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Binti S, Edeen PT, Fay DS. Loss of the Na + /K + cation pump CATP-1 suppresses nekl -associated molting defects. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.15.585189. [PMID: 38559007 PMCID: PMC10979969 DOI: 10.1101/2024.03.15.585189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
The conserved C. elegans protein kinases NEKL-2 and NEKL-3 regulate multiple steps of membrane trafficking and are required for larval molting. Through a forward genetic screen we identified a loss-of-function mutation in catp-1 as a suppressor of molting defects in synthetically lethal nekl-2; nekl-3 double mutants. catp-1 is predicted to encode a membrane- associated P4-type ATPase involved in Na + -K + exchange. Moreover, a mutation predicted to abolish CATP-1 ion-pump activity also suppressed nekl-2; nekl-3 mutants. Endogenously tagged CATP-1 was primarily expressed in epidermal (hypodermal) cells within punctate structures located at or near the apical plasma membrane. Through whole genome sequencing, we identified two additional nekl-2; nekl-3 suppressor strains containing coding-altering mutations in catp-1 but found that neither mutation, when introduced into nekl-2; nekl-3 mutants using CRISPR methods, was sufficient to elicit robust suppression of molting defects. Our data also suggested that the two catp-1 isoforms, catp-1a and catp-1b , may in some contexts be functionally redundant. On the basis of previously published studies, we tested the hypothesis that loss of catp-1 may suppress nekl -associated defects by inducing partial entry into the dauer pathway. Contrary to expectations, however, we failed to obtain evidence that loss of catp-1 suppresses nekl-2; nekl-3 defects through a dauer-associated mechanism or that loss of catp-1 leads to entry into the pre-dauer L2d stage. As such, loss of catp-1 may suppress nekl- associated molting and membrane trafficking defects by altering electrochemical gradients within membrane-bound compartments.
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Robb E, McCammick EM, Wells D, McVeigh P, Gardiner E, Armstrong R, McCusker P, Mousley A, Clarke N, Marks NJ, Maule AG. Transcriptomic analysis supports a role for the nervous system in regulating growth and development of Fasciola hepatica juveniles. PLoS Negl Trop Dis 2022; 16:e0010854. [PMCID: PMC9639813 DOI: 10.1371/journal.pntd.0010854] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 09/28/2022] [Indexed: 11/09/2022] Open
Abstract
Fasciola spp. liver flukes have significant impacts in veterinary and human medicine. The absence of a vaccine and increasing anthelmintic resistance threaten sustainable control and underscore the need for novel flukicides. Functional genomic approaches underpinned by in vitro culture of juvenile Fasciola hepatica facilitate control target validation in the most pathogenic life stage. Comparative transcriptomics of in vitro and in vivo maintained 21 day old F. hepatica finds that 86% of genes are expressed at similar levels across maintenance treatments suggesting commonality in core biological functioning within these juveniles. Phenotypic comparisons revealed higher cell proliferation and growth rates in the in vivo juveniles compared to their in vitro counterparts. These phenotypic differences were consistent with the upregulation of neoblast-like stem cell and cell-cycle associated genes in in vivo maintained worms. The more rapid growth/development of in vivo juveniles was further evidenced by a switch in cathepsin protease expression profiles, dominated by cathepsin B in in vitro juveniles and by cathepsin L in in vivo juveniles. Coincident with more rapid growth/development was the marked downregulation of both classical and peptidergic neuronal signalling components in in vivo maintained juveniles, supporting a role for the nervous system in regulating liver fluke growth and development. Differences in the miRNA complements of in vivo and in vitro juveniles identified 31 differentially expressed miRNAs, including fhe-let-7a-5p, fhe-mir-124-3p and miRNAs predicted to target Wnt-signalling, which supports a key role for miRNAs in driving the growth/developmental differences in the in vitro and in vivo maintained juvenile liver fluke. Widespread differences in the expression of neuronal genes in juvenile fluke grown in vitro and in vivo expose significant interplay between neuronal signalling and the rate of growth/development, encouraging consideration of neuronal targets in efforts to dysregulate growth/development for parasite control.
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Affiliation(s)
- Emily Robb
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
- * E-mail: (ER); (EMM); (AGM)
| | - Erin M. McCammick
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
- * E-mail: (ER); (EMM); (AGM)
| | - Duncan Wells
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
| | - Paul McVeigh
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
| | - Erica Gardiner
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
| | - Rebecca Armstrong
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
| | - Paul McCusker
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
| | - Angela Mousley
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
| | - Nathan Clarke
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
| | - Nikki J. Marks
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
| | - Aaron G. Maule
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
- * E-mail: (ER); (EMM); (AGM)
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Huang M, Wang X, Banerjee M, Mukherji ST, Kutz LC, Zhao A, Sepanski M, Fan CM, Zhu GZ, Tian J, Wang DZ, Zhu H, Xie ZJ, Pierre SV, Cai L. Regulation of Myogenesis by a Na/K-ATPase α1 Caveolin-Binding Motif. Stem Cells 2022; 40:133-148. [PMID: 35257186 PMCID: PMC8943859 DOI: 10.1093/stmcls/sxab012] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 09/25/2021] [Indexed: 01/12/2024]
Abstract
The N-terminal caveolin-binding motif (CBM) in Na/K-ATPase (NKA) α1 subunit is essential for cell signaling and somitogenesis in animals. To further investigate the molecular mechanism, we have generated CBM mutant human-induced pluripotent stem cells (iPSCs) through CRISPR/Cas9 genome editing and examined their ability to differentiate into skeletal muscle (Skm) cells. Compared with the parental wild-type human iPSCs, the CBM mutant cells lost their ability of Skm differentiation, which was evidenced by the absence of spontaneous cell contraction, marker gene expression, and subcellular myofiber banding structures in the final differentiated induced Skm cells. Another NKA functional mutant, A420P, which lacks NKA/Src signaling function, did not produce a similar defect. Indeed, A420P mutant iPSCs retained intact pluripotency and ability of Skm differentiation. Mechanistically, the myogenic transcription factor MYOD was greatly suppressed by the CBM mutation. Overexpression of a mouse Myod cDNA through lentiviral delivery restored the CBM mutant cells' ability to differentiate into Skm. Upstream of MYOD, Wnt signaling was demonstrated from the TOPFlash assay to have a similar inhibition. This effect on Wnt activity was further confirmed functionally by defective induction of the presomitic mesoderm marker genes BRACHYURY (T) and MESOGENIN1 (MSGN1) by Wnt3a ligand or the GSK3 inhibitor/Wnt pathway activator CHIR. Further investigation through immunofluorescence imaging and cell fractionation revealed a shifted membrane localization of β-catenin in CBM mutant iPSCs, revealing a novel molecular component of NKA-Wnt regulation. This study sheds light on a genetic regulation of myogenesis through the CBM of NKA and control of Wnt/β-catenin signaling.
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Affiliation(s)
- Minqi Huang
- Marshall Institute for Interdisciplinary Research (MIIR) at Marshall University, Huntington, WV 25703, USA
| | - Xiaoliang Wang
- Marshall Institute for Interdisciplinary Research (MIIR) at Marshall University, Huntington, WV 25703, USA
- Joan C. Edwards School of Medicine at Marshall University, Huntington, WV 25703, USA
| | - Moumita Banerjee
- Marshall Institute for Interdisciplinary Research (MIIR) at Marshall University, Huntington, WV 25703, USA
| | - Shreya T Mukherji
- Marshall Institute for Interdisciplinary Research (MIIR) at Marshall University, Huntington, WV 25703, USA
| | - Laura C Kutz
- Marshall Institute for Interdisciplinary Research (MIIR) at Marshall University, Huntington, WV 25703, USA
| | - Aijie Zhao
- Marshall Institute for Interdisciplinary Research (MIIR) at Marshall University, Huntington, WV 25703, USA
| | - Michael Sepanski
- Department of Embryology, Carnegie Institution for Science, 3520 San Martin Drive, Baltimore, MD 21218, USA
| | - Chen-Ming Fan
- Department of Embryology, Carnegie Institution for Science, 3520 San Martin Drive, Baltimore, MD 21218, USA
| | - Guo-Zhang Zhu
- Department of Biological Sciences, Marshall University, Huntington, WV 25703, USA
| | - Jiang Tian
- Marshall Institute for Interdisciplinary Research (MIIR) at Marshall University, Huntington, WV 25703, USA
- Joan C. Edwards School of Medicine at Marshall University, Huntington, WV 25703, USA
| | - Da-Zhi Wang
- University of South Florida Health Heart Institute, Morsani College of Medicine, University of South Florida, 560 Channelside Drive, Tampa, FL 33602, USA
| | - Hua Zhu
- Department of Surgery, The Ohio State University, 396 Biomedical Research Tower, 460 W. 12th Avenue, Columbus, OH 43210, USA
| | - Zi-Jian Xie
- Marshall Institute for Interdisciplinary Research (MIIR) at Marshall University, Huntington, WV 25703, USA
| | - Sandrine V Pierre
- Marshall Institute for Interdisciplinary Research (MIIR) at Marshall University, Huntington, WV 25703, USA
| | - Liquan Cai
- Marshall Institute for Interdisciplinary Research (MIIR) at Marshall University, Huntington, WV 25703, USA
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Johnson CK, Fernandez-Abascal J, Wang Y, Wang L, Bianchi L. The Na +-K +-ATPase is needed in glia of touch receptors for responses to touch in C. elegans. J Neurophysiol 2020; 123:2064-2074. [PMID: 32292107 PMCID: PMC7444924 DOI: 10.1152/jn.00636.2019] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 03/15/2020] [Accepted: 04/10/2020] [Indexed: 01/04/2023] Open
Abstract
Four of the five types of mammalian mechanosensors are composed of nerve endings and accessory cells. In Caenorhabditis elegans we showed that glia support the function of nose touch neurons via the activity of glial Na+ and K+ channels. We show here that a third regulator of Na+ and K+, the Na+-K+-ATPase, is needed in glia of nose touch neurons for touch. Importantly, we show that two Na+-K+-ATPase genes are needed for the function rather than structural integrity and that their ion transport activity is crucial for touch. Finally, when glial Na+-K+-ATPase genes are knocked out, touch can be restored by activation of a third Na+-K+-ATPase. Taken together, these data show the requirement in glia of touch neurons of the function of the Na+-K+-ATPase. These data underscore the importance of the homeostasis of Na+ and K+, most likely in the space surrounding touch neurons, in touch sensation, a function that might be conserved across species.NEW & NOTEWORTHY Increasing evidence supports that accessory cells in mechanosensors regulate neuronal output; however, the glial molecular mechanisms that control this regulation are not fully understood. We show here in Caenorhabditis elegans that specific glial Na+-K+-ATPase genes are needed for nose touch-avoidance behavior. Our data support the requirement of these Na+-K+-ATPases for homeostasis of Na+ and K+ in nose touch receptors. Our data add to our understanding of glial regulation of mechanosensors.
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Affiliation(s)
- Christina K Johnson
- Department Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, Florida
| | - Jesus Fernandez-Abascal
- Department Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, Florida
| | - Ying Wang
- Department Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, Florida
| | - Lei Wang
- Department Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, Florida
| | - Laura Bianchi
- Department Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, Florida
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Transposon Insertion Mutagenesis in Mice for Modeling Human Cancers: Critical Insights Gained and New Opportunities. Int J Mol Sci 2020; 21:ijms21031172. [PMID: 32050713 PMCID: PMC7036786 DOI: 10.3390/ijms21031172] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 01/30/2020] [Accepted: 02/03/2020] [Indexed: 02/07/2023] Open
Abstract
Transposon mutagenesis has been used to model many types of human cancer in mice, leading to the discovery of novel cancer genes and insights into the mechanism of tumorigenesis. For this review, we identified over twenty types of human cancer that have been modeled in the mouse using Sleeping Beauty and piggyBac transposon insertion mutagenesis. We examine several specific biological insights that have been gained and describe opportunities for continued research. Specifically, we review studies with a focus on understanding metastasis, therapy resistance, and tumor cell of origin. Additionally, we propose further uses of transposon-based models to identify rarely mutated driver genes across many cancers, understand additional mechanisms of drug resistance and metastasis, and define personalized therapies for cancer patients with obesity as a comorbidity.
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Chisholm AD, Xu S. The Caenorhabditis elegans epidermis as a model skin. II: differentiation and physiological roles. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2012; 1:879-902. [PMID: 23539358 DOI: 10.1002/wdev.77] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The Caenorhabditis elegans epidermis forms one of the principal barrier epithelia of the animal. Differentiation of the epidermis begins in mid embryogenesis and involves apical-basal polarization of the cytoskeletal and secretory systems as well as cellular junction formation. Secretion of the external cuticle layers is one of the major developmental and physiological specializations of the epidermal epithelium. The four post-embryonic larval stages are separated by periodic moults, in which the epidermis generates a new cuticle with stage-specific characteristics. The differentiated epidermis also plays key roles in endocrine signaling, fat storage, and ionic homeostasis. The epidermis is intimately associated with the development and function of the nervous system, and may have glial-like roles in modulating neuronal function. The epidermis provides passive and active defenses against skin-penetrating pathogens and can repair small wounds. Finally, age-dependent deterioration of the epidermis is a prominent feature of aging and may affect organismal aging and lifespan.
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Affiliation(s)
- Andrew D Chisholm
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA.
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Insulin/Insulin-like growth factor signaling controls non-Dauer developmental speed in the nematode Caenorhabditis elegans. Genetics 2010; 187:337-43. [PMID: 20944013 DOI: 10.1534/genetics.110.123323] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Identified as a major pathway controlling entry in the facultative dauer diapause stage, the DAF-2/Insulin receptor (InsR) signaling acts in multiple developmental and physiological regulation events in Caenorhabditis elegans. Here we identified a role of the insulin-like pathway in controlling developmental speed during the C. elegans second larval stage. This role relies on the canonical DAF-16/FOXO-dependent branch of the insulin-like signaling and is largely independent of dauer formation. Our studies provide further evidence for broad conservation of insulin/insulin-like growth factor (IGF) functions in developmental speed control.
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Salaün C, Leroy C, Rousseau A, Boitez V, Beck L, Friedlander G. Identification of a novel transport-independent function of PiT1/SLC20A1 in the regulation of TNF-induced apoptosis. J Biol Chem 2010; 285:34408-18. [PMID: 20817733 DOI: 10.1074/jbc.m110.130989] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
PiT1/SLC20A1 is a sodium-dependent P(i) transporter expressed by most mammalian cells. Interestingly, PiT1 transcription has been shown to be up-regulated by the tumor necrosis factor α (TNF), and we have now investigated the possible involvement of PiT1 in TNF-induced apoptosis. We show that PiT1-depleted cells are more sensitive to the proapoptotic activity of TNF (i.e. when the antiapoptotic NFκB pathway is inactivated). These observations were made in the human HeLa cancer cell line either transiently or stably depleted in PiT1 by RNA interference and in immortalized mouse embryonic fibroblasts isolated from PiT1 knock-out embryos. Depletion of the closely related family member PiT2 had no effect on TNF-induced apoptosis, showing that this effect was specific to PiT1. The increased sensitivity of PiT1-depleted cells was evident regardless of the presence or absence of extracellular P(i), suggesting that a defect in P(i) uptake was not involved in the observed phenotype. Importantly, we show that the re-expression of a P(i) uptake mutant of PiT1 in PiT1(-/-) mouse embryonic fibroblasts delays apoptosis as efficiently as the WT protein, showing that this function of PiT1 is unrelated to its transport activity. Caspase-8 is more activated in PiT1-depleted cells, and our data reveal that the sustained activation of the MAPK JNK is up-regulated in response to TNF. JNK activity is actually involved in PiT1-depleted cell death because specific JNK inhibitors delay apoptosis.
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Affiliation(s)
- Christine Salaün
- Growth and Signaling Research Center, INSERM U845, F-75015 Paris, France.
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Manipulating the Caenorhabditis elegans genome using mariner transposons. Genetica 2009; 138:541-9. [PMID: 19347589 DOI: 10.1007/s10709-009-9362-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2009] [Accepted: 03/20/2009] [Indexed: 12/16/2022]
Abstract
Tc1, one of the founding members of the Tc1/mariner transposon superfamily, was identified in the nematode Caenorhabditis elegans more than 25 years ago. Over the years, Tc1 and other endogenous mariner transposons became valuable tools for mutagenesis and targeted gene inactivation in C. elegans. However, transposition is naturally repressed in the C. elegans germline by an RNAi-like mechanism, necessitating the use of mutant strains in which transposition was globally derepressed, which causes drawbacks such as uncontrolled proliferation of the transposons in the genome and accumulation of background mutations. The more recent mobilization of the Drosophila mariner transposon Mos1 in the C. elegans germline circumvented the problems inherent to endogenous transposons. Mos1 transposition strictly depends on the expression of the Mos transposase, which can be controlled in the germline using inducible promoters. First, Mos1 can be used for insertional mutagenesis. The mobilization of Mos1 copies present on an extrachromosomal array results in the generation of a small number of Mos1 genomic insertions that can be rapidly cloned by inverse PCR. Second, Mos1 insertions can be used for genome engineering. Triggering the excision of a genomic Mos1 insertion causes a chromosomal break, which can be repaired by transgene-instructed gene conversion. This process is used to introduce specific changes in a given gene, such as point mutations, deletions or insertions of a tag, and to create single-copy transgenes.
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Sáez AG, Lozano E, Zaldívar-Riverón A. Evolutionary history of Na,K-ATPases and their osmoregulatory role. Genetica 2009; 136:479-90. [PMID: 19214758 DOI: 10.1007/s10709-009-9356-0] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2008] [Accepted: 01/26/2009] [Indexed: 01/07/2023]
Abstract
The Na/K pump, or Na,K-ATPase, is a key enzyme to the homeostasis of osmotic pressure, cell volume, and the maintenance of electrochemical gradients. Its alpha subunit, which holds most of its functions, belongs to a large family of ATPases known as P-type, and to the subfamily IIC, which also includes H,K-ATPases. In this study, we attempt to describe the evolutionary history of IIC ATPases by doing phylogenetic analysis with most of the currently available protein sequences (over 200), and pay special attention to the relationship between their diversity and their osmoregulatory role. We include proteins derived from many completed or ongoing genome projects, many of whose IIC ATPases have not been phylogenetically analyzed previously. We show that the most likely origin of IIC proteins is prokaryotic, and that many of them are present in non-metazoans, such as algae, protozoans or fungi. We also suggest that the pre-metazoan ancestor, represented by the choanoflagellate Monosiga brevicollis, whose genome has been sequenced, presented at least two IIC-type proteins. One of these proteins would have given rise to most current animal IIC ATPases, whereas the other apparently evolved into a lineage that, so far, has only been found in nematodes. We also propose that early deuterostomes presented a single IIC gene, from which all the extant diversity of vertebrate IIC proteins originated by gene and genome duplications.
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Affiliation(s)
- Alberto G Sáez
- Department of Biodiversity and Evolutionary Biology, Museo Nacional de Ciencias Naturales, CSIC, Madrid, Spain.
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Doi M, Iwasaki K. Na+/K+ ATPase regulates the expression and localization of acetylcholine receptors in a pump activity-independent manner. Mol Cell Neurosci 2008; 38:548-58. [PMID: 18599311 DOI: 10.1016/j.mcn.2008.05.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2007] [Revised: 04/21/2008] [Accepted: 05/05/2008] [Indexed: 10/22/2022] Open
Abstract
Na+/K+ ATPase is a plasma membrane-localized sodium pump that maintains the ion gradients between the extracellular and intracellular environments, which in turn controls the cellular resting membrane potential.Recent evidence suggests that the pump is also localized at synapses and regulates synaptic efficacy.However, its precise function at the synapse is unknown. Here we show that two mutations in the alpha subunit of the eat-6 Na+/K+ ATPase in Caenorhabditis elegans dramatically increase the sensitivity to acetylcholine(Ach) agonists and alter the localization of nicotinic Ach receptors at the neuromuscular junction (NMJ).These defects can be rescued by mutated EAT-6 proteins which lack its pump activity, suggesting the presence of a novel function for Ach signaling. The Na+/K+ ATPase accumulates at postsynaptic sites and appears to surround Ach receptors to maintain rigid clusters at the NMJ. Our findings suggest a pump activity-independent, allele-specific role for Na+/K+ ATPase on postsynaptic organization and synaptic efficacy.
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Affiliation(s)
- Motomichi Doi
- Neuroscience Research Institute, AIST, Tsukuba, Ibaraki 305-8566, Japan.
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Abstract
We describe a protocol for mutating genes in the nematode Caenorhabditis elegans using the Mos1 transposon of Drosophila mauritiana. Mutated genes containing a Mos1 insertion are molecularly tagged by this heterologous transposable element. Mos1 insertions can therefore be identified in as little as 3 weeks using only basic molecular biology techniques. Mutagenic efficiency of Mos1 is tenfold lower than classical chemical mutagens. However, the ease and speed with which mutagenic insertions can be mapped compares favorably with the vast amount of work involved in classical genetic mapping. Therefore, Mos1 could be the tool of choice when screening procedures are efficient. In addition, Mos1 mutagenesis can greatly simplify the mapping of mutations that exhibit low penetrance, subtle or synthetic phenotypes. The recent development of targeted engineering of C. elegans loci carrying Mos1 insertions further increases the attractiveness of Mos1-mediated mutagenesis.
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