase in Ca2' release from internal stores (i.e. ER, vacuole, or mitochondria) or both.There is evidence that the biosynthesis and metabolism of polyphosphoinositides occur in higher plant cells (6,20,24 MATERIALS AND METHODS Protoplast Isolation. Wild carrot cells (Daucus carota L.) which yield fusogenic protoplasts, were grown in suspension culture as described previously (4). Protoplasts were isolated by placing 0.3 g of cells in 20 ml solution containing 2% Driselase (Plenum Scientific Co., Hackensack, NJ), 0.4 molal sorbitol, 2 mM EGTA, and 1 mm Mes (pH 4.8) at 25°C on a rotary shaker (125 rpm) for 1.5 h for the 45Ca24 efflux experiments and for 2 h for the 45Ca2+ influx experiments. The protoplasts were centrifuged (40g) and the supernatant discarded. The recovered protoplasts were washed twice with an osmoticum solution consisting of 0.45 molal sorbitol and 0.5 mM Mes (pH 6).4"Ca2 Influx. For calcium influx experiments, protoplasts (1-2 mg protein/ml) were incubated in 8 ml osmoticum containing 45Ca2" (0.4 MCi/ml) to a final Ca2" concentration of approximately 1 uM. The protoplast suspension was placed on the rotary shaker (90 rpm) at 25°C. At intervals, 3 aliquots of 200 ,l were taken and protoplasts spun in a Beckman Microfuge B through a supporting and separating gradient formed, in order from the bottom, by 50 Ml of 5% dextran (mol wt = 17,900) in osmoticum, 50 ,ul silicone oil (p = 1.03), 50 ,l 2 mM EGTA in osmoticum, and 50 gl silicone oil (p = 1.01). The protoplast pellet was collected at the bottom of the microfuge tubes. The microfuge tips were cut and the protoplast pellet resuspended in 300 Ml deionized H20. Aliquots of 100,l ofthe resuspended protoplasts were dissolved in 7 ml Scintiverse-Il (Fisher

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Release of Ca2+ from a non-mitochondrial store site in peritoneal macrophages treated with saponin by inositol 1,4,5-trisphosphate

Cited by 166 publications

References 20 publications

Reversible interactions between smooth domains of the endoplasmic reticulum and mitochondria are regulated by physiological cytosolic Ca2+ levels

Reversible interactions between smooth domains of the endoplasmic reticulum and mitochondria are regulated by physiological cytosolic Ca2+ levels

Emerging roles of inositol 1,4,5-trisphosphate signaling in cardiac myocytes

myo-Inositol Trisphosphate Mobilizes Calcium from Fusogenic Carrot (Daucus carota L.) Protoplasts

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