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James W Putney, Natacha Steinckwich-Besançon, Takuro Numaga-Tomita, Felicity M Davis, Pooja N Desai, Diane M D'Agostin, Shilan Wu, Gary S Bird
Store-operated calcium channels provide calcium signals to the cytoplasm of a wide variety of cell types. The basic components of this signaling mechanism include a mechanism for discharging Ca(2+) stores (commonly but not exclusively phospholipase C and inositol 1,4,5-trisphosphate), a sensor in the endoplasmic reticulum that also serves as an activator of the plasma membrane channel (STIM1 and STIM2), and the store-operated channel (Orai1, 2 or 3). The advent of mice genetically altered to reduce store-operated calcium entry globally or in specific cell types has provided important tools to understand the functions of these widely encountered channels in specific and clinically important physiological systems...
November 29, 2016: Biochimica et Biophysica Acta
Hua Zhang, Suya Sun, Lili Wu, Ekaterina Pchitskaya, Olga Zakharova, Klementina Fon Tacer, Ilya Bezprozvanny
: Mushroom dendritic spine structures are essential for memory storage and the loss of mushroom spines may explain memory defects in aging and Alzheimer's disease (AD). The stability of mushroom spines depends on stromal interaction molecule 2 (STIM2)-mediated neuronal-store-operated Ca(2+) influx (nSOC) pathway, which is compromised in AD mouse models, in aging neurons, and in sporadic AD patients. Here, we demonstrate that the Transient Receptor Potential Canonical 6 (TRPC6) and Orai2 channels form a STIM2-regulated nSOC Ca(2+) channel complex in hippocampal mushroom spines...
November 23, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Joanna Gruszczynska-Biegala, Maria Sladowska, Jacek Kuznicki
The process of store-operated calcium entry (SOCE) leads to refilling the endoplasmic reticulum (ER) with calcium ions (Ca(2+)) after their release into the cytoplasm. Interactions between (ER)-located Ca(2+) sensors (stromal interaction molecule 1 [STIM1] and STIM2) and plasma membrane-located Ca(2+) channel-forming protein (Orai1) underlie SOCE and are well described in non-excitable cells. In neurons, however, SOCE appears to be more complex because of the importance of Ca(2+) influx via voltage-gated or ionotropic receptor-operated Ca(2+) channels...
2016: Frontiers in Cellular Neuroscience
Axel R Concepcion, Martin Vaeth, Larry E Wagner, Miriam Eckstein, Lee Hecht, Jun Yang, David Crottes, Maximilian Seidl, Hyosup P Shin, Carl Weidinger, Scott Cameron, Stuart E Turvey, Thomas Issekutz, Isabelle Meyts, Rodrigo S Lacruz, Mario Cuk, David I Yule, Stefan Feske
Eccrine sweat glands are essential for sweating and thermoregulation in humans. Loss-of-function mutations in the Ca2+ release-activated Ca2+ (CRAC) channel genes ORAI1 and STIM1 abolish store-operated Ca2+ entry (SOCE), and patients with these CRAC channel mutations suffer from anhidrosis and hyperthermia at high ambient temperatures. Here we have shown that CRAC channel-deficient patients and mice with ectodermal tissue-specific deletion of Orai1 (Orai1K14Cre) or Stim1 and Stim2 (Stim1/2K14Cre) failed to sweat despite normal sweat gland development...
November 1, 2016: Journal of Clinical Investigation
Clark A Briggs, Shreaya Chakroborty, Grace E Stutzmann
The current state of the AD research field is highly dynamic is some respects, while seemingly stagnant in others. Regarding the former, our current lack of understanding of initiating disease mechanisms, the absence of effective treatment options, and the looming escalation of AD patients is energizing new research directions including a much-needed re-focusing on early pathogenic mechanisms, validating novel targets, and investigating relevant biomarkers, among other exciting new efforts to curb disease progression and foremost, preserve memory function...
September 20, 2016: Biochemical and Biophysical Research Communications
Elena Popugaeva, Ekaterina Pchitskaya, Ilya Bezprozvanny
Alzheimer's disease (AD) is the disease of lost memories. Synaptic loss is a major reason for memory defects in AD. Signaling pathways involved in memory loss in AD are under intense investigation. The role of deranged neuronal calcium (Ca(2+)) signaling in synaptic loss in AD is described in this review. Familial AD (FAD) mutations in presenilins are linked directly with synaptic Ca(2+) signaling abnormalities, most likely by affecting endoplasmic reticulum (ER) Ca(2+) leak function of presenilins. Excessive ER Ca(2+) release via type 2 ryanodine receptors (RyanR2) is observed in AD spines due to increase in expression and function of RyanR2...
September 15, 2016: Biochemical and Biophysical Research Communications
Zili Zhang, Jian Wang, Jianxing He, Xiansheng Zeng, Xindong Chen, Mingmei Xiong, Qipeng Zhou, Meihua Guo, Defu Li, Wenju Lu
OBJECTIVE: Store operated calcium channels (SOCCs) and Receptor-operated calcium channels (ROCCs) are important pathways participating in regulation of intracellular Ca(2 +) concentration in various cell types. The purpose of our study is to determine whether genetic variations in key components of SOCCs and ROCCs are associated with lung cancer risk. METHODS: We identified 236 tagSNPs in 9 key genes related to SOCCs and ROCCs (TRPC1, TRPC3, TRPC4, TRPC6, TRPC7, ORAI1, ORAI2, STIM1, and STIM2) and evaluated their association with lung cancer risk in a two-stage case-control study with a total of 2433 lung cancer cases and 2433 cancer-free controls using Illumina high throughput genotyping platform...
September 2016: Meta Gene
Xuhua Mao, Jianfeng Zhang, Yue Han, Chao Luan, Yu Hu, Zhimin Hao, Min Chen
Antigen specific B cells undergo a process termed affinity maturation in the germinal centers of secondary lymphoid organs where B cells with high affinity receptors are selected to mature into antibody-producing cells or to the memory B cell pool. It is known that B cell antigen receptor (BCR) signaling plays pivotal role in this selection process. Calcium influx is an essential component of BCR signaling. The current report is to determine the effect of calcium influx on antibody affinity maturation. In our studies, mice deficient for both endoplasmic reticulum calciumsensor Stim1 and Stim2 was immunized with T-cell dependent and independent antigens...
August 27, 2016: Oncotarget
Kenrick An Fu Yap, Mahesh Shivarama Shetty, Gisela Garcia-Alvarez, Bo Lu, Durgadevi Alagappan, Masatsugu Oh-Hora, Sreedharan Sajikumar, Marc Fivaz
STIM2 is an integral membrane protein of the endoplasmic reticulum (ER) that regulates the activity of plasma membrane (PM) channels at ER-PM contact sites. Recent studies show that STIM2 promotes spine maturation and surface expression of the AMPA receptor (AMPAR) subunit GluA1, hinting at a probable role in synaptic plasticity. Here, we used a Stim2 cKO mouse to explore the function of STIM2 in Long-Term Potentiation (LTP) and Depression (LTD), two widely-studied models of synaptic plasticity implicated in information storage...
August 18, 2016: Neurobiology of Learning and Memory
Eduard Korkotian, Efrat Oni-Biton, Menahem Segal
The possible role of store operated calcium entry (SOCE) through the Orai1 channel in the formation and functions of dendritic spines was studied in cultured hippocampal neurons. In calcium store-depleted neurons a transient elevation of extracellular calcium concentration ([Ca(2+) ]o) caused a rise in [Ca(2+) ]i that was mediated by activation of the SOCE. The store depletion resulted in an increase in STIM2 (an endoplasmic calcium sensor) association with Orai1 in dendritic spines. The response to the rise in [Ca(2+) ]o was larger in spines endowed with a cluster of Orai1 molecules than in spines devoid of Orai1...
July 9, 2016: Journal of Physiology
Francesco Moccia, Estella Zuccolo, Valentina Poletto, Ilaria Turin, Germano Guerra, Paolo Pedrazzoli, Vittorio Rosti, Camillo Porta, Daniela Montagna
An increase in intracellular Ca2+ concentration plays a key role in the establishment of many cancer hallmarks, including aberrant proliferation, migration, invasion, resistance to apoptosis and angiogenesis. The dysregulation of Ca2+ entry is one of the most subtle mechanisms by which cancer cells overwhelm their normal counterparts and gain the adaptive advantages that result in tumour growth, vascularisation and dissemination throughout the organism. Both constitutive and agonist-induced Ca2+ influx may be mediated by store-dependent as well as store-independent Ca2+ entry routes...
2016: Current Medicinal Chemistry
Martin Vaeth, Miriam Eckstein, Patrick J Shaw, Lina Kozhaya, Jun Yang, Friederike Berberich-Siebelt, Robert Clancy, Derya Unutmaz, Stefan Feske
T follicular helper (Tfh) cells promote affinity maturation of B cells in germinal centers (GCs), whereas T follicular regulatory (Tfr) cells limit the GC reaction. Store-operated Ca(2+) entry (SOCE) through Ca(2+) release-activated Ca(2+) (CRAC) channels mediated by STIM and ORAI proteins is a fundamental signaling pathway in T lymphocytes. Conditional deletion of Stim1 and Stim2 genes in T cells abolished SOCE and strongly reduced antibody-mediated immune responses following viral infection caused by impaired differentiation and function of Tfh cells...
June 21, 2016: Immunity
Xinghua Gao, Jingsheng Xia, Frances M Munoz, Melissa T Manners, Rong Pan, Olimpia Meucci, Yue Dai, Huijuan Hu
BACKGROUND: Our previous study demonstrated that a store-operated calcium channel (SOCC) inhibitor (YM-58483) has central analgesic effects. However, the cellular and molecular mechanisms of such effects remain to be determined. It is well-known that glial cells play important roles in central sensitization. SOC entry (SOCE) has been implicated in many cell types including cortical astrocytes. However, the role of the SOCC family in the function of astrocytes has not been determined. Here, we thoroughly investigated the expression and the functional significance of SOCCs in spinal astrocytes...
2016: Journal of Neuroinflammation
Dong Min Shin, Aran Son, Seonghee Park, Min Seuk Kim, Malini Ahuja, Shmuel Muallem
The Ca(2+) second messenger is initiated at ER/PM junctions and propagates into the cell interior to convey the receptor information. The signal is maintained by Ca(2+) influx across the plasma membrane through the Orai and TRPC channels. These Ca(2+) influx channels form complexes at ER/PM junctions with the ER Ca(2+) sensor STIM1, which activates the channels. The function of STIM1 is modulated by other STIM isoforms like STIM1L, STIM2 and STIM2.1/STIM2β and by SARAF, which mediates the Ca(2+)-dependent inhibition of Orai channels...
2016: Advances in Experimental Medicine and Biology
Rajesh Bhardwaj, Matthias A Hediger, Nicolas Demaurex
STIM1 and ORAI1 constitute the core machinery of the ubiquitous store-operated calcium entry pathway and loss of function in these proteins is associated with severe immune and muscular disorders. Other isoforms-STIM1L, STIM2, ORAI2 and ORAI3 exhibit varied expression levels in different cell types along with several other interaction partners and thereby play different roles to facilitate, regulate and fine-tune the calcium entry. STIM proteins convey the Ca(2+) store-depletion message to the PM and thereby participate in refilling of the ER by physically interacting with the Ca(2+)-selective ORAI channels at the PM...
August 2016: Cell Calcium
Tünde Molnár, Oleg Yarishkin, Anthony Iuso, Peter Barabas, Bryan Jones, Robert E Marc, Tam T T Phuong, David Križaj
UNLABELLED: The endoplasmic reticulum (ER) is at the epicenter of astrocyte Ca(2+) signaling. We sought to identify the molecular mechanism underlying store-operated calcium entry that replenishes ER stores in mouse Müller cells. Store depletion, induced through blockade of sequestration transporters in Ca(2+)-free saline, induced synergistic activation of canonical transient receptor potential 1 (TRPC1) and Orai channels. Store-operated TRPC1 channels were identified by their electrophysiological properties, pharmacological blockers, and ablation of the Trpc1 gene...
March 16, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Xiu-Li Kuang, Yimei Liu, Yuhua Chang, Jing Zhou, He Zhang, Yiping Li, Jia Qu, Shengzhou Wu
Dysfunction of the ubiquitin-proteasome system (UPS) and calcium homeostasis has been implicated in the neurodegeneration of Alzheimer's and Parkinson's diseases. The cytosolic calcium concentration is maintained by store-operated calcium entry (SOCE), which is repressed by Alzheimer's disease-associated mutants, such as mutant presenilins. We hypothesized that inhibition of UPS impacts SOCE. This study showed that pretreatment with sub-lethal levels of proteasome inhibitors, including MG-132 and clasto-lactacystin-β-lactone (LA), reduced SOCE after depletion of endoplasmic reticulum calcium in rat neurons...
April 2016: Cell Calcium
Kathrin Dörr, Tatiana Kilch, Sven Kappel, Dalia Alansary, Gertrud Schwär, Barbara A Niemeyer, Christine Peinelt
N-glycosylation of cell surface proteins affects protein function, stability, and interaction with other proteins. Orai channels, which mediate store-operated Ca(2+) entry (SOCE), are composed of N-glycosylated subunits. Upon activation by Ca(2+) sensor proteins (stromal interaction molecules STIM1 or STIM2) in the endoplasmic reticulum, Orai Ca(2+) channels in the plasma membrane mediate Ca(2+) influx. Lectins are carbohydrate-binding proteins, and Siglecs are a family of sialic acid-binding lectins with immunoglobulin-like repeats...
March 8, 2016: Science Signaling
Yoshihiro Baba
Alterations in the cytosolic concentration of calcium ions (Ca(2+)) are important signals for various physiological events. The engagement of B cell receptors (BCR) results in the transient release of Ca(2+) into cytosol from endoplasmic reticulum (ER) stores. In turn, this decrease in ER luminal Ca(2+) concentration triggers the opening of Ca(2+) channels in the plasma membrane, inducing a sustained influx of extracellular Ca(2+) into cells. These processes are referred to as store-operated Ca(2+) entry (SOCE), which is an essential pathway for continuous Ca(2+) signaling...
2016: Yakugaku Zasshi: Journal of the Pharmaceutical Society of Japan
Barbara A Niemeyer
A wide variety of cellular function depends on the dynamics of intracellular Ca(2+) signals. Especially for relatively slow and lasting processes such as gene expression, cell proliferation, and often migration, cells rely on the store-operated Ca(2+) entry (SOCE) pathway, which is particularly prominent in immune cells. SOCE is initiated by the sensor proteins (STIM1, STIM2) located within the endoplasmic reticulum (ER) registering the Ca(2+) concentration within the ER, and upon its depletion, cluster and trap Orai (Orai1-3) proteins located in the plasma membrane (PM) into ER-PM junctions...
May 1, 2016: American Journal of Physiology. Cell Physiology
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