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The ataxia-linked E1081Q mutation affects the sub-plasma membrane Ca 2+-microdomains by tuning PMCA3 activity. Cell Death Dis 2022; 13:855. [PMID: 36207321 PMCID: PMC9546857 DOI: 10.1038/s41419-022-05300-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 09/22/2022] [Accepted: 09/26/2022] [Indexed: 01/23/2023]
Abstract
Calcium concentration must be finely tuned in all eukaryotic cells to ensure the correct performance of its signalling function. Neuronal activity is exquisitely dependent on the control of Ca2+ homeostasis: its alterations ultimately play a pivotal role in the origin and progression of many neurodegenerative processes. A complex toolkit of Ca2+ pumps and exchangers maintains the fluctuation of cytosolic Ca2+ concentration within the appropriate threshold. Two ubiquitous (isoforms 1 and 4) and two neuronally enriched (isoforms 2 and 3) of the plasma membrane Ca2+ATPase (PMCA pump) selectively regulate cytosolic Ca2+ transients by shaping the sub-plasma membrane (PM) microdomains. In humans, genetic mutations in ATP2B1, ATP2B2 and ATP2B3 gene have been linked with hearing loss, cerebellar ataxia and global neurodevelopmental delay: all of them were found to impair pump activity. Here we report three additional mutations in ATP2B3 gene corresponding to E1081Q, R1133Q and R696H amino acids substitution, respectively. Among them, the novel missense mutation (E1081Q) immediately upstream the C-terminal calmodulin-binding domain (CaM-BD) of the PMCA3 protein was present in two patients originating from two distinct families. Our biochemical and molecular studies on PMCA3 E1081Q mutant have revealed a splicing variant-dependent effect of the mutation in shaping the sub-PM [Ca2+]. The E1081Q substitution in the full-length b variant abolished the capacity of the pump to reduce [Ca2+] in the sub-PM microdomain (in line with the previously described ataxia-related PMCA mutations negatively affecting Ca2+ pumping activity), while, surprisingly, its introduction in the truncated a variant selectively increased Ca2+ extrusion activity in the sub-PM Ca2+ microdomains. These results highlight the importance to set a precise threshold of [Ca2+] by fine-tuning the sub-PM microdomains and the different contribution of the PMCA splice variants in this regulation.
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2
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Lewis MA, Ingham NJ, Chen J, Pearson S, Di Domenico F, Rekhi S, Allen R, Drake M, Willaert A, Rook V, Pass J, Keane T, Adams DJ, Tucker AS, White JK, Steel KP. Identification and characterisation of spontaneous mutations causing deafness from a targeted knockout programme. BMC Biol 2022; 20:67. [PMID: 35296311 PMCID: PMC8928630 DOI: 10.1186/s12915-022-01257-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 02/17/2022] [Indexed: 11/30/2022] Open
Abstract
Background Mice carrying targeted mutations are important for investigating gene function and the role of genes in disease, but off-target mutagenic effects associated with the processes of generating targeted alleles, for instance using Crispr, and culturing embryonic stem cells, offer opportunities for spontaneous mutations to arise. Identifying spontaneous mutations relies on the detection of phenotypes segregating independently of targeted alleles, and having a broad estimate of the level of mutations generated by intensive breeding programmes is difficult given that many phenotypes are easy to miss if not specifically looked for. Here we present data from a large, targeted knockout programme in which mice were analysed through a phenotyping pipeline. Such spontaneous mutations segregating within mutant lines may confound phenotypic analyses, highlighting the importance of record-keeping and maintaining correct pedigrees. Results Twenty-five lines out of 1311 displayed different deafness phenotypes that did not segregate with the targeted allele. We observed a variety of phenotypes by Auditory Brainstem Response (ABR) and behavioural assessment and isolated eight lines showing early-onset severe progressive hearing loss, later-onset progressive hearing loss, low frequency hearing loss, or complete deafness, with vestibular dysfunction. The causative mutations identified include deletions, insertions, and point mutations, some of which involve new genes not previously associated with deafness while others are new alleles of genes known to underlie hearing loss. Two of the latter show a phenotype much reduced in severity compared to other mutant alleles of the same gene. We investigated the ES cells from which these lines were derived and determined that only one of the 8 mutations could have arisen in the ES cell, and in that case, only after targeting. Instead, most of the non-segregating mutations appear to have occurred during breeding of mutant mice. In one case, the mutation arose within the wildtype colony used for expanding mutant lines. Conclusions Our data show that spontaneous mutations with observable effects on phenotype are a common side effect of intensive breeding programmes, including those underlying targeted mutation programmes. Such spontaneous mutations segregating within mutant lines may confound phenotypic analyses, highlighting the importance of record-keeping and maintaining correct pedigrees. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-022-01257-8.
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Affiliation(s)
- Morag A Lewis
- Wolfson Centre for Age-Related Diseases, King's College London, London, SE1 1UL, England. .,Wellcome Sanger Institute, Hinxton, CB10 1SA, England.
| | - Neil J Ingham
- Wolfson Centre for Age-Related Diseases, King's College London, London, SE1 1UL, England.,Wellcome Sanger Institute, Hinxton, CB10 1SA, England
| | - Jing Chen
- Wolfson Centre for Age-Related Diseases, King's College London, London, SE1 1UL, England.,Wellcome Sanger Institute, Hinxton, CB10 1SA, England
| | | | - Francesca Di Domenico
- Wolfson Centre for Age-Related Diseases, King's College London, London, SE1 1UL, England
| | - Sohinder Rekhi
- Wolfson Centre for Age-Related Diseases, King's College London, London, SE1 1UL, England
| | - Rochelle Allen
- Wolfson Centre for Age-Related Diseases, King's College London, London, SE1 1UL, England
| | - Matthew Drake
- Wolfson Centre for Age-Related Diseases, King's College London, London, SE1 1UL, England
| | - Annelore Willaert
- Research Group of Experimental Oto-Rhino-Laryngology, Department of Neurosciences, KU Leuven - University of Leuven, Leuven, Belgium
| | - Victoria Rook
- Wolfson Centre for Age-Related Diseases, King's College London, London, SE1 1UL, England
| | - Johanna Pass
- Wolfson Centre for Age-Related Diseases, King's College London, London, SE1 1UL, England.,Wellcome Sanger Institute, Hinxton, CB10 1SA, England
| | - Thomas Keane
- Wellcome Sanger Institute, Hinxton, CB10 1SA, England
| | - David J Adams
- Wellcome Sanger Institute, Hinxton, CB10 1SA, England
| | - Abigail S Tucker
- Centre for Craniofacial and Regenerative Biology, King's College London, London, SE1 9RT, England
| | | | - Karen P Steel
- Wolfson Centre for Age-Related Diseases, King's College London, London, SE1 1UL, England.,Wellcome Sanger Institute, Hinxton, CB10 1SA, England
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3
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Crosstalk among Calcium ATPases: PMCA, SERCA and SPCA in Mental Diseases. Int J Mol Sci 2021; 22:ijms22062785. [PMID: 33801794 PMCID: PMC8000800 DOI: 10.3390/ijms22062785] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 03/07/2021] [Accepted: 03/08/2021] [Indexed: 12/20/2022] Open
Abstract
Calcium in mammalian neurons is essential for developmental processes, neurotransmitter release, apoptosis, and signal transduction. Incorrectly processed Ca2+ signal is well-known to trigger a cascade of events leading to altered response to variety of stimuli and persistent accumulation of pathological changes at the molecular level. To counterbalance potentially detrimental consequences of Ca2+, neurons are equipped with sophisticated mechanisms that function to keep its concentration in a tightly regulated range. Calcium pumps belonging to the P-type family of ATPases: plasma membrane Ca2+-ATPase (PMCA), sarco/endoplasmic Ca2+-ATPase (SERCA) and secretory pathway Ca2+-ATPase (SPCA) are considered efficient line of defense against abnormal Ca2+ rises. However, their role is not limited only to Ca2+ transport, as they present tissue-specific functionality and unique sensitive to the regulation by the main calcium signal decoding protein—calmodulin (CaM). Based on the available literature, in this review we analyze the contribution of these three types of Ca2+-ATPases to neuropathology, with a special emphasis on mental diseases.
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4
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Chen J, Sitsel A, Benoy V, Sepúlveda MR, Vangheluwe P. Primary Active Ca 2+ Transport Systems in Health and Disease. Cold Spring Harb Perspect Biol 2020; 12:cshperspect.a035113. [PMID: 31501194 DOI: 10.1101/cshperspect.a035113] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Calcium ions (Ca2+) are prominent cell signaling effectors that regulate a wide variety of cellular processes. Among the different players in Ca2+ homeostasis, primary active Ca2+ transporters are responsible for keeping low basal Ca2+ levels in the cytosol while establishing steep Ca2+ gradients across intracellular membranes or the plasma membrane. This review summarizes our current knowledge on the three types of primary active Ca2+-ATPases: the sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA) pumps, the secretory pathway Ca2+- ATPase (SPCA) isoforms, and the plasma membrane Ca2+-ATPase (PMCA) Ca2+-transporters. We first discuss the Ca2+ transport mechanism of SERCA1a, which serves as a reference to describe the Ca2+ transport of other Ca2+ pumps. We further highlight the common and unique features of each isoform and review their structure-function relationship, expression pattern, regulatory mechanisms, and specific physiological roles. Finally, we discuss the increasing genetic and in vivo evidence that links the dysfunction of specific Ca2+-ATPase isoforms to a broad range of human pathologies, and highlight emerging therapeutic strategies that target Ca2+ pumps.
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Affiliation(s)
- Jialin Chen
- Laboratory of Cellular Transport Systems, Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium
| | - Aljona Sitsel
- Laboratory of Cellular Transport Systems, Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium
| | - Veronick Benoy
- Laboratory of Cellular Transport Systems, Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium
| | - M Rosario Sepúlveda
- Department of Cell Biology, Faculty of Sciences, University of Granada, 18071 Granada, Spain
| | - Peter Vangheluwe
- Laboratory of Cellular Transport Systems, Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium
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5
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Bortolozzi M, Mammano F. PMCA2 pump mutations and hereditary deafness. Neurosci Lett 2019; 663:18-24. [PMID: 29452611 DOI: 10.1016/j.neulet.2017.09.059] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Revised: 09/25/2017] [Accepted: 09/28/2017] [Indexed: 01/21/2023]
Abstract
Hair cells of the inner ear detect sound stimuli, inertial or gravitational forces by deflection of their apical stereocilia. A small number of stereociliary cation-selective mechanotransduction (MET) channels admit K+ and Ca2+ ions into the cytoplasm promoting hair cell membrane depolarization and, consequently, neurotransmitter release at the cell basolateral pole. Ca2+ influx into the stereocilia compartment is counteracted by the unusual w/a splicing variant of plasma-membrane calcium-pump isoform 2 (PMCA2) which, unlike other PMCA2 variants, increases only marginally its activity in response to a rapid variation of the cytoplasmic free Ca2+ concentration ([Ca2+]c). Missense mutations of PMCA2w/a cause deafness and loss of balance in humans. Mouse models in which the pump is genetically ablated or mutated show hearing and balance impairment, which correlates with defects in homeostatic regulation of stereociliary [Ca2+]c, decreased sensitivity of mechanotransduction channels to hair bundle displacement and progressive degeneration of the organ of Corti. These results highlight a critical role played by the PMCA2w/a pump in the control of hair cell function and survival, and provide mechanistic insight into the etiology of deafness and vestibular disorders.
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Affiliation(s)
- Mario Bortolozzi
- University of Padua, Department of Physics and Astronomy "G. Galilei", Padua, Italy; Venetian Institute of Molecular Medicine (VIMM), Padua, Italy; CNR Institute of Protein Biochemistry, Naples, Italy.
| | - Fabio Mammano
- University of Padua, Department of Physics and Astronomy "G. Galilei", Padua, Italy; Venetian Institute of Molecular Medicine (VIMM), Padua, Italy; CNR Institute of Cell Biology and Neurobiology, Monterotondo Scalo, Rome, Italy
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6
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Hajieva P, Baeken MW, Moosmann B. The role of Plasma Membrane Calcium ATPases (PMCAs) in neurodegenerative disorders. Neurosci Lett 2019; 663:29-38. [PMID: 29452613 DOI: 10.1016/j.neulet.2017.09.033] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 09/11/2017] [Accepted: 09/14/2017] [Indexed: 01/27/2023]
Abstract
Selective degeneration of differentiated neurons in the brain is the unifying feature of neurodegenerative disorders such as Parkinson's disease (PD) or Alzheimer's disease (AD). A broad spectrum of evidence indicates that initially subtle, but temporally early calcium dysregulation may be central to the selective neuronal vulnerability observed in these slowly progressing, chronic disorders. Moreover, it has long been evident that excitotoxicity and its major toxic effector mechanism, neuronal calcium overload, play a decisive role in the propagation of secondary neuronal death after acute brain injury from trauma or ischemia. Under physiological conditions, neuronal calcium homeostasis is maintained by a fine-tuned interplay between calcium influx and releasing mechanisms (Ca2+-channels), and calcium efflux mechanisms (Ca2+-pumps and -exchangers). Central functional components of the calcium efflux machinery are the Plasma Membrane Calcium ATPases (PMCAs), which represent high-affinity calcium pumps responsible for the ATP-dependent removal of calcium out of the cytosol. Beyond a growing body of experimental evidence, it is their high expression level, their independence of secondary ions or membrane potential, their profound redox regulation and autoregulation, their postsynaptic localization in close proximity to the primary mediators of pathological calcium influx, i.e. NMDA receptors, as well as evolutionary considerations which all suggest a pivotal role of the PMCAs in the etiology of neurodegeneration and make them equally challenging and alluring candidates for drug development. This review aims to summarize the recent literature on the role of PMCAs in the pathogenesis of neurodegenerative disorders.
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Affiliation(s)
- Parvana Hajieva
- Institute for Pathobiochemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany.
| | - Marius W Baeken
- Institute for Pathobiochemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Bernd Moosmann
- Institute for Pathobiochemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
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7
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Smits JJ, Oostrik J, Beynon AJ, Kant SG, de Koning Gans PAM, Rotteveel LJC, Klein Wassink-Ruiter JS, Free RH, Maas SM, van de Kamp J, Merkus P, Koole W, Feenstra I, Admiraal RJC, Lanting CP, Schraders M, Yntema HG, Pennings RJE, Kremer H. De novo and inherited loss-of-function variants of ATP2B2 are associated with rapidly progressive hearing impairment. Hum Genet 2018; 138:61-72. [PMID: 30535804 PMCID: PMC6514080 DOI: 10.1007/s00439-018-1965-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 11/30/2018] [Indexed: 01/21/2023]
Abstract
ATP2B2 encodes the PMCA2 Ca2+ pump that plays an important role in maintaining ion homeostasis in hair cells among others by extrusion of Ca2+ from the stereocilia to the endolymph. Several mouse models have been described for this gene; mice heterozygous for loss-of-function defects display a rapidly progressive high-frequency hearing impairment. Up to now ATP2B2 has only been reported as a modifier, or in a digenic mechanism with CDH23 for hearing impairment in humans. Whole exome sequencing in hearing impaired index cases of Dutch and Polish origins revealed five novel heterozygous (predicted to be) loss-of-function variants of ATP2B2. Two variants, c.1963G>T (p.Glu655*) and c.955delG (p.Ala319fs), occurred de novo. Three variants c.397+1G>A (p.?), c.1998C>A (p.Cys666*), and c.2329C>T (p.Arg777*), were identified in families with an autosomal dominant inheritance pattern of hearing impairment. After normal newborn hearing screening, a rapidly progressive high-frequency hearing impairment was diagnosed at the age of about 3–6 years. Subjects had no balance complaints and vestibular testing did not yield abnormalities. There was no evidence for retrocochlear pathology or structural inner ear abnormalities. Although a digenic inheritance pattern of hearing impairment has been reported for heterozygous missense variants of ATP2B2 and CDH23, our findings indicate a monogenic cause of hearing impairment in cases with loss-of-function variants of ATP2B2.
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Affiliation(s)
- Jeroen J Smits
- Hearing and Genes, Department of Otorhinolaryngology, Head and Neck Surgery, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jaap Oostrik
- Hearing and Genes, Department of Otorhinolaryngology, Head and Neck Surgery, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Andy J Beynon
- Hearing and Genes, Department of Otorhinolaryngology, Head and Neck Surgery, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Sarina G Kant
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Pia A M de Koning Gans
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | | | | | - Rolien H Free
- Department of Otorhinolaryngology, Head and Neck Surgery, University Medical Center Groningen, Groningen, The Netherlands
| | - Saskia M Maas
- Department of Clinical Genetics, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Jiddeke van de Kamp
- Department of Clinical Genetics, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Paul Merkus
- Department of Otolaryngology, Head and Neck Surgery, Ear and Hearing, Amsterdam Public Health Research Institute, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Wouter Koole
- Hearing and Genes, Department of Human Genetics, Radboud University Medical Center, Internal postal code 855, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Ilse Feenstra
- Hearing and Genes, Department of Human Genetics, Radboud University Medical Center, Internal postal code 855, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Ronald J C Admiraal
- Hearing and Genes, Department of Otorhinolaryngology, Head and Neck Surgery, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Cornelis P Lanting
- Hearing and Genes, Department of Otorhinolaryngology, Head and Neck Surgery, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Margit Schraders
- Hearing and Genes, Department of Otorhinolaryngology, Head and Neck Surgery, Radboud University Medical Center, Nijmegen, The Netherlands
- Hearing and Genes, Department of Human Genetics, Radboud University Medical Center, Internal postal code 855, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Helger G Yntema
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
- Hearing and Genes, Department of Human Genetics, Radboud University Medical Center, Internal postal code 855, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Ronald J E Pennings
- Hearing and Genes, Department of Otorhinolaryngology, Head and Neck Surgery, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Hannie Kremer
- Hearing and Genes, Department of Otorhinolaryngology, Head and Neck Surgery, Radboud University Medical Center, Nijmegen, The Netherlands.
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands.
- Hearing and Genes, Department of Human Genetics, Radboud University Medical Center, Internal postal code 855, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands.
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8
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Gong D, Chi X, Ren K, Huang G, Zhou G, Yan N, Lei J, Zhou Q. Structure of the human plasma membrane Ca 2+-ATPase 1 in complex with its obligatory subunit neuroplastin. Nat Commun 2018; 9:3623. [PMID: 30190470 PMCID: PMC6127144 DOI: 10.1038/s41467-018-06075-7] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 08/08/2018] [Indexed: 11/25/2022] Open
Abstract
Plasma membrane Ca2+-ATPases (PMCAs) are key regulators of global Ca2+ homeostasis and local intracellular Ca2+ dynamics. Recently, Neuroplastin (NPTN) and basigin were identified as previously unrecognized obligatory subunits of PMCAs that dramatically increase the efficiency of PMCA-mediated Ca2+ clearance. Here, we report the cryo-EM structure of human PMCA1 (hPMCA1) in complex with NPTN at a resolution of 4.1 Å for the overall structure and 3.9 Å for the transmembrane domain. The single transmembrane helix of NPTN interacts with the TM8-9-linker and TM10 of hPMCA1. The subunits are required for the hPMCA1 functional activity. The NPTN-bound hPMCA1 closely resembles the E1-Mg2+ structure of endo(sarco)plasmic reticulum Ca2+ ATPase and the Ca2+ site is exposed through a large open cytoplasmic pathway. This structure provides insight into how the subunits bind to the PMCAs and serves as an important basis for understanding the functional mechanisms of this essential calcium pump family. The plasma membrane Ca2+ ATPase (PMCA) is essential for maintaining Ca2+ homeostasis in eukaryotic cells, and neuroplastin (NPTN) was recently identified as an obligatory subunit of PMCA. Here the authors present the cryo-EM structure of NPTN bound to human PMCA1, which reveals that the NPTN transmembrane (TM) helix interacts with TM10 and the TM8-9-linker of PMCA1.
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Affiliation(s)
- Deshun Gong
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
| | - Ximin Chi
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Kang Ren
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Gaoxingyu Huang
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Gewei Zhou
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Nieng Yan
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China.,Department of Molecular Biology, Princeton University, Princeton, NJ, 08544, USA
| | - Jianlin Lei
- Technology Center for Protein Sciences, Ministry of Education Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Qiang Zhou
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Medicine, Tsinghua University, Beijing, 100084, China.
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9
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Vicario M, Zanni G, Vallese F, Santorelli F, Grinzato A, Cieri D, Berto P, Frizzarin M, Lopreiato R, Zonta F, Ferro S, Sandre M, Marin O, Ruzzene M, Bertini E, Zanotti G, Brini M, Calì T, Carafoli E. A V1143F mutation in the neuronal-enriched isoform 2 of the PMCA pump is linked with ataxia. Neurobiol Dis 2018; 115:157-166. [PMID: 29655659 DOI: 10.1016/j.nbd.2018.04.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 03/21/2018] [Accepted: 04/09/2018] [Indexed: 12/13/2022] Open
Abstract
The fine regulation of intracellular calcium is fundamental for all eukaryotic cells. In neurons, Ca2+ oscillations govern the synaptic development, the release of neurotransmitters and the expression of several genes. Alterations of Ca2+ homeostasis were found to play a pivotal role in neurodegenerative progression. The maintenance of proper Ca2+ signaling in neurons demands the continuous activity of Ca2+ pumps and exchangers to guarantee physiological cytosolic concentration of the cation. The plasma membrane Ca2+ATPases (PMCA pumps) play a key role in the regulation of Ca2+ handling in selected sub-plasma membrane microdomains. Among the four basic PMCA pump isoforms existing in mammals, isoforms 2 and 3 are particularly enriched in the nervous system. In humans, genetic mutations in the PMCA2 gene in association with cadherin 23 mutations have been linked to hearing loss phenotypes, while those occurring in the PMCA3 gene were associated with X-linked congenital cerebellar ataxias. Here we describe a novel missense mutation (V1143F) in the calmodulin binding domain (CaM-BD) of the PMCA2 protein. The mutant pump was present in a patient showing congenital cerebellar ataxia but no overt signs of deafness, in line with the absence of mutations in the cadherin 23 gene. Biochemical and molecular dynamics studies on the mutated PMCA2 have revealed that the V1143F substitution alters the binding of calmodulin to the CaM-BD leading to impaired Ca2+ ejection.
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Affiliation(s)
- Mattia Vicario
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Ginevra Zanni
- Department of Neurosciences, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Francesca Vallese
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | | | - Alessandro Grinzato
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Domenico Cieri
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Paola Berto
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Martina Frizzarin
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Raffaele Lopreiato
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Francesco Zonta
- Shanghai Institute of Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China; Department of Biomedical Sciences, Institute of Cell Biology and Neurobiology, Italian National Research Council, 00015 Monterotondo, Rome, Italy
| | - Stefania Ferro
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Michele Sandre
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Oriano Marin
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Maria Ruzzene
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Enrico Bertini
- Department of Neurosciences, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Giuseppe Zanotti
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Marisa Brini
- Department of Biology, University of Padova, Italy.
| | - Tito Calì
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy; Padua Neuroscience Center (PNC), University of Padua, 35122 Padova, Italy.
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10
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Strehler EE, Thayer SA. Evidence for a role of plasma membrane calcium pumps in neurodegenerative disease: Recent developments. Neurosci Lett 2018; 663:39-47. [PMID: 28827127 PMCID: PMC5816698 DOI: 10.1016/j.neulet.2017.08.035] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 08/09/2017] [Accepted: 08/14/2017] [Indexed: 01/20/2023]
Abstract
Plasma membrane Ca2+ ATPases (PMCAs) are a major system for calcium extrusion from all cells. Different PMCA isoforms and splice variants are involved in the precise temporal and spatial handling of Ca2+ signals and the re-establishment of resting Ca2+ levels in the nervous system. Lack or inappropriate expression of specific PMCAs leads to characteristic neuronal phenotypes, which may be reciprocally exacerbated by genetic predisposition through alleles in other genes that modify PMCA interactions, regulation, and function. PMCA dysfunction is often poorly compensated in neurons and may lead to changes in synaptic transmission, altered excitability and, with long-term calcium overload, eventual cell death. Decrease and functional decline of PMCAs are hallmarks of neurodegeneration during aging, and mutations in specific PMCAs are responsible for neuronal dysfunction and accelerated neurodegeneration in many sensory and cognitive diseases.
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Affiliation(s)
- Emanuel E Strehler
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine and Science, Rochester, MN, USA; Department of Biomedicine, University of Basel, Basel, Switzerland.
| | - Stanley A Thayer
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN, USA.
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11
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The PMCA pumps in genetically determined neuronal pathologies. Neurosci Lett 2018; 663:2-11. [DOI: 10.1016/j.neulet.2017.11.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2017] [Revised: 11/06/2017] [Accepted: 11/06/2017] [Indexed: 12/22/2022]
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12
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Stafford N, Wilson C, Oceandy D, Neyses L, Cartwright EJ. The Plasma Membrane Calcium ATPases and Their Role as Major New Players in Human Disease. Physiol Rev 2017; 97:1089-1125. [PMID: 28566538 DOI: 10.1152/physrev.00028.2016] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 01/20/2017] [Accepted: 01/23/2017] [Indexed: 02/07/2023] Open
Abstract
The Ca2+ extrusion function of the four mammalian isoforms of the plasma membrane calcium ATPases (PMCAs) is well established. There is also ever-increasing detail known of their roles in global and local Ca2+ homeostasis and intracellular Ca2+ signaling in a wide variety of cell types and tissues. It is becoming clear that the spatiotemporal patterns of expression of the PMCAs and the fact that their abundances and relative expression levels vary from cell type to cell type both reflect and impact on their specific functions in these cells. Over recent years it has become increasingly apparent that these genes have potentially significant roles in human health and disease, with PMCAs1-4 being associated with cardiovascular diseases, deafness, autism, ataxia, adenoma, and malarial resistance. This review will bring together evidence of the variety of tissue-specific functions of PMCAs and will highlight the roles these genes play in regulating normal physiological functions and the considerable impact the genes have on human disease.
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Affiliation(s)
- Nicholas Stafford
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Claire Wilson
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Delvac Oceandy
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Ludwig Neyses
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Elizabeth J Cartwright
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
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13
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Vicario M, Calì T, Cieri D, Vallese F, Bortolotto R, Lopreiato R, Zonta F, Nardella M, Micalizzi A, Lefeber DJ, Valente EM, Bertini E, Zanotti G, Zanni G, Brini M, Carafoli E. A novel PMCA3 mutation in an ataxic patient with hypomorphic phosphomannomutase 2 (PMM2) heterozygote mutations: Biochemical characterization of the pump defect. Biochim Biophys Acta Mol Basis Dis 2017; 1863:3303-3312. [PMID: 28807751 DOI: 10.1016/j.bbadis.2017.08.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 07/28/2017] [Accepted: 08/09/2017] [Indexed: 11/28/2022]
Abstract
The neuron-restricted isoform 3 of the plasma membrane Ca2+ ATPase plays a major role in the regulation of Ca2+ homeostasis in the brain, where the precise control of Ca2+ signaling is a necessity. Several function-affecting genetic mutations in the PMCA3 pump associated to X-linked congenital cerebellar ataxias have indeed been described. Interestingly, the presence of co-occurring mutations in additional genes suggest their synergistic action in generating the neurological phenotype as digenic modulators of the role of PMCA3 in the pathologies. Here we report a novel PMCA3 mutation (G733R substitution) in the catalytic P-domain of the pump in a patient affected by non-progressive ataxia, muscular hypotonia, dysmetria and nystagmus. Biochemical studies of the pump have revealed impaired ability to control cellular Ca2+ handling both under basal and under stimulated conditions. A combined analysis by homology modeling and molecular dynamics have revealed a role for the mutated residue in maintaining the correct 3D configuration of the local structure of the pump. Mutation analysis in the patient has revealed two additional function-impairing compound heterozygous missense mutations (R123Q and G214S substitution) in phosphomannomutase 2 (PMM2), a protein that catalyzes the isomerization of mannose 6-phosphate to mannose 1-phosphate. These mutations are known to be associated with Type Ia congenital disorder of glycosylation (PMM2-CDG), the most common group of disorders of N-glycosylation. The findings highlight the association of PMCA3 mutations to cerebellar ataxia and strengthen the possibility that PMCAs act as digenic modulators in Ca2+-linked pathologies.
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Affiliation(s)
- Mattia Vicario
- Department of Biomedical Sciences, University of Padova, 35131 Padova, (Italy)
| | - Tito Calì
- Department of Biomedical Sciences, University of Padova, 35131 Padova, (Italy)
| | - Domenico Cieri
- Department of Biomedical Sciences, University of Padova, 35131 Padova, (Italy)
| | - Francesca Vallese
- Department of Biomedical Sciences, University of Padova, 35131 Padova, (Italy)
| | - Raissa Bortolotto
- Department of Biomedical Sciences, University of Padova, 35131 Padova, (Italy)
| | - Raffaele Lopreiato
- Department of Biomedical Sciences, University of Padova, 35131 Padova, (Italy)
| | - Francesco Zonta
- Shanghai Institute of Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China; Department of Biomedical Sciences, Institute of Cell Biology and Neurobiology, Italian National Research Council, 00015, Monterotondo, Rome, Italy
| | - Marta Nardella
- Department of Neurosciences, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | | | - Dirk J Lefeber
- Department of Neurology, Translational Metabolic Laboratory, Donders Institute for Brain, Cognition, and Behavior, Radboudumc, Nijmegen, The Netherlands
| | - Enza Maria Valente
- Neurogenetics Unit, IRCCS Santa Lucia Foundation, Rome, Italy; Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Enrico Bertini
- Department of Neurosciences, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Giuseppe Zanotti
- Department of Biomedical Sciences, University of Padova, 35131 Padova, (Italy)
| | - Ginevra Zanni
- Department of Neurosciences, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
| | - Marisa Brini
- Department of Biology, University of Padova, Italy.
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14
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Brini M, Carafoli E, Calì T. The plasma membrane calcium pumps: focus on the role in (neuro)pathology. Biochem Biophys Res Commun 2017; 483:1116-1124. [DOI: 10.1016/j.bbrc.2016.07.117] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 07/26/2016] [Indexed: 12/20/2022]
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15
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Weatherstone JH, Kopp-Scheinpflug C, Pilati N, Wang Y, Forsythe ID, Rubel EW, Tempel BL. Maintenance of neuronal size gradient in MNTB requires sound-evoked activity. J Neurophysiol 2016; 117:756-766. [PMID: 27881722 PMCID: PMC5304411 DOI: 10.1152/jn.00528.2016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 11/21/2016] [Indexed: 12/12/2022] Open
Abstract
Neurons of the medial nucleus of the trapezoid body (MNTB) act as fast-spiking inhibitory interneurons within the auditory brain stem. The MNTB is topographically organized, with low sound frequencies encoded laterally and high frequencies medially. We discovered a cell size gradient along this axis: lateral neurons are larger than medial neurons. The absence of this gradient in deaf mice lacking plasma membrane calcium ATPase 2 suggests an activity-dependent, calcium-mediated mechanism that controls neuronal soma size. The medial nucleus of the trapezoid body (MNTB) is an important source of inhibition during the computation of sound location. It transmits fast and precisely timed action potentials at high frequencies; this requires an efficient calcium clearance mechanism, in which plasma membrane calcium ATPase 2 (PMCA2) is a key component. Deafwaddler (dfw2J) mutant mice have a null mutation in PMCA2 causing deafness in homozygotes (dfw2J/dfw2J) and high-frequency hearing loss in heterozygotes (+/dfw2J). Despite the deafness phenotype, no significant differences in MNTB volume or cell number were observed in dfw2J homozygous mutants, suggesting that PMCA2 is not required for MNTB neuron survival. The MNTB tonotopic axis encodes high to low sound frequencies across the medial to lateral dimension. We discovered a cell size gradient along this axis: lateral neuronal somata are significantly larger than medially located somata. This size gradient is decreased in +/dfw2J and absent in dfw2J/dfw2J. The lack of acoustically driven input suggests that sound-evoked activity is required for maintenance of the cell size gradient. This hypothesis was corroborated by selective elimination of auditory hair cell activity with either hair cell elimination in Pou4f3 DTR mice or inner ear tetrodotoxin (TTX) treatment. The change in soma size was reversible and recovered within 7 days of TTX treatment, suggesting that regulation of the gradient is dependent on synaptic activity and that these changes are plastic rather than permanent. NEW & NOTEWORTHY Neurons of the medial nucleus of the trapezoid body (MNTB) act as fast-spiking inhibitory interneurons within the auditory brain stem. The MNTB is topographically organized, with low sound frequencies encoded laterally and high frequencies medially. We discovered a cell size gradient along this axis: lateral neurons are larger than medial neurons. The absence of this gradient in deaf mice lacking plasma membrane calcium ATPase 2 suggests an activity-dependent, calcium-mediated mechanism that controls neuronal soma size.
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Affiliation(s)
- Jessica H Weatherstone
- Virginia Merrill Bloedel Hearing Research Center, Department of Otolaryngology-Head and Neck Surgery, and Department of Pharmacology, University of Washington School of Medicine, Seattle, Washington.,Virginia Merrill Bloedel Hearing Research Center, Department of Otolaryngology-Head and Neck Surgery, and Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, Washington
| | - Conny Kopp-Scheinpflug
- Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, United Kingdom; .,Division of Neurobiology, Department Biology II, Ludwig-Maximilians University Munich, Planegg-Martinsried, Germany
| | - Nadia Pilati
- Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, United Kingdom.,Autifony Srl Laboratories, Medicines Research Centre, Verona, Italy; and
| | - Yuan Wang
- Virginia Merrill Bloedel Hearing Research Center, Department of Otolaryngology-Head and Neck Surgery, and Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, Washington.,Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida
| | - Ian D Forsythe
- Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, United Kingdom
| | - Edwin W Rubel
- Virginia Merrill Bloedel Hearing Research Center, Department of Otolaryngology-Head and Neck Surgery, and Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, Washington
| | - Bruce L Tempel
- Virginia Merrill Bloedel Hearing Research Center, Department of Otolaryngology-Head and Neck Surgery, and Department of Pharmacology, University of Washington School of Medicine, Seattle, Washington.,Virginia Merrill Bloedel Hearing Research Center, Department of Otolaryngology-Head and Neck Surgery, and Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, Washington
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16
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Bortolozzi M, Mammano F. PMCA2w/a Splice Variant: A Key Regulator of Hair Cell Mechano-transduction Machinery. REGULATION OF CA2+-ATPASES,V-ATPASES AND F-ATPASES 2016:27-45. [DOI: 10.1007/978-3-319-24780-9_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
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17
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Ryan ZC, Craig TA, Filoteo AG, Westendorf JJ, Cartwright EJ, Neyses L, Strehler EE, Kumar R. Deletion of the intestinal plasma membrane calcium pump, isoform 1, Atp2b1, in mice is associated with decreased bone mineral density and impaired responsiveness to 1, 25-dihydroxyvitamin D3. Biochem Biophys Res Commun 2015; 467:152-6. [PMID: 26392310 DOI: 10.1016/j.bbrc.2015.09.087] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 09/16/2015] [Indexed: 01/01/2023]
Abstract
The physiological importance of the intestinal plasma membrane calcium pump, isoform 1, (Pmca1, Atp2b1), in calcium absorption and homeostasis has not been previously demonstrated in vivo. Since global germ-line deletion of the Pmca1 in mice is associated with embryonic lethality, we selectively deleted the Pmca1 in intestinal absorptive cells. Mice with loxP sites flanking exon 2 of the Pmca1 gene (Pmca1(fl/fl)) were crossed with mice expressing Cre recombinase in the intestine under control of the villin promoter to give mice in which the Pmca1 had been deleted in the intestine (Pmca1(EKO) mice). Pmca1(EKO) mice were born at a reduced frequency and were small at the time of birth when compared to wild-type (Wt) littermates. At two months of age, Pmca1(EKO) mice fed a 0.81% calcium, 0.34% phosphorus, normal vitamin D diet had reduced whole body bone mineral density (P < 0.037), and reduced femoral bone mineral density (P < 0.015). There was a trend towards lower serum calcium and higher serum parathyroid hormone (PTH) and 1α,25-dihydroxyvitamin D3 (1α,25(OH)2D3) concentrations in Pmca1(EKO) mice compared to Wt mice but the changes were not statistically significant. The urinary phosphorus/creatinine ratio was increased in Pmca1(EKO) mice (P < 0.004). Following the administration of 200 ng of 1α,25(OH)2D3 intraperitoneally to Wt mice, active intestinal calcium transport increased ∼2-fold, whereas Pmca1(EKO) mice administered an equal amount of 1α,25(OH)2D3 failed to show an increase in active calcium transport. Deletion of the Pmca1 in the intestine is associated with reduced growth and bone mineralization, and a failure to up-regulate calcium absorption in response to 1α,25(OH)2D3.
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Affiliation(s)
- Zachary C Ryan
- Nephrology Research, Department of Internal Medicine, Mayo Clinic College of Medicine, Rochester, MN, 55905, USA
| | - Theodore A Craig
- Nephrology Research, Department of Internal Medicine, Mayo Clinic College of Medicine, Rochester, MN, 55905, USA
| | - Adelaida G Filoteo
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN, 55905, USA
| | - Jennifer J Westendorf
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN, 55905, USA; Department of Orthopedic Surgery, Mayo Clinic College of Medicine, Rochester, MN, 55905, USA
| | | | - Ludwig Neyses
- Institute of Cardiovascular Sciences, University of Manchester, Manchester, M13 9PT, UK; University of Luxembourg, L-4365, Esch-sur-Alzette, Luxembourg
| | - Emanuel E Strehler
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN, 55905, USA.
| | - Rajiv Kumar
- Nephrology Research, Department of Internal Medicine, Mayo Clinic College of Medicine, Rochester, MN, 55905, USA; Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN, 55905, USA.
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18
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Strehler EE. Plasma membrane calcium ATPases: From generic Ca(2+) sump pumps to versatile systems for fine-tuning cellular Ca(2.). Biochem Biophys Res Commun 2015; 460:26-33. [PMID: 25998731 DOI: 10.1016/j.bbrc.2015.01.121] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 01/21/2015] [Indexed: 10/23/2022]
Abstract
The plasma membrane calcium ATPases (PMCAs) are ATP-driven primary ion pumps found in all eukaryotic cells. They are the major high-affinity calcium extrusion system for expulsion of Ca(2+) ions from the cytosol and help restore the low resting levels of intracellular [Ca(2+)] following the temporary elevation of Ca(2+) generated during Ca(2+) signaling. Due to their essential role in the maintenance of cellular Ca(2+) homeostasis they were initially thought to be "sump pumps" for Ca(2+) removal needed by all cells to avoid eventual calcium overload. The discovery of multiple PMCA isoforms and alternatively spliced variants cast doubt on this simplistic assumption, and revealed instead that PMCAs are integral components of highly regulated multi-protein complexes fulfilling specific roles in calcium-dependent signaling originating at the plasma membrane. Biochemical, genetic, and physiological studies in gene-manipulated and mutant animals demonstrate the important role played by specific PMCAs in distinct diseases including those affecting the peripheral and central nervous system, cardiovascular disease, and osteoporosis. Human PMCA gene mutations and allelic variants associated with specific disorders continue to be discovered and underline the crucial role of different PMCAs in particular cells, tissues and organs.
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Affiliation(s)
- Emanuel E Strehler
- Department of Biochemistry and Molecular Biology, Guggenheim 16-11A1, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA.
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19
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Hess EJ, Jinnah H. Mouse Models of Dystonia. Mov Disord 2015. [DOI: 10.1016/b978-0-12-405195-9.00027-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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20
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Modeling Disorders of Movement. Mov Disord 2015. [DOI: 10.1016/b978-0-12-405195-9.00002-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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21
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Brini M, Calì T, Ottolini D, Carafoli E. Neuronal calcium signaling: function and dysfunction. Cell Mol Life Sci 2014; 71:2787-814. [PMID: 24442513 PMCID: PMC11113927 DOI: 10.1007/s00018-013-1550-7] [Citation(s) in RCA: 429] [Impact Index Per Article: 42.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 12/15/2013] [Accepted: 12/30/2013] [Indexed: 01/07/2023]
Abstract
Calcium (Ca(2+)) is an universal second messenger that regulates the most important activities of all eukaryotic cells. It is of critical importance to neurons as it participates in the transmission of the depolarizing signal and contributes to synaptic activity. Neurons have thus developed extensive and intricate Ca(2+) signaling pathways to couple the Ca(2+) signal to their biochemical machinery. Ca(2+) influx into neurons occurs through plasma membrane receptors and voltage-dependent ion channels. The release of Ca(2+) from the intracellular stores, such as the endoplasmic reticulum, by intracellular channels also contributes to the elevation of cytosolic Ca(2+). Inside the cell, Ca(2+) is controlled by the buffering action of cytosolic Ca(2+)-binding proteins and by its uptake and release by mitochondria. The uptake of Ca(2+) in the mitochondrial matrix stimulates the citric acid cycle, thus enhancing ATP production and the removal of Ca(2+) from the cytosol by the ATP-driven pumps in the endoplasmic reticulum and the plasma membrane. A Na(+)/Ca(2+) exchanger in the plasma membrane also participates in the control of neuronal Ca(2+). The impaired ability of neurons to maintain an adequate energy level may impact Ca(2+) signaling: this occurs during aging and in neurodegenerative disease processes. The focus of this review is on neuronal Ca(2+) signaling and its involvement in synaptic signaling processes, neuronal energy metabolism, and neurotransmission. The contribution of altered Ca(2+) signaling in the most important neurological disorders will then be considered.
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Affiliation(s)
- Marisa Brini
- Department of Biology, University of Padova, Via U.Bassi, 58/b, 35131 Padua, Italy
| | - Tito Calì
- Department of Biology, University of Padova, Via U.Bassi, 58/b, 35131 Padua, Italy
| | - Denis Ottolini
- Department of Biology, University of Padova, Via U.Bassi, 58/b, 35131 Padua, Italy
| | - Ernesto Carafoli
- Venetian Institute for Molecular Medicine (VIMM), Via G.Orus, 2, 35129 Padua, Italy
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22
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Ex vivo visualization of the mouse otoconial layer compared with micro-computed tomography. Otol Neurotol 2014; 36:311-7. [PMID: 24892370 DOI: 10.1097/mao.0000000000000376] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
HYPOTHESIS Micro-computed tomography (micro-CT) is useful for assessing the 3-dimensional (3D) morphology and age-related changes of the otoconial layer. BACKGROUND Wriggle mouse Sagami (WMS) is a mutant of the plasma membrane Ca2+ ATPase type2 gene (Atp2b2) with deficits in the saccular otoconia. We examined the effectiveness of micro-CT in evaluating the otoconial layer of WMS and C57BL/6J mice. METHODS Otic capsules of C57BL/6J mice at different fixation time were examined using micro-CT to evaluate the effects of the fixation time on the otoconial layer. Otic capsules of Atp2b2(wri/wri), Atp2b2(wri/+), and Atp2b2(+/+) mice at P14, P21, and the age of 3 months were used to analyze age-related changes in the otoconial layer. A series of cross-section and 3D reconstructed images of the otoconial layer were obtained. The micro-CT findings were compared with the otic capsule findings cleared in methyl salicylate using stereomicroscopy. RESULTS Micro-CT produced high-resolution images of the otoconial layer, thereby providing information regarding the spatial configuration and 3D curvature. There were no changes between the different fixation times. In the Atp2b2(wri/+) and Atp2b2(+/+) mice, the saccular and utricular otoconial layers were normal among all age groups. In the Atp2b2(wri/wri) mice, the saccular otoconial layer decreased on P14 and was absent on P21, whereas the utricular otoconial layer disappeared at 3 months of age. CONCLUSION We obtained precise information regarding the mouse otoconial layer with minimum artifacts. This method is expected to improve our understanding of the physiologic function and age-related changes in otolith organs.
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Carpinelli MR, Manning MG, Kile BT, Burt RA. Two ENU-induced alleles of Atp2b2 cause deafness in mice. PLoS One 2013; 8:e67479. [PMID: 23826306 PMCID: PMC3691321 DOI: 10.1371/journal.pone.0067479] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Accepted: 05/14/2013] [Indexed: 12/12/2022] Open
Abstract
Over 120 loci are known to cause inherited hearing loss in humans. The deafness gene has been identified for only half of these loci. With the aim of identifying some of the remaining deafness genes, we performed an ethylnitrosourea mutagenesis screen for deaf mice. We isolated two mutants with semi-dominant hearing loss, Deaf11 and Deaf13. Both contained causative mutations in Atp2b2, which encodes the plasma membrane calcium ATPase 2. The Atp2b2Deaf11 mutation leads to a p. I1023S substitution in the tenth transmembrane domain. The Atp2b2Deaf13 mutation leads to a p. R561S substitution in the catalytic core. Mice homozygous for these mutations display profound hearing loss. Heterozygotes display mild to moderate, progressive hearing loss.
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Affiliation(s)
- Marina R Carpinelli
- Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia.
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Watson CJ, Tempel BL. A new Atp2b2 deafwaddler allele, dfw(i5), interacts strongly with Cdh23 and other auditory modifiers. Hear Res 2013; 304:41-8. [PMID: 23792079 DOI: 10.1016/j.heares.2013.06.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Revised: 05/22/2013] [Accepted: 06/08/2013] [Indexed: 12/24/2022]
Abstract
Tight regulation of calcium (Ca2+) concentrations in the stereocilia bundles of auditory hair cells of the inner ear is critical to normal auditory transduction. The plasma membrane Ca2+ ATPase 2 (PMCA2), encoded by the Atp2b2 gene, is the primary mechanism for clearance of Ca2+ from auditory stereocilia, keeping intracellular levels low, and also contributes to maintaining adequate levels of extracellular Ca2+ in the endolymph. This study characterizes a novel null Atp2b2 allele, dfw(i5), by examining cochlear anatomy, vestibular function and auditory physiology in mutant mice. Loss of auditory function in PMCA2 mutants can be attributed to dysregulation of intracellular Ca2+ inside the stereocilia bundles. However, extracellular Ca2+ ions surrounding the stereocilia are also required for rigidity of cadherin 23, a component of the stereocilia tip-link encoded by the Cdh23 gene. This study further resolves the interaction between Atp2b2 and Cdh23 in a gene dosage and frequency-dependent manner, and finds that low frequencies are significantly affected by the interaction. In +/dfw(i5) mice, one mutant copy of Cdh23 is sufficient to cause broad frequency hearing impairment. Additionally, we report another modifying interaction with Atp2b2 on auditory sensitivity, possibly caused by an unidentified hearing loss gene in mice.
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Affiliation(s)
- Claire J Watson
- The Virginia Merrill Bloedel Hearing Research Center, Department of Pharmacology, University of Washington, Box 357280, Seattle, WA 98195, USA
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Brini M, Calì T, Ottolini D, Carafoli E. The plasma membrane calcium pump in health and disease. FEBS J 2013; 280:5385-97. [PMID: 23413890 DOI: 10.1111/febs.12193] [Citation(s) in RCA: 122] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 02/04/2013] [Accepted: 02/13/2013] [Indexed: 12/12/2022]
Abstract
The Ca(2+) ATPases of the plasma membrane (PMCA pumps) export Ca(2+) from all eukaryotic cells. In mammals they are the products of four separate genes. PMCA types 1 and 4 are distributed ubiquitously; PMCA types 2 and 3 are restricted to some tissues, the most important being the nervous system. Alternative splicing at two sites greatly increases the number of pump isoforms. The two ubiquitous isoforms are no longer considered as only housekeeping pumps as they also perform tissue-specific functions. The PMCAs are classical P-type pumps, their reaction cycle repeating that of all other pumps of the family. Their 3D structure has not been solved, but molecular modeling on SERCA pump templates shows the essential structural pattern of the latter. PMCAs are regulated by calmodulin, which interacts with high affinity with their cytosolic C-terminal tail. A second calmodulin-binding domain with lower affinity is present in some splicing variants of the pump. The PMCAs are essential to the regulation of cellular Ca(2+), but the all-important Ca(2+) signal is ambivalent: defects in its control generate various pathologies, the most thoroughly studied being those of genetic origin. Genetic defects of PMCA function produce disease phenotypes: the best characterized is a form of deafness in mice and in humans linked to PMCA2 mutations. A cerebellar X-linked human ataxia has recently been found to be caused by a mutation in the calmodulin-binding domain of PMCA3.
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Affiliation(s)
- Marisa Brini
- Department of Comparative Biomedicine and Food Science, University of Padova, Italy
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Filip P, Lungu OV, Bareš M. Dystonia and the cerebellum: a new field of interest in movement disorders? Clin Neurophysiol 2013; 124:1269-76. [PMID: 23422326 DOI: 10.1016/j.clinph.2013.01.003] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2012] [Revised: 01/06/2013] [Accepted: 01/08/2013] [Indexed: 11/17/2022]
Abstract
Although dystonia has traditionally been regarded as a basal ganglia dysfunction, recent provocative evidence has emerged of cerebellar involvement in the pathophysiology of this enigmatic disease. This review synthesizes the data suggesting that the cerebellum plays an important role in dystonia etiology, from neuroanatomical research of complex networks showing that the cerebellum is connected to a wide range of other central nervous system structures involved in movement control to animal models indicating that signs of dystonia are due to cerebellum dysfunction and completely disappear after cerebellectomy, and finally to clinical observations in secondary dystonia patients with various types of cerebellar lesions. We propose that dystonia is a large-scale dysfunction, involving not only cortico-basal ganglia-thalamo-cortical pathways, but the cortico-ponto-cerebello-thalamo-cortical loop as well. Even in the absence of traditional "cerebellar signs" in most dystonia patients, there are more subtle indications of cerebellar dysfunction. It is clear that as long as the cerebellum's role in dystonia genesis remains unexamined, it will be difficult to significantly improve the current standards of dystonia treatment or to provide curative treatment.
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Affiliation(s)
- Pavel Filip
- Central European Institute of Technology, CEITEC MU, Behavioral and Social Neuroscience Research Group, Masaryk University, Brno, Czech Republic
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Strehler EE. Plasma membrane calcium ATPases as novel candidates for therapeutic agent development. JOURNAL OF PHARMACY & PHARMACEUTICAL SCIENCES : A PUBLICATION OF THE CANADIAN SOCIETY FOR PHARMACEUTICAL SCIENCES, SOCIETE CANADIENNE DES SCIENCES PHARMACEUTIQUES 2013; 16:190-206. [PMID: 23958189 PMCID: PMC3869240 DOI: 10.18433/j3z011] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Plasma membrane Ca2+ ATPases (PMCAs) are highly regulated transporters responsible for Ca2+ extrusion from all eukaryotic cells. Different PMCA isoforms are implicated in various tasks of Ca2+ regulation including bulk Ca2+ transport and localized Ca2+ signaling in specific membrane microdomains. Accumulating evidence shows that loss, mutation or inappropriate expression of different PMCAs is associated with pathologies ranging from hypertension, low bone density and male infertility to hearing loss and cerebellar ataxia. Compared to Ca2+ influx channels, PMCAs have lagged far behind as targets for drug development, mainly due to the lack of detailed understanding of their structure and specific function. This is rapidly changing thanks to integrated efforts combining biochemical, structural, cellular and physiological studies suggesting that selective modulation of PMCA isoforms may be of therapeutic value in the management of different and complex diseases. Both structurally informed rational design and high-throughput small molecule library screenings are promising strategies that are expected to lead to specific and isoform-selective modulators of PMCA function. This short review will provide an overview of the diverse roles played by PMCA isoforms in different cells and tissues and their emerging involvement in pathophysiological processes, summarize recent progress in obtaining structural information on the PMCAs, and discuss current and future strategies to develop specific PMCA inhibitors and activators for potential therapeutic applications.
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Affiliation(s)
- Emanuel E Strehler
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN, USA.
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Ceriani F, Mammano F. Calcium signaling in the cochlea - Molecular mechanisms and physiopathological implications. Cell Commun Signal 2012; 10:20. [PMID: 22788415 PMCID: PMC3408374 DOI: 10.1186/1478-811x-10-20] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Accepted: 07/12/2012] [Indexed: 12/20/2022] Open
Abstract
Calcium ions (Ca2+) regulate numerous and diverse aspects of cochlear and vestibular physiology. This review focuses on the Ca2+ control of mechanotransduction and synaptic transmission in sensory hair cells, as well as on Ca2+ signalling in non-sensory cells of the developing cochlea.
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Affiliation(s)
- Federico Ceriani
- Dipartimento di Fisica e Astronomia "G, Galilei", Università di Padova, 35131, Padova, Italy.
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Giacomello M, De Mario A, Primerano S, Brini M, Carafoli E. Hair cells, plasma membrane Ca2+ ATPase and deafness. Int J Biochem Cell Biol 2012; 44:679-83. [DOI: 10.1016/j.biocel.2012.02.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Revised: 01/24/2012] [Accepted: 02/03/2012] [Indexed: 11/29/2022]
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Giacomello M, De Mario A, Lopreiato R, Primerano S, Campeol M, Brini M, Carafoli E. Mutations in PMCA2 and hereditary deafness: A molecular analysis of the pump defect. Cell Calcium 2011; 50:569-76. [DOI: 10.1016/j.ceca.2011.09.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Accepted: 09/19/2011] [Indexed: 10/16/2022]
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Carafoli E. The plasma membrane calcium pump in the hearing process: physiology and pathology. SCIENCE CHINA-LIFE SCIENCES 2011; 54:686-90. [PMID: 21786191 DOI: 10.1007/s11427-011-4200-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2011] [Accepted: 06/22/2011] [Indexed: 10/18/2022]
Abstract
Mammalian cells express four different plasma membrane Ca(2+) ATPases. Two of them (PMCA1 and PMCA4) are expressed ubiquitously, and are considered housekeeping isoforms. Two (PMCA2 and PMCA4) have tissue restricted distribution. They are abundantly expressed in the brain and in nervous tissue-derived cell types. The primary transcripts of all PMCAs undergo alternative splicing, generating a large number of additional isoforms. Splicing occurs at site A, in the N-terminal moiety of the pump, and at site C, within the C-terminal calmodulin binding domain: The pumps are canonical targets of calmodulin stimulation. The site C insertion leads to a truncation of the pump about 50 residues short of the original C-terminal. One of the pumps (PMCA2) has special properties: It displays high activity even in the absence of the natural activator calmodulin, and has a particularly complex pattern of alternative splicing at both sites A and C. A variant of the PMCA2 pump containing an insert at site A and truncated C-terminally is the resident isoform of the pump in the stereocilia of hair cells of the inner ear. It exports Ca(2+) to the endolymph that bathes the stereocilia less efficiently than the full length, non-inserted PMCA2 pump. The proper functioning of hair cells demands the precise maintenance of the Ca(2+) balance between hair cells and the endolymph. Disturbances in the balance affect the process of mechano-electrical transduction, which depends on the ability of the stereociliar bundle to deflect in response to sound waves. The tip links that organize the bundle are formed by the Ca(2+) binding protein cadherin 23 and by protocadherin 15: Disturbances of the Ca(2+) binding by cadherin 23 and/or of the ability of the PMCA2 variant of the stereocilia to export Ca(2+) to the endolymph generate hearing loss phenotypes. Such phenotypes have now been described in mice and humans. In some cases they are linked to mutations of both cadherin 23 and the PMCA2 pump, but in other cases they may be generated by mutations of particular severity in only one of the two proteins. The PMCA2 defect that leads to deafness has now been analyzed molecularly: It affects the long range, unstimulated ability of PMCA2 to export Ca(2+).
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Affiliation(s)
- Ernesto Carafoli
- Venetian Institute of Molecular Medicine, University of Padova, Padua, Italy.
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Cartwright EJ, Oceandy D, Austin C, Neyses L. Ca2+ signalling in cardiovascular disease: the role of the plasma membrane calcium pumps. SCIENCE CHINA-LIFE SCIENCES 2011; 54:691-8. [DOI: 10.1007/s11427-011-4199-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Accepted: 06/10/2011] [Indexed: 12/25/2022]
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Xu L, Wang Z, Xiong X, Gu X, Gao X, Gao X. Identification of a novel point mutation of mouse Atp2b2 induced by N-ethyl-N-nitrosourea mutagenesis. Exp Anim 2011; 60:71-8. [PMID: 21325754 DOI: 10.1538/expanim.60.71] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
N-ethyl-N-nitrosourea (ENU)-induced mutagenesis is an important approach in the study of gene function and the establishment of human disease models. Here we report an ENU-induced mutation, Elfin, as a mouse model with hearing loss. Homozygous mutants were deaf and displayed severe ataxia, while heterozygous mice had a significant hearing loss. Histological analysis of the inner ear revealed that Elfin had progressive degeneration of the organ of Corti, spiral ganglion cells and an absence of otoconia in the vestibular system. The new mutation was mapped to chromosome 6 between microsatellite markers D6Mit39 and D6Mit254, where the Ca(2+)-ATPase type 2 (Atp2b2) gene resides. Sequence analysis revealed a unique T-to-A transition mutation at amino acid 655 resulting in Ile-to-Asn substitution. These results for the Elfin mutant confirm the role of ATP2B2 in balance, hearing and formation of otoconia and suggest it may serve as a new model of human hereditary hearing loss.
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Affiliation(s)
- Lin Xu
- Department of Otolaryngology and Head & Neck Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008, China
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Abstract
Ca(2+) acts as a fundamental signal transduction element in inner ear, delivering information about sound, acceleration and gravity through a small number of mechanotransduction channels in the hair cell stereocilia and voltage activated Ca(2+) channels at the ribbon synapse, where it drives neurotransmission. The mechanotransduction process relies on the endocochlear potential, an electrical potential difference between endolymph and perilymph, the two fluids bathing respectively the apical and basolateral membrane of the cells in the organ of Corti. In mouse models, deafness and lack or reduction of the endocochlear potential correlate with ablation of connexin (Cx) 26 or 30. These Cxs form heteromeric channels assembled in a network of gap junction plaques connecting the supporting and epithelial cells of the organ of Corti presumably for K(+) recycle and transfer of key metabolites, for example, the Ca(2+) -mobilizing second messenger IP(3) . Ca(2+) signaling in these cells could play a crucial role in regulating Cx expression and function. Another district where Ca(2+) signaling alterations link to hearing loss is hair cell apex, where ablation or missense mutations of the PMCA2 Ca(2+) -pump of the stereocilia cause deafness and loss of balance. If less Ca(2+) is exported from the stereocilia, as in the PMCA2 mouse mutants, Ca(2+) concentration in endolymph is expected to fall causing an alteration of the mechanotransduction process. This may provide a clue as to why, in some cases, PMCA2 mutations potentiated the deafness phenotype induced by coexisting mutations of cadherin-23 (Usher syndrome type 1D), a single pass membrane Ca(2+) binding protein that is abundantly expressed in the stereocilia.
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Affiliation(s)
- Fabio Mammano
- Department of Physics "G. Galilei," University of Padova, Italy.
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Brandenburger T, Strehler EE, Filoteo AG, Caride AJ, Aumüller G, Post H, Schwarz A, Wilhelm B. Switch of PMCA4 splice variants in bovine epididymis results in altered isoform expression during functional sperm maturation. J Biol Chem 2011; 286:7938-7946. [PMID: 21187283 PMCID: PMC3048680 DOI: 10.1074/jbc.m110.142836] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2010] [Revised: 11/02/2010] [Indexed: 11/06/2022] Open
Abstract
Ca(2+) and Ca(2+)-dependent signals are essential for sperm maturation and fertilization. In mouse sperm the plasma membrane Ca(2+)-ATPase (PMCA) isoform 4 plays a crucial role in Ca(2+) transport. The two major splice variants of PMCA4 are PMCA4a and PMCA4b. PMCA4a differs from PMCA4b in the mechanism of calmodulin binding and activation. PMCA4a shows a much higher basal activity and is more effective than PMCA4b in returning Ca(2+) to resting levels. Knock-out mice carrying a PMCA4-null mutation are infertile because their sperm cannot achieve a hyperactivated state of motility. As sperm reach functional maturity during their transit through the epididymis, the expression of PMCA4a and 4b was assessed in bull testis and epididymis. Quantitative PCR revealed that PMCA4b is the major splice variant in testis, caput, and corpus epididymidis. In contrast, PMCA4a is the major splice variant in cauda epididymidis, whereas sperm are transcriptionally silent. Immunohistochemical staining using a new antibody against bovine PMCA4a located the PMCA4a to the apical membrane of the epithelium of cauda epididymidis, whereas testis, caput, and corpus epididymidis were negative. Western blotting of testis, epididymis, and sperm isolated from caput and cauda epididymidis showed a much higher level of PMCA4a in cauda epididymidis and sperm from cauda epididymidis compared with testis membranes and sperm from caput epididymidis. These findings suggest that PMCA4a is transferred to bovine sperm membranes in cauda epididymidis. This isoform switch may facilitate a higher calcium turnover in sperm necessary to traverse the female genital tract.
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Affiliation(s)
- Timo Brandenburger
- From the Department of Anatomy and Cell Biology, Philipps-University, 35037 Marburg, Germany,; the Department of Anesthesiology, University Hospital Düsseldorf, 40225 Düsseldorf, Germany, and.
| | - Emanuel E Strehler
- the Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
| | - Adelaida G Filoteo
- the Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
| | - Ariel J Caride
- the Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, Minnesota 55905
| | - Gerhard Aumüller
- From the Department of Anatomy and Cell Biology, Philipps-University, 35037 Marburg, Germany
| | - Heidi Post
- From the Department of Anatomy and Cell Biology, Philipps-University, 35037 Marburg, Germany
| | - Anja Schwarz
- From the Department of Anatomy and Cell Biology, Philipps-University, 35037 Marburg, Germany
| | - Beate Wilhelm
- From the Department of Anatomy and Cell Biology, Philipps-University, 35037 Marburg, Germany
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Cartwright EJ, Neyses L. Evaluation of plasma membrane calcium/calmodulin-dependent ATPase isoform 4 as a potential target for fertility control. Handb Exp Pharmacol 2010:79-95. [PMID: 20839088 DOI: 10.1007/978-3-642-02062-9_6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
The array of contraceptives currently available is clearly inadequate and does not meet consumer demands since it is estimated that up to a quarter of all pregnancies worldwide are unintended. There is, therefore, an overwhelming global need to develop new effective, safe, ideally non-hormonal contraceptives for both male and female use. The contraceptive field, unlike other areas such as cancer, has a dearth of new targets. We have addressed this issue and propose that isoform 4 of the plasma membrane calcium ATPase is a potentially exciting novel target for fertility control. The plasma membrane calcium ATPase is a ubiquitously expressed calcium pump whose primary function in the majority of cells is to extrude calcium to the extracellular milieu. Two isoforms of this gene family, PMCA1 and PMCA4, are expressed in spermatozoa, with PMCA4 being the predominant isoform. Although this gene is ubiquitously expressed, its function is highly tissue-specific. Genetic deletion of PMCA4, in PMCA4 knockout mice, led to 100% infertility specifically in the male mutant mice due to a selective defect in sperm motility. It is important to note that the gene deletion did not affect normal mating characteristics in these mice. This phenotype was mimicked in wild-type sperm treated with the non-specific PMCA inhibitor 5-(and 6-) carboxyeosin diacetate succinimidyl ester; a proof-of-principle that inhibition of PMCA4 has potential importance in the control of fertility. This review outlines the potential for PMCA4 to be a novel target for fertility control by acting to inhibit sperm motility. It will outline the characteristics that make this target drugable and will describe methodologies to identify and validate novel inhibitors of this target.
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Affiliation(s)
- Elizabeth J Cartwright
- Cardiovascular Medicine, University of Manchester, Room 1.302 Stopford Building, Oxford Road, Manchester, UK.
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LeDoux MS. Animal models of dystonia: Lessons from a mutant rat. Neurobiol Dis 2010; 42:152-61. [PMID: 21081162 DOI: 10.1016/j.nbd.2010.11.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Revised: 10/15/2010] [Accepted: 11/09/2010] [Indexed: 01/25/2023] Open
Abstract
Dystonia is a motor sign characterized by involuntary muscle contractions which produce abnormal postures. Genetic factors contribute significantly to primary dystonia. In comparison, secondary dystonia can be caused by a wide variety of metabolic, structural, infectious, toxic and inflammatory insults to the nervous system. Although classically ascribed to dysfunction of the basal ganglia, studies of diverse animal models have pointed out that dystonia is a network disorder with important contributions from abnormal olivocerebellar signaling. In particular, work with the dystonic (dt) rat has engendered dramatic paradigm shifts in dystonia research. The dt rat manifests generalized dystonia caused by deficiency of the neuronally restricted protein caytaxin. Electrophysiological and biochemical studies have shown that defects at the climbing fiber-Purkinje cell synapse in the dt rat lead to abnormal bursting firing patterns in the cerebellar nuclei, which increases linearly with postnatal age. In a general sense, the dt rat has shown the scientific and clinical communities that dystonia can arise from dysfunctional cerebellar cortex. Furthermore, work with the dt rat has provided evidence that dystonia (1) is a neurodevelopmental network disorder and (2) can be driven by abnormal cerebellar output. In large part, work with other animal models has expanded upon studies in the dt rat and shown that primary dystonia is a multi-nodal network disorder associated with defective sensorimotor integration. In addition, experiments in genetically engineered models have been used to examine the underlying cellular pathologies that drive primary dystonia. This article is part of a Special Issue entitled "Advances in dystonia".
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Affiliation(s)
- Mark S LeDoux
- University of Tennessee Health Science Center, Department of Neurology, 855 Monroe Avenue, Link Building, Suite 415, Memphis, TN 38163, USA.
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Bortolozzi M, Brini M, Parkinson N, Crispino G, Scimemi P, De Siati RD, Di Leva F, Parker A, Ortolano S, Arslan E, Brown SD, Carafoli E, Mammano F. The novel PMCA2 pump mutation Tommy impairs cytosolic calcium clearance in hair cells and links to deafness in mice. J Biol Chem 2010; 285:37693-703. [PMID: 20826782 PMCID: PMC2988374 DOI: 10.1074/jbc.m110.170092] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The mechanotransduction process in hair cells in the inner ear is associated with the influx of calcium from the endolymph. Calcium is exported back to the endolymph via the splice variant w/a of the PMCA2 of the stereocilia membrane. To further investigate the role of the pump, we have identified and characterized a novel ENU-induced mouse mutation, Tommy, in the PMCA2 gene. The mutation causes a non-conservative E629K change in the second intracellular loop of the pump that harbors the active site. Tommy mice show profound hearing impairment from P18, with significant differences in hearing thresholds between wild type and heterozygotes. Expression of mutant PMCA2 in CHO cells shows calcium extrusion impairment; specifically, the long term, non-stimulated calcium extrusion activity of the pump is inhibited. Calcium extrusion was investigated directly in neonatal organotypic cultures of the utricle sensory epithelium in Tommy mice. Confocal imaging combined with flash photolysis of caged calcium showed impairment of calcium export in both Tommy heterozygotes and homozygotes. Immunofluorescence studies of the organ of Corti in homozygous Tommy mice showed a progressive base to apex degeneration of hair cells after P40. Our results on the Tommy mutation along with previously observed interactions between cadherin-23 and PMCA2 mutations in mouse and humans underline the importance of maintaining the appropriate calcium concentrations in the endolymph to control the rigidity of cadherin and ensure the function of interstereocilia links, including tip links, of the stereocilia bundle.
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Affiliation(s)
- Mario Bortolozzi
- Department of Physics G Galilei, University of Padua, Padua 35131, Italy
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Abstract
Ca2+-ATPases (pumps) are key actors in the regulation of Ca2+ in eukaryotic cells and are thus essential to the correct functioning of the cell machinery. They have high affinity for Ca2+ and can efficiently regulate it down to very low concentration levels. Two of the pumps have been known for decades (the SERCA and PMCA pumps); one (the SPCA pump) has only become known recently. Each pump is the product of a multigene family, the number of isoforms being further increased by alternative splicing of the primary transcripts. The three pumps share the basic features of the catalytic mechanism but differ in a number of properties related to tissue distribution, regulation, and role in the cellular homeostasis of Ca2+. The molecular understanding of the function of the pumps has received great impetus from the solution of the three-dimensional structure of one of them, the SERCA pump. These spectacular advances in the structure and molecular mechanism of the pumps have been accompanied by the emergence and rapid expansion of the topic of pump malfunction, which has paralleled the rapid expansion of knowledge in the topic of Ca2+-signaling dysfunction. Most of the pump defects described so far are genetic: when they are very severe, they produce gross and global disturbances of Ca2+ homeostasis that are incompatible with cell life. However, pump defects may also be of a type that produce subtler, often tissue-specific disturbances that affect individual components of the Ca2+-controlling and/or processing machinery. They do not bring cells to immediate death but seriously compromise their normal functioning.
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The novel mouse mutation Oblivion inactivates the PMCA2 pump and causes progressive hearing loss. PLoS Genet 2008; 4:e1000238. [PMID: 18974863 PMCID: PMC2568954 DOI: 10.1371/journal.pgen.1000238] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2008] [Accepted: 09/25/2008] [Indexed: 11/19/2022] Open
Abstract
Progressive hearing loss is common in the human population, but we have few clues to the molecular basis. Mouse mutants with progressive hearing loss offer valuable insights, and ENU (N-ethyl-N-nitrosourea) mutagenesis is a useful way of generating models. We have characterised a new ENU-induced mouse mutant, Oblivion (allele symbol Obl), showing semi-dominant inheritance of hearing impairment. Obl/+ mutants showed increasing hearing impairment from post-natal day (P)20 to P90, and loss of auditory function was followed by a corresponding base to apex progression of hair cell degeneration. Obl/Obl mutants were small, showed severe vestibular dysfunction by 2 weeks of age, and were completely deaf from birth; sensory hair cells were completely degenerate in the basal turn of the cochlea, although hair cells appeared normal in the apex. We mapped the mutation to Chromosome 6. Mutation analysis of Atp2b2 showed a missense mutation (2630C-->T) in exon 15, causing a serine to phenylalanine substitution (S877F) in transmembrane domain 6 of the PMCA2 pump, the resident Ca(2+) pump of hair cell stereocilia. Transmembrane domain mutations in these pumps generally are believed to be incompatible with normal targeting of the protein to the plasma membrane. However, analyses of hair cells in cultured utricular maculae of Obl/Obl mice and of the mutant Obl pump in model cells showed that the protein was correctly targeted to the plasma membrane. Biochemical and biophysical characterisation showed that the pump had lost a significant portion of its non-stimulated Ca(2+) exporting ability. These findings can explain the progressive loss of auditory function, and indicate the limits in our ability to predict mechanism from sequence alone.
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Post H, Gutberlet J, Wiche R, Aumüller G, Wilhelm B. The localization of PMCA1b in epithelial cells and aposomes of the rat coagulating gland is influenced by androgens. Prostate 2008; 68:1076-85. [PMID: 18395836 DOI: 10.1002/pros.20769] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Rat coagulating gland epithelial cells export proteins by an apocrine secretion mode within membrane blebs arising from the apical plasma membrane. Using a pan-PMCA antibody, we have recently shown the plasma membrane Ca(2+)-ATPase (PMCA) being part of the apical plasma membrane of epithelial cells and incorporated into the aposomal membrane. The mRNA of PMCA isoforms 1 and 4 respectively, have been detected by RT-PCR in rat coagulating gland. METHODS In order to identify which PMCA isoform is integrated into aposomes during apocrine secretion and whether or not PMCA export is influenced by androgens RT-PCR, in situ hybridization, Western blotting, and immunofluorescence experiments were performed. RESULTS PMCA1b is the isoform which is expressed and located in the apical plasma membrane of coagulating gland epithelial cells and is integrated into the aposomal membrane. In contrast, PMCA4 mRNA and protein are restricted to the stroma. Androgen deprivation by castration within 14 days leads to an accumulation of PMCA1b in coagulating gland epithelium, while aposomes are not detected anymore. CONCLUSIONS We showed for the first time that PMCA isoform 1b is released via aposomes of the epithelial cells of the rat coagulating gland and that the localization of PMCA1b in the epithelial cells is influenced by androgens.
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Affiliation(s)
- Heidi Post
- Department of Anatomy and Cell Biology, Philipps-University, Marburg, Germany
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Guerini D, Coletto L, Carafoli E. Exporting calcium from cells. Cell Calcium 2008; 38:281-9. [PMID: 16102821 DOI: 10.1016/j.ceca.2005.06.032] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2005] [Accepted: 06/28/2005] [Indexed: 01/11/2023]
Abstract
All eukaryotic cells import Ca2+ through a number of variously gated plasma membrane channels. Once inside cells, Ca2+ transmits information to a large number of (enzyme) targets. Eventually, it must be exported again, to prevent the overloading of the cytosol with Ca2+. Two systems export Ca2+ from cells: a high affinity, low capacity Ca2+-ATPase, and a lower affinity, but much larger capacity, Na+/Ca2+ exchanger. The ATPase (commonly called the Ca2+ pump) is the fine-tuner of cell Ca2+, as it functions well even if the concentration of the ion drops below the microM level. It is a large enzyme, with 10 transmembrane domains and a C-terminal cytosolic tail that contains regulatory sites, including a calmodulin-binding domain. Four distinct gene products plus a large number of splice variants have been described. Some are tissue specific, the isoform 2 being specifically expressed in the sensorial cells of the Corti organ in the inner-ear. Its genetic absence causes deafness in mice. Two different families of the Na+/Ca2+ exchanger exist, one of which, originally described in photoreceptors, transports K+ and Ca2+ in exchange for Na+. The exchanger is particularly active in excitable cells, e.g., heart, where the necessity cyclically arises to rapidly eject large amounts of Ca2+. In addition to heart, the exchanger is particularly important to neurons: the cleavage of the most important neuronal isoform (NCX3) by calpains activated by excitotoxic treatments generates Ca2+ overload and eventually cell death.
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Sun XY, Chen ZY, Hayashi Y, Kanou Y, Takagishi Y, Oda SI, Murata Y. Insertion of an intracisternal A particle retrotransposon element in plasma membrane calcium ATPase 2 gene attenuates its expression and produces an ataxic phenotype in joggle mutant mice. Gene 2008; 411:94-102. [DOI: 10.1016/j.gene.2008.01.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2007] [Revised: 01/15/2008] [Accepted: 01/17/2008] [Indexed: 12/01/2022]
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Abstract
In mammals, four different genes encode four PMCA (plasma-membrane Ca(2+)-ATPase) isoforms. PMCA1 and 4 are expressed ubiquitously, and PMCA2 and 3 are expressed predominantly in the central nervous system. More than 30 variants are generated by mechanisms of alternative splicing. The physiological meaning of the existence of so many isoforms is not clear, but evidently it must be related to the cell-specific demands of Ca(2+) homoeostasis. Recent studies suggest that the alternatively spliced regions in PMCA are responsible for specific targeting to plasma membrane domains, and proteins that bind specifically to the pumps could contribute to further regulation of Ca(2+) control. In addition, the combination of proteins obtained by alternative splicing occurring at two different sites could be responsible for different functional characteristics of the pumps.
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Physiological implications of the interaction between the plasma membrane calcium pump and nNOS. Pflugers Arch 2008; 457:665-71. [DOI: 10.1007/s00424-008-0455-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2007] [Revised: 01/07/2008] [Accepted: 01/14/2008] [Indexed: 10/24/2022]
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46
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Expression and localization of PMCA4 in rat testis and epididymis. Histochem Cell Biol 2007; 129:331-43. [DOI: 10.1007/s00418-007-0362-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/14/2007] [Indexed: 10/22/2022]
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Prasad V, Okunade G, Liu L, Paul RJ, Shull GE. Distinct phenotypes among plasma membrane Ca2+-ATPase knockout mice. Ann N Y Acad Sci 2007; 1099:276-86. [PMID: 17446468 DOI: 10.1196/annals.1387.029] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Ca2+ gradients across the plasma membrane, required for Ca2+ homeostasis and signaling, are maintained in part by plasma membrane Ca2+-ATPase (PMCA) isoforms 1-4. Gene targeting has been used to analyze the functions of PMCA1, PMCA2, and PMCA4 in mice. PMCA1 null mutant embryos die during the preimplantation stage, and loss of a single copy of the PMCA1 gene contributes to apoptosis in vascular smooth muscle. PMCA2 deficiency in sensory hair cells of the inner ear causes deafness and balance defects, most likely by affecting both intracellular Ca2+ and extracellular Ca2+ in the endolymph. PMCA2 is required for viability of certain neurons, consistent with a major role in maintenance of intracellular Ca2+. Surprisingly, loss of PMCA2 in lactating mammary glands causes a sharp reduction in milk Ca2+, consistent with a macrocalcium secretory function. Although PMCA4 is widely expressed and is the most abundant isoform in some tissues, null mutants appear healthy. However, male PMCA4 null mutants are infertile due to a failure of hyperactivated sperm motility resulting from the absence of PMCA4 in the sperm tail, and Ca2+ signaling in B lymphocytes, involving interactions between PMCA4, CD22, and the tyrosine phosphatase SHP-1, is defective. Studies of bladder smooth muscle from PMCA4 null mutants and PMCA1 heterozygous mice suggest that PMCA1 and PMCA4 play different roles in smooth muscle contractility, with PMCA1 contributing to overall Ca2+ clearance and PMCA4 being required for carbachol-stimulated contraction. These phenotypes indicate that PMCA1 serves essential housekeeping functions, whereas PMCA4 and particularly PMCA2 serve more specialized physiological functions.
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Affiliation(s)
- Vikram Prasad
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, 231 Bethesda Avenue, ML 524, Cincinnati, OH 45267-0524, USA
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Bednarek EM, Schaheen L, Gaubatz J, Jorgensen EM, Fares H. The plasma membrane calcium ATPase MCA-3 is required for clathrin-mediated endocytosis in scavenger cells of Caenorhabditis elegans. Traffic 2007; 8:543-53. [PMID: 17343680 DOI: 10.1111/j.1600-0854.2007.00547.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Plasma membrane Ca2+ ATPases (PMCAs) maintain proper intracellular Ca2+ levels by extruding Ca2+ from the cytosol. PMCA genes and splice forms are expressed in tissue-specific patterns in vertebrates, suggesting that these isoforms may regulate specific biological processes. However, knockout mutants die as embryos or undergo cell death; thus, it is unclear whether other cell processes utilize PMCAs or whether these pumps are largely committed to the control of toxic levels of calcium. Here, we analyze the role of the PMCA gene, mca-3, in Caenorhabditis elegans. We report that partial loss-of-function mutations disrupt clathrin-mediated endocytosis in a class of scavenger cells called coelomocytes. Moreover, components of early endocytic machinery are mislocalized in mca-3 mutants, including phosphatidylinositol-4,5-bisphosphate, clathrin and the Eps15 homology (EH) domain protein RME-1. This defect in endocytosis in the coelomocytes can be reversed by lowering calcium. Together, these data support a function for PMCAs in the regulation of endocytosis in the C. elegans coelomocytes. In addition, they suggest that endocytosis can be blocked by high calcium levels.
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Affiliation(s)
- Ewa M Bednarek
- Department of Biology and Howard Hughes Medical Institute, University of Utah, Salt Lake City, UT 84112, USA
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Abstract
In mammals, four different genes encode four PMCA isoforms. PMCA1 and PMCA4 are expressed ubiquitously. PMCA2 and PMCA3 are expressed prevalently in the central nervous systems. More than 30 variants are generated by mechanisms of alternative splicing. The physiological meaning of the existence of such elevated number of isoforms is not clear, but it would be plausible to relate it to the cell-specific demands of Ca2+ homeostasis. To characterize functional specificity of PMCA variants we have investigated two aspects: the effects of the overexpression of the different PMCA variants on cellular Ca2+ handling and the existence of possible isoform-specific interactions with partner proteins using a yeast two-hybrid technique. The four basic PMCA isoforms were coexpressed in CHO cells together with the Ca2+-sensitive recombinant photoprotein aequorin. The effects of their overexpression on Ca2+ homeostasis were monitored in the living cells. They had revealed that the ubiquitous isoforms 1 and 4 are less effective in reducing the Ca2+ peaks generated by cell stimulation as compared to the neuron-specific isoforms 2 and 3. To establish whether these differences were related to different and new physiological regulators of the pump, the 90 N-terminal residues of PMCA2 and PMCA4 have been used as baits for the search of molecular partners. Screening of a human brain cDNA library with the PMCA4 bait specified the epsilon-isoform of protein 14-3-3, whereas no 14-3-3 epsilon clone was obtained with the PMCA2 bait. Overexpression of PMCA4/14-3-3 epsilon (but not of PMCA2/14-3-3 epsilon) in HeLa cells together with targeted aequorins showed that the ability of the cells to export Ca2+ was impaired. Thus, the interaction with 14-3-3 epsilon inhibited PMCA4 but not PMCA2. The role of PMCA2 has been further characterized by Ca2+ measurements in cells overexpressing different splicing variants. The results indicated that the combination of alternative splicing at two different sites in the pump structure was responsible for different functional characteristics of the pumps.
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Affiliation(s)
- Teuta Domi
- Department of Biochemistry, University of Padova, Viale G. Colombo 3, 35121 Padova, Italy
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SUN XY, CHEN ZY, KANOU Y, TAKAGISHI Y, HAYASHI Y, OHNO T, MURATA Y, ODA SI. Mapping of jog Locus to the Region between D6Mit104 and D6Mit336 on Mouse Chromosome 6. Exp Anim 2007; 56:389-92. [DOI: 10.1538/expanim.56.389] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Affiliation(s)
- Xiao-yang SUN
- Department of Genetics, Division of Stress Adaptation and Protection, Research Institute of Environmental Medicine, Nagoya University
| | - Zi-yan CHEN
- Laboratory of Animal Management & Resources, Graduate School of Bioagricultural Sciences, Nagoya University
| | - Yasuhiko KANOU
- Department of Genetics, Division of Stress Adaptation and Protection, Research Institute of Environmental Medicine, Nagoya University
| | - Yoshiko TAKAGISHI
- Department of Genetics, Division of Stress Adaptation and Protection, Research Institute of Environmental Medicine, Nagoya University
| | - Yoshitaka HAYASHI
- Department of Genetics, Division of Stress Adaptation and Protection, Research Institute of Environmental Medicine, Nagoya University
| | - Tamio OHNO
- Institute for Laboratory Animal Research, Graduate School of Medicine, Nagoya University
| | - Yoshiharu MURATA
- Department of Genetics, Division of Stress Adaptation and Protection, Research Institute of Environmental Medicine, Nagoya University
| | - Sen-ichi ODA
- Laboratory of Animal Management & Resources, Graduate School of Bioagricultural Sciences, Nagoya University
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