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Soh MS, Cheng X, Vijayaraghavan T, Vernon A, Liu J, Neumann B. Disruption of genes associated with Charcot-Marie-Tooth type 2 lead to common behavioural, cellular and molecular defects in Caenorhabditis elegans. PLoS One 2020; 15:e0231600. [PMID: 32294113 PMCID: PMC7159224 DOI: 10.1371/journal.pone.0231600] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 03/26/2020] [Indexed: 11/23/2022] Open
Abstract
Charcot-Marie-Tooth (CMT) disease is an inherited peripheral motor and sensory neuropathy. The disease is divided into demyelinating (CMT1) and axonal (CMT2) neuropathies, and although we have gained molecular information into the details of CMT1 pathology, much less is known about CMT2. Due to its clinical and genetic heterogeneity, coupled with a lack of animal models, common underlying mechanisms remain elusive. In order to gain an understanding of the normal function of genes associated with CMT2, and to draw direct comparisons between them, we have studied the behavioural, cellular and molecular consequences of mutating nine different genes in the nematode Caenorhabditis elegans (lin-41/TRIM2, dyn-1/DNM2, unc-116/KIF5A, fzo-1/MFN2, osm-9/TRPV4, cua-1/ATP7A, hsp-25/HSPB1, hint-1/HINT1, nep-2/MME). We show that C. elegans defective for these genes display debilitated movement in crawling and swimming assays. Severe morphological defects in cholinergic motors neurons are also evident in two of the mutants (dyn-1 and unc-116). Furthermore, we establish methods for quantifying muscle morphology and use these to demonstrate that loss of muscle structure occurs in the majority of mutants studied. Finally, using electrophysiological recordings of neuromuscular junction (NMJ) activity, we uncover reductions in spontaneous postsynaptic current frequency in lin-41, dyn-1, unc-116 and fzo-1 mutants. By comparing the consequences of mutating numerous CMT2-related genes, this study reveals common deficits in muscle structure and function, as well as NMJ signalling when these genes are disrupted.
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Affiliation(s)
- Ming S. Soh
- Neuroscience Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, Australia
| | - Xinran Cheng
- Neuroscience Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, Australia
| | - Tarika Vijayaraghavan
- Neuroscience Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, Australia
| | - Arwen Vernon
- Neuroscience Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, Australia
| | - Jie Liu
- Neuroscience Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, Australia
| | - Brent Neumann
- Neuroscience Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, Australia
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Griffin EF, Caldwell KA, Caldwell GA. Genetic and Pharmacological Discovery for Alzheimer's Disease Using Caenorhabditis elegans. ACS Chem Neurosci 2017; 8:2596-2606. [PMID: 29022701 DOI: 10.1021/acschemneuro.7b00361] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The societal burden presented by Alzheimer's disease warrants both innovative and expedient means by which its underlying molecular causes can be both identified and mechanistically exploited to discern novel therapeutic targets and strategies. The conserved characteristics, defined neuroanatomy, and advanced technological application of Caenorhabditis elegans render this metazoan an unmatched tool for probing neurotoxic factors. In addition, its short lifespan and importance in the field of aging make it an ideal organism for modeling age-related neurodegenerative disease. As such, this nematode system has demonstrated its value in predicting functional modifiers of human neurodegenerative disorders. Here, we review how C. elegans has been utilized to model Alzheimer's disease. Specifically, we present how the causative neurotoxic peptides, amyloid-β and tau, contribute to disease-like neurodegeneration in C. elegans and how they translate to human disease. Furthermore, we describe how a variety of transgenic animal strains, each with distinct utility, have been used to identify both genetic and pharmacological modifiers of toxicity in C. elegans. As technological advances improve the prospects for intervention, the rapidity, unparalleled accuracy, and scale that C. elegans offers researchers for defining functional modifiers of neurodegeneration should speed the discovery of improved therapies for Alzheimer's disease.
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Affiliation(s)
- Edward F. Griffin
- Department
of Biological Sciences, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Kim A. Caldwell
- Department
of Biological Sciences, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Guy A. Caldwell
- Department
of Biological Sciences, The University of Alabama, Tuscaloosa, Alabama 35487, United States
- Departments
of Neurology and Neurobiology, Center for Neurodegeneration and Experimental
Therapeutics, The University of Alabama School of Medicine at Birmingham, Birmingham, Alabama 35294, United States
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WANTED - Dead or alive: Myotubularins, a large disease-associated protein family. Adv Biol Regul 2016; 63:49-58. [PMID: 27666502 DOI: 10.1016/j.jbior.2016.09.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 09/13/2016] [Accepted: 09/13/2016] [Indexed: 11/21/2022]
Abstract
Myotubularins define a large family of proteins conserved through evolution. Several members are mutated in different neuromuscular diseases including centronuclear myopathies and Charcot-Marie-Tooth (CMT) neuropathies, or are linked to a predisposition to obesity and cancer. While some members have phosphatase activity against the 3-phosphate of phosphoinositides, regulating the phosphorylation status of PtdIns3P and PtdIns(3,5)P2 implicated in membrane trafficking and autophagy, and producing PtdIns5P, others lack key residues in the catalytic site and are classified as dead-phosphatases. However, these dead phosphatases regulate phosphoinositide-dependent cellular pathways by binding to catalytically active myotubularins. Here we review previous studies on the molecular regulation and physiological roles of myotubularins. We also used the recent myotubularins three-dimensional structures to underline key residues that are mutated in neuromuscular diseases and required for enzymatic activity. In addition, through database mining and analysis, expression profile and specific isoforms of the different myotubularins are described in depth, as well as a revisited protein interaction network. Comparison of the interactome and expression data for each myotubularin highlights specific protein complexes and tissues where myotubularins should have a key regulatory role.
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Li L, Wan T, Wan M, Liu B, Cheng R, Zhang R. The effect of the size of fluorescent dextran on its endocytic pathway. Cell Biol Int 2015; 39:531-9. [DOI: 10.1002/cbin.10424] [Citation(s) in RCA: 112] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 12/19/2014] [Indexed: 02/05/2023]
Affiliation(s)
- Lei Li
- Key Laboratory of Molecular Biophysics of the Ministry of Education; College of Life Science and Technology; Huazhong University of Science and Technology; Wuhan 430074 P. R. China
| | - Tao Wan
- Key Laboratory of Molecular Biophysics of the Ministry of Education; College of Life Science and Technology; Huazhong University of Science and Technology; Wuhan 430074 P. R. China
| | - Min Wan
- Key Laboratory of Molecular Biophysics of the Ministry of Education; College of Life Science and Technology; Huazhong University of Science and Technology; Wuhan 430074 P. R. China
| | - Bei Liu
- Key Laboratory of Molecular Biophysics of the Ministry of Education; College of Life Science and Technology; Huazhong University of Science and Technology; Wuhan 430074 P. R. China
| | - Ran Cheng
- Key Laboratory of Molecular Biophysics of the Ministry of Education; College of Life Science and Technology; Huazhong University of Science and Technology; Wuhan 430074 P. R. China
| | - Rongying Zhang
- Key Laboratory of Molecular Biophysics of the Ministry of Education; College of Life Science and Technology; Huazhong University of Science and Technology; Wuhan 430074 P. R. China
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Kozubowski L, Thompson JW, Cardenas ME, Moseley MA, Heitman J. Association of calcineurin with the COPI protein Sec28 and the COPII protein Sec13 revealed by quantitative proteomics. PLoS One 2011; 6:e25280. [PMID: 21984910 PMCID: PMC3184950 DOI: 10.1371/journal.pone.0025280] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Accepted: 08/30/2011] [Indexed: 11/29/2022] Open
Abstract
Calcineurin is a calcium-calmodulin-dependent serine/threonine specific protein phosphatase operating in key cellular processes governing responses to extracellular cues. Calcineurin is essential for growth at high temperature and virulence of the human fungal pathogen Cryptococcus neoformans but the underlying mechanism is unknown. We performed a mass spectrometry analysis to identify proteins that associate with the calcineurin A catalytic subunit (Cna1) in C. neoformans cells grown under non-stress and high temperature stress conditions. A novel prioritization strategy for mass spectrometry data from immunoprecipitation experiments identified putative substrates and proteins potentially operating with calcineurin in common pathways. Cna1 co-purified with proteins involved in membrane trafficking including the COPI component Sec28 and the COPII component Sec13. The association of Cna1 with Sec28 and Sec13 was confirmed by co-immunoprecipitation. Cna1 exhibited a dramatic change in subcellular localization during high temperature stress from diffuse cytoplasmic to ER-associated puncta and the mother-bud neck and co-localized with Sec28 and Sec13.
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Affiliation(s)
- Lukasz Kozubowski
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America.
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Xue J, Graham ME, Novelle AE, Sue N, Gray N, McNiven MA, Smillie KJ, Cousin MA, Robinson PJ. Calcineurin selectively docks with the dynamin Ixb splice variant to regulate activity-dependent bulk endocytosis. J Biol Chem 2011; 286:30295-30303. [PMID: 21730063 DOI: 10.1074/jbc.m111.273110] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Depolarization of nerve terminals stimulates rapid dephosphorylation of two isoforms of dynamin I (dynI), mediated by the calcium-dependent phosphatase calcineurin (CaN). Dephosphorylation at the major phosphorylation sites Ser-774/778 promotes a dynI-syndapin I interaction for a specific mode of synaptic vesicle endocytosis called activity-dependent bulk endocytosis (ADBE). DynI has two main splice variants at its extreme C terminus, long or short (dynIxa and dynIxb) varying only by 20 (xa) or 7 (xb) residues. Recombinant GST fusion proteins of dynIxa and dynIxb proline-rich domains (PRDs) were used to pull down interacting proteins from rat brain nerve terminals. Both bound equally to syndapin, but dynIxb PRD exclusively bound to the catalytic subunit of CaNA, which recruited CaNB. Binding of CaN was increased in the presence of calcium and was accompanied by further recruitment of calmodulin. Point mutations showed that the entire C terminus of dynIxb is a CaN docking site related to a conserved CaN docking motif (PXIXI(T/S)). This sequence is unique to dynIxb among all other dynamin variants or genes. Peptide mimetics of the dynIxb tail blocked CaN binding in vitro and selectively inhibited depolarization-evoked dynI dephosphorylation in nerve terminals but not of other dephosphins. Therefore, docking to dynIxb is required for the regulation of both dynI splice variants, yet it does not regulate the phosphorylation cycle of other dephosphins. The peptide blocked ADBE, but not clathrin-mediated endocytosis of synaptic vesicles. Our results indicate that Ca(2+) influx regulates assembly of a fully active CaN-calmodulin complex selectively on the tail of dynIxb and that the complex is recruited to sites of ADBE in nerve terminals.
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Affiliation(s)
- Jing Xue
- Cell Signalling Unit, Children's Medical Research Institute, University of Sydney, Locked Bag 23, Wentworthville 2145, New South Wales, Australia
| | - Mark E Graham
- Cell Signalling Unit, Children's Medical Research Institute, University of Sydney, Locked Bag 23, Wentworthville 2145, New South Wales, Australia
| | - Aimee E Novelle
- Cell Signalling Unit, Children's Medical Research Institute, University of Sydney, Locked Bag 23, Wentworthville 2145, New South Wales, Australia
| | - Nancy Sue
- Cell Signalling Unit, Children's Medical Research Institute, University of Sydney, Locked Bag 23, Wentworthville 2145, New South Wales, Australia
| | - Noah Gray
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota 55905
| | - Mark A McNiven
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota 55905
| | - Karen J Smillie
- Membrane Biology Group, Centre for Integrative Physiology, University of Edinburgh, George Square, Edinburgh EH8 9XD, United Kingdom
| | - Michael A Cousin
- Membrane Biology Group, Centre for Integrative Physiology, University of Edinburgh, George Square, Edinburgh EH8 9XD, United Kingdom
| | - Phillip J Robinson
- Cell Signalling Unit, Children's Medical Research Institute, University of Sydney, Locked Bag 23, Wentworthville 2145, New South Wales, Australia.
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Abstract
Calcineurin is a serine/threonine protein phosphatase controlled by Ca(2+) and calmodulin that has been implicated in various signaling pathways. Previously, we reported that calcineurin regulates coelomocyte endocytosis in Caenorhabditis elegans. So far, simple and powerful in vivo approaches have been developed to study various endocytic processes in C. elegans. Using these in vivo assays, we further analyzed the endocytic phenotypes of calcineurin mutants. We observed that the calcineurin mutants were defective in apical endocytosis in the intestine as well as synaptic vesicle recycling in the nerve cord. However, we found that calcineurin mutants displayed normal receptor-mediated endocytosis in oocytes. Therefore, our results suggest that calcineurin may regulate specific sets of endocytic processes in nematode.
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Affiliation(s)
- Hyun-Ok Song
- Department of Life Science, BK21 (Life Science for Global Warming Team), College of Natural Sciences, Hanyang University, Seoul 133-791, Korea
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