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Pajić T, Stevanović K, Todorović NV, Krmpot AJ, Živić M, Savić-Šević S, Lević SM, Stanić M, Pantelić D, Jelenković B, Rabasović MD. In vivo femtosecond laser nanosurgery of the cell wall enabling patch-clamp measurements on filamentous fungi. MICROSYSTEMS & NANOENGINEERING 2024; 10:47. [PMID: 38590818 PMCID: PMC10999429 DOI: 10.1038/s41378-024-00664-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 12/01/2023] [Accepted: 12/19/2023] [Indexed: 04/10/2024]
Abstract
Studying the membrane physiology of filamentous fungi is key to understanding their interactions with the environment and crucial for developing new therapeutic strategies for disease-causing pathogens. However, their plasma membrane has been inaccessible for a micron-sized patch-clamp pipette for pA current recordings due to the rigid chitinous cell wall. Here, we report the first femtosecond IR laser nanosurgery of the cell wall of the filamentous fungi, which enabled patch-clamp measurements on protoplasts released from hyphae. A reproducible and highly precise (diffraction-limited, submicron resolution) method for obtaining viable released protoplasts was developed. Protoplast release from the nanosurgery-generated incisions in the cell wall was achieved from different regions of the hyphae. The plasma membrane of the obtained protoplasts formed tight and high-resistance (GΩ) contacts with the recording pipette. The entire nanosurgical procedure followed by the patch-clamp technique could be completed in less than 1 hour. Compared to previous studies using heterologously expressed channels, this technique provides the opportunity to identify new ionic currents and to study the properties of the ion channels in the protoplasts of filamentous fungi in their native environment.
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Grants
- Ministarstvo Prosvete, Nauke i Tehnološkog Razvoja (Ministry of Education, Science and Technological Development of the Republic of Serbia)
- This work was supported by the Ministry of Science, Technological Development and Innovations, Republic of Serbia [contract number: 451-03-47/2023-01/200178]; The Project Advanced Biophysical Methods for Soil Targeted Fungi-Based Biocontrol Agents - BioPhysFUN [Grant number 4545] from Program DEVELOPMENT – Green program of cooperation between science and industry, Science Fund of the Republic of Serbia
- This work was supported by the Ministry of Science, Technological Development and Innovations, Republic of Serbia [contract number: 451-03-47/2023-01/200007]; The Project Advanced Biophysical Methods for Soil Targeted Fungi-Based Biocontrol Agents - BioPhysFUN [Grant number 4545] from Program DEVELOPMENT – Green program of cooperation between science and industry, Science Fund of the Republic of Serbia
- The Project Advanced Biophysical Methods for Soil Targeted Fungi-Based Biocontrol Agents - BioPhysFUN [Grant number 4545] from Program DEVELOPMENT – Green program of cooperation between science and industry, Science Fund of the Republic of Serbia; the Project HEMMAGINERO [Grant number 6066079] from Program PROMIS, Science Fund of the Republic of Serbia; and the Institute of Physics Belgrade, through the grant by the Ministry of Science, Technological Development and Innovations of the Republic of Serbia.
- The Institute of Physics Belgrade, through the grant by the Ministry of Science, Technological Development and Innovations of the Republic of Serbia
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Affiliation(s)
- Tanja Pajić
- Institute of Physiology and Biochemistry “Ivan Djaja”, Faculty of Biology, University of Belgrade, Studentski trg 16, 11158 Belgrade, Serbia
| | - Katarina Stevanović
- Institute of Physiology and Biochemistry “Ivan Djaja”, Faculty of Biology, University of Belgrade, Studentski trg 16, 11158 Belgrade, Serbia
| | - Nataša V. Todorović
- Institute for Biological Research “Siniša Stanković”, University of Belgrade, National Institute of the Republic of Serbia, Bulevar Despota Stefana 142, 11000 Belgrade, Serbia
| | - Aleksandar J. Krmpot
- Institute of Physics Belgrade, University of Belgrade, National Institute of the Republic of Serbia, Pregrevica 118, 11080 Belgrade, Serbia
| | - Miroslav Živić
- Institute of Physiology and Biochemistry “Ivan Djaja”, Faculty of Biology, University of Belgrade, Studentski trg 16, 11158 Belgrade, Serbia
| | - Svetlana Savić-Šević
- Institute of Physics Belgrade, University of Belgrade, National Institute of the Republic of Serbia, Pregrevica 118, 11080 Belgrade, Serbia
| | - Steva M. Lević
- University of Belgrade, Faculty of Agriculture, Nemanjina Street 6, 11080 Belgrade, Serbia
| | - Marina Stanić
- Institute for Multidisciplinary Research, University of Belgrade, Kneza Višeslava 1, 11030 Belgrade, Serbia
| | - Dejan Pantelić
- Institute of Physics Belgrade, University of Belgrade, National Institute of the Republic of Serbia, Pregrevica 118, 11080 Belgrade, Serbia
| | - Brana Jelenković
- Institute of Physics Belgrade, University of Belgrade, National Institute of the Republic of Serbia, Pregrevica 118, 11080 Belgrade, Serbia
| | - Mihailo D. Rabasović
- Institute of Physics Belgrade, University of Belgrade, National Institute of the Republic of Serbia, Pregrevica 118, 11080 Belgrade, Serbia
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2
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Dong XY. Calcium Ion Channels in Saccharomyces cerevisiae. J Fungi (Basel) 2023; 9:jof9050524. [PMID: 37233235 DOI: 10.3390/jof9050524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 04/25/2023] [Accepted: 04/25/2023] [Indexed: 05/27/2023] Open
Abstract
Regulating calcium ion (Ca2+) channels to improve the cell cycle and metabolism is a promising technology, ensuring increased cell growth, differentiation, and/or productivity. In this regard, the composition and structure of Ca2+ channels play a vital role in controlling the gating states. In this review, Saccharomyces cerevisiae, as a model eukaryotic organism and an essential industrial microorganism, was used to discuss the effect of its type, composition, structure, and gating mechanism on the activity of Ca2+ channels. Furthermore, the advances in the application of Ca2+ channels in pharmacology, tissue engineering, and biochemical engineering are summarized, with a special focus on exploring the receptor site of Ca2+ channels for new drug design strategies and different therapeutic uses, targeting Ca2+ channels to produce functional replacement tissues, creating favorable conditions for tissue regeneration, and regulating Ca2+ channels to enhance biotransformation efficiency.
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Affiliation(s)
- Xiao-Yu Dong
- College of Life and Health, Dalian University, Dalian 116622, China
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Cai H, Zhang H, Guo DH, Wang Y, Gu J. Genomic Data Mining Reveals Abundant Uncharacterized Transporters in Coccidioides immitis and Coccidioides posadasii. J Fungi (Basel) 2022; 8:jof8101064. [PMID: 36294626 PMCID: PMC9604845 DOI: 10.3390/jof8101064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 10/01/2022] [Accepted: 10/08/2022] [Indexed: 11/16/2022] Open
Abstract
Coccidioides immitis and Coccidioides posadasii are causative agents of coccidioidomycosis, commonly known as Valley Fever. The increasing Valley Fever cases in the past decades, the expansion of endemic regions, and the rising azole drug-resistant strains have underscored an urgent need for a better understanding of Coccidioides biology and new antifungal strategies. Transporters play essential roles in pathogen survival, growth, infection, and adaptation, and are considered as potential drug targets. However, the composition and roles of transport machinery in Coccidioides remain largely unknown. In this study, genomic data mining revealed an abundant, uncharacterized repertoire of transporters in Coccidioides genomes. The catalog included 1288 and 1235 transporter homologs in C. immitis and C. posadasii, respectively. They were further annotated to class, subclass, family, subfamily and range of substrates based on the Transport Classification (TC) system. They may play diverse roles in nutrient uptake, metabolite secretion, ion homeostasis, drug efflux, or signaling. This study represents an initial effort for a systems-level characterization of the transport machinery in these understudied fungal pathogens.
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Affiliation(s)
- Hong Cai
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX 78249, USA
- South Texas Center for Emerging Infectious Diseases, University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Hao Zhang
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX 78249, USA
- South Texas Center for Emerging Infectious Diseases, University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Daniel H. Guo
- Strake Jesuit College Preparatory, Houston, TX 77036, USA
| | - Yufeng Wang
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX 78249, USA
- South Texas Center for Emerging Infectious Diseases, University of Texas at San Antonio, San Antonio, TX 78249, USA
- Correspondence: (Y.W.); (J.G.)
| | - Jianying Gu
- Department of Biology, College of Staten Island, City University of New York, Staten Island, New York, NY 10314, USA
- Correspondence: (Y.W.); (J.G.)
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Cui H, Jiang M, Zhou W, Gao M, He R, Huang Y, Chu PK, Yu XF. Carrier-Free Cellular Transport of CRISPR/Cas9 Ribonucleoprotein for Genome Editing by Cold Atmospheric Plasma. BIOLOGY 2021; 10:biology10101038. [PMID: 34681136 PMCID: PMC8533602 DOI: 10.3390/biology10101038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 09/22/2021] [Accepted: 09/24/2021] [Indexed: 12/16/2022]
Abstract
Simple Summary CRISPR/Cas9 system as a potential gene editing platform has been widely applied in biological engineering and disease therapies. To achieve precise gene targeting, active CRISPR/Cas9 components must be efficiently transported to targeted cells. As a simple and effective strategy, Cold Atmospheric Plasma (CAP) treatment has been demonstrated for the transmembrane delivery of various exogenous materials. In comparison with carrier-dependent delivery methods, this carrier-free platform provides a promising alternative to circumvent the obstacles of biosafety and complicated preparation processes. In this work, a CAP-based CRISPR/Cas9 carrier-free delivery platform has been established and corresponding mechanism related to efficient transportation has been explored. Briefly, the efficient production of bioactive species in culture media after CAP treatment alters cell membrane potential and permeability, which facilitates cytosolic delivery of active CRISPR/Cas9 components via passive diffusion and ATP-dependent endocytosis pathways, resulting in efficient genome editing and gene silencing. This carrier-free strategy using CAP-based transportation may also be extended to other active biomolecules in drug delivery and gene therapy. Abstract A carrier-free CRISPR/Cas9 ribonucleoprotein delivery strategy for genome editing mediated by a cold atmospheric plasma (CAP) is described. The CAP is promising in many biomedical applications due to efficient production of bioactive ionized species. The MCF-7 cancer cells after CAP exposure exhibit increased extracellular reactive oxygen and nitrogen species (RONS) and altered membrane potential and permeability. Hence, transmembrane transport of Ca2+ into the cells increases and accelerates ATP hydrolysis, resulting in enhanced ATP-dependent endocytosis. Afterwards, the increased Ca2+ and ATP contents promote the release of cargo into cytoplasm due to the enhanced endosomal escape. The increased membrane permeability also facilitates passive diffusion of foreign species across the membrane into the cytosol. After CAP exposure, the MCF-7 cells incubated with Cas9 ribonucleoprotein (Cas9-sgRNA complex, Cas9sg) with a size of about 15 nm show 88.9% uptake efficiency and 65.9% nuclear import efficiency via passive diffusion and ATP-dependent endocytosis pathways. The efficient transportation of active Cas9sg after the CAP treatment leads to 21.7% and 30.2% indel efficiencies in HEK293T and MCF-7 cells, respectively. This CAP-mediated transportation process provides a simple and robust alternative for the delivery of active CRISPR/Cas9 ribonucleoprotein. Additionally, the technique can be extended to other macro-biomolecules and nanomaterials to cater to different biomedical applications.
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Affiliation(s)
- Haodong Cui
- Materials Interfaces Center, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China; (H.C.); (M.J.); (M.G.); (Y.H.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Min Jiang
- Materials Interfaces Center, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China; (H.C.); (M.J.); (M.G.); (Y.H.)
| | - Wenhua Zhou
- Materials Interfaces Center, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China; (H.C.); (M.J.); (M.G.); (Y.H.)
- University of Chinese Academy of Sciences, Beijing 100049, China
- Correspondence: (W.Z.); (R.H.); (X.-F.Y.)
| | - Ming Gao
- Materials Interfaces Center, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China; (H.C.); (M.J.); (M.G.); (Y.H.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Rui He
- Materials Interfaces Center, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China; (H.C.); (M.J.); (M.G.); (Y.H.)
- Correspondence: (W.Z.); (R.H.); (X.-F.Y.)
| | - Yifan Huang
- Materials Interfaces Center, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China; (H.C.); (M.J.); (M.G.); (Y.H.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Paul K. Chu
- Department of Physics, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China;
- Department of Materials Science and Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China
- Department of Biomedical Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China
| | - Xue-Feng Yu
- Materials Interfaces Center, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China; (H.C.); (M.J.); (M.G.); (Y.H.)
- University of Chinese Academy of Sciences, Beijing 100049, China
- Correspondence: (W.Z.); (R.H.); (X.-F.Y.)
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5
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Oliveira NK, Frank LA, Squizani ED, Reuwsaat JCV, Marques BM, Motta H, Garcia AWA, Kinskovski UP, Barcellos VA, Schrank A, Pohlmann AR, Staats CC, Guterres SS, Vainstein MH, Kmetzsch L. New nanotechnological formulation based on amiodarone-loaded lipid core nanocapsules displays anticryptococcal effect. Eur J Pharm Sci 2021; 162:105816. [PMID: 33757827 DOI: 10.1016/j.ejps.2021.105816] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Revised: 02/21/2021] [Accepted: 03/18/2021] [Indexed: 01/01/2023]
Abstract
Cryptococcus neoformans is the etiological agent of cryptococcal meningoencephalitis. The recommended available treatment has low efficiency, with high toxicity and resistance as recurrent problems. In the search of new treatment protocols, the proposal of new pharmacological approaches is considered an innovative strategy, mainly nanotechnological systems considering fungal diseases. The antiarrhythmic drug amiodarone has demonstrated antifungal activity against a range of fungi, including C. neoformans. Here, considering the importance of calcium storage mediated by transporters on cryptococcal virulence, we evaluated the use of the calcium channel blocker amiodarone as an alternative therapy for cryptococcosis. C. neoformans displayed high sensitivity to amiodarone, which was also synergistic with fluconazole. Amiodarone treatment influenced some virulence factors, interrupting the calcium-calcineurin signaling pathway. Experiments with murine cryptococcosis models revealed that amiodarone treatment increased the fungal burden in the lungs, while its combination with fluconazole did not improve treatment compared to fluconazole alone. In addition, we have developed different innovative nanotechnological formulations, one of which combining two drugs with different mechanisms of action. Lipid-core nanocapsules (LNC) loaded with amiodarone (LNCAMD), fluconazole (LNCFLU) and both (LNCAMD+FLU) were produced to achieve a better efficacy in vivo. In an intranasal model of treatment, all the LNC formulations had an antifungal effect. In an intraperitoneal treatment, LNCAMD showed an enhanced anticryptococcal effect compared to the free drug, whereas LNCFLU or LNCAMD+FLU displayed no differences from the free drugs. In this way, nanotechnology using amiodarone formulations could be an effective therapy for cryptococcal infections.
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Affiliation(s)
| | - Luiza Abrahão Frank
- Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul, Porto Alegre RS, Brazil
| | - Eamim Daidrê Squizani
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | | | | | - Heryk Motta
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | | | - Uriel Perin Kinskovski
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | | | - Augusto Schrank
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Departamento de Biologia Molecular e Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Adriana Raffin Pohlmann
- Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul, Porto Alegre RS, Brazil; Departamento de Química Orgânica, Instituto de Química, Universidade Federal do Rio Grande do Sul, Porto Alegre RS, Brazil
| | - Charley Christian Staats
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Departamento de Biologia Molecular e Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Sílvia Stanisçuaski Guterres
- Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul, Porto Alegre RS, Brazil
| | - Marilene Henning Vainstein
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Departamento de Biologia Molecular e Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Lívia Kmetzsch
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Departamento de Biologia Molecular e Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
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6
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Squizani ED, Reuwsaat JC, Motta H, Tavanti A, Kmetzsch L. Calcium: a central player in Cryptococcus biology. FUNGAL BIOL REV 2021. [DOI: 10.1016/j.fbr.2021.03.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Cation Transporters of Candida albicans-New Targets to Fight Candidiasis? Biomolecules 2021; 11:biom11040584. [PMID: 33923411 PMCID: PMC8073359 DOI: 10.3390/biom11040584] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 04/14/2021] [Indexed: 02/07/2023] Open
Abstract
Candidiasis is the wide-spread fungal infection caused by numerous strains of yeast, with the prevalence of Candida albicans. The current treatment of candidiasis is becoming rather ineffective and costly owing to the emergence of resistant strains; hence, the exploration of new possible drug targets is necessary. The most promising route is the development of novel antibiotics targeting this pathogen. In this review, we summarize such candidates found in C. albicans and those involved in the transport of (metal) cations, as the latter are essential for numerous processes within the cell; hence, disruption of their fluxes can be fatal for C. albicans.
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8
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Squizani ED, Reuwsaat JCV, Lev S, Motta H, Sperotto J, Kaufman-Francis K, Desmarini D, Vainstein MH, Staats CC, Djordjevic JT, Kmetzsch L. Calcium Binding Protein Ncs1 Is Calcineurin Regulated in Cryptococcus neoformans and Essential for Cell Division and Virulence. mSphere 2020; 5:e00761-20. [PMID: 32907953 PMCID: PMC7485688 DOI: 10.1128/msphere.00761-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 08/28/2020] [Indexed: 12/24/2022] Open
Abstract
Intracellular calcium (Ca2+) is crucial for signal transduction in Cryptococcus neoformans, the major cause of fatal fungal meningitis. The calcineurin pathway is the only Ca2+-requiring signaling cascade implicated in cryptococcal stress adaptation and virulence, with Ca2+ binding mediated by the EF-hand domains of the Ca2+ sensor protein calmodulin. In this study, we identified the cryptococcal ortholog of neuronal calcium sensor 1 (Ncs1) as a member of the EF-hand superfamily. We demonstrated that Ncs1 has a role in Ca2+ homeostasis under stress and nonstress conditions, as the ncs1Δ mutant is sensitive to a high Ca2+ concentration and has an elevated basal Ca2+ level. Furthermore, NCS1 expression is induced by Ca2+, with the Ncs1 protein adopting a punctate subcellular distribution. We also demonstrate that, in contrast to the case with Saccharomyces cerevisiae, NCS1 expression in C. neoformans is regulated by the calcineurin pathway via the transcription factor Crz1, as NCS1 expression is reduced by FK506 treatment and CRZ1 deletion. Moreover, the ncs1Δ mutant shares a high temperature and high Ca2+ sensitivity phenotype with the calcineurin and calmodulin mutants (cna1Δ and cam1Δ), and the NCS1 promoter contains two calcineurin/Crz1-dependent response elements (CDRE1). Ncs1 deficiency coincided with reduced growth, characterized by delayed bud emergence and aberrant cell division, and hypovirulence in a mouse infection model. In summary, our data show that Ncs1 has a significant role as a Ca2+ sensor in C. neoformans, working with calcineurin to regulate Ca2+ homeostasis and, consequently, promote fungal growth and virulence.IMPORTANCECryptococcus neoformans is the major cause of fungal meningitis in HIV-infected patients. Several studies have highlighted the important contributions of Ca2+ signaling and homeostasis to the virulence of C. neoformans Here, we identify the cryptococcal ortholog of neuronal calcium sensor 1 (Ncs1) and demonstrate its role in Ca2+ homeostasis, bud emergence, cell cycle progression, and virulence. We also show that Ncs1 function is regulated by the calcineurin/Crz1 signaling cascade. Our work provides evidence of a link between Ca2+ homeostasis and cell cycle progression in C. neoformans.
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Affiliation(s)
- Eamim Daidrê Squizani
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre, Rio Grande do Sul, Brazil
| | | | - Sophie Lev
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Sydney, New South Wales, Australia
- Sydney Medical School-Westmead, University of Sydney, Sydney, New South Wales, Australia
- Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, New South Wales, Australia
| | - Heryk Motta
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre, Rio Grande do Sul, Brazil
| | - Julia Sperotto
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre, Rio Grande do Sul, Brazil
| | - Keren Kaufman-Francis
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Sydney, New South Wales, Australia
- Sydney Medical School-Westmead, University of Sydney, Sydney, New South Wales, Australia
- Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, New South Wales, Australia
| | - Desmarini Desmarini
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Sydney, New South Wales, Australia
- Sydney Medical School-Westmead, University of Sydney, Sydney, New South Wales, Australia
- Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, New South Wales, Australia
| | - Marilene Henning Vainstein
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre, Rio Grande do Sul, Brazil
| | - Charley Christian Staats
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre, Rio Grande do Sul, Brazil
| | - Julianne T Djordjevic
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Sydney, New South Wales, Australia
- Sydney Medical School-Westmead, University of Sydney, Sydney, New South Wales, Australia
- Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, New South Wales, Australia
| | - Lívia Kmetzsch
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre, Rio Grande do Sul, Brazil
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9
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Hayashi T, Oishi K, Kimura M, Iida K, Iida H. Highly conserved extracellular residues mediate interactions between pore-forming and regulatory subunits of the yeast Ca 2+ channel related to the animal VGCC/NALCN family. J Biol Chem 2020; 295:13008-13022. [PMID: 32690610 PMCID: PMC7489899 DOI: 10.1074/jbc.ra120.014378] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 07/14/2020] [Indexed: 12/23/2022] Open
Abstract
Yeasts and fungi generate Ca2+ signals in response to environmental stresses through Ca2+ channels essentially composed of Cch1 and Mid1. Cch1 is homologous to the pore-forming α1 subunit of animal voltage-gated Ca2+ channels (VGCCs) and sodium leak channels nonselective (NALCNs), whereas Mid1 is a membrane-associated protein similar to the regulatory α2/δ subunit of VGCCs and the regulatory subunit of NALCNs. Although the physiological roles of Cch1/Mid1 channels are known, their molecular regulation remains elusive, including subunit interactions regulating channel functionality. Herein, we identify amino acid residues involved in interactions between the pore-forming Cch1 subunit and the essential regulatory Mid1 subunit of Saccharomyces cerevisiae. In vitro mutagenesis followed by functional assays and co-immunoprecipitation experiments reveal that three residues present in a specific extracellular loop in the repeat III region of Cch1 are required for interaction with Mid1, and that one essential Mid1 residue is required for interaction with Cch1. Importantly, these residues are necessary for Ca2+ channel activity and are highly conserved in fungal and animal counterparts. We discuss that this unique subunit interaction-based regulatory mechanism for Cch1 differs from that of VGCCs/NALCNs.
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Affiliation(s)
- Takuto Hayashi
- Department of Biology, Tokyo Gakugei University, 4-1-1 Nukuikita-machi, Koganei, Tokyo, Japan
| | - Keita Oishi
- Department of Biology, Tokyo Gakugei University, 4-1-1 Nukuikita-machi, Koganei, Tokyo, Japan
| | - Midori Kimura
- Department of Biology, Tokyo Gakugei University, 4-1-1 Nukuikita-machi, Koganei, Tokyo, Japan
| | - Kazuko Iida
- Department of Biology, Tokyo Gakugei University, 4-1-1 Nukuikita-machi, Koganei, Tokyo, Japan; Laboratory of Biomembrane, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya, Tokyo, Japan
| | - Hidetoshi Iida
- Department of Biology, Tokyo Gakugei University, 4-1-1 Nukuikita-machi, Koganei, Tokyo, Japan.
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10
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Lange M, Peiter E. Calcium Transport Proteins in Fungi: The Phylogenetic Diversity of Their Relevance for Growth, Virulence, and Stress Resistance. Front Microbiol 2020; 10:3100. [PMID: 32047484 PMCID: PMC6997533 DOI: 10.3389/fmicb.2019.03100] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 12/20/2019] [Indexed: 12/26/2022] Open
Abstract
The key players of calcium (Ca2+) homeostasis and Ca2+ signal generation, which are Ca2+ channels, Ca2+/H+ antiporters, and Ca2+-ATPases, are present in all fungi. Their coordinated action maintains a low Ca2+ baseline, allows a fast increase in free Ca2+ concentration upon a stimulus, and terminates this Ca2+ elevation by an exponential decrease – hence forming a Ca2+ signal. In this respect, the Ca2+ signaling machinery is conserved in different fungi. However, does the similarity of the genetic inventory that shapes the Ca2+ peak imply that if “you’ve seen one, you’ve seen them all” in terms of physiological relevance? Individual studies have focused mostly on a single species, and mechanisms elucidated in few model organisms are usually extrapolated to other species. This mini-review focuses on the physiological relevance of the machinery that maintains Ca2+ homeostasis for growth, virulence, and stress responses. It reveals common and divergent functions of homologous proteins in different fungal species. In conclusion, for the physiological role of these Ca2+ transport proteins, “seen one,” in many cases, does not mean: “seen them all.”
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Affiliation(s)
- Mario Lange
- Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences, Faculty of Natural Sciences III, Martin Luther University of Halle-Wittenberg, Halle (Saale), Germany
| | - Edgar Peiter
- Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences, Faculty of Natural Sciences III, Martin Luther University of Halle-Wittenberg, Halle (Saale), Germany
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11
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Qian H, Chen Q, Zhang S, Lu L. The Claudin Family Protein FigA Mediates Ca 2+ Homeostasis in Response to Extracellular Stimuli in Aspergillus nidulans and Aspergillus fumigatus. Front Microbiol 2018; 9:977. [PMID: 29867880 PMCID: PMC5962676 DOI: 10.3389/fmicb.2018.00977] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 04/25/2018] [Indexed: 11/16/2022] Open
Abstract
The claudin family protein Fig1 is a unique fungal protein that is involved in pheromone-induced calcium influx and membrane fusion during the mating of Saccharomyces cerevisiae and Candida albicans. Whether and how Fig1 regulates Ca2+ homeostasis in response to extracellular stimuli is poorly understood. Previously, we found Aspergillus nidulans FigA, a homolog of Fig1 in S. cerevisiae, similar to the high-affinity calcium uptake system, is required for normal growth under low-Ca2+ minimal medium. In this study, using the calcium-sensitive photoprotein aequorin to monitor cytosolic free calcium concentration ([Ca2+]c) in living cells, we found that the FigA dysfunction decreases the transient [Ca2+]c induced by a high extracellular calcium stress. Furthermore, FigA acts synergistically with CchA (a high-affinity Ca2+ channel) to coordinate cytoplasmic Ca2+ influx in response to an extracellular Ca2+ stimulus. Moreover, FigA mediates ER stress-induced transient [Ca2+]c in the presence or absence of extracellular calcium. Most importantly, these [Ca2+]c responses mediated by FigA are closely related to its conserved claudin superfamily motif, which is also required for hyphal growth and asexual development in A. nidulans. Finally, the function of FigA in Aspergillus fumigatus, the most common airborne human fungal pathogen was studied. The result showed that the two FigA homologous in A. nidulans and A. fumigatus have a large degree of functional homology not only in asexual development but also in regulating transient [Ca2+]c. Our study expands the knowledge of claudin family protein FigA in Ca2+ homeostasis in response to extracellular stimuli.
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Affiliation(s)
- Hui Qian
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Qiuyi Chen
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Shizhu Zhang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Ling Lu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China
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12
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Truong M, Monahan LG, Carter DA, Charles IG. Repurposing drugs to fast-track therapeutic agents for the treatment of cryptococcosis. PeerJ 2018; 6:e4761. [PMID: 29740519 PMCID: PMC5937474 DOI: 10.7717/peerj.4761] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 04/21/2018] [Indexed: 12/21/2022] Open
Abstract
Many infectious diseases disproportionately affect people in the developing world. Cryptococcal meningitis is one of the most common mycoses in HIV-AIDS patients, with the highest burden of disease in sub-Saharan Africa. Current best treatment regimens still result in unacceptably high mortality rates, and more effective antifungal agents are needed urgently. Drug development is hampered by the difficulty of developing effective antifungal agents that are not also toxic to human cells, and by a reluctance among pharmaceutical companies to invest in drugs that cannot guarantee a high financial return. Drug repurposing, where existing drugs are screened for alternative activities, is becoming an attractive approach in antimicrobial discovery programs, and various compound libraries are now commercially available. As these drugs have already undergone extensive optimisation and passed regulatory hurdles this can fast-track their progress to market for new uses. This study screened the Screen-Well Enzo library of 640 compounds for candidates that phenotypically inhibited the growth of Cryptococcus deuterogattii. The anthelminthic agent flubendazole, and L-type calcium channel blockers nifedipine, nisoldipine and felodipine, appeared particularly promising and were tested in additional strains and species. Flubendazole was very active against all pathogenic Cryptococcus species, with minimum inhibitory concentrations of 0.039-0.156 μg/mL, and was equally effective against isolates that were resistant to fluconazole. While nifedipine, nisoldipine and felodipine all inhibited Cryptococcus, nisoldipine was also effective against Candida, Saccharomyces and Aspergillus. This study validates repurposing as a rapid approach for finding new agents to treat neglected infectious diseases.
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Affiliation(s)
- Megan Truong
- The ithree institute, University of Technology Sydney, Sydney, NSW, Australia
| | - Leigh G Monahan
- The ithree institute, University of Technology Sydney, Sydney, NSW, Australia
| | - Dee A Carter
- School of Life and Environmental Sciences and the Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, NSW, Australia
| | - Ian G Charles
- The ithree institute, University of Technology Sydney, Sydney, NSW, Australia.,Quadram Institute Bioscience, Norwich Research Park, Norwich, United Kingdom
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Squizani ED, Oliveira NK, Reuwsaat JCV, Marques BM, Lopes W, Gerber AL, de Vasconcelos ATR, Lev S, Djordjevic JT, Schrank A, Vainstein MH, Staats CC, Kmetzsch L. Cryptococcal dissemination to the central nervous system requires the vacuolar calcium transporter Pmc1. Cell Microbiol 2017; 20. [PMID: 29113016 DOI: 10.1111/cmi.12803] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 10/27/2017] [Accepted: 10/30/2017] [Indexed: 12/26/2022]
Abstract
Cryptococcus neoformans is a basidiomycetous yeast and the cause of cryptococcosis in immunocompromised individuals. The most severe form of the disease is meningoencephalitis, which is one of the leading causes of death in HIV/AIDS patients. In order to access the central nervous system, C. neoformans relies on the activity of certain virulence factors such as urease, which allows transmigration through the blood-brain barrier. In this study, we demonstrate that the calcium transporter Pmc1 enables C. neoformans to penetrate the central nervous system, because the pmc1 null mutant failed to infect and to survive within the brain parenchyma in a murine systemic infection model. To investigate potential alterations in transmigration pathways in these mutants, global expression profiling of the pmc1 mutant strain was undertaken, and genes associated with urease, the Ca2+ -calcineurin pathway, and capsule assembly were identified as being differentially expressed. Also, a decrease in urease activity was observed in the calcium transporter null mutants. Finally, we demonstrate that the transcription factor Crz1 regulates urease activity and that the Ca2+ -calcineurin signalling pathway positively controls the transcription of calcium transporter genes and factors related to transmigration.
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Affiliation(s)
| | | | | | | | - William Lopes
- Centro de Biotecnologia, UFRGS, Porto Alegre, RS, Brazil
| | - Alexandra L Gerber
- Laboratório Nacional de Computação Científica (LNCC), Petrópolis, RJ, Brazil
| | | | - Sophie Lev
- Fungal Pathogenesis Laboratory, Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Westmead, NSW, Australia
| | - Julianne T Djordjevic
- Fungal Pathogenesis Laboratory, Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Westmead, NSW, Australia
| | | | | | | | - Lívia Kmetzsch
- Centro de Biotecnologia, UFRGS, Porto Alegre, RS, Brazil
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Kim HS, Kim JE, Son H, Frailey D, Cirino R, Lee YW, Duncan R, Czymmek KJ, Kang S. Roles of three Fusarium graminearum membrane Ca 2+ channels in the formation of Ca 2+ signatures, growth, development, pathogenicity and mycotoxin production. Fungal Genet Biol 2017; 111:30-46. [PMID: 29175365 DOI: 10.1016/j.fgb.2017.11.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 11/11/2017] [Accepted: 11/15/2017] [Indexed: 02/06/2023]
Abstract
Similar to animals and plants, external stimuli cause dynamic spatial and temporal changes of cytoplasmic Ca2+ in fungi. Such changes are referred as the Ca2+ signature and control cellular responses by modulating the activity or location of diverse Ca2+-binding proteins (CBPs) and also indirectly affecting proteins that interact with CBPs. To understand the mechanism underpinning Ca2+ signaling, therefore, characterization of how Ca2+ moves to and from the cytoplasm to create Ca2+ signatures under different conditions is fundamental. Three genes encoding plasma membrane Ca2+ channels in a Fusarium graminearum strain that expresses a fluorescent protein-based Ca2+ indicator in the cytoplasm were mutagenized to investigate their roles in the generation of Ca2+ signatures under different growth conditions and genetic backgrounds. The genes disrupted include CCH1 and MID1, which encode a high affinity Ca2+ uptake system, and FIG1, encoding a low affinity Ca2+ channel. Resulting mutants were also analyzed for growth, development, pathogenicity and mycotoxin production to determine how loss of each of the genes alters these traits. To investigate whether individual genes influence the function and expression of other genes, phenotypes and Ca2+ signatures of their double and triple mutants, as well as their expression patterns, were analyzed.
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Affiliation(s)
- Hye-Seon Kim
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA; Delaware Biotechnology Institute, Newark, DE 19711, USA
| | - Jung-Eun Kim
- Department of Plant Pathology & Environmental Microbiology, Pennsylvania State University, University Park, PA 16802, USA
| | - Hokyoung Son
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Daniel Frailey
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Robert Cirino
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Yin-Won Lee
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Randall Duncan
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Kirk J Czymmek
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA; Delaware Biotechnology Institute, Newark, DE 19711, USA
| | - Seogchan Kang
- Department of Plant Pathology & Environmental Microbiology, Pennsylvania State University, University Park, PA 16802, USA.
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Hwu FY, Lai MW, Liou RF. PpMID1 Plays a Role in the Asexual Development and Virulence of Phytophthora parasitica. Front Microbiol 2017; 8:610. [PMID: 28469602 PMCID: PMC5395580 DOI: 10.3389/fmicb.2017.00610] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 03/27/2017] [Indexed: 01/01/2023] Open
Abstract
Phytophthora parasitica is a notorious oomycete pathogen that causes severe disease in a wide variety of crop species. Infection of plants involves mainly its asexual life stage, including papillate sporangia and biflagellated zoospores, which are the primary dispersal and infection agents of this pathogen. Calcium signaling has been thought as the key regulator for sporangium formation and zoospore differentiation. However, not much is known about the molecular players involved in these processes. In Saccharomyces cerevisiae, mating pheromone-induced death 1 (MID1) encodes a component of a putative calcium channel. Here, we identified and characterized the function of PpMID1, an MID1 homolog from P. parasitica. The expression of PpMID1 was high in sporangia. Gene silencing of PpMID1 resulted in the formation of sporangia that lacked papilla and showed a tendency for direct germination. Notably, in response to cold shock to induce zoospore formation, these sporangia showed no sign of cytoplasmic cleavage and thereby failed to form zoospores. Nonetheless, the addition of CaCl2 or MgCl2 partially recovered the silenced sporangia phenotype, with the formation of papillate sporangia similar to those of the wild type and the release of zoospores upon cold shock. As well, virulence toward Nicotiana benthamiana was reduced in the PpMID1-silenced transformants. These results indicate a role of PpMID1 in the asexual development and virulence of P. parasitica.
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Affiliation(s)
- Fang-Yu Hwu
- Department of Plant Pathology and Microbiology, National Taiwan UniversityTaipei, Taiwan
| | - Ming-Wei Lai
- Department of Plant Pathology and Microbiology, National Taiwan UniversityTaipei, Taiwan
| | - Ruey-Fen Liou
- Department of Plant Pathology and Microbiology, National Taiwan UniversityTaipei, Taiwan
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16
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Gupta P, Chanda R, Rai N, Kataria VK, Kumar N. Antihypertensive, Amlodipine Besilate Inhibits Growth and Biofilm of Human Fungal Pathogen Candida. Assay Drug Dev Technol 2016; 14:291-297. [DOI: 10.1089/adt.2016.714] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
- Payal Gupta
- Department of Biotechnology, Graphic Era University, Dehradun, India
| | - Reshmi Chanda
- Department of Microbiology, Shri Guru Ram Rai Institute of Medical and Health Sciences, Dehradun, India
| | - Nishant Rai
- Department of Biotechnology, Graphic Era University, Dehradun, India
| | - Vijay K. Kataria
- Department of Microbiology, Shri Guru Ram Rai Institute of Medical and Health Sciences, Dehradun, India
| | - Navin Kumar
- Department of Biotechnology, Graphic Era University, Dehradun, India
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Heat Stress Modulates Mycelium Growth, Heat Shock Protein Expression, Ganoderic Acid Biosynthesis, and Hyphal Branching of Ganoderma lucidum via Cytosolic Ca2. Appl Environ Microbiol 2016; 82:4112-4125. [PMID: 27129961 DOI: 10.1128/aem.01036-16] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 04/25/2016] [Indexed: 12/23/2022] Open
Abstract
UNLABELLED Heat stress (HS) influences the growth and development of organisms. Thus, a comprehensive understanding of how organisms sense HS and respond to it is required. Ganoderma lucidum, a higher basidiomycete with bioactive secondary metabolites, has become a potential model system due to the complete sequencing of its genome, transgenic systems, and reliable reverse genetic tools. In this study, we found that HS inhibited mycelium growth, reduced hyphal branching, and induced the accumulation of ganoderic acid biosynthesis and heat shock proteins (HSPs) in G. lucidum Our data showed that HS induced a significant increase in cytosolic Ca(2+) concentration. Further evidence showed that Ca(2+) might be a factor in the HS-mediated regulation of hyphal branching, ganoderic acid (GA) biosynthesis, and the accumulation of HSPs. Our results further showed that the calcium-permeable channel gene (cch)-silenced and phosphoinositide-specific phospholipase gene (plc)-silenced strains reduced the HS-induced increase in HSP expression compared with that observed for the wild type (WT). This study demonstrates that cytosolic Ca(2+) participates in heat shock signal transduction and regulates downstream events in filamentous fungi. IMPORTANCE Ganoderma lucidum, a higher basidiomycete with bioactive secondary metabolites, has become a potential model system for evaluating how environmental factors regulate the development and secondary metabolism of basidiomycetes. Heat stress (HS) is an important environmental challenge. In this study, we found that HS inhibited mycelium growth, reduced hyphal branching, and induced HSP expression and ganoderic acid biosynthesis in G. lucidum Further evidence showed that Ca(2+) might be a factor in the HS-mediated regulation of hyphal branching, GA biosynthesis, and the accumulation of HSPs. This study demonstrates that cytosolic Ca(2+) participates in heat shock signal transduction and regulates downstream events in filamentous fungi. Our research offers a new way to understand the mechanism underlying the physiological and metabolic responses to other environmental factors in G. lucidum This research may also provide the basis for heat shock signal transduction studies of other fungi.
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Lange M, Weihmann F, Schliebner I, Horbach R, Deising HB, Wirsel SGR, Peiter E. The Transient Receptor Potential (TRP) Channel Family in Colletotrichum graminicola: A Molecular and Physiological Analysis. PLoS One 2016; 11:e0158561. [PMID: 27359114 PMCID: PMC4928787 DOI: 10.1371/journal.pone.0158561] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 06/19/2016] [Indexed: 12/02/2022] Open
Abstract
Calcium (Ca2+) is a universal second messenger in all higher organisms and centrally involved in the launch of responses to environmental stimuli. Ca2+ signals in the cytosol are initiated by the activation of Ca2+ channels in the plasma membrane and/or in endomembranes. Yeast (Saccharomyces cerevisiae) contains a Ca2+-permeable channel of the TRP family, TRPY1, which is localized in the vacuolar membrane and contributes to cytosolic free Ca2+ ([Ca2+]cyt) elevations, for example in response to osmotic upshock. A TRPY1 homologue in the rice blast fungus is known to be important for growth and pathogenicity. To determine the role of the TRP channel family in the maize pathogen Colletotrichum graminicola, proteins homologous to TRPY1 were searched. This identified not one, but four genes in the C. graminicola genome, which had putative orthologs in other fungi, and which we named CgTRPF1 through 4. The topology of the CgTRPF proteins resembled that of TRPY1, albeit with a variable number of transmembrane (TM) domains additional to the six-TM-domain core and a diverse arrangement of putatively Ca2+-binding acidic motifs. All CgTRPF genes were expressed in axenic culture and throughout the infection of maize. Like TRPY1, all TRPF proteins of C. graminicola were localized intracellularly, albeit three of them were found not in large vacuoles, but co-localized in vesicular structures. Deletion strains for the CgTRPF genes were not altered in processes thought to involve Ca2+ release from internal stores, i.e. spore germination, the utilization of complex carbon sources, and the generation of tip-focussed [Ca2+]cyt spikes. Heterologous expression of CgTRPF1 through 4 in a tryp1Δ yeast mutant revealed that none of the channels mediated the release of Ca2+ in response to osmotic upshock. Accordingly, aequorin-based [Ca2+]cyt measurements of C. graminicola showed that in this fungus, osmotic upshock-triggered [Ca2+]cyt elevations were generated entirely by influx of Ca2+ from the extracellular space. Cgtrpf mutants did not show pathogenicity defects in leaf infection assays. In summary, our study reveals major differences between different fungi in the contribution of TRP channels to Ca2+-mediated signal transduction.
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Affiliation(s)
- Mario Lange
- Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences (IAEW), Faculty of Natural Sciences III, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
- Interdisciplinary Centre for Crop Plant Research (IZN), Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Fabian Weihmann
- Phytopathology and Plant Protection, Institute of Agricultural and Nutritional Sciences (IAEW), Faculty of Natural Sciences III, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Ivo Schliebner
- Phytopathology and Plant Protection, Institute of Agricultural and Nutritional Sciences (IAEW), Faculty of Natural Sciences III, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
- Interdisciplinary Centre for Crop Plant Research (IZN), Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Ralf Horbach
- Phytopathology and Plant Protection, Institute of Agricultural and Nutritional Sciences (IAEW), Faculty of Natural Sciences III, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
- Interdisciplinary Centre for Crop Plant Research (IZN), Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Holger B. Deising
- Phytopathology and Plant Protection, Institute of Agricultural and Nutritional Sciences (IAEW), Faculty of Natural Sciences III, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
- Interdisciplinary Centre for Crop Plant Research (IZN), Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Stefan G. R. Wirsel
- Phytopathology and Plant Protection, Institute of Agricultural and Nutritional Sciences (IAEW), Faculty of Natural Sciences III, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
- Interdisciplinary Centre for Crop Plant Research (IZN), Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Edgar Peiter
- Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences (IAEW), Faculty of Natural Sciences III, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
- Interdisciplinary Centre for Crop Plant Research (IZN), Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
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The Cch1-Mid1 High-Affinity Calcium Channel Contributes to the Virulence of Cryptococcus neoformans by Mitigating Oxidative Stress. EUKARYOTIC CELL 2015; 14:1135-43. [PMID: 26385891 DOI: 10.1128/ec.00100-15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 09/12/2015] [Indexed: 01/20/2023]
Abstract
Pathogenic fungi have developed mechanisms to cope with stresses imposed by hosts. For Cryptococcus spp., this implies active defense mechanisms that attenuate and ultimately overcome the onslaught of oxidative stresses in macrophages. Among cellular pathways within Cryptococcus neoformans' arsenal is the plasma membrane high-affinity Cch1-Mid1 calcium (Ca(2+)) channel (CMC). Here we show that CMC has an unexpectedly complex and disparate role in mitigating oxidative stress. Upon inhibiting the Ccp1-mediated oxidative response pathway with antimycin, strains of C. neoformans expressing only Mid1 displayed enhanced growth, but this was significantly attenuated upon H2O2 exposure in the absence of Mid1, suggesting a regulatory role for Mid1 acting through the Ccp1-mediated oxidative stress response. This notion is further supported by the interaction detected between Mid1 and Ccp1 (cytochrome c peroxidase). In contrast, Cch1 appears to have a more general role in promoting cryptococci survival during oxidative stress. A strain lacking Cch1 displayed a growth defect in the presence of H2O2 without BAPTA [(1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid, cesium salt] or additional stressors such as antimycin. Consistent with a greater contribution of Cch1 to oxidative stress tolerance, an intracellular growth defect was observed for the cch1Δ strain in the macrophage cell line J774A.1. Interestingly, while the absence of either Mid1 or Cch1 significantly compromises the ability of C. neoformans to tolerate oxidative stress, the absence of both Mid1 and Cch1 has a negligible effect on C. neoformans growth during H2O2 stress, suggesting the existence of a compensatory mechanism that becomes active in the absence of CMC.
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Wang Y, Wang J, Cheng J, Xu D, Jiang L. Genetic interactions between the Golgi Ca2+/H+ exchanger Gdt1 and the plasma membrane calcium channel Cch1/Mid1 in the regulation of calcium homeostasis, stress response and virulence in Candida albicans. FEMS Yeast Res 2015. [PMID: 26208803 DOI: 10.1093/femsyr/fov069] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The Golgi-localized Saccharomyces cerevisiae ScGdt1 is a member of the cation/Ca(2+) exchanger superfamily. We show here that Candida albicans CaGdt1 is the functional homolog of ScGdt1 in calcium sensitivity, and shows genetic interactions with CaCch1 or CaMid1 in response to ER stresses. In addition, similar to ScCCH1 and ScMID1, deletion of either CaCCH1 or CaMID1 leads to a growth sensitivity of cells to cold stress, which can be suppressed by deletion of CaGDT1. Furthermore, deletion of CaCCH1 leads to a severe delay in filamentation of C. albicans cells, and this defect is abolished by deletion of CaGDT1. In contrast, CaGDT1 does not show genetic interaction with CaMID1 in filamentation. Interestingly, C. albicans cells lacking both CaMID1 and CaGDT1 exhibit an intermediate virulence between C. albicans cells lacking CaCCH1 (non-virulent) and C. albicans cells lacking CaGDT1 (partially virulent), while C. albicans cells lacking both CaCCH1 and CaGDT1 are not virulent in a mouse model of systemic candidiasis. Therefore, CaGdt1 genetically interacts with the plasma membrane calcium channel, CaCch1/CaMid1, in the response of C. albicans cells to cold and ER stresses and antifungal drug challenge as well as in filamentation and virulence.
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Affiliation(s)
- Yanan Wang
- The National Engineering Laboratory for Cereal Fermentation Technology, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Junjun Wang
- The National Engineering Laboratory for Cereal Fermentation Technology, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Jianqing Cheng
- School of Medicine, Jiangnan University, Wuxi 214122, China
| | - Dayong Xu
- The National Engineering Laboratory for Cereal Fermentation Technology, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Linghuo Jiang
- The National Engineering Laboratory for Cereal Fermentation Technology, School of Biotechnology, Jiangnan University, Wuxi 214122, China
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Components of the calcium-calcineurin signaling pathway in fungal cells and their potential as antifungal targets. EUKARYOTIC CELL 2015; 14:324-34. [PMID: 25636321 DOI: 10.1128/ec.00271-14] [Citation(s) in RCA: 119] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
In recent years, the emergence of fungal resistance has become frequent, partly due to the widespread clinical use of fluconazole, which is minimally toxic and effective in the prevention and treatment of Candida albicans infections. The limited selection of antifungal drugs for clinical fungal infection therapy has prompted us to search for new antifungal drug targets. Calcium, which acts as the second messenger in both mammals and fungi, plays a direct role in controlling the expression patterns of its signaling systems and has important roles in cell survival. In addition, calcium and some of the components, mainly calcineurin, in the fungal calcium signaling pathway mediate fungal resistance to antifungal drugs. Therefore, an overview of the components of the fungal calcium-calcineurin signaling network and their potential roles as antifungal targets is urgently needed. The calcium-calcineurin signaling pathway consists of various channels, transporters, pumps, and other proteins or enzymes. Many transcriptional profiles have indicated that mutant strains that lack some of these components are sensitized to fluconazole or other antifungal drugs. In addition, many researchers have identified efficient compounds that exhibit antifungal activity by themselves or in combination with antifungal drugs by targeting some of the components in the fungal calcium-calcineurin signaling pathway. This targeting disrupts Ca(2+) homeostasis, which suggests that this pathway contains potential targets for the development of new antifungal drugs.
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de Castro PA, Chiaratto J, Winkelströter LK, Bom VLP, Ramalho LNZ, Goldman MHS, Brown NA, Goldman GH. The involvement of the Mid1/Cch1/Yvc1 calcium channels in Aspergillus fumigatus virulence. PLoS One 2014; 9:e103957. [PMID: 25083783 PMCID: PMC4118995 DOI: 10.1371/journal.pone.0103957] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Accepted: 07/03/2014] [Indexed: 11/30/2022] Open
Abstract
Aspergillus fumigatus is a major opportunistic pathogen and allergen of mammals. Calcium homeostasis and signaling is essential for numerous biological processes and also influences A. fumigatus pathogenicity. The presented study characterized the function of the A. fumigatus homologues of three Saccharomyces cerevisiae calcium channels, voltage-gated Cch1, stretch-activated Mid1 and vacuolar Yvc1. The A. fumigatus calcium channels cchA, midA and yvcA were regulated at transcriptional level by increased calcium levels. The YvcA::GFP fusion protein localized to the vacuoles. Both ΔcchA and ΔmidA mutant strains showed reduced radial growth rate in nutrient-poor minimal media. Interestingly, this growth defect in the ΔcchA strain was rescued by the exogenous addition of CaCl2. The ΔcchA, ΔmidA, and ΔcchA ΔmidA strains were also sensitive to the oxidative stress inducer, paraquat. Restriction of external Ca2+ through the addition of the Ca2+-chelator EGTA impacted upon the growth of the ΔcchA and ΔmidA strains. All the A. fumigatus ΔcchA, ΔmidA, and ΔyvcA strains demonstrated attenuated virulence in a neutropenic murine model of invasive pulmonary aspergillosis. Infection with the parental strain resulted in a 100% mortality rate at 15 days post-infection, while the mortality rate of the ΔcchA, ΔmidA, and ΔyvcA strains after 15 days post-infection was only 25%. Collectively, this investigation strongly indicates that CchA, MidA, and YvcA play a role in A. fumigatus calcium homeostasis and virulence.
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Affiliation(s)
- Patrícia Alves de Castro
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Jéssica Chiaratto
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Lizziane K. Winkelströter
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Vinícius Leite Pedro Bom
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | | | - Maria Helena S. Goldman
- Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Neil Andrew Brown
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Gustavo H. Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
- National Laboratory of Science and Technology of Bioethanol (CTBE), Campinas, Brazil
- * E-mail:
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Roberts SK, McAinsh M, Cantopher H, Sandison S. Calcium dependence of eugenol tolerance and toxicity in Saccharomyces cerevisiae. PLoS One 2014; 9:e102712. [PMID: 25036027 PMCID: PMC4103870 DOI: 10.1371/journal.pone.0102712] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 06/21/2014] [Indexed: 11/18/2022] Open
Abstract
Eugenol is a plant-derived phenolic compound which has recognised therapeutical potential as an antifungal agent. However little is known of either its fungicidal activity or the mechanisms employed by fungi to tolerate eugenol toxicity. A better exploitation of eugenol as a therapeutic agent will therefore depend on addressing this knowledge gap. Eugenol initiates increases in cytosolic Ca2+ in Saccharomyces cerevisiae which is partly dependent on the plasma membrane calcium channel, Cch1p. However, it is unclear whether a toxic cytosolic Ca2+elevation mediates the fungicidal activity of eugenol. In the present study, no significant difference in yeast survival was observed following transient eugenol treatment in the presence or absence of extracellular Ca2+. Furthermore, using yeast expressing apoaequorin to report cytosolic Ca2+ and a range of eugenol derivatives, antifungal activity did not appear to be coupled to Ca2+ influx or cytosolic Ca2+ elevation. Taken together, these results suggest that eugenol toxicity is not dependent on a toxic influx of Ca2+. In contrast, careful control of extracellular Ca2+ (using EGTA or BAPTA) revealed that tolerance of yeast to eugenol depended on Ca2+ influx via Cch1p. These findings expose significant differences between the antifungal activity of eugenol and that of azoles, amiodarone and carvacrol. This study highlights the potential to use eugenol in combination with other antifungal agents that exhibit differing modes of action as antifungal agents to combat drug resistant infections.
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Affiliation(s)
- Stephen K. Roberts
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, United Kingdom
- * E-mail:
| | - Martin McAinsh
- Lancaster Environment Centre, Lancaster University, Lancaster, United Kingdom
| | - Hanna Cantopher
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, United Kingdom
| | - Sean Sandison
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, United Kingdom
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24
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Jiang H, Shen Y, Liu W, Lu L. Deletion of the putative stretch-activated ion channel Mid1 is hypervirulent in Aspergillus fumigatus. Fungal Genet Biol 2014; 62:62-70. [DOI: 10.1016/j.fgb.2013.11.003] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Revised: 11/04/2013] [Accepted: 11/07/2013] [Indexed: 12/22/2022]
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25
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Alber J, Jiang L, Geyer J. CaRch1p does not functionally interact with the high-affinity Ca(2+) influx system (HACS) of Candida albicans. Yeast 2013; 30:449-57. [PMID: 24123457 DOI: 10.1002/yea.2981] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 09/06/2013] [Accepted: 09/16/2013] [Indexed: 11/09/2022] Open
Abstract
The plasma membrane protein CaRch1p of Candida albicans, homologous to the human solute carrier protein SLC10A7, is involved in the regulation of calcium homeostasis. C. albicans cells lacking CaRCH1 are hypersensitive to high extracellular Ca(2+) concentrations and show increased tolerance to ketoconazole (KCZ). We assume a higher basal Ca(2+) influx in the rch1/rch1 mutant strain at low extracellular Ca(2+) concentrations, which is not detrimental to C. albicans cells but may be sufficient to activate calcineurin, finally resulting in an increased tolerance to KCZ. However, at 8 µg/ml KCZ plus 3 mm Ca(2+) the rch1/rch1 mutant and the wild-type strains showed identical growth. By further increasing the Ca(2+) concentration to 30 mm, this phenotype was completely reversed and the rch1/rch1 mutant strain became extremely sensitive to 8 µg/ml KCZ, probably due to synergistic toxic effects of Ca(2+) and KCZ under these conditions. Furthermore, we aimed to clarify whether CaRch1p interacts with the Cch1p component of the voltage-gated calcium influx channel Cch1p/Mid1p in C. albicans cells. As disruption of the two alleles of CCH1 in the rch1/rch1 mutant strain did not alter its hypersensitivity to high extracellular Ca(2+) , and as this phenotype was completely abolished by low amounts of Mg(2+) in the rch1/rch1 mutant as well as in the cch1/cch1 rch1/rch1 double mutant, we conclude that CaRch1p is a functional component of the low-affinity calcium uptake system (LACS) system and does not functionally interact with Cch1p.
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Affiliation(s)
- Joerg Alber
- Institute of Pharmacology and Toxicology, Justus Liebig University of Giessen, Germany
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26
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Kmetzsch L, Staats CC, Cupertino JB, Fonseca FL, Rodrigues ML, Schrank A, Vainstein MH. The calcium transporter Pmc1 provides Ca2+ tolerance and influences the progression of murine cryptococcal infection. FEBS J 2013; 280:4853-64. [PMID: 23895559 DOI: 10.1111/febs.12458] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 07/15/2013] [Accepted: 07/26/2013] [Indexed: 01/14/2023]
Abstract
The Ca(2+)-calcineurin signaling pathway in the human fungal pathogen Cryptococcus neoformans is essential for adaptation to the host environment during infection. Calcium transporters regulate cytosolic calcium concentrations, providing Ca(2+) loading into storage organelles. The three calcium transporters that have been characterized in C. neoformans, Cch1, Eca1 and Vcx1, are required for fungal virulence, supporting a role for calcium-mediated signaling in cryptococcal pathogenesis. In the present study, we report the functional characterization of the putative vacuolar calcium ATPase Pmc1 in C. neoformans. Our results demonstrate that Pmc1 provides tolerance to high Ca(2+) concentrations. The double knockout of C. neoformans PMC1 and VCX1 genes impaired the intracellular calcium transport, resulting in a significant increase in cytosolic calcium levels. Furthermore, Pmc1 was essential for both the progression of pulmonary infection and brain colonization in mice, emphasizing the crucial role of calcium signaling and transport for cryptococcal pathogenesis.
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Affiliation(s)
- Livia Kmetzsch
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Brazil
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27
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Troppens DM, Chu M, Holcombe LJ, Gleeson O, O'Gara F, Read ND, Morrissey JP. The bacterial secondary metabolite 2,4-diacetylphloroglucinol impairs mitochondrial function and affects calcium homeostasis in Neurospora crassa. Fungal Genet Biol 2013; 56:135-46. [PMID: 23624246 DOI: 10.1016/j.fgb.2013.04.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Revised: 03/25/2013] [Accepted: 04/12/2013] [Indexed: 10/26/2022]
Abstract
The bacterial secondary metabolite 2,4-diacetylphloroglucinol (DAPG) is of interest as an active ingredient of biological control strains of Pseudomonas fluorescens and as a potential lead pharmaceutical molecule because of its capacity to inhibit growth of diverse microbial and non-microbial cells. The mechanism by which this occurs is unknown and in this study the filamentous fungus Neurospora crassa was used as a model to investigate the effects of DAPG on a eukaryotic cell. Colony growth, conidial germination and cell fusion assays confirmed the inhibitory nature of DAPG towards N. crassa. A number of different fluorescent dyes and fluorescent protein reporters were used to assess the effects of DAPG treatment on mitochondrial and other cellular functions. DAPG treatment led to changes in mitochondrial morphology, and rapid loss of mitochondrial membrane potential. These effects are likely to be responsible for the toxicity of DAPG. It was also found that DAPG treatment caused extracellular calcium to be taken up by conidial germlings leading to a transient increase in cytosolic free Ca(2+) with a distinct concentration dependent Ca(2+) signature.
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28
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Cch1 and Mid1 are functionally required for vegetative growth under low-calcium conditions in the phytopathogenic ascomycete Botrytis cinerea. EUKARYOTIC CELL 2013; 12:712-24. [PMID: 23475703 DOI: 10.1128/ec.00338-12] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
In the filamentous phytopathogen Botrytis cinerea, the Ca(2+)/calcineurin signaling cascade has been shown to play an important role in fungal growth, differentiation, and virulence. This study deals with the functional characterization of two components of this pathway, the putative calcium channel proteins Cch1 and Mid1. The cch1 and mid1 genes were deleted, and single and double knockout mutants were analyzed during different stages of the fungal life cycle. Our data indicate that Cch1 and Mid1 are functionally required for vegetative growth under conditions of low extracellular calcium, since the growth of both deletion mutants is strongly impaired when they are exposed to the Ca(2+)-chelating agents EGTA and 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA). The impact of external Ca(2+) was investigated by supplementing with CaCl(2) and the ionophore A23187, both of which resulted in elevated growth for all mutants. However, deletion of either gene had no impact on germination, sporulation, hyphal morphology, or virulence. By use of the aequorin reporter system to measure intracellular calcium levels, no differences between the mutant strains and the wild type were obtained. Localization studies revealed a subcellular distribution of the Mid1-green fluorescent protein (GFP) fusion protein in network-like filaments, probably the endoplasmic reticulum (ER) membranes, indicating that Mid1 is not a plasma membrane-located calcium channel in B. cinerea.
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29
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Activity of the calcium channel pore Cch1 is dependent on a modulatory region of the subunit Mid1 in Cryptococcus neoformans. EUKARYOTIC CELL 2012; 12:142-50. [PMID: 23175710 DOI: 10.1128/ec.00130-12] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Calcium (Ca(2+))-mediated signaling events in fungal pathogens such as Cryptococcus neoformans are central to physiological processes, including those that mediate stress responses and promote virulence. The Cch1-Mid1 channel (CMC) represents the only high-affinity Ca(2+) channel in the plasma membrane of fungal cells; consequently, cryptococci cannot survive in low-Ca(2+) environments in the absence of CMC. Previous electrophysiological characterization revealed that Cch1, the predicted channel pore, and Mid1, a binding partner of Cch1, function as a store-operated Ca(2+)-selective channel gated by depletion of endoplasmic reticulum (ER) Ca(2+) stores. Cryptococci lacking CMC did not survive ER stress, indicating its critical role in restoring Ca(2+) homeostasis. Despite the requirement for Mid1 in promoting Ca(2+) influx via Cch1, identification of the role of Mid1 remains elusive. Here we show that the C-terminal tail of Mid1 is a modulatory region that impinges on Cch1 channel activity directly and mediates the trafficking of Mid1 to the plasma membrane. This region consists of the last 24 residues of Mid1, and the functional expression of Mid1 in a human embryonic cell line (HEK293) and in C. neoformans is dependent on this domain. Substitutions of arginine (R619A) or cysteine (C621A) in the modulatory region failed to target Mid1 to the plasma membrane and prevented CMC activity. Interestingly, loss of a predicted protein kinase C (PKC)-phosphorylated serine residue (S605A) had no effect on Mid1 trafficking but did alter the kinetics of Cch1 channel activity. Thus, establishment of Ca(2+) homeostasis in C. neoformans is dependent on a modulatory domain of Mid1.
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30
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Kubitschek-Barreira PH, Curty N, Neves GWP, Gil C, Lopes-Bezerra LM. Differential proteomic analysis of Aspergillus fumigatus morphotypes reveals putative drug targets. J Proteomics 2012; 78:522-34. [PMID: 23128298 DOI: 10.1016/j.jprot.2012.10.022] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 10/01/2012] [Accepted: 10/25/2012] [Indexed: 10/27/2022]
Abstract
Aspergillus fumigatus is the main etiological agent of invasive aspergillosis, an important opportunistic infection for neutropenic patients. The main risk groups are patients with acute leukemia and bone marrow transplantation recipients. The lack of an early diagnostic test together with the limited spectrum of antifungal drugs remains a setback to the successful treatment of this disease. During invasive infection the inhaled fungal conidia enter the morphogenic cycle leading to angioinvasive hyphae. This work aimed to study differentially expressed proteins of A. fumigatus during morphogenesis. To achieve this goal, a 2D-DIGE approach was applied to study surface proteins extractable by reducing agents of two A. fumigatus morphotypes: germlings and hyphae. Sixty-three differentially expressed proteins were identified by MALDI-ToF/MS. We observed that proteins associated with biosynthetic pathways and proteins with multiple functions (miscellaneous) were over-expressed in the early stages of germination, while in hyphae, the most abundant proteins detected were related to metabolic processes or have unknown functions. Among the most interesting proteins regulated during morphogenesis, two putative drug targets were identified, the translational factor, eEF3 and the CipC-like protein. Neither of these proteins are present in mammalian cells.
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Affiliation(s)
- Paula H Kubitschek-Barreira
- Laboratório de Micologia Celular e Proteômica, Instituto de Biologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil
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31
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Wang S, Cao J, Liu X, Hu H, Shi J, Zhang S, Keller NP, Lu L. Putative calcium channels CchA and MidA play the important roles in conidiation, hyphal polarity and cell wall components in Aspergillus nidulans. PLoS One 2012; 7:e46564. [PMID: 23071589 PMCID: PMC3470553 DOI: 10.1371/journal.pone.0046564] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Accepted: 08/31/2012] [Indexed: 11/25/2022] Open
Abstract
Although the high affinity Ca2+ channel, Cch1, and its subunit Mid1 have been investigated and evaluated in yeast and some of filamentous fungi, little is known about the function of their homologs in the Aspergilli. Here, we have functionally characterized the yeast homologs, CchA and MidA, in Aspergillus nidulans using conditional and null deletion mutants. CchA and MidA not only have functional benefits of fast growth, which is consistent with Cch1 and Mid1 in yeast, but also have unique and complex roles in regulating conidiation, hyphal polarity and cell wall components in low-calcium environments. The defect of CchA or MidA resulted in a sharp reduction in the number of conidiospores, accompanied by abnormal metulae, and undeveloped-phialides at a higher density of inoculum. Most interestingly, these conidiation defects in mutants can, remarkably, be rescued either by extra-cellular Ca2+ in a calcineurin-dependent way or by osmotic stress in a calcineurin-independent way. Moreover, the fact that the phenotypic defects are not exacerbated by the presence of the double deletion, together with the Y2H assay, indicates that CchA and MidA may form a complex to function together. Our findings suggest that the high-affinity Ca2+ channel may represent a viable and completely unexplored avenue to reduce conidiation in the Aspergilli.
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Affiliation(s)
- Sha Wang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences; Nanjing Normal University, Nanjing, China
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32
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Roberts SK, McAinsh M, Widdicks L. Cch1p mediates Ca2+ influx to protect Saccharomyces cerevisiae against eugenol toxicity. PLoS One 2012; 7:e43989. [PMID: 23028482 PMCID: PMC3441571 DOI: 10.1371/journal.pone.0043989] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Accepted: 07/27/2012] [Indexed: 11/19/2022] Open
Abstract
Eugenol has antifungal activity and is recognised as having therapeutic potential. However, little is known of the cellular basis of its antifungal activity and a better understanding of eugenol tolerance should lead to better exploitation of eugenol in antifungal therapies. The model yeast, Saccharomyces cerevisiae, expressing apoaequorin was used to show that eugenol induces cytosolic Ca2+ elevations. We investigated the eugenol Ca2+ signature in further detail and show that exponentially growing cells exhibit Ca2+ elevation resulting exclusively from the influx of Ca2+ across the plasma membrane whereas in stationary growth phase cells Ca2+ influx from intracellular and extracellular sources contribute to the eugenol-induced Ca2+ elevation. Ca2+ channel deletion yeast mutants were used to identify the pathways mediating Ca2+ influx; intracellular Ca2+ release was mediated by the vacuolar Ca2+ channel, Yvc1p, whereas the Ca2+ influx across the plasma membrane could be resolved into Cch1p-dependent and Cch1p-independent pathways. We show that the growth of yeast devoid the plasma membrane Ca2+ channel, Cch1p, was hypersensitive to eugenol and that this correlated with reduced Ca2+ elevations. Taken together, these results indicate that a cch1p-mediated Ca2+ influx is part of an intracellular signal which protects against eugenol toxicity. This study provides fresh insight into the mechanisms employed by fungi to tolerate eugenol toxicity which should lead to better exploitation of eugenol in antifungal therapies.
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Affiliation(s)
- Stephen K Roberts
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, United Kingdom.
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33
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Yu Q, Wang H, Cheng X, Xu N, Ding X, Xing L, Li M. Roles of Cch1 and Mid1 in morphogenesis, oxidative stress response and virulence in Candida albicans. Mycopathologia 2012; 174:359-69. [PMID: 22886468 DOI: 10.1007/s11046-012-9569-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Accepted: 07/18/2012] [Indexed: 12/21/2022]
Abstract
Ca(2+) channel Cch1, and its subunit Mid1, has been suggested as the protein complex responsible for mediating Ca(2+) influx, which is often employed by fungal cells to maintain cell survival. The abilities of morphological switch and response to stress conditions are closely related to pathogenicity in Candida albicans. Cch1 and Mid1 activity are required for virulence of Cryptococcus neoformans and Claviceps purpurea, respectively. To investigate whether Cch1 and Mid1 also play a role in the virulence of C. albicans, we constructed cch1Δ/Δ and mid1Δ/Δ mutant strains for functional analysis of CCH1 and MID1. Although both of the mutants displayed the ability of yeast-to-hypha transition, they were defective in hyphae maintenance and invasive growth. Interestingly, deletion of CCH1 or MID1 in C. albicans led to an obvious defect phenotype in oxidative stress response. Moreover, the virulence of the mutants was reduced in a mouse model. Our results demonstrated that Cch1 and Mid1 activity are related to the virulence of C. albicans and may provide a new antifungal target.
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Affiliation(s)
- Qilin Yu
- College of Life Science, Nankai Universitdy, Tianjin 300071, China
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34
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Prole DL, Taylor CW. Identification and analysis of cation channel homologues in human pathogenic fungi. PLoS One 2012; 7:e42404. [PMID: 22876320 PMCID: PMC3410928 DOI: 10.1371/journal.pone.0042404] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Accepted: 07/05/2012] [Indexed: 01/08/2023] Open
Abstract
Fungi are major causes of human, animal and plant disease. Human fungal infections can be fatal, but there are limited options for therapy, and resistance to commonly used anti-fungal drugs is widespread. The genomes of many fungi have recently been sequenced, allowing identification of proteins that may become targets for novel therapies. We examined the genomes of human fungal pathogens for genes encoding homologues of cation channels, which are prominent drug targets. Many of the fungal genomes examined contain genes encoding homologues of potassium (K+), calcium (Ca2+) and transient receptor potential (Trp) channels, but not sodium (Na+) channels or ligand-gated channels. Some fungal genomes contain multiple genes encoding homologues of K+ and Trp channel subunits, and genes encoding novel homologues of voltage-gated Kv channel subunits are found in Cryptococcus spp. Only a single gene encoding a homologue of a plasma membrane Ca2+ channel was identified in the genome of each pathogenic fungus examined. These homologues are similar to the Cch1 Ca2+ channel of Saccharomyces cerevisiae. The genomes of Aspergillus spp. and Cryptococcus spp., but not those of S. cerevisiae or the other pathogenic fungi examined, also encode homologues of the mitochondrial Ca2+ uniporter (MCU). In contrast to humans, which express many K+, Ca2+ and Trp channels, the genomes of pathogenic fungi encode only very small numbers of K+, Ca2+ and Trp channel homologues. Furthermore, the sequences of fungal K+, Ca2+, Trp and MCU channels differ from those of human channels in regions that suggest differences in regulation and susceptibility to drugs.
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Affiliation(s)
- David L Prole
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, United Kingdom.
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35
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Liebeskind BJ, Hillis DM, Zakon HH. Phylogeny unites animal sodium leak channels with fungal calcium channels in an ancient, voltage-insensitive clade. Mol Biol Evol 2012; 29:3613-6. [PMID: 22821012 DOI: 10.1093/molbev/mss182] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Proteins in the superfamily of voltage-gated ion channels mediate behavior across the tree of life. These proteins regulate the movement of ions across cell membranes by opening and closing a central pore that controls ion flow. The best-known members of this superfamily are the voltage-gated potassium, calcium (Ca(v)), and sodium (Na(v)) channels, which underlie impulse conduction in nerve and muscle. Not all members of this family are opened by changes in voltage, however. NALCN (NA(+) leak channel nonselective) channels, which encode a voltage-insensitive "sodium leak" channel, have garnered a growing interest. This study examines the phylogenetic relationship among Na(v)/Ca(v) voltage-gated and voltage-insensitive channels in the eukaryotic group Opisthokonta, which includes animals, fungi, and their unicellular relatives. We show that NALCN channels diverged from voltage-gated channels before the divergence of fungi and animals and that the closest relatives of NALCN channels are fungal calcium channels, which they functionally resemble.
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Affiliation(s)
- Benjamin J Liebeskind
- Section of Integrative Biology and Center for Computational Biology and Bioinformatics, University of Texas, USA.
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36
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Kmetzsch L, Staats CC, Rodrigues ML, Schrank A, Vainstein MH. Calcium signaling components in the human pathogen: Cryptococcus neoformans. Commun Integr Biol 2011; 4:186-7. [PMID: 21655435 DOI: 10.4161/cib.4.2.14271] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2010] [Accepted: 11/22/2010] [Indexed: 11/19/2022] Open
Abstract
Calcium signaling through calmodulin and the phosphatase calcineurin are required for key events of the biology of the human pathogen Cryptococcus neoformans, including mating, morphogenesis, growth at 37°C and virulence. In a recent work we described the functional characterization of a new component of this calcium signaling network: the vacuolar calcium exchanger Vcx1. This transporter is involved in calcium tolerance and virulence in C. neoformans. Two other uncharacterized calcium transporters which are putative orthologs of Saccharomyces cerevisiae PMC1 (a vacuolar calcium ATPase) and PMR1 (a Golgi calcium ATPase) are also functional in C. neoformans. No ortholog of CRZ1, the target of calcineurin in other fungi, has been identified in C. neoformans, indicating a high complexity in cryptococcal calcium-related pathways. Future studies are necessary for the complete understanding of calcium signaling regulation in C. neoformans.
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Affiliation(s)
- Livia Kmetzsch
- Centro de Biotecnologia; Universidade Federal do Rio Grande do Sul; Porto Alegre, RS, Brazil
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37
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Martin DC, Kim H, Mackin NA, Maldonado-Báez L, Evangelista CC, Beaudry VG, Dudgeon DD, Naiman DQ, Erdman SE, Cunningham KW. New regulators of a high affinity Ca2+ influx system revealed through a genome-wide screen in yeast. J Biol Chem 2011; 286:10744-54. [PMID: 21252230 DOI: 10.1074/jbc.m110.177451] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The bakers' yeast Saccharomyces cerevisiae utilizes a high affinity Ca(2+) influx system (HACS) to survive assaults by mating pheromones, tunicamycin, and azole-class antifungal agents. HACS consists of two known subunits, Cch1 and Mid1, that are homologous and analogous to the catalytic α-subunits and regulatory α2δ-subunits of mammalian voltage-gated calcium channels, respectively. To search for additional subunits and regulators of HACS, a collection of gene knock-out mutants was screened for abnormal uptake of Ca(2+) after exposure to mating pheromone or to tunicamycin. The screen revealed that Ecm7 is required for HACS function in most conditions. Cycloheximide chase experiments showed that Ecm7 was stabilized by Mid1, and Mid1 was stabilized by Cch1 in non-signaling conditions, suggesting they all interact. Ecm7 is a member of the PMP-22/EMP/MP20/Claudin superfamily of transmembrane proteins that includes γ-subunits of voltage-gated calcium channels. Eleven additional members of this superfamily were identified in yeast, but none was required for HACS activity in response to the stimuli. Remarkably, many dozens of genes involved in vesicle-mediated trafficking and protein secretion were required to prevent spontaneous activation of HACS. Taken together, the findings suggest that HACS and calcineurin monitor performance of the membrane trafficking system in yeasts and coordinate compensatory processes. Conservation of this quality control system in Candida glabrata suggests that many pathogenic species of fungi may utilize HACS and calcineurin to resist azoles and other compounds that target membrane biosynthesis.
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Affiliation(s)
- D Christian Martin
- Department of Biology, Johns Hopkins University, Baltimore, Maryland 21218, USA
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The vacuolar Ca²(+) exchanger Vcx1 is involved in calcineurin-dependent Ca²(+) tolerance and virulence in Cryptococcus neoformans. EUKARYOTIC CELL 2010; 9:1798-805. [PMID: 20889719 DOI: 10.1128/ec.00114-10] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Cryptococcus neoformans is an encapsulated yeast that causes a life-threatening meningoencephalitis in immunocompromised individuals. The ability to survive and proliferate at the human body temperature is an essential virulence attribute of this pathogen. This trait is controlled in part by the Ca²(+)-calcineurin pathway, which senses and utilizes cytosolic calcium for signaling. In the present study, the identification of the C. neoformans gene VCX1, which encodes a vacuolar calcium exchanger, is reported. The VCX1 knockout results in hypersensitivity to the calcineurin inhibitor cyclosporine A at 35°C, but not at 30°C. Furthermore, high concentrations of CaCl₂ lead to growth inhibition of the vcx1 mutant strain only in the presence of cyclosporine A, indicating that Vcx1 acts in parallel with calcineurin. The loss of VCX1 does not influence cell wall integrity or capsule size but decreases secretion of the major capsular polysaccharide glucuronoxylomannan (GXM) in culture supernatants.Vcx1 also influences C. neoformans phagocytosis by murine macrophages and is required for full virulence in mice. Analysis of cellular distribution by confocal microscopy confirmed the vacuolar localization of Vcx1 in C. neoformans cells.
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40
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Gamarra S, Rocha EMF, Zhang YQ, Park S, Rao R, Perlin DS. Mechanism of the synergistic effect of amiodarone and fluconazole in Candida albicans. Antimicrob Agents Chemother 2010; 54:1753-61. [PMID: 20194694 PMCID: PMC2863688 DOI: 10.1128/aac.01728-09] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2009] [Revised: 01/29/2010] [Accepted: 02/20/2010] [Indexed: 11/20/2022] Open
Abstract
The antiarrhythmic drug amiodarone has been found to have fungicidal activity. In Saccharomyces cerevisiae, its antifungal activity is mediated by calcium overload stress, which leads to a rapid nuclear accumulation of the calcineurin-regulated transcription factor CRZ1. In addition, low doses of amiodarone have been reported to be synergistic with fluconazole in fluconazole-resistant Candida albicans. To establish its mechanism of toxicity in C. albicans, we used expression profiling of key pathway genes to examine cellular responses to amiodarone alone and in combination with fluconazole. Gene expression profiling of 59 genes was done in five C. albicans strains (three fluconazole-susceptible strains and two fluconazole-resistant strains) after amiodarone and/or fluconazole exposure. Of the 59 genes, 27 analyzed showed a significant change (>2-fold) in expression levels after amiodarone exposure. The up- or downregulated genes included genes involved in Ca(2+) homeostasis, cell wall synthesis, vacuolar/lysosomal transport, diverse pathway regulation, stress response, and pseudohyphal morphogenesis. As expected, fluconazole induces an increase in ergosterol pathway genes expression levels. The combination treatment significantly dampened the transcriptional response to either drug, suggesting that synergism was due to an inhibition of compensatory response pathways. This dampening resulted in a decrease in total ergosterol levels and decreased pseudohyphal formation, a finding consistent with decreased virulence in a murine candidiasis model.
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Affiliation(s)
- Soledad Gamarra
- Public Health Research Institute, New Jersey Medical School-UMDNJ, Newark, New Jersey 07103-3535, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Elousa Maria F. Rocha
- Public Health Research Institute, New Jersey Medical School-UMDNJ, Newark, New Jersey 07103-3535, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Yong-Qiang Zhang
- Public Health Research Institute, New Jersey Medical School-UMDNJ, Newark, New Jersey 07103-3535, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Steven Park
- Public Health Research Institute, New Jersey Medical School-UMDNJ, Newark, New Jersey 07103-3535, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Rajini Rao
- Public Health Research Institute, New Jersey Medical School-UMDNJ, Newark, New Jersey 07103-3535, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - David S. Perlin
- Public Health Research Institute, New Jersey Medical School-UMDNJ, Newark, New Jersey 07103-3535, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
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Hong MP, Vu K, Bautos J, Gelli A. Cch1 restores intracellular Ca2+ in fungal cells during endoplasmic reticulum stress. J Biol Chem 2010; 285:10951-8. [PMID: 20123986 DOI: 10.1074/jbc.m109.056218] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Pathogens endure and proliferate during infection by exquisitely coping with the many stresses imposed by the host to prevent pathogen survival. Recent evidence has shown that fungal pathogens and yeast respond to insults to the endoplasmic reticulum (ER) by initiating Ca(2+) influx across their plasma membrane. Although the high affinity Ca(2+) channel, Cch1, and its subunit Mid1, have been suggested as the protein complex responsible for mediating Ca(2+) influx, a direct demonstration of the gating mechanism of the Cch1 channel remains elusive. In this first mechanistic study of Cch1 channel activity we show that the Cch1 channel from the model human fungal pathogen, Cryptococcus neoformans, is directly activated by the depletion of intracellular Ca(2+) stores. Electrophysiological analysis revealed that agents that enable ER Ca(2+) store depletion promote the development of whole cell inward Ca(2+) currents through Cch1 that are effectively blocked by La(3+) and dependent on the presence of Mid1. Cch1 is permeable to both Ca(2+) and Ba(2+); however, unexpectedly, in contrast to Ca(2+) currents, Ba(2+) currents are steeply voltage-dependent. Cch1 maintains a strong Ca(2+) selectivity even in the presence of high concentrations of monovalent ions. Single channel analysis indicated that Cch1 channel conductance is small, similar to that reported for the Ca(2+) current I(CRAC). This study demonstrates that Cch1 functions as a store-operated Ca(2+)-selective channel that is gated by intracellular Ca(2+) depletion. The inability of cryptococcal cells that lacked the Cch1-Mid1 channel to survive ER stress suggests that Cch1 and its co-regulator, Mid1, are critical players in the restoration of Ca(2+) homeostasis.
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Affiliation(s)
- Min-Pyo Hong
- Department of Pharmacology, School of Medicine, University of California, Davis, California 95616, USA
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42
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Elucidating the Candida albicans calcineurin signaling cascade controlling stress response and virulence. Fungal Genet Biol 2009; 47:107-16. [PMID: 19755168 DOI: 10.1016/j.fgb.2009.09.002] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2009] [Revised: 08/31/2009] [Accepted: 09/09/2009] [Indexed: 11/24/2022]
Abstract
The protein phosphatase calcineurin is a key mediator of virulence and antifungal susceptibility of multiple fungal pathogens including Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus, and has clinical potential as a therapeutic target to increase the efficacy of the current antifungal armamentarium. Despite the importance of this signaling pathway, few components of the calcineurin-signaling pathway are known in C. albicans. Here we identified and analyzed additional components of the C. albicans calcineurin cascade, including the RCN1 (regulator of calcineurin1), MID1, and CCH1 genes, which mediate calcineurin functions in other species. When heterologously expressed in Saccharomyces cerevisiae, C. albicans Rcn1 inhibited calcineurin function. Although rcn1/rcn1, mid1/mid1, and cch1/cch1 mutant strains share some phenotypes with calcineurin mutants, they do not completely recapitulate the phenotypes of a calcineurin mutant strain. These studies extend our understanding of the C. albicans calcineurin signaling cascade and its host-niche specific role in virulence.
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The functional expression of toxic genes: lessons learned from molecular cloning of CCH1, a high-affinity Ca2+ channel. Anal Biochem 2009; 393:234-41. [PMID: 19580778 DOI: 10.1016/j.ab.2009.06.039] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2009] [Revised: 06/28/2009] [Accepted: 06/30/2009] [Indexed: 11/22/2022]
Abstract
Some genes cannot be cloned by conventional methods because in most cases the genes or gene products are toxic to Escherichia coli. CCH1 is a high-affinity Ca(2+) channel present in the plasma membrane of Cryptococcus neoformans and other fungi. Like many toxic genes, the molecular cloning of CCH1 has been a major challenge; consequently, direct studies of CCH1 channel activity in heterologous expression systems have been impossible. We have devised a straightforward approach that resulted in the molecular cloning and functional expression of CCH1 by exploiting homologous recombination both in vitro and in vivo. This approach precluded the standard enzyme digestion-mediated ligation reactions and the subsequent isolation of plasmids from E. coli. The shuttle plasmid carrying CCH1-GFP, which was prepared in vitro and propagated in yeast, was successfully expressed in the mammalian cell line HEK293 (human embryonic kidney 293). CCH1 transcripts were detected only in HEK293 cells transfected with the plasmid DNA. Fluorescence microscopy studies revealed the expression of CCH1-GFP fusion protein on the cell surface of HEK293 cells, similar to the localization pattern of a well-characterized plasma membrane-associated K(+) channel. This approach will be particularly useful for genes that encode ion channels and transporters that cannot be cloned by conventional techniques requiring E. coli.
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Abstract
Pathogens must be able to overcome both host defenses and antimicrobial treatment in order to successfully infect and maintain colonization of the host. One way fungi accomplish this feat and overcome intercellular toxin accumulation is efflux pumps, in particular ATP-binding cassette transporters and transporters of the major facilitator superfamily. Members of these two superfamilies remove many toxic compounds by coupling transport with ATP hydrolysis or a proton gradient, respectively. Fungal genomes encode a plethora of members of these families of transporters compared to other organisms. In this review we discuss the role these two fungal superfamilies of transporters play in virulence and resistance to antifungal agents. These efflux transporters are responsible not only for export of compounds involved in pathogenesis such as secondary metabolites, but also export of host-derived antimicrobial compounds. In addition, we examine the current knowledge of these transporters in resistance of pathogens to clinically relevant antifungal agents.
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Affiliation(s)
- Jeffrey J. Coleman
- Division of Infectious Diseases, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Eleftherios Mylonakis
- Division of Infectious Diseases, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
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45
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Abstract
Efficient communication with the environment is critical for all living organisms. Fungi utilize complex signalling systems to sense their environments and control proliferation, development and in some cases virulence. Well-studied signalling pathways include the protein kinase A/cyclic AMP (cAMP), protein kinase C (PKC)/mitogen-activated protein kinase (MAPK), lipid signalling cascades, and the calcium-calcineurin signalling pathway. The human pathogenic basidiomycetous fungus Cryptococcus neoformans deploys sensitive signalling systems to survive in the human host, leading to life-threatening meningoencephalitis. Known virulence traits of this fungus, including the antioxidant melanin production, the antiphagocytic polysaccharide capsule and the ability to grow at 37 degrees C, are orchestrated by complex signalling networks, whose understanding is crucial to better treat, diagnose and prevent cryptococcosis.
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Affiliation(s)
- Lukasz Kozubowski
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
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46
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Teng J, Goto R, Iida K, Kojima I, Iida H. Ion-channel blocker sensitivity of voltage-gated calcium-channel homologue Cch1 in Saccharomyces cerevisiae. Microbiology (Reading) 2008; 154:3775-3781. [DOI: 10.1099/mic.0.2008/021089-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Jinfeng Teng
- Laboratory of Cell Biology, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Gunma 371-8510, Japan
- Department of Biology, Tokyo Gakugei University, 4-1-1 Nukui kita-machi, Koganei-shi, Tokyo 184-8501, Japan
| | - Rika Goto
- Department of Biology, Tokyo Gakugei University, 4-1-1 Nukui kita-machi, Koganei-shi, Tokyo 184-8501, Japan
| | - Kazuko Iida
- Biomembrane Signaling Project 2, Tokyo Metropolitan Institute of Medical Science, 3-18-22 Honkomagome, Bunkyo-ku, Tokyo 113-8613, Japan
| | - Itaru Kojima
- Laboratory of Cell Biology, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Gunma 371-8510, Japan
| | - Hidetoshi Iida
- Department of Bioenvironmental Science, Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Higashiyama 5-1, Myodaiji, Okazaki, Aichi 444-8787, Japan
- Department of Biology, Tokyo Gakugei University, 4-1-1 Nukui kita-machi, Koganei-shi, Tokyo 184-8501, Japan
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47
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Shi J, Chen W, Liu Q, Chen S, Hu H, Turner G, Lu L. Depletion of the MobB and CotA complex in Aspergillus nidulans causes defects in polarity maintenance that can be suppressed by the environment stress. Fungal Genet Biol 2008; 45:1570-81. [DOI: 10.1016/j.fgb.2008.08.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2008] [Revised: 08/18/2008] [Accepted: 08/19/2008] [Indexed: 11/30/2022]
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Evidence for the role of calcineurin in morphogenesis and calcium homeostasis during mycelium-to-yeast dimorphism of Paracoccidioides brasiliensis. EUKARYOTIC CELL 2008; 7:1856-64. [PMID: 18776037 DOI: 10.1128/ec.00110-08] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Paracoccidioides brasiliensis is a dimorphic fungus that causes paracoccidioidomycosis, the most prevalent human deep mycosis in Latin America. The dimorphic transition from mycelium to yeast (M-Y) is triggered by a temperature shift from 25 degrees C to 37 degrees C and is critical for pathogenicity. Intracellular Ca(2+) levels increased in hyphae immediately after temperature-induced dimorphism. The chelation of Ca(2+) with extracellular (EGTA) or intracellular (BAPTA) calcium chelators inhibited temperature-induced dimorphism, whereas the addition of extracellular Ca(2+) accelerated dimorphism. The calcineurin inhibitor cyclosporine A (CsA), but not tacrolimus (FK506), effectively decreased cell growth, halted the M-Y transition that is associated with virulence, and caused aberrant growth morphologies for all forms of P. brasiliensis. The difference between CsA and FK506 was ascribed by the higher levels of cyclophilins contrasted to FKBPs, the intracellular drug targets required for calcineurin suppression. Chronic exposure to CsA abolished intracellular Ca(2+) homeostasis and decreased mRNA transcription of the CCH1 gene for the plasma membrane Ca(2+) channel in yeast-form cells. CsA had no detectable effect on multidrug resistance efflux pumps, while the effect of FK506 on rhodamine excretion was not correlated with the transition to yeast form. In this study, we present evidence that Ca(2+)/calmodulin-dependent phosphatase calcineurin controls hyphal and yeast morphology, M-Y dimorphism, growth, and Ca(2+) homeostasis in P. brasiliensis and that CsA is an effective chemical block for thermodimorphism in this organism. The effects of calcineurin inhibitors on P. brasiliensis reinforce the therapeutic potential of these drugs in a combinatory approach with antifungal drugs to treat endemic paracoccidioidomycosis.
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Elongation factor 3, EF3, associates with the calcium channel Cch1 and targets Cch1 to the plasma membrane in Cryptococcus neoformans. EUKARYOTIC CELL 2008; 7:1118-26. [PMID: 18503003 DOI: 10.1128/ec.00116-08] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Ca2+-mediated signaling events in eukaryotic cells are initiated by Ca2+ channels located in the plasma membranes and endomembranes. Cch1, a high-affinity Ca2+ channel in the plasma membranes of Cryptococcus neoformans and other fungi, plays a role in many different cellular processes, but the mechanisms that regulate Cch1 are not well understood. A Ras recruitment two-hybrid screen was used to identify protein partners of Cch1 as a means of identifying possible mechanisms of channel regulation. Here, we show that Cch1 specifically associates with a cytoplasmic protein known as elongation factor 3 (EF3). The robust interaction between the cytosolic C terminus of the Cch1 protein and EF3 shown here was confirmed by demonstrating that Cch1 could coimmunoprecipitate with EF3 in yeast lysates. To examine the effects of EF3 on Cch1 behavior, we altered the EF3 gene function by constructing a C. neoformans antisense EF3 repression strain. Our results show that the repression of EF3 led to the mislocalization of Cch1, suggesting a role for EF3 in targeting Cch1 to the plasma membrane of C. neoformans. Consistent with this notion, the antisense EF3 repression strain displayed a growth defect under conditions of limited extracellular Ca2+. Collectively, these results suggest that EF3 and Cch1 are functionally coupled and that EF3 has a function apart from its role in the protein translation cycle.
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50
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Lew RR, Abbas Z, Anderca MI, Free SJ. Phenotype of a mechanosensitive channel mutant, mid-1, in a filamentous fungus, Neurospora crassa. EUKARYOTIC CELL 2008; 7:647-55. [PMID: 18296620 PMCID: PMC2292622 DOI: 10.1128/ec.00411-07] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2007] [Accepted: 02/12/2008] [Indexed: 12/21/2022]
Abstract
In the yeast Saccharomyces cerevisiae, the MID1 (mating-induced death) gene encodes a stretch-activated channel which is required for successful mating; the mutant phenotype is rescued by elevated extracellular calcium. Homologs of the MID1 gene are found in fungi that are morphologically complex compared to yeast, both Basidiomycetes and Ascomycetes. We explored the phenotype of a mid-1 knockout mutant in the filamentous ascomycete Neurospora crassa. The mutant exhibits lower growth vigor than the wild type (which is not rescued by replete calcium) and mates successfully. Thus, the role of the MID-1 protein differs from that of the homologous gene product in yeast. Hyphal cytology, growth on diverse carbon sources, turgor regulation, and circadian rhythms of the mid-1 mutant are all similar to those of the wild type. However, basal turgor is lower than wild type, as is the activity of the plasma membrane H(+)-ATPase (measured by cyanide [CN(-)]-induced depolarization of the energy-dependent component of the membrane potential). In addition, the mutant is unable to grow at low extracellular Ca(2+) levels or when cytoplasmic Ca(2+) is elevated with the Ca(2+) ionophore A23187. We conclude that the MID-1 protein plays a role in regulation of ion transport via Ca(2+) homeostasis and signaling. In the absence of normal ion transport activity, the mutant exhibits poorer growth.
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Affiliation(s)
- Roger R Lew
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario M3J 1P3, Canada.
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