1
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Chandra S. The restriction of calcium influx in metaphase and post-metaphase stages of cell division revealed by imaging secondary ion mass spectrometry (SIMS). J Microsc 2023; 290:125-133. [PMID: 36864642 PMCID: PMC10133040 DOI: 10.1111/jmi.13182] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 02/09/2023] [Accepted: 02/27/2023] [Indexed: 03/04/2023]
Abstract
A secondary ion mass spectrometry (SIMS)-based isotopic imaging technique of ion microscopy was used for observing calcium influx in single renal epithelial LLC-PK1 cells. The CAMECA IMS-3f SIMS instrument, used in the study, is capable of producing isotopic images of single cells at 500 nm spatial resolution. Due to the high-vacuum requirements of the instrument the cells were prepared cryogenically with a freeze-fracture method and frozen freeze-dried cells were used for SIMS analysis. The influx of calcium was imaged directly by exposure of cells to 44 Ca stable isotope in the extracellular buffer for 10 min. The 44 Ca influx was measured at mass 44 and the distribution of endogenous calcium at mass 40 (40 Ca) in the same cell. A direct comparison of interphase cells to cells undergoing division revealed that calcium influx is restricted in metaphase and post-metaphase stages of cell division. This restriction is lifted in late cytokinesis. The net influx of 44 Ca in 10 min was approximately half under calcium influx restriction in comparison to interphase cells. Under calcium influx restriction the 44 Ca concentration was the same between the mitotic chromosome and the cytoplasm. These observations indicate that the endoplasmic reticulum (ER) calcium uptake is compromised under calcium influx restriction in cells undergoing division.
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Affiliation(s)
- Subhash Chandra
- Department of Biomedical Engineering, Cornell SIMS Laboratory, Cornell University, Ithaca, New York
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2
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Yu F, Machaca K. The STIM1 Phosphorylation Saga. Cell Calcium 2022; 103:102551. [DOI: 10.1016/j.ceca.2022.102551] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 02/01/2022] [Accepted: 02/03/2022] [Indexed: 01/11/2023]
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3
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Tam N, Lai KP, Kong RYC. Comparative transcriptomic analysis reveals reproductive impairments caused by PCBs and OH-PCBs through the dysregulation of ER and AR signaling. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 802:149913. [PMID: 34474298 DOI: 10.1016/j.scitotenv.2021.149913] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 08/20/2021] [Accepted: 08/22/2021] [Indexed: 06/13/2023]
Abstract
Reports have highlighted the presence of PCBs and their metabolites, OH-PCBs, in human serum as well as their endocrine-disrupting effects on reproductive function through direct interactions with the androgen receptor (AR) and estrogen receptor (ER). However, the molecular mechanisms directly linking the actions of PCBs and OH-PCBs on the AR and ER to induce reproductive impairment remain poorly understood. In this study, we characterized the cellular response to PCBs and OH-PCBs acting on AR and ER transactivation at the transcriptome level coupled with bioinformatics analysis to identify the downstream pathways of androgen and estrogen signaling that leads to reproductive dysfunction. We first confirmed the agonistic and antagonistic effects of several PCBs and OH-PCBs on AR- and ER-mediated reporter gene activity using the androgen-responsive LNCaP and estrogen-responsive MCF-7 cell lines, respectively. Anti-estrogenic activity was not detected among the tested compounds; however, we found that in addition to anti-androgenic and estrogenic activity, PCB 28 and PCB 138 exhibited androgenic activity, while most of the tested OH-PCBs showed a synergistic effect on DHT-mediated transactivation of the AR. Bioinformatics analysis of transcriptome profiles from selected PCBs and OH-PCBs revealed various pathways that were dysregulated depending on their agonistic, antagonistic, or synergistic effects. The OH-PCBs with estrogenic activity affected pathways including vitamin metabolism and calcium transport. Other notable dysregulated pathways include cholesterol transport in response to androgenic PCBs, thyroid hormone metabolism in response to anti-androgenic PCBs, and antioxidant pathways in response to androgen-synergistic OH-PCBs. Our results demonstrate that PCBs and OH-PCBs directly alter specific pathways through androgen- or estrogen-mediated signaling, thereby providing additional insights into the mechanisms by which these compounds cause reproductive dysfunction.
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Affiliation(s)
- Nathan Tam
- Department of Chemistry, City University of Hong Kong, Hong Kong, China
| | - Keng Po Lai
- Laboratory of Environmental Pollution and Integrative Omics, Guilin Medical University, Guilin, PR China; Department of Chemistry, City University of Hong Kong, Hong Kong, China; State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, China.
| | - Richard Yuen Chong Kong
- Department of Chemistry, City University of Hong Kong, Hong Kong, China; State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, China.
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4
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Hammad AS, Yu F, Botheju WS, Elmi A, Alcantara-Adap E, Machaca K. Phosphorylation of STIM1 at ERK/CDK sites is dispensable for cell migration and ER partitioning in mitosis. Cell Calcium 2021; 100:102496. [PMID: 34715400 DOI: 10.1016/j.ceca.2021.102496] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 09/20/2021] [Accepted: 10/15/2021] [Indexed: 12/24/2022]
Abstract
Store-operated Ca2+ entry (SOCE) is a ubiquitous Ca2+ influx pathway required for multiple physiological functions including cell motility. SOCE is triggered in response to depletion of intracellular Ca2+ stores following the activation of the endoplasmic reticulum (ER) Ca2+ sensor STIM1, which recruits the plasma membrane (PM) Ca2+ channel Orai1 at ER-PM junctions. STIM1 is phosphorylated dynamically, and this phosphorylation has been implicated in several processes including SOCE inactivation during M-phase, maximal SOCE activation, ER segregation during mitosis, and cell migration. Human STIM1 has 10 Ser/Thr residues in its cytosolic domain that match the ERK/CDK consensus phosphorylation. We recently generated a mouse knock-in line where wild-type STIM1 was replaced by a non-phosphorylatable STIM1 with all ten S/Ts mutated to Ala (STIM1-10A). Here, we generate mouse embryonic fibroblasts (MEF) from the STIM1-10A mouse line and a control MEF line (WT) that express wild-type STIM1 from a congenic mouse strain. These lines offer a unique model to address the role of STIM1 phosphorylation at endogenous expression levels in contrast to previous studies that relied mostly on overexpression. We show that STIM1 phosphorylation at ERK/CDK sites is not required for SOCE activation, cell migration, or ER partitioning during mitosis. These results rule out STIM1 phosphorylation as a regulator of SOCE, migration, and ER distribution in mitosis.
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Affiliation(s)
- Ayat S Hammad
- Calcium Signaling Group, Research Department, Weill Cornell Medicine Qatar, Education City, Qatar Foundation, Doha, Qatar; College of Health and Life Science, Hamad bin Khalifa University, Doha, Qatar
| | - Fang Yu
- Calcium Signaling Group, Research Department, Weill Cornell Medicine Qatar, Education City, Qatar Foundation, Doha, Qatar; Department of Physiology & Biophysicis, Weill Cornell Medicine, New York, USA
| | | | - Asha Elmi
- Calcium Signaling Group, Research Department, Weill Cornell Medicine Qatar, Education City, Qatar Foundation, Doha, Qatar; College of Health and Life Science, Hamad bin Khalifa University, Doha, Qatar
| | - Ethel Alcantara-Adap
- Calcium Signaling Group, Research Department, Weill Cornell Medicine Qatar, Education City, Qatar Foundation, Doha, Qatar; Department of Physiology & Biophysicis, Weill Cornell Medicine, New York, USA
| | - Khaled Machaca
- Calcium Signaling Group, Research Department, Weill Cornell Medicine Qatar, Education City, Qatar Foundation, Doha, Qatar; Department of Physiology & Biophysicis, Weill Cornell Medicine, New York, USA.
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5
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Hodeify R, Dib M, Alcantara-Adap E, Courjaret R, Nader N, Reyes CZ, Hammad AS, Hubrack S, Yu F, Machaca K. The carboxy terminal coiled-coil modulates Orai1 internalization during meiosis. Sci Rep 2021; 11:2290. [PMID: 33504898 PMCID: PMC7840751 DOI: 10.1038/s41598-021-82048-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 12/30/2020] [Indexed: 12/19/2022] Open
Abstract
Regulation of Ca2+ signaling is critical for the progression of cell division, especially during meiosis to prepare the egg for fertilization. The primary Ca2+ influx pathway in oocytes is Store-Operated Ca2+ Entry (SOCE). SOCE is tightly regulated during meiosis, including internalization of the SOCE channel, Orai1. Orai1 is a four-pass membrane protein with cytosolic N- and C-termini. Orai1 internalization requires a caveolin binding motif (CBM) in the N-terminus as well as the C-terminal cytosolic domain. However, the molecular determinant for Orai1 endocytosis in the C-terminus are not known. Here we show that the Orai1 C-terminus modulates Orai1 endocytosis during meiosis through a structural motif that is based on the strength of the C-terminal intersubunit coiled coil (CC) domains. Deletion mutants show that a minimal C-terminal sequence after transmembrane domain 4 (residues 260–275) supports Orai1 internalization. We refer to this region as the C-terminus Internalization Handle (CIH). Access to CIH however is dependent on the strength of the intersubunit CC. Mutants that increase the stability of the coiled coil prevent internalization independent of specific mutation. We further used human and Xenopus Orai isoforms with different propensity to form C-terminal CC and show a strong correlation between the strength of the CC and Orai internalization. Furthermore, Orai1 internalization does not depend on clathrin, flotillin or PIP2. Collectively these results argue that Orai1 internalization requires both the N-terminal CBM and C-terminal CIH where access to CIH is controlled by the strength of intersubunit C-terminal CC.
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Affiliation(s)
- Rawad Hodeify
- Department of Physiology and Biophysics, Ca2+ signaling Group, Weill Cornell Medicine Qatar, Education City, Qatar Foundation, Doha, Qatar.,Department of Biotechnology, American University of Ras Al Khaimah, Ras al Khaimah, UAE
| | - Maya Dib
- Department of Physiology and Biophysics, Ca2+ signaling Group, Weill Cornell Medicine Qatar, Education City, Qatar Foundation, Doha, Qatar
| | - Ethel Alcantara-Adap
- Department of Physiology and Biophysics, Ca2+ signaling Group, Weill Cornell Medicine Qatar, Education City, Qatar Foundation, Doha, Qatar
| | - Raphael Courjaret
- Department of Physiology and Biophysics, Ca2+ signaling Group, Weill Cornell Medicine Qatar, Education City, Qatar Foundation, Doha, Qatar
| | - Nancy Nader
- Department of Physiology and Biophysics, Ca2+ signaling Group, Weill Cornell Medicine Qatar, Education City, Qatar Foundation, Doha, Qatar
| | - Cleo Z Reyes
- Department of Physiology and Biophysics, Ca2+ signaling Group, Weill Cornell Medicine Qatar, Education City, Qatar Foundation, Doha, Qatar.,Lehigh Valley Health Network, Allentown, PA, USA
| | - Ayat S Hammad
- College of Health and Life Sciences, Hamad Bin Khalifa University, Doha, Qatar
| | - Satanay Hubrack
- Department of Physiology and Biophysics, Ca2+ signaling Group, Weill Cornell Medicine Qatar, Education City, Qatar Foundation, Doha, Qatar.,Sidra Medicine, Doha, Qatar
| | - Fang Yu
- Department of Physiology and Biophysics, Ca2+ signaling Group, Weill Cornell Medicine Qatar, Education City, Qatar Foundation, Doha, Qatar
| | - Khaled Machaca
- Department of Physiology and Biophysics, Ca2+ signaling Group, Weill Cornell Medicine Qatar, Education City, Qatar Foundation, Doha, Qatar.
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6
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Remodeling of ER-plasma membrane contact sites but not STIM1 phosphorylation inhibits Ca 2+ influx in mitosis. Proc Natl Acad Sci U S A 2019; 116:10392-10401. [PMID: 31064875 PMCID: PMC6535005 DOI: 10.1073/pnas.1821399116] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The mechanisms blocking Ca2+ influx in mitosis are complex and involve a decrease in stable endoplasmic reticulum (ER)–plasma membrane (PM) contact sites and degradation of the ER Ca2+ sensor stromal interaction molecule 1 (STIM1) but not its phosphorylation. This challenges the current view that STIM1 phosphorylation is essential for mitotic store-operated Ca2+ entry inhibition and sheds light on the dynamics of ER–PM contact sites and of Ca2+ influx in mitosis. Store-operated Ca2+ entry (SOCE), mediated by the endoplasmic reticulum (ER) Ca2+ sensor stromal interaction molecule 1 (STIM1) and the plasma membrane (PM) channel Orai1, is inhibited during mitosis. STIM1 phosphorylation has been suggested to mediate this inhibition, but it is unclear whether additional pathways are involved. Here, we demonstrate using various approaches, including a nonphosphorylatable STIM1 knock-in mouse, that STIM1 phosphorylation is not required for SOCE inhibition in mitosis. Rather, multiple pathways converge to inhibit Ca2+ influx in mitosis. STIM1 interacts with the cochaperone BAG3 and localizes to autophagosomes in mitosis, and STIM1 protein levels are reduced. The density of ER–PM contact sites (CSs) is also dramatically reduced in mitosis, thus physically preventing STIM1 and Orai1 from interacting to activate SOCE. Our findings provide insights into ER–PM CS remodeling during mitosis and a mechanistic explanation of the inhibition of Ca2+ influx that is required for cell cycle progression.
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7
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Reconstitution of Intracellular Calcium Signaling in Xenopus Egg Extracts. Methods Mol Biol 2019. [PMID: 30737685 DOI: 10.1007/978-1-4939-9009-2_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Generation of calcium signal in the cytoplasm of fertilized or parthenogenetically activated eggs has been extensively studied in the intact eggs of several biological species. Calcium transient was found to elicit a plethora of biochemical and cellular events in these cells. Remarkably, intracellular calcium signaling can also be reconstituted in cell-free environment. In this chapter, we describe the methods that allow reconstitution, detection, and quantification of the calcium signal in cell-free extracts of Xenopus oocytes and eggs.
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8
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Carvacho I, Piesche M, Maier TJ, Machaca K. Ion Channel Function During Oocyte Maturation and Fertilization. Front Cell Dev Biol 2018; 6:63. [PMID: 29998105 PMCID: PMC6028574 DOI: 10.3389/fcell.2018.00063] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 06/04/2018] [Indexed: 12/20/2022] Open
Abstract
The proper maturation of both male and female gametes is essential for supporting fertilization and the early embryonic divisions. In the ovary, immature fully-grown oocytes that are arrested in prophase I of meiosis I are not able to support fertilization. Acquiring fertilization competence requires resumption of meiosis which encompasses the remodeling of multiple signaling pathways and the reorganization of cellular organelles. Collectively, this differentiation endows the egg with the ability to activate at fertilization and to promote the egg-to-embryo transition. Oocyte maturation is associated with changes in the electrical properties of the plasma membrane and alterations in the function and distribution of ion channels. Therefore, variations on the pattern of expression, distribution, and function of ion channels and transporters during oocyte maturation are fundamental to reproductive success. Ion channels and transporters are important in regulating membrane potential, but also in the case of calcium (Ca2+), they play a critical role in modulating intracellular signaling pathways. In the context of fertilization, Ca2+ has been shown to be the universal activator of development at fertilization, playing a central role in early events associated with egg activation and the egg-to-embryo transition. These early events include the block of polyspermy, the completion of meiosis and the transition to the embryonic mitotic divisions. In this review, we discuss the role of ion channels during oocyte maturation, fertilization and early embryonic development. We will describe how ion channel studies in Xenopus oocytes, an extensively studied model of oocyte maturation, translate into a greater understanding of the role of ion channels in mammalian oocyte physiology.
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Affiliation(s)
- Ingrid Carvacho
- Department of Biology and Chemistry, Faculty of Basic Sciences, Universidad Católica del Maule, Talca, Chile
| | - Matthias Piesche
- Biomedical Research Laboratories, Medicine Faculty, Universidad Católica del Maule, Talca, Chile
| | - Thorsten J. Maier
- Department of Anesthesiology, Intensive Care Medicine and Pain Therapy, Goethe-University Hospital, Frankfurt, Germany
| | - Khaled Machaca
- Department of Physiology and Biophysics, Weill Cornell-Medicine-Qatar, Education City, Qatar Foundation, Doha, Qatar
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9
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Ferrer-Buitrago M, Bonte D, De Sutter P, Leybaert L, Heindryckx B. Single Ca 2+ transients vs oscillatory Ca 2+ signaling for assisted oocyte activation: limitations and benefits. Reproduction 2017; 155:R105-R119. [PMID: 29122969 DOI: 10.1530/rep-17-0098] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 11/06/2017] [Accepted: 11/09/2017] [Indexed: 11/08/2022]
Abstract
Oocyte activation is a calcium (Ca2+)-dependent process that has been investigated in depth, in particular, regarding its impact on assisted reproduction technology (ART). Following a standard model of signal transduction, Ca2+ drives the meiotic progression upon fertilization in all species studied to date. However, Ca2+ changes during oocyte activation are species specific, and they can be classified in two modalities based on the pattern defined by the Ca2+ signature: a single Ca2+ transient (e.g. amphibians) or repetitive Ca2+ transients called Ca2+ oscillations (e.g. mammals). Interestingly, assisted oocyte activation (AOA) methods have highlighted the ability of mammalian oocytes to respond to single Ca2+ transients with normal embryonic development. In this regard, there is evidence supporting that cellular events during the process of oocyte activation are initiated by different number of Ca2+ oscillations. Moreover, it was proposed that oocyte activation and subsequent embryonic development are dependent on the total summation of the Ca2+ peaks, rather than to a specific frequency pattern of Ca2+ oscillations. The present review aims to demonstrate the complexity of mammalian oocyte activation by describing the series of Ca2+-linked physiological events involved in mediating the egg-to-embryo transition. Furthermore, mechanisms of AOA and the limitations and benefits associated with the application of different activation agents are discussed.
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Affiliation(s)
- Minerva Ferrer-Buitrago
- Ghent-Fertility and Stem Cell Team (G-FaST)Department for Reproductive Medicine, Ghent University Hospital, Ghent, Belgium
| | - Davina Bonte
- Ghent-Fertility and Stem Cell Team (G-FaST)Department for Reproductive Medicine, Ghent University Hospital, Ghent, Belgium
| | - Petra De Sutter
- Ghent-Fertility and Stem Cell Team (G-FaST)Department for Reproductive Medicine, Ghent University Hospital, Ghent, Belgium
| | - Luc Leybaert
- Physiology GroupDepartment of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Björn Heindryckx
- Ghent-Fertility and Stem Cell Team (G-FaST)Department for Reproductive Medicine, Ghent University Hospital, Ghent, Belgium
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10
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Bernhardt ML, Padilla-Banks E, Stein P, Zhang Y, Williams CJ. Store-operated Ca 2+ entry is not required for fertilization-induced Ca 2+ signaling in mouse eggs. Cell Calcium 2017; 65:63-72. [PMID: 28222911 DOI: 10.1016/j.ceca.2017.02.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 02/07/2017] [Accepted: 02/07/2017] [Indexed: 01/01/2023]
Abstract
Repetitive oscillations in cytoplasmic Ca2+ due to periodic Ca2+ release from the endoplasmic reticulum (ER) drive mammalian embryo development following fertilization. Influx of extracellular Ca2+ to support the refilling of ER stores is required for sustained Ca2+ oscillations, but the mechanisms underlying this Ca2+ influx are controversial. Although store-operated Ca2+ entry (SOCE) is an appealing candidate mechanism, several groups have arrived at contradictory conclusions regarding the importance of SOCE in oocytes and eggs. To definitively address this question, Ca2+ influx was assessed in oocytes and eggs lacking the major components of SOCE, the ER Ca2+ sensor STIM proteins, and the plasma membrane Ca2+ channel ORAI1. We generated oocyte-specific conditional knockout (cKO) mice for Stim1 and Stim2, and also generated Stim1/2 double cKO mice. Females lacking one or both STIM proteins were fertile and their ovulated eggs displayed normal patterns of Ca2+ oscillations following fertilization. In addition, no impairment was observed in ER Ca2+ stores or Ca2+ influx following store depletion. Similar studies were performed on eggs from mice globally lacking ORAI1; no abnormalities were observed. Furthermore, spontaneous Ca2+ influx was normal in oocytes from Stim1/2 cKO and ORAI1-null mice. Finally, we tested if TRPM7-like channels could support spontaneous Ca2+ influx, and found that it was largely prevented by NS8593, a TRPM7-specific inhibitor. Fertilization-induced Ca2+ oscillations were also impaired by NS8593. Combined, these data robustly show that SOCE is not required to support appropriate Ca2+ signaling in mouse oocytes and eggs, and that TRPM7-like channels may contribute to Ca2+ influx that was previously attributed to SOCE.
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Affiliation(s)
- Miranda L Bernhardt
- Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Elizabeth Padilla-Banks
- Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Paula Stein
- Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Yingpei Zhang
- Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Carmen J Williams
- Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA.
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11
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SOCE proteins, STIM1 and Orai1, are localized to the cleavage furrow during cytokinesis of the first and second cell division cycles in zebrafish embryos. ZYGOTE 2016; 24:880-889. [PMID: 27702423 DOI: 10.1017/s0967199416000216] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In zebrafish embryos, distinct Ca2+ transients are localized to the early cleavage furrows during the first few cell division cycles. These transients are generated mainly by release via IP3Rs in the endoplasmic reticulum, and they are necessary for furrow positioning, propagation, deepening and apposition. We previously showed, via the use of inhibitors, that store-operated Ca2+ entry (SOCE) also appears to be essential for maintaining the IP3R-mediated elevated levels of [Ca2+]i for the extended periods required for the completion of successful furrow deepening and daughter cell apposition in these large embryonic cells. Here, newly fertilized, dechorionated embryos were fixed at various times during the first and second cell division cycles and immunolabelled with antibodies to STIM1 and/or Orai1 (key components of SOCE). We show that both of these proteins have a dynamic pattern of localization during cytokinesis of the first two cell division cycles. These new data help to support our previous inhibitor results, and provide additional evidence that SOCE contributes to the maintenance of the sustained elevated Ca2+ that is required for the successful completion of cytokinesis in the large cells of embryonic zebrafish.
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12
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Courjaret R, Dib M, Machaca K. Store-Operated Ca 2+ Entry in Oocytes Modulate the Dynamics of IP 3 -Dependent Ca 2+ Release From Oscillatory to Tonic. J Cell Physiol 2016; 232:1095-1103. [PMID: 27504787 DOI: 10.1002/jcp.25513] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 08/08/2016] [Indexed: 11/10/2022]
Abstract
Ca2+ signaling is ubiquitous and mediates various cellular functions encoded in its spatial, temporal, and amplitude features. Here, we investigate the role of store-operated Ca2+ entry (SOCE) in regulating the temporal dynamics of Ca2+ signals in Xenopus oocytes, which can be either oscillatory or tonic. Oscillatory Ca2+ release from intracellular stores is typically observed at physiological agonist concentration. When Ca2+ release leads to Ca2+ store depletion, this triggers the activation of SOCE that translates into a low-amplitude tonic Ca2+ signal. SOCE has also been implicated in fueling Ca2+ oscillations when activated at low levels. Here, we show that sustained SOCE activation in the presence of IP3 to gate IP3 receptors (IP3 R) results in a pump-leak steady state across the endoplasmic reticulum (ER) membrane that inhibits Ca2+ oscillations and produces a tonic Ca2+ signal. Tonic signaling downstream of SOCE activation relies on focal Ca2+ entry through SOCE ER-plasma membrane (PM) junctions, Ca2+ uptake into the ER, followed by release through open IP3 Rs at distant sites, a process we refer to as "Ca2+ teleporting." Therefore, sustained SOCE activation in the presence of an IP3 -dependent "leak" pathway at the ER membrane results in a switch from oscillatory to tonic Ca2+ signaling. J. Cell. Physiol. 232: 1095-1103, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Raphaël Courjaret
- Department of Physiology and Biophysics, Weill Cornell Medicine Qatar, Doha, Qatar
| | - Maya Dib
- Department of Physiology and Biophysics, Weill Cornell Medicine Qatar, Doha, Qatar
| | - Khaled Machaca
- Department of Physiology and Biophysics, Weill Cornell Medicine Qatar, Doha, Qatar
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13
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Courjaret R, Machaca K. Xenopus Oocyte As a Model System to Study Store-Operated Ca(2+) Entry (SOCE). Front Cell Dev Biol 2016; 4:66. [PMID: 27446917 PMCID: PMC4919926 DOI: 10.3389/fcell.2016.00066] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 06/09/2016] [Indexed: 11/16/2022] Open
Abstract
Store-operated Ca2+ entry (SOCE) is a ubiquitous Ca2+ influx pathway at the cell membrane that is regulated by Ca2+ content in intracellular stores. SOCE is important for a multitude of physiological processes, including muscle development, T-cell activation, and fertilization. Therefore, understanding the molecular regulation of SOCE is imperative. SOCE activation requires conformational and spatial changes in proteins located in both the endoplasmic reticulum and plasma membrane. This leads to the generation of an ionic current of very small amplitude. Both biochemical and electrophysiological parameters of SOCE can be difficult to record in small mammalian cells. In this protocol we present the different methodologies that enable the study of SOCE in a unique model system, the frog oocyte, which provides several advantages and have contributed significantly to our understanding of SOCE regulation.
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Affiliation(s)
- Raphaël Courjaret
- Department of Physiology and Biophysics, Weill Cornell Medicine Qatar, Education City, Qatar Foundation Doha, Qatar
| | - Khaled Machaca
- Department of Physiology and Biophysics, Weill Cornell Medicine Qatar, Education City, Qatar Foundation Doha, Qatar
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14
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Courjaret R, Hodeify R, Hubrack S, Ibrahim A, Dib M, Daas S, Machaca K. The Ca2+-activated Cl- channel Ano1 controls microvilli length and membrane surface area in the oocyte. J Cell Sci 2016; 129:2548-58. [PMID: 27173493 DOI: 10.1242/jcs.188367] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 05/02/2016] [Indexed: 12/12/2022] Open
Abstract
Ca(2+)-activated Cl(-) channels (CaCCs) play important physiological functions in epithelia and other tissues. In frog oocytes the CaCC Ano1 regulates resting membrane potential and the block to polyspermy. Here, we show that Ano1 expression increases the oocyte surface, revealing a novel function for Ano1 in regulating cell morphology. Confocal imaging shows that Ano1 increases microvilli length, which requires ERM-protein-dependent linkage to the cytoskeleton. A dominant-negative form of the ERM protein moesin precludes the Ano1-dependent increase in membrane area. Furthermore, both full-length and the truncated dominant-negative forms of moesin co-localize with Ano1 to the microvilli, and the two proteins co-immunoprecipitate. The Ano1-moesin interaction limits Ano1 lateral membrane mobility and contributes to microvilli scaffolding, therefore stabilizing larger membrane structures. Collectively, these results reveal a newly identified role for Ano1 in shaping the plasma membrane during oogenesis, with broad implications for the regulation of microvilli in epithelia.
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Affiliation(s)
- Raphael Courjaret
- Department of Physiology and Biophysics, Weill Cornell Medical College in Qatar, Education City - Qatar Foundation, Luqta Street, PO Box 24144, Doha 24144, Qatar
| | - Rawad Hodeify
- Department of Physiology and Biophysics, Weill Cornell Medical College in Qatar, Education City - Qatar Foundation, Luqta Street, PO Box 24144, Doha 24144, Qatar
| | - Satanay Hubrack
- Department of Physiology and Biophysics, Weill Cornell Medical College in Qatar, Education City - Qatar Foundation, Luqta Street, PO Box 24144, Doha 24144, Qatar
| | - Awab Ibrahim
- Department of Physiology and Biophysics, Weill Cornell Medical College in Qatar, Education City - Qatar Foundation, Luqta Street, PO Box 24144, Doha 24144, Qatar
| | - Maya Dib
- Department of Physiology and Biophysics, Weill Cornell Medical College in Qatar, Education City - Qatar Foundation, Luqta Street, PO Box 24144, Doha 24144, Qatar
| | - Sahar Daas
- Department of Physiology and Biophysics, Weill Cornell Medical College in Qatar, Education City - Qatar Foundation, Luqta Street, PO Box 24144, Doha 24144, Qatar
| | - Khaled Machaca
- Department of Physiology and Biophysics, Weill Cornell Medical College in Qatar, Education City - Qatar Foundation, Luqta Street, PO Box 24144, Doha 24144, Qatar
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15
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Aseervatham J, Tran L, Machaca K, Boudker O. The Role of Flexible Loops in Folding, Trafficking and Activity of Equilibrative Nucleoside Transporters. PLoS One 2015; 10:e0136779. [PMID: 26406980 PMCID: PMC4583308 DOI: 10.1371/journal.pone.0136779] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 08/07/2015] [Indexed: 11/25/2022] Open
Abstract
Equilibrative nucleoside transporters (ENTs) are integral membrane proteins, which reside in plasma membranes of all eukaryotic cells and mediate thermodynamically downhill transport of nucleosides. This process is essential for nucleoside recycling, and also plays a key role in terminating adenosine-mediated cellular signaling. Furthermore, ENTs mediate the uptake of many drugs, including anticancer and antiviral nucleoside analogues. The structure and mechanism, by which ENTs catalyze trans-membrane transport of their substrates, remain unknown. To identify the core of the transporter needed for stability, activity, and for its correct trafficking to the plasma membrane, we have expressed human ENT deletion mutants in Xenopus laevis oocytes and determined their localization, transport properties and susceptibility to inhibition. We found that the carboxyl terminal trans-membrane segments are essential for correct protein folding and trafficking. In contrast, the soluble extracellular and intracellular loops appear to be dispensable, and must be involved in the fine-tuning of transport regulation.
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Affiliation(s)
- Jaya Aseervatham
- Department of Physiology and Biophysics, Weill Cornell Medical College in Qatar, Qatar foundation, Education City, Doha, Qatar
| | - Lucky Tran
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, United States of America
| | - Khaled Machaca
- Department of Physiology and Biophysics, Weill Cornell Medical College in Qatar, Qatar foundation, Education City, Doha, Qatar
| | - Olga Boudker
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, United States of America
- * E-mail:
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16
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The role of IP3 receptor channel clustering in Ca2+ wave propagation during oocyte maturation. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015. [PMID: 24560141 DOI: 10.1016/b978-0-12-397897-4.00006-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
During oocyte maturation, the calcium-signaling machinery undergoes a dramatic remodeling resulting in distinctly different calcium-release patterns on all organizational scales from puffs to waves. The dynamics of the Ca(2+) release wave in mature as compared to immature oocytes are defined by a slower propagation speed and longer duration of the high Ca(2+) plateau. In this chapter, we use computational modeling to identify the changes in the signaling machinery, which contribute most significantly to the alterations observed in Ca(2+) wave propagation during Xenopus oocyte maturation. In addition to loss of store-operated calcium entry and internalization of plasma membrane pumps, we propose that spatial reorganization of the IP3 receptors in the plane of the ER membrane is a key factor for the observed signaling changes in Ca(2+) wave propagation.
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17
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Calcium signaling and meiotic exit at fertilization in Xenopus egg. Int J Mol Sci 2014; 15:18659-76. [PMID: 25322156 PMCID: PMC4227238 DOI: 10.3390/ijms151018659] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 10/01/2014] [Accepted: 10/09/2014] [Indexed: 11/16/2022] Open
Abstract
Calcium is a universal messenger that mediates egg activation at fertilization in all sexually reproducing species studied. However, signaling pathways leading to calcium generation and the mechanisms of calcium-induced exit from meiotic arrest vary substantially among species. Here, we review the pathways of calcium signaling and the mechanisms of meiotic exit at fertilization in the eggs of the established developmental model, African clawed frog, Xenopus laevis. We also discuss calcium involvement in the early fertilization-induced events in Xenopus egg, such as membrane depolarization, the increase in intracellular pH, cortical granule exocytosis, cortical contraction, contraction wave, cortical rotation, reformation of the nuclear envelope, sperm chromatin decondensation and sister chromatid segregation.
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18
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Mid-range Ca2+ signalling mediated by functional coupling between store-operated Ca2+ entry and IP3-dependent Ca2+ release. Nat Commun 2014; 5:3916. [PMID: 24867608 DOI: 10.1038/ncomms4916] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 04/17/2014] [Indexed: 11/08/2022] Open
Abstract
The versatility and universality of Ca(2+) signals stem from the breadth of their spatial and temporal dynamics. Spatially, Ca(2+) signalling is well studied in the microdomain scale, close to a Ca(2+) channel, and at the whole-cell level. However, little is known about how local Ca(2+) signals are regulated to specifically activate spatially distant effectors without a global Ca(2+) rise. Here we show that an intricate coupling between the inositol 1,4,5 trisphosphate (IP3) receptor, SERCA pump and store-operated Ca(2+) entry (SOCE) allows for efficient mid-range Ca(2+) signalling. Ca(2+) flowing through SOCE is taken up into the ER lumen by the SERCA pump, only to be re-released by IP3Rs to activate distal Ca(2+)-activated Cl(-) channels (CaCCs). This CaCC regulation contributes to setting the membrane potential of the cell. Hence functional coupling between SOCE, SERCA and IP3R limits local Ca(2+) diffusion and funnels Ca(2+) through the ER lumen to activate a spatially separate Ca(2+) effector.
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19
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Pozo-Guisado E, Martin-Romero FJ. The regulation of STIM1 by phosphorylation. Commun Integr Biol 2013; 6:e26283. [PMID: 24505502 PMCID: PMC3914909 DOI: 10.4161/cib.26283] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Accepted: 08/27/2013] [Indexed: 12/31/2022] Open
Abstract
Calcium ion (Ca(2+)) concentration plays a key role in cell signaling in eukaryotic cells. At the cellular level, Ca(2+) directly participates in such diverse cellular events as adhesion and migration, differentiation, contraction, secretion, synaptic transmission, fertilization, and cell death. As a consequence of these diverse actions, the cytosolic concentration of free Ca(2+) is tightly regulated by the coordinated activity of Ca(2+) channels, Ca(2+) pumps, and Ca(2+)-binding proteins. Although many of these regulators have been studied in depth, other proteins have been described recently, and naturally far less is known about their contribution to cell physiology. Within this last group of proteins, STIM1 has emerged as a major contributor to Ca(2+) signaling by means of its activity as Ca(2+) channel regulator. STIM1 is a protein resident mainly, but not exclusively, in the endoplasmic reticulum (ER), and activates a set of plasma membrane Ca(2+) channels termed store-operated calcium channels (SOCs) when the concentration of free Ca(2+) within the ER drops transiently as a result of Ca(2+) release from this compartment. Knowledge regarding the molecular architecture of STIM1 has grown considerably during the last years, and several structural domains within STIM1 have been reported to be required for the specific molecular interactions with other important players in Ca(2+) signaling, such as Ca(2+) channels and microtubules. Within the modulators of STIM1, phosphorylation has been shown to both activate and inactivate STIM1-dependent Ca(2+) entry depending on the cell type, cell cycle phase, and the specific residue that becomes modified. Here we shall review current knowledge regarding the modulation of STIM1 by phosphorylation.
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Affiliation(s)
- Eulalia Pozo-Guisado
- Department of Biochemistry and Molecular Biology; School of Life Sciences; University of Extremadura; Badajoz, Spain
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20
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Cheon B, Lee HC, Wakai T, Fissore RA. Ca2+ influx and the store-operated Ca2+ entry pathway undergo regulation during mouse oocyte maturation. Mol Biol Cell 2013; 24:1396-410. [PMID: 23468522 PMCID: PMC3639051 DOI: 10.1091/mbc.e13-01-0065] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Changes in Ca2+ homeostasis render oocytes competent to undergo [Ca2+]i oscillations and activation. During mouse oocyte maturation Ca2+ influx and SOCE are down-regulated, whereas [Ca2+]ER content increases. Bypassing the down-regulation of Ca2+ influx disturbs oocyte maturation. In preparation for fertilization, mammalian oocytes undergo optimization of the mechanisms that regulate calcium homeostasis. Among these changes is the increase in the content of the Ca2+ stores ([Ca2+]ER), a process that requires Ca2+ influx. Nevertheless, the mechanism(s) that mediates this influx remains obscure, although is known that [Ca2+]ER can regulate Ca2+ influx via store-operated Ca2+ entry (SOCE). We find that during maturation, as [Ca2+]ER increases, Ca2+ influx decreases. We demonstrate that mouse oocytes/eggs express the two molecular components of SOCE—stromal interaction molecule 1 (Stim1) and Orai1—and expression of human (h) Stim1 increases Ca2+ influx in a manner that recapitulates endogenous SOCE. We observe that the cellular distribution of hStim1 and hOrai1 during maturation undergoes sweeping changes that curtail their colocalization during the later stages of maturation. Coexpression of hStim1 and hOrai1 enhances influx throughout maturation but increases basal Ca2+ levels only in GV oocytes. Further, expression of a constitutive active form of hStim1 plus Orai1, which increases basal Ca2+ throughout maturation, disturbs resumption of meiosis. Taken together, our results demonstrate that Ca2+ influx and SOCE are regulated during maturation and that alteration of Ca2+ homeostasis undermines maturation in mouse oocytes.
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Affiliation(s)
- Banyoon Cheon
- Molecular and Cellular Biology Program, University of Massachusetts, Amherst, MA 01002, USA
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21
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Lee B, Palermo G, Machaca K. Downregulation of store-operated Ca2+ entry during mammalian meiosis is required for the egg-to-embryo transition. J Cell Sci 2013; 126:1672-81. [PMID: 23424198 DOI: 10.1242/jcs.121335] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A specialized Ca(2+) transient at fertilization represents the universal driver for the egg-to-embryo transition. Ca(2+) signaling remodels during oocyte maturation to endow the egg with the capacity to produce the specialized Ca(2+) transient at fertilization, which takes the form of a single (e.g. Xenopus) or multiple (e.g. mouse) Ca(2+) spikes depending on the species. Store-operated Ca(2+) entry (SOCE) is the predominant Ca(2+) influx pathway in vertebrate oocytes, and in Xenopus SOCE completely inactivates during meiosis. Here, we show that SOCE is downregulated during mouse meiosis, but remains active in mature metaphase II eggs. SOCE inhibition is due to a decreased ability of the Ca(2+) sensor STIM1 to translocate to the cortical endoplasmic reticulum domain and due to internalization of Orai1. Reversing SOCE downregulation by overexpression of STIM1 and Orai1 prolongs the Ca(2+) oscillations at egg activation and disrupts the egg-to-embryo transition. Thus, SOCE downregulation during mammalian oocyte maturation is a crucial determinant of the fertilization-specific Ca(2+) transient, egg activation and early embryonic development.
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Affiliation(s)
- Bora Lee
- Center for Reproductive Medicine and Infertility, Weill Cornell Medical College, New York, NY 10021, USA
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22
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Abstract
Growing oocytes are arrested at the first prophase of meiosis which is morphologically identified by the presence of a large and vesicular nucleus, called the germinal vesicle. The dissolution of the germinal vesicle marks the resumption of meiosis during which the oocyte undergoes massive modifications up to the second meiotic block, which is removed at fertilization. The interval between the first and the second meiotic block is defined as maturation and the events occurring during this period are crucial for ovulation, fertilization, and embryo development. Oocytes are excitable cells that react to stimuli by modifying their electrical properties as a consequence of ion currents flowing through ion channels on the plasma membrane. These electrical changes have been largely described at fertilization whereas little information is available during oocyte maturation. The aim of this review is to give an overview on the involvement of ion channels and ion currents during oocyte maturation in species from invertebrates to mammals. The results summarized here point to the possible functional role of ion channels underlying oocyte growth and maturation.
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23
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Alternative Forms of the Store-Operated Calcium Entry Mediators, STIM1 and Orai1. CURRENT TOPICS IN MEMBRANES 2013; 71:109-23. [DOI: 10.1016/b978-0-12-407870-3.00005-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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24
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Nader N, Kulkarni RP, Dib M, Machaca K. How to make a good egg!: The need for remodeling of oocyte Ca(2+) signaling to mediate the egg-to-embryo transition. Cell Calcium 2012; 53:41-54. [PMID: 23266324 DOI: 10.1016/j.ceca.2012.11.015] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Revised: 11/26/2012] [Accepted: 11/27/2012] [Indexed: 11/19/2022]
Abstract
The egg-to-embryo transition marks the initiation of multicellular organismal development and is mediated by a specialized Ca(2+) transient at fertilization. This explosive Ca(2+) signal has captured the interest and imagination of scientists for many decades, given its cataclysmic nature and necessity for the egg-to-embryo transition. Learning how the egg acquires the competency to generate this Ca(2+) transient at fertilization is essential to our understanding of the mechanisms controlling egg and the transition to embryogenesis. In this review we discuss our current knowledge of how Ca(2+) signaling pathways remodel during oocyte maturation in preparation for fertilization with a special emphasis on the frog oocyte as additional reviews in this issue will touch on this in other species.
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Affiliation(s)
- Nancy Nader
- Department of Physiology and Biophysics, Weill Cornell Medical College in Qatar (WCMC-Q), Education City, Qatar Foundation, Qatar
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25
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Ca(2+) homeostasis and regulation of ER Ca(2+) in mammalian oocytes/eggs. Cell Calcium 2012; 53:63-7. [PMID: 23260016 DOI: 10.1016/j.ceca.2012.11.010] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 11/02/2012] [Accepted: 11/03/2012] [Indexed: 11/23/2022]
Abstract
The activation of the developmental program in mammalian eggs relies on the initiation at the time of fertilization of repeated rises in the intracellular concentration of free calcium ([Ca(2+)](i)), also known as [Ca(2+)](i) oscillations. The ability to mount the full complement of oscillations is only achieved at the end of oocyte maturation, at the metaphase stage of meiosis II (MII). Over the last decades research has focused on addressing the mechanisms by which the sperm initiates the oscillations and identification of the channels that mediate intracellular Ca(2+) release. This review will describe the up-to-date knowledge of other aspects of Ca(2+) homeostasis in mouse oocytes, such as the mechanisms that transport Ca(2+) out of the cytosol into the endoplasmic reticulum (ER), the Ca(2+) store of the oocyte/egg, into other organelles and also those that extrude Ca(2+). Evidence pointing to channels in the plasma membrane that mediate Ca(2+) entry from the extracellular milieu, which is required for the persistence of the oscillations, is also discussed, along with the modifications that these mechanisms undergo during maturation. Lastly, we highlight areas where additional research is needed to obtain a better understating of the molecules and mechanisms that regulate Ca(2+) homeostasis in this unique Ca(2+) signaling system.
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26
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Miao YL, Williams CJ. Calcium signaling in mammalian egg activation and embryo development: the influence of subcellular localization. Mol Reprod Dev 2012; 79:742-56. [PMID: 22888043 DOI: 10.1002/mrd.22078] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2012] [Accepted: 07/27/2012] [Indexed: 11/07/2022]
Abstract
Calcium (Ca(2+) ) signals drive the fundamental events surrounding fertilization and the activation of development in all species examined to date. Initial studies of Ca(2+) signaling at fertilization in marine animals were tightly linked to new discoveries of bioluminescent proteins and their use as fluorescent Ca(2+) sensors. Since that time, there has been rapid progress in our understanding of the key functions for Ca(2+) in many cell types and of the impact of cellular localization on Ca(2+) signaling pathways. In this review, which focuses on mammalian egg activation, we consider how Ca(2+) is regulated and stored at different stages of oocyte development and examine the functions of molecules that serve as both regulators of Ca(2+) release and effectors of Ca(2+) signals. We then summarize studies exploring how Ca(2+) directs downstream effectors mediating both egg activation and later signaling events required for successful preimplantation embryo development. Throughout this review, we focus attention on how localization of Ca(2+) signals influences downstream signaling events, and attempt to highlight gaps in our knowledge that are ripe for future research.
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Affiliation(s)
- Yi-Liang Miao
- Reproductive Medicine Group, Laboratory of Reproductive and Developmental Toxicology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina 27709, USA
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27
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Jeseta M, Marin M, Tichovska H, Melicharova P, Cailliau-Maggio K, Martoriati A, Lescuyer-Rousseau A, Beaujois R, Petr J, Sedmikova M, Bodart JF. Nitric oxide-donor SNAP induces Xenopus eggs activation. PLoS One 2012; 7:e41509. [PMID: 22911804 PMCID: PMC3402422 DOI: 10.1371/journal.pone.0041509] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Accepted: 06/22/2012] [Indexed: 12/11/2022] Open
Abstract
Nitric oxide (NO) is identified as a signaling molecule involved in many cellular or physiological functions including meiotic maturation and parthenogenetic activation of mammalian oocytes. We observed that nitric oxide donor SNAP was potent to induce parthenogenetic activation in Xenopus eggs. NO-scavenger CPTIO impaired the effects of SNAP, providing evidence for the effects of the latter to be specific upon NO release. In Xenopus eggs, SNAP treatment induced pigment rearrangement, pronucleus formation and exocytosis of cortical granules. At a biochemical level, SNAP exposure lead to MAPK and Rsk inactivation within 30 minutes whereas MPF remained active, in contrast to calcium ionophore control where MPF activity dropped rapidly. MAPK inactivation could be correlated to pronuclear envelope reformation observed. In SNAP-treated eggs, a strong increase in intracellular calcium level was observed. NO effects were impaired in calcium-free or calcium limited medium, suggesting that that parthenogenetic activation of Xenopus oocytes with a NO donor was mainly calcium-dependent.
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Affiliation(s)
- Michal Jeseta
- Veterinary Research Institute, Department of Genetics and Reproduction, Brno, Czech Republic.
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28
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Silvestre F, Fissore RA, Tosti E, Boni R. [Ca2+
]i
rise at in vitro maturation in bovine cumulus-oocyte complexes. Mol Reprod Dev 2012; 79:369-79. [DOI: 10.1002/mrd.22038] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Accepted: 03/07/2012] [Indexed: 01/31/2023]
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29
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Calcium influx-mediated signaling is required for complete mouse egg activation. Proc Natl Acad Sci U S A 2012; 109:4169-74. [PMID: 22371584 DOI: 10.1073/pnas.1112333109] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mammalian fertilization is accompanied by oscillations in egg cytoplasmic calcium (Ca(2+)) concentrations that are critical for completion of egg activation. These oscillations are initiated by Ca(2+) release from inositol 1,4,5-trisphosphate (IP(3))-sensitive intracellular stores. We tested the hypothesis that Ca(2+) influx across the plasma membrane was a requisite component of egg activation signaling, and not simply a Ca(2+) source for store repletion. Using intracytoplasmic sperm injection (ICSI) and standard in vitro fertilization (IVF), we found that Ca(2+) influx was not required to initiate resumption of meiosis II. However, even if multiple oscillations in intracellular Ca(2+) occurred, in the absence of Ca(2+) influx, the fertilized eggs failed to emit the second polar body, resulting in formation of three pronuclei. Additional experiments using the Ca(2+) chelator, BAPTA/AM, demonstrated that Ca(2+) influx is sufficient to support polar body emission and pronucleus formation after only a single sperm-induced Ca(2+) transient, whereas BAPTA/AM-treated ICSI or fertilized eggs cultured in Ca(2+)-free medium remained arrested in metaphase II. Inhibition of store-operated Ca(2+) entry had no effect on ICSI-induced egg activation, so Ca(2+) influx through alternative channels must participate in egg activation signaling. Ca(2+) influx appears to be upstream of CaMKIIγ activity because eggs can be parthenogenetically activated with a constitutively active form of CaMKIIγ in the absence of extracellular Ca(2+). These results suggest that Ca(2+) influx at fertilization not only maintains Ca(2+) oscillations by replenishing Ca(2+) stores, but also activates critical signaling pathways upstream of CaMKIIγ that are required for second polar body emission.
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30
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Wakai T, Vanderheyden V, Yoon SY, Cheon B, Zhang N, Parys JB, Fissore RA. Regulation of inositol 1,4,5-trisphosphate receptor function during mouse oocyte maturation. J Cell Physiol 2012; 227:705-17. [PMID: 21465476 DOI: 10.1002/jcp.22778] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
At the time of fertilization, an increase in the intracellular Ca(2+) concentration ([Ca(2+)](i)) underlies egg activation and initiation of development in all species studied to date. The inositol 1,4,5-trisphosphate receptor (IP(3)R1), which is mostly located in the endoplasmic reticulum (ER) mediates the majority of this Ca(2+) release. The sensitivity of IP(3)R1, that is, its Ca(2+) releasing capability, is increased during oocyte maturation so that the optimum [Ca(2+)](i) response concurs with fertilization, which in mammals occurs at metaphase of second meiosis. Multiple IP(3)R1 modifications affect its sensitivity, including phosphorylation, sub-cellular localization, and ER Ca(2+) concentration ([Ca(2+)](ER)). Here, we evaluated using mouse oocytes how each of these factors affected IP(3)R1 sensitivity. The capacity for IP(3)-induced Ca(2+) release markedly increased at the germinal vesicle breakdown stage, although oocytes only acquire the ability to initiate fertilization-like oscillations at later stages of maturation. The increase in IP(3)R1 sensitivity was underpinned by an increase in [Ca(2+)](ER) and receptor phosphorylation(s) but not by changes in IP(3)R1 cellular distribution, as inhibition of the former factors reduced Ca(2+) release, whereas inhibition of the latter had no impact. Therefore, the results suggest that the regulation of [Ca(2+)](ER) and IP(3)R1 phosphorylation during maturation enhance IP(3)R1 sensitivity rendering oocytes competent to initiate oscillations at the expected time of fertilization. The temporal discrepancy between the initiation of changes in IP(3)R1 sensitivity and acquisition of mature oscillatory capacity suggest that other mechanisms that regulate Ca(2+) homeostasis also shape the pattern of oscillations in mammalian eggs.
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Affiliation(s)
- Takuya Wakai
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, Massachusetts 01003, USA
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31
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Marin M. Calcium Signaling in Xenopus oocyte. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 740:1073-94. [DOI: 10.1007/978-94-007-2888-2_49] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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32
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Martín-Romero FJ, López-Guerrero AM, Álvarez IS, Pozo-Guisado E. Role of Store-Operated Calcium Entry During Meiotic Progression and Fertilization of Mammalian Oocytes. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2012; 295:291-328. [DOI: 10.1016/b978-0-12-394306-4.00014-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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33
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Endoplasmic reticulum remodeling tunes IP₃-dependent Ca²+ release sensitivity. PLoS One 2011; 6:e27928. [PMID: 22140486 PMCID: PMC3227640 DOI: 10.1371/journal.pone.0027928] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2011] [Accepted: 10/27/2011] [Indexed: 11/19/2022] Open
Abstract
The activation of vertebrate development at fertilization relies on IP3-dependent Ca2+ release, a pathway that is sensitized during oocyte maturation. This sensitization has been shown to correlate with the remodeling of the endoplasmic reticulum into large ER patches, however the mechanisms involved are not clear. Here we show that IP3 receptors within ER patches have a higher sensitivity to IP3 than those in the neighboring reticular ER. The lateral diffusion rate of IP3 receptors in both ER domains is similar, and ER patches dynamically fuse with reticular ER, arguing that IP3 receptors exchange freely between the two ER compartments. These results suggest that increasing the density of IP3 receptors through ER remodeling is sufficient to sensitize IP3-dependent Ca2+ release. Mathematical modeling supports this concept of ‘geometric sensitization’ of IP3 receptors as a population, and argues that it depends on enhanced Ca2+-dependent cooperativity at sub-threshold IP3 concentrations. This represents a novel mechanism of tuning the sensitivity of IP3 receptors through ER remodeling during meiosis.
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34
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Silvestre F, Boni R, Fissore RA, Tosti E. Ca2+ signaling during maturation of cumulus-oocyte complex in mammals. Mol Reprod Dev 2011; 78:744-56. [PMID: 21656870 DOI: 10.1002/mrd.21332] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2011] [Accepted: 05/11/2011] [Indexed: 11/06/2022]
Abstract
Under the influence of gonadotropins or growth factors, a close cooperation develops between cumulus cells and the oocyte that is implicated in transmitting signals involved in maintaining or releasing the meiotic arrest in the oocyte. While cyclic adenosine 5'-monophosphate (cAMP) is a key molecule in maintaining the meiotic arrest, calcium (Ca(2+)) may play a role in controlling either spontaneous or gonadotropin-induced oocyte maturation, possibly by modulating intracytoplasmic cAMP concentrations via Ca(2+)-sensitive adenylate cyclases. This review focuses on the mechanisms related to the origin of the Ca(2+) wave that travels from the cumulus cells to the oocyte, and discusses the source of variations affecting the dynamics of this wave.
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Affiliation(s)
- F Silvestre
- Animal Physiology and Evolution Laboratory, Stazione Zoologica Anton Dohrn, Naples, Italy.
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35
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36
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Smyth JT, Hwang SY, Tomita T, DeHaven WI, Mercer JC, Putney JW. Activation and regulation of store-operated calcium entry. J Cell Mol Med 2011; 14:2337-49. [PMID: 20807283 PMCID: PMC3074973 DOI: 10.1111/j.1582-4934.2010.01168.x] [Citation(s) in RCA: 206] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The process of store-operated Ca2+ entry (SOCE), whereby Ca2+ influx across the plasma membrane is activated in response to depletion of intracellular Ca2+ stores in the endoplasmic reticulum (ER), has been under investigation for greater than 25 years; however, only in the past 5 years have we come to understand this mechanism at the molecular level. A surge of recent experimentation indicates that STIM molecules function as Ca2+ sensors within the ER that, upon Ca2+ store depletion, rearrange to sites very near to the plasma membrane. At these plasma membrane-ER junctions, STIM interacts with and activates SOCE channels of the Orai family. The molecular and biophysical data that have led to these findings are discussed in this review, as are several controversies within this rapidly expanding field.
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Affiliation(s)
- Jeremy T Smyth
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences-NIH, Department of Health and Human Services, Research Triangle Park, NC 27709, USA
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Yu F, Sun L, Courjaret R, Machaca K. Role of the STIM1 C-terminal domain in STIM1 clustering. J Biol Chem 2011; 286:8375-8384. [PMID: 21220431 DOI: 10.1074/jbc.m110.188789] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Store-operated Ca(2+) entry (SOCE) represents a ubiquitous Ca(2+) influx pathway activated by the filling state of intracellular Ca(2+) stores. SOCE is mediated by coupling of STIM1, the endoplasmic reticulum Ca(2+) sensor, to the Orai1 channel. SOCE inactivates during meiosis, partly because of the inability of STIM1 to cluster in response to store depletion. STIM1 has several functional domains, including the Orai1 interaction domain (STIM1 Orai Activating Region (SOAR) or CRAC Activation Domain (CAD)) and STIM1 homomerization domain. When Ca(2+) stores are full, these domains are inactive to prevent constitutive Ca(2+) entry. Here we show, using the Xenopus oocyte as an expression system, that the C-terminal 200 residues of STIM1 are important to maintain STIM1 in an inactive state when Ca(2+) stores are full, through predicted intramolecular shielding of the active STIM1 domains (SOAR/CAD and STIM1 homomerization domain). Interestingly, our data argue that the C-terminal 200 residues accomplish this through a steric hindrance mechanism because they can be substituted by GFP or mCherry while maintaining all aspects of STIM1 function. We further show that STIM1 clustering inhibition during meiosis is independent of the C-terminal 200 residues.
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Affiliation(s)
- Fang Yu
- From the Department of Physiology and Biophysics, Weill Cornell Medical College in Qatar, Qatar Foundation, Education City, Doha 24144, Qatar
| | - Lu Sun
- From the Department of Physiology and Biophysics, Weill Cornell Medical College in Qatar, Qatar Foundation, Education City, Doha 24144, Qatar
| | - Raphael Courjaret
- From the Department of Physiology and Biophysics, Weill Cornell Medical College in Qatar, Qatar Foundation, Education City, Doha 24144, Qatar
| | - Khaled Machaca
- From the Department of Physiology and Biophysics, Weill Cornell Medical College in Qatar, Qatar Foundation, Education City, Doha 24144, Qatar.
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Yu F, Sun L, Machaca K. Constitutive recycling of the store-operated Ca2+ channel Orai1 and its internalization during meiosis. ACTA ACUST UNITED AC 2010; 191:523-35. [PMID: 21041445 PMCID: PMC3003315 DOI: 10.1083/jcb.201006022] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The egg's competency to activate at fertilization and transition to embryogenesis is dependent on its ability to generate a fertilization-specific Ca(2+) transient. To endow the egg with this capacity, Ca(2+) signals remodel during oocyte maturation, including inactivation of the primary Ca(2+) influx pathway store-operated Ca(2+) entry (SOCE). SOCE inactivation is coupled to internalization of the SOCE channel, Orai1. In this study, we show that Orai1 internalizes during meiosis through a caveolin (Cav)- and dynamin-dependent endocytic pathway. Cav binds to Orai1, and we map a Cav consensus-binding site in the Orai1 N terminus, which is required for Orai1 internalization. Furthermore, at rest, Orai1 actively recycles between an endosomal compartment and the cell membrane through a Rho-dependent endocytic pathway. A significant percentage of total Orai1 is intracellular at steady state. Store depletion completely shifts endosomal Orai1 to the cell membrane. These results define vesicular trafficking mechanisms in the oocyte that control Orai1 subcellular localization at steady state, during meiosis, and after store depletion.
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Affiliation(s)
- Fang Yu
- Department of Physiology and Biophysics, Weill Cornell Medical College in Qatar, Education City, Qatar Foundation, Doha, Qatar
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39
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Machaca K. Ca(2+) signaling, genes and the cell cycle. Cell Calcium 2010; 48:243-50. [PMID: 21084120 DOI: 10.1016/j.ceca.2010.10.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Revised: 10/06/2010] [Accepted: 10/06/2010] [Indexed: 11/30/2022]
Abstract
Changes in the concentration and spatial distribution of Ca(2+) ions in the cytoplasm constitute a ubiquitous intracellular signaling module in cellular physiology. With the advent of Ca(2+) dyes that allow direct visualization of Ca(2+) transients, combined with powerful experimental tools such as electrophysiological recordings, intracellular Ca(2+) transients have been implicated in practically every aspect of cellular physiology, including cellular proliferation. Ca(2+) signals are associated with different phases of the cell cycle and interfering with Ca(2+) signaling or downstream pathways often disrupts progression of the cell cycle. Although there exists a dependence between Ca(2+) signals and the cell cycle the mechanisms involved are not well defined and given the cross-talk between Ca(2+) and other signaling modules, it is difficult to assess the exact role of Ca(2+) signals in cell cycle progression. Two exceptions however, include fertilization and T-cell activation, where well-defined roles for Ca(2+) signals in mediating progression through specific stages of the cell cycle have been clearly established. In the case of T-cell activation Ca(2+) regulates entry into the cell cycle through the induction of gene transcription.
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Affiliation(s)
- Khaled Machaca
- Department of Physiology and Biophysics, Weill Cornell Medical College in Qatar (WCMC-Q), PO Box 24144, Education City - Qatar Foundation, Doha, Qatar.
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40
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Arredouani A, Yu F, Sun L, Machaca K. Regulation of store-operated Ca2+ entry during the cell cycle. J Cell Sci 2010; 123:2155-62. [PMID: 20554894 DOI: 10.1242/jcs.069690] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cytoplasmic Ca(2+) signals are central to numerous cell physiological processes, including cellular proliferation. Historically, much of the research effort in this area has focused on the role of Ca(2+) signals in cell-cycle progression. It is becoming clear, however, that the relationship between Ca(2+) signaling and the cell cycle is a 'two-way street'. Specifically, Ca(2+)-signaling pathways are remodeled during M phase, leading to altered Ca(2+) dynamics. Such remodeling probably better serves the large variety of functions that cells must perform during cell division compared with during interphase. This is clearly the case during oocyte meiosis, because remodeling of Ca(2+) signals partially defines the competence of the egg to activate at fertilization. Store-operated Ca(2+) entry (SOCE) is a ubiquitous Ca(2+)-signaling pathway that is regulated during M phase. In this Commentary, we discuss the latest advances in our understanding of how SOCE is regulated during cell division.
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Affiliation(s)
- Abdelilah Arredouani
- Department of Physiology and Biophysics, Weill Cornell Medical College in Qatar (WCMC-Q), Education City, Qatar Foundation, Doha, Qatar
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41
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Terhag J, Cavara NA, Hollmann M. Cave Canalem: How endogenous ion channels may interfere with heterologous expression in Xenopus oocytes. Methods 2010; 51:66-74. [DOI: 10.1016/j.ymeth.2010.01.034] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2009] [Revised: 01/26/2010] [Accepted: 01/27/2010] [Indexed: 10/19/2022] Open
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Smyth JT, Petranka JG, Boyles RR, DeHaven WI, Fukushima M, Johnson KL, Williams JG, Putney JW. Erratum: Phosphorylation of STIM1 underlies suppression of store-operated calcium entry during mitosis. Nat Cell Biol 2010. [DOI: 10.1038/ncb0210-199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Smyth JT, Petranka JG, Boyles RR, DeHaven WI, Fukushima M, Johnson KL, Williams JG, Putney JW. Phosphorylation of STIM1 underlies suppression of store-operated calcium entry during mitosis. Nat Cell Biol 2009; 11:1465-72. [PMID: 19881501 PMCID: PMC3552519 DOI: 10.1038/ncb1995] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2009] [Accepted: 08/21/2009] [Indexed: 12/13/2022]
Abstract
Store-operated Ca(2+) entry (SOCE) and Ca(2+) release-activated Ca(2+) currents (I(crac)) are strongly suppressed during cell division, the only known physiological situation in which Ca(2+) store depletion is uncoupled from the activation of Ca(2+) influx [corrected]. We found that the endoplasmic reticulum (ER) Ca(2+) sensor STIM1 failed to rearrange into near-plasma membrane puncta in mitotic cells, a critical step in the SOCE-activation pathway. We also found that STIM1 from mitotic cells is recognized by the phospho-specific MPM-2 antibody, suggesting that STIM1 is phosphorylated during mitosis. Removal of ten MPM-2 recognition sites by truncation at amino acid 482 abolished MPM-2 recognition of mitotic STIM1, and significantly rescued STIM1 rearrangement and SOCE response in mitosis. We identified Ser 486 and Ser 668 as mitosis-specific phosphorylation sites, and STIM1 containing mutations of these sites to alanine also significantly rescued mitotic SOCE. Therefore, phosphorylation of STIM1 at Ser 486 and Ser 668, and possibly other sites, underlies suppression of SOCE during mitosis.
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Affiliation(s)
- Jeremy T Smyth
- Laboratory of Signal Transduction and National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC 27709, USA
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44
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Orai1 internalization and STIM1 clustering inhibition modulate SOCE inactivation during meiosis. Proc Natl Acad Sci U S A 2009; 106:17401-6. [PMID: 19805124 DOI: 10.1073/pnas.0904651106] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Store-operated Ca(2+) entry (SOCE) is a ubiquitous Ca(2+) influx pathway activated in response to depletion of intracellular Ca(2+) stores. SOCE is a primary modulator of intracellular Ca(2+) dynamics, which specify cellular responses. Interestingly, SOCE inactivates during M phase but the mechanisms involved remain unclear. SOCE is mediated by clustering of the ER Ca(2+) sensor STIM1 in response to Ca(2+) store depletion, leading to gating of the plasma membrane SOCE channel Orai1. Here we show that SOCE inactivation in meiosis is the result of internalization of Orai1 into an intracellular vesicular compartment and to the inability of STIM1 to cluster in response to store depletion. At rest, Orai1 continuously recycles between the cell membrane and an endosomal compartment. We further show that STIM1-STIM1 interactions are inhibited during meiosis, which appears to mediate the inability of STIM1 to form puncta following store depletion. In contrast, STIM1-Orai1 interactions remain functional during meiosis. Combined, the removal of Orai1 from the cell membrane and STIM1 clustering inhibition effectively uncouple store depletion from SOCE activation in meiosis. Although STIM1 is phosphorylated during meiosis, phosphomimetic and alanine substitution mutations do not modulate STIM1 clustering, arguing that phosphorylation does not mediate STIM1 clustering inhibition during meiosis.
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45
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Vanderheyden V, Wakai T, Bultynck G, De Smedt H, Parys JB, Fissore RA. Regulation of inositol 1,4,5-trisphosphate receptor type 1 function during oocyte maturation by MPM-2 phosphorylation. Cell Calcium 2009; 46:56-64. [PMID: 19482353 PMCID: PMC2774721 DOI: 10.1016/j.ceca.2009.04.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2009] [Revised: 04/27/2009] [Accepted: 04/28/2009] [Indexed: 11/30/2022]
Abstract
Egg activation and further embryo development require a sperm-induced intracellular Ca(2+) signal at the time of fertilization. Prior to fertilization, the egg's Ca(2+) machinery is therefore optimized. To this end, during oocyte maturation, the sensitivity, i.e. the Ca(2+) releasing ability, of the inositol 1,4,5-trisphosphate receptor type 1 (IP(3)R1), which is responsible for most of this Ca(2+) release, markedly increases. In this study, the recently discovered specific Polo-like kinase (Plk) inhibitor BI2536 was used to investigate the role of Plk1 in this process. BI2536 inactivates Plk1 in oocytes at the early stages of maturation and significantly decreases IP(3)R1 phosphorylation at an MPM-2 epitope at this stage. Moreover, this decrease in Plk1-dependent MPM-2 phosphorylation significantly lowers IP(3)R1 sensitivity. Finally, using in vitro phosphorylation techniques we identified T(2656) as a major Plk1 site on IP(3)R1. We therefore propose that the initial increase in IP(3)R1 sensitivity during oocyte maturation is underpinned by IP(3)R1 phosphorylation at an MPM-2 epitope(s).
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Affiliation(s)
- Veerle Vanderheyden
- Laboratory of Molecular and Cellular Signalling, Department of Molecular Cell Biology, K.U. Leuven, Campus Gasthuisberg, O&N1 Bus 802, B-3000 Leuven, Belgium
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46
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Sun L, Haun S, Jones RC, Edmondson RD, Machaca K. Kinase-dependent regulation of inositol 1,4,5-trisphosphate-dependent Ca2+ release during oocyte maturation. J Biol Chem 2009; 284:20184-96. [PMID: 19473987 DOI: 10.1074/jbc.m109.004515] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Fertilization induces a species-specific Ca(2+) transient with specialized spatial and temporal dynamics, which are essential to temporally encode egg activation events such as the block to polyspermy and resumption of meiosis. Eggs acquire the competence to produce the fertilization-specific Ca(2+) transient during oocyte maturation, which encompasses dramatic potentiation of inositol 1,4,5-trisphosphate (IP(3))-dependent Ca(2+) release. Here we show that increased IP(3) receptor (IP(3)R) sensitivity is initiated at the germinal vesicle breakdown stage of maturation, which correlates with maturation promoting factor (MPF) activation. Extensive phosphopeptide mapping of the IP(3)R resulted in approximately 70% coverage and identified three residues, Thr-931, Thr-1136, and Ser-114, which are specifically phosphorylated during maturation. Phospho-specific antibody analyses show that Thr-1136 phosphorylation requires MPF activation. Activation of either MPF or the mitogen-activated protein kinase cascade independently, functionally sensitizes IP(3)-dependent Ca(2+) release. Collectively, these data argue that the kinase cascades driving meiotic maturation potentiates IP(3)-dependent Ca(2+) release, possibly trough direct phosphorylation of the IP(3)R.
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Affiliation(s)
- Lu Sun
- Department of Physiology and Biophysics, University of Arkansas for Medical Science, Little Rock, Arkansas 72205, USA
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47
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Gómez-Fernández C, Pozo-Guisado E, Gañán-Parra M, Perianes MJ, Alvarez IS, Martín-Romero FJ. Relocalization of STIM1 in mouse oocytes at fertilization: early involvement of store-operated calcium entry. Reproduction 2009; 138:211-21. [PMID: 19470709 DOI: 10.1530/rep-09-0126] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Calcium waves represent one of the most important intracellular signaling events in oocytes at fertilization required for the exit from metaphase arrest and the resumption of the cell cycle. The molecular mechanism ruling this signaling has been described in terms of the contribution of intracellular calcium stores to calcium spikes. In this work, we considered the possible contribution of store-operated calcium entry (SOCE) to this signaling, by studying the localization of the protein STIM1 in oocytes. STIM1 has been suggested to play a key role in the recruitment and activation of plasma membrane calcium channels, and we show here that mature mouse oocytes express this protein distributed in discrete clusters throughout their periphery in resting cells, colocalizing with the endoplasmic reticulum marker calreticulin. However, immunolocalization of the endogenous STIM1 showed considerable redistribution over larger areas or patches covering the entire periphery of the oocyte during Ca(2+) store depletion induced with thapsigargin or ionomycin. Furthermore, pharmacological activation of endogenous phospholipase C induced a similar pattern of redistribution of STIM1 in the oocyte. Finally, fertilization of mouse oocytes revealed a significant and rapid relocalization of STIM1, similar to that found after pharmacological Ca(2+) store depletion. This particular relocalization supports a role for STIM1 and SOCE in the calcium signaling during early stages of fertilization.
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Affiliation(s)
- Carolina Gómez-Fernández
- Departamento de Biología Celular, Reproductive and Developmental Biology Group (ReDes), Universidad de Extremadura, Badajoz, Spain
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48
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Russa AD, Ishikita N, Masu K, Akutsu H, Saino T, Satoh YI. Microtubule remodeling mediates the inhibition of store-operated calcium entry (SOCE) during mitosis in COS-7 cells. ACTA ACUST UNITED AC 2009; 71:249-63. [PMID: 19359807 DOI: 10.1679/aohc.71.249] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Regulation of the intracellular calcium ion concentration ([Ca(2+)](i)) is critical, because calcium signaling controls diverse and vital cellular processes such as secretion, proliferation, division, gene transcription, and apoptosis. Store-operated calcium entry (SOCE) is the main mechanism through which non-excitable cells replenish and thus maintain this delicate balance. There is limited evidence which indicates that SOCE may be inhibited during mitosis, and the mechanisms leading to the presumed inhibition has not been elucidated. In the present study, we examined and compared the [Ca(2+)](i) dynamics of COS-7 cells in mitotic and non-mitotic phases with special reference paid to SOCE. Laser scanning confocal microscopy to monitor [Ca(2+)](i) dynamics revealed that SOCE was progressively inhibited in mitosis and became virtually absent during the metaphase. We used various cytoskeletal modifying drugs and immunofluorescence to assess the contribution of microtubule and actin filaments in SOCE signaling. Nocodazole treatment caused microtubule reorganization and retraction from the cell periphery that mimicked the natural mitotic microtubule remodeling that was also accompanied by SOCE inhibition. Short exposure to paclitaxel, a microtubule-stabilizing drug, bolstered SOCE, whereas long exposure resulted in microtubule disruption and SOCE inhibition. Actin-modifying drugs did not affect SOCE. These findings indicate that mitotic microtubule remodeling plays a significant role in the inhibition of SOCE during mitosis.
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Affiliation(s)
- Afadhali Denis Russa
- Department of Anatomy (Cell Biology Group), Iwate Medical University School of Medicine, Uchimaru, Morioka, Japan
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49
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El-Jouni W, Haun S, Machaca K. Internalization of plasma membrane Ca2+-ATPase during Xenopus oocyte maturation. Dev Biol 2008; 324:99-107. [PMID: 18823969 DOI: 10.1016/j.ydbio.2008.09.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2008] [Revised: 08/14/2008] [Accepted: 09/08/2008] [Indexed: 11/30/2022]
Abstract
A transient increase in intracellular Ca(2+) is the universal signal for egg activation at fertilization. Eggs acquire the ability to mount the specialized fertilization-specific Ca(2+) signal during oocyte maturation. The first Ca(2+) transient following sperm entry in vertebrate eggs has a slow rising phase followed by a sustained plateau. The molecular determinants of the sustained plateau are poorly understood. We have recently shown that a critical determinant of Ca(2+) signaling differentiation during oocyte maturation is internalization of the plasma membrane calcium ATPase (PMCA). PMCA internalization is representative of endocytosis of several integral membrane proteins during oocyte maturation, a requisite process for early embryogenesis. Here we investigate the mechanisms regulating PMCA internalization. To track PMCA trafficking in live cells we cloned a full-length cDNA of Xenopus PMCA1, and show that GFP-tagged PMCA traffics in a similar fashion to endogenous PMCA. Functional data show that MPF activation during oocyte maturation is required for full PMCA internalization. Pharmacological and co-localization studies argue that PMCA is internalized through a lipid raft endocytic pathway. Deletion analysis reveal a requirement for the N-terminal cytoplasmic domain for efficient internalization. Together these studies define the mechanistic requirements for PMCA internalization during oocyte maturation.
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Affiliation(s)
- Wassim El-Jouni
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, AR, USA
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50
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Ullah G, Jung P, Machaca K. Modeling Ca2+ signaling differentiation during oocyte maturation. Cell Calcium 2007; 42:556-64. [PMID: 17349690 DOI: 10.1016/j.ceca.2007.01.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2006] [Revised: 01/19/2007] [Accepted: 01/25/2007] [Indexed: 10/23/2022]
Abstract
Ca2+ is a fundamental intracellular signal that mediates a variety of disparate physiological functions often in the same cell. Ca2+ signals span a wide range of spatial and temporal scales, which endow them with the specificity required to induce defined cellular functions. Furthermore, Ca2+ signaling is highly plastic as it is modulated dynamically during normal physiological development and under pathological conditions. However, the molecular mechanisms underlying Ca2+ signaling differentiation during cellular development remain poorly understood. Oocyte maturation in preparation for fertilization provides an exceptionally well-suited model to elucidate Ca2+ signaling regulation during cellular development. This is because a Ca2+ signal with specialized spatial and temporal dynamics is universally essential for egg activation at fertilization. Here we use mathematical modeling to define the critical determinants of Ca2+ signaling differentiation during oocyte maturation. We show that increasing IP3 receptor (IP3R) affinity replicates both elementary and global Ca2+ dynamics observed experimentally following oocyte maturation. Furthermore, our model reveals that because of the Ca2+ dependency of both SERCA and the IP3R, increased IP3R affinity shifts the system's equilibrium to a new steady state of high cytosolic Ca2+, which is essential for fertilization. Therefore our model provides unique insights into how relatively small alterations of the basic molecular mechanisms of Ca2+ signaling components can lead to dramatic alterations in the spatio-temporal properties of Ca2+ dynamics.
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Affiliation(s)
- Ghanim Ullah
- Department of Physics and Astronomy and Quantitative Biology Institute, Ohio University, Athens, OH 45701, USA
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