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Dai M, Du W, Lu L, Zhang S. Transcription factors SltA and CrzA reversely regulate calcium homeostasis under calcium-limited conditions. Appl Environ Microbiol 2023; 89:e0117023. [PMID: 37874299 PMCID: PMC10686095 DOI: 10.1128/aem.01170-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 09/11/2023] [Indexed: 10/25/2023] Open
Abstract
IMPORTANCE Calcium ions are ubiquitous intracellular signaling molecules for many signaling pathways regulating the fungal response to stress and antifungal drugs. The concentration of intracellular calcium is tightly regulated in its storage, release, and distribution. CrzA is the best-studied transcription factor that regulates this process under sufficient calcium or other external signals. However, CrzA was excluded from nuclei and then lost transcriptional activation under calcium-limited conditions. The regulators in the Ca2+ signaling pathway under calcium-limited conditions remain unclear. Here, we identified SltA as a key regulator in the Ca2+ signaling pathway under calcium-limited conditions, and the underlying mechanisms were further explored in Aspergillus fumigatus. These findings reveal a transcriptional control pathway that precisely regulates calcium homeostasis under calcium-limited conditions.
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Affiliation(s)
- Mengyao Dai
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
| | - Wenlong Du
- Department of Bioinformatics, School of Life Sciences, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Ling Lu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
| | - Shizhu Zhang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
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2
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Rivera A, Young Lim W, Park E, Dome PA, Hoy MJ, Spasojevic I, Sun S, Averette AF, Pina-Oviedo S, Juvvadi PR, Steinbach WJ, Ciofani M, Hong J, Heitman J. Enhanced fungal specificity and in vivo therapeutic efficacy of a C-22-modified FK520 analog against C. neoformans. mBio 2023; 14:e0181023. [PMID: 37737622 PMCID: PMC10653846 DOI: 10.1128/mbio.01810-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 07/19/2023] [Indexed: 09/23/2023] Open
Abstract
IMPORTANCE Fungal infections cause significant morbidity and mortality globally. The therapeutic armamentarium against these infections is limited, and the development of antifungal drugs has been hindered by the evolutionary conservation between fungi and the human host. With rising resistance to the current antifungal arsenal and an increasing at-risk population, there is an urgent need for the development of new antifungal compounds. The FK520 analogs described in this study display potent antifungal activity as a novel class of antifungals centered on modifying an existing orally active FDA-approved therapy. This research advances the development of much-needed newer antifungal treatment options with novel mechanisms of action.
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Affiliation(s)
- Angela Rivera
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina, USA
| | - Won Young Lim
- Department of Chemistry, Duke University, Durham, North Carolina, USA
| | - Eunchong Park
- Department of Integrative Immunobiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Patrick A. Dome
- Department of Chemistry, Duke University, Durham, North Carolina, USA
| | - Michael J. Hoy
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Ivan Spasojevic
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, USA
| | - Sheng Sun
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Anna Floyd Averette
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Sergio Pina-Oviedo
- Department of Pathology, Duke University Medical Center, Durham, North Carolina, USA
| | - Praveen R. Juvvadi
- Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - William J. Steinbach
- Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Maria Ciofani
- Department of Integrative Immunobiology, Duke University Medical Center, Durham, North Carolina, USA
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Jiyong Hong
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina, USA
- Department of Chemistry, Duke University, Durham, North Carolina, USA
| | - Joseph Heitman
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina, USA
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA
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3
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Rivera A, Lim WY, Park E, Dome PA, Hoy MJ, Spasojevic I, Sun S, Averette AF, Pina-Oviedo S, Juvvadi PR, Steinbach WJ, Ciofani M, Hong J, Heitman J. Enhanced fungal specificity and in vivo therapeutic efficacy of a C-22 modified FK520 analog against C. neoformans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.05.543712. [PMID: 37333270 PMCID: PMC10274662 DOI: 10.1101/2023.06.05.543712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Fungal infections are of mounting global concern, and the current limited treatment arsenal poses challenges when treating such infections. In particular, infections by Cryptococcus neoformans are associated with high mortality, emphasizing the need for novel therapeutic options. Calcineurin is a protein phosphatase that mediates fungal stress responses, and calcineurin inhibition by the natural product FK506 blocks C. neoformans growth at 37°C. Calcineurin is also required for pathogenesis. However, because calcineurin is conserved in humans, and inhibition with FK506 results in immunosuppression, the use of FK506 as an anti-infective agent is precluded. We previously elucidated the structures of multiple fungal calcineurin-FK506-FKBP12 complexes and implicated the C-22 position on FK506 as a key point for differential modification of ligand inhibition of the mammalian versus fungal target proteins. Through in vitro antifungal and immunosuppressive testing of FK520 (a natural analog of FK506) derivatives, we identified JH-FK-08 as a lead candidate for further antifungal development. JH-FK-08 exhibited significantly reduced immunosuppressive activity and both reduced fungal burden and prolonged survival of infected animals. JH-FK-08 exhibited additive activity in combination with fluconazole in vivo . These findings further advance calcineurin inhibition as an antifungal therapeutic approach. Importance Fungal infections cause significant morbidity and mortality globally. The therapeutic armamentarium against these infections is limited and development of antifungal drugs has been hindered by the evolutionary conservation between fungi and the human host. With rising resistance to the current antifungal arsenal and an increasing at-risk population, there is an urgent need for the development of new antifungal compounds. The FK520 analogs described in this study display potent antifungal activity as a novel class of antifungals centered on modifying an existing orally-active FDA approved therapy. This research advances the development of much needed newer antifungal treatment options with novel mechanisms of action.
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Chadwick BJ, Ross BE, Lin X. Molecular Dissection of Crz1 and Its Dynamic Subcellular Localization in Cryptococcus neoformans. J Fungi (Basel) 2023; 9:jof9020252. [PMID: 36836365 PMCID: PMC9963361 DOI: 10.3390/jof9020252] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 02/01/2023] [Accepted: 02/08/2023] [Indexed: 02/17/2023] Open
Abstract
Across lower eukaryotes, the transcription factor Crz1 is dephosphorylated by calcineurin, which facilitates Crz1 translocation to the nucleus to regulate gene expression. In the fungal pathogen Cryptococcus neoformans, calcineurin-Crz1 signaling maintains calcium homeostasis, thermotolerance, cell wall integrity, and morphogenesis. How Crz1 distinguishes different stressors and differentially regulates cellular responses is poorly understood. Through monitoring Crz1 subcellular localization over time, we found that Crz1 transiently localizes to granules after exposure to high temperature or calcium. These granules also host the phosphatase calcineurin and Pub1, a ribonucleoprotein stress granule marker, suggesting a role of stress granules in modulating calcineurin-Crz1 signaling. Additionally, we constructed and analyzed an array of Crz1 truncation mutants. We identified the intrinsically disordered regions in Crz1 contribute to proper stress granule localization, nuclear localization, and function. Our results provide the groundwork for further determination of the mechanisms behind the complex regulation of Crz1.
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Affiliation(s)
| | | | - Xiaorong Lin
- Department of Plant Biology, University of Georgia, Athens, GA 30602, USA
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA
- Correspondence:
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Campanella JEM, Candido TDS, Barbosa LCB, Gomes AAS, Leite CA, Higashi ES, Barbugli PA, Fontes MRDM, Bertolini MC. The Neurospora crassa PCL-1 cyclin is a PHO85-1 (PGOV) kinase partner that directs the complex to glycogen metabolism and is involved in calcium metabolism regulation. Front Microbiol 2022; 13:1078972. [PMID: 36620034 PMCID: PMC9815767 DOI: 10.3389/fmicb.2022.1078972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 12/06/2022] [Indexed: 12/24/2022] Open
Abstract
Cyclins are a family of proteins characterized by possessing a cyclin box domain that mediates binding to cyclin dependent kinases (CDKs) partners. In this study, the search for a partner cyclin of the PHO85-1 CDK retrieved PCL-1 an ortholog of yeast Pcls (for Pho85 cyclins) that performs functions common to Pcls belonging to different cyclin families. We show here that PCL-1, as a typical cyclin, is involved in cell cycle control and cell progression. In addition, PCL-1 regulates glycogen metabolism; Δpcl-1 cells accumulate higher glycogen levels than wild-type cells and the glycogen synthase (GSN) enzyme is less phosphorylated and, therefore, more active in the mutant cells. Together with PHO85-1, PCL-1 phosphorylates in vitro GSN at the Ser636 amino acid residue. Modeling studies identified PHO85-1 and PCL-1 as a CDK/cyclin complex, with a conserved intermolecular region stabilized by hydrophobic and polar interactions. PCL-1 is also involved in calcium and NaCl stress response. Δpcl-1 cells are sensitive to high NaCl concentration; on the contrary, they grow better and overexpress calcium responsive genes under high calcium chloride concentration compared to the wild-type strain. The expression of the calcium-responsive CRZ-1 transcription factor is modulated by PCL-1, and this transcription factor seems to be less phosphorylated in Δpcl-1 cells since exhibits nuclear location in these cells in the absence of calcium. Our results show that PCL-1 locates at different cell regions suggesting that it may determine its activity by controlling its intracellular location and reveal an interesting functional divergence between yeast and filamentous fungus cyclins.
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Affiliation(s)
- Jonatas Erick Maimoni Campanella
- Departamento de Bioquímica e Química Orgânica, Instituto de Química, Universidade Estadual Paulista, Araraquara, São Paulo, Brazil
| | - Thiago de Souza Candido
- Departamento de Bioquímica e Química Orgânica, Instituto de Química, Universidade Estadual Paulista, Araraquara, São Paulo, Brazil
| | - Luiz Carlos Bertucci Barbosa
- Departamento de Bioquímica e Química Orgânica, Instituto de Química, Universidade Estadual Paulista, Araraquara, São Paulo, Brazil
| | - Antoniel Augusto Severo Gomes
- Departamento de Biofísica e Farmacologia, Instituto de Biociências, Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
| | - Carla Andréa Leite
- Departamento de Bioquímica e Química Orgânica, Instituto de Química, Universidade Estadual Paulista, Araraquara, São Paulo, Brazil
| | - Erika Silva Higashi
- Departamento de Bioquímica e Química Orgânica, Instituto de Química, Universidade Estadual Paulista, Araraquara, São Paulo, Brazil
| | - Paula Aboud Barbugli
- Departamento de Materiais Dentários e Prótese, Faculdade de Odontologia, Universidade Estadual Paulista, Araraquara, São Paulo, Brazil
| | - Marcos Roberto de Matos Fontes
- Departamento de Biofísica e Farmacologia, Instituto de Biociências, Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
| | - Maria Célia Bertolini
- Departamento de Bioquímica e Química Orgânica, Instituto de Química, Universidade Estadual Paulista, Araraquara, São Paulo, Brazil
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Calcineurin Inhibitor CN585 Exhibits Off-Target Effects in the Human Fungal Pathogen Aspergillus fumigatus. J Fungi (Basel) 2022; 8:jof8121281. [PMID: 36547614 PMCID: PMC9788591 DOI: 10.3390/jof8121281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 11/29/2022] [Accepted: 12/03/2022] [Indexed: 12/12/2022] Open
Abstract
Calcineurin (CN) is an attractive antifungal target as it is critical for growth, stress response, drug resistance, and virulence in fungal pathogens. The immunosuppressive drugs, tacrolimus (FK506) and cyclosporin A (CsA), are fungistatic and specifically inhibit CN through binding to their respective immunophilins, FK506-binding protein (FKBP12), and cyclophilin (CypA). We are focused on CN structure-based approaches for the development of non-immunosuppressive FK506 analogs as antifungal therapeutics. Here, we examined the effect of the novel CN inhibitor, CN585, on the growth of the human pathogen Aspergillus fumigatus, the most common cause of invasive aspergillosis. Unexpectedly, in contrast to FK506, CN585 exhibited off-target effect on A. fumigatus wild-type and the azole- and echinocandin-resistant strains. Unlike with FK506 and CsA, the A. fumigatus CN, FKBP12, CypA mutants (ΔcnaA, Δfkbp12, ΔcypA) and various FK506-resistant mutants were all sensitive to CN585. Furthermore, in contrast to FK506 the cytosolic to nuclear translocation of the CN-dependent transcription factor (CrzA-GFP) was not inhibited by CN585. Molecular docking of CN585 onto human and A. fumigatus CN complexes revealed differential potential binding sites between human CN versus A. fumigatus CN. Our results indicate CN585 may be a non-specific inhibitor of CN with a yet undefined antifungal mechanism of activity.
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Zhai P, Ma Y, Du W, Lu L. The metal chaperone protein MtmA plays important roles in antifungal drug susceptibility in Aspergillus fumigatus. Front Microbiol 2022; 13:1062282. [DOI: 10.3389/fmicb.2022.1062282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 11/21/2022] [Indexed: 12/04/2022] Open
Abstract
Drug-resistant fungal infections are emerging as an important clinical problem. In general, antifungal resistance results from increased target expression or mutations within the target protein sequence. However, the molecular mechanisms of non-drug target mutations of antifungal resistance in fungal pathogens remain to be explored. Previous studies indicated that the metal chaperone protein Mtm1 is required for mitochondrial Sod2 activation and responses to oxidative stress in yeast and in the fungal pathogen Aspergillus fumigatus, but there is no report of MtmA-related antifungal resistance. In this study, we found that repressed expression of MtmA (only 10% expression) using a conditional promoter resulted in significantly enhanced itraconazole resistance, which was not the result of highly expressed drug targets Erg11A and Erg11B. Furthermore, we demonstrated that repressed expression of MtmA results in upregulation of a series of multidrug resistance-associated transport genes, which may cause multidrug resistance. Further mechanistic studies revealed that inhibition of MtmA expression led to abnormal activation of the calcium signaling system and prompted persistent nucleation of the calcium signaling transcription factor CrzA. Our findings suggest that the metal chaperone protein MtmA is able to negatively regulate fungal resistance via affecting calcium signaling pathway.
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Ancuceanu R, Hovaneț MV, Cojocaru-Toma M, Anghel AI, Dinu M. Potential Antifungal Targets for Aspergillus sp. from the Calcineurin and Heat Shock Protein Pathways. Int J Mol Sci 2022; 23:ijms232012543. [PMID: 36293395 PMCID: PMC9603945 DOI: 10.3390/ijms232012543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 10/13/2022] [Accepted: 10/15/2022] [Indexed: 11/16/2022] Open
Abstract
Aspergillus species, especially A. fumigatus, and to a lesser extent others (A. flavus, A. niger, A. terreus), although rarely pathogenic to healthy humans, can be very aggressive to immunocompromised patients (they are opportunistic pathogens). Although survival rates for such infections have improved in recent decades following the introduction of azole derivatives, they remain a clinical challenge. The fact that current antifungals act as fungistatic rather than fungicide, that they have limited safety, and that resistance is becoming increasingly common make the need for new, more effective, and safer therapies to become more acute. Over the last decades, knowledge about the molecular biology of A. fumigatus and other Aspergillus species, and particularly of calcineurin, Hsp90, and their signaling pathway proteins, has progressed remarkably. Although calcineurin has attracted much interest, its adverse effects, particularly its immunosuppressive effects, make it less attractive than it might at first appear. The situation is not very different for Hsp90. Other proteins from their signaling pathways, such as protein kinases phosphorylating the four SPRR serine residues, CrzA, rcnA, pmcA-pmcC (particularly pmcC), rfeF, BAR adapter protein(s), the phkB histidine kinase, sskB MAP kinase kinase, zfpA, htfA, ctfA, SwoH (nucleoside diphosphate kinase), CchA, MidA, FKBP12, the K27 lysine position from Hsp90, PkcA, MpkA, RlmA, brlA, abaA, wetA, other heat shock proteins (Hsp70, Hsp40, Hsp12) currently appear promising and deserve further investigation as potential targets for antifungal drug development.
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Affiliation(s)
- Robert Ancuceanu
- Faculty of Pharmacy, Carol Davila University of Medicine and Pharmacy, 020956 Bucharest, Romania
- Correspondence: (R.A.); (M.V.H.)
| | - Marilena Viorica Hovaneț
- Faculty of Pharmacy, Carol Davila University of Medicine and Pharmacy, 020956 Bucharest, Romania
- Correspondence: (R.A.); (M.V.H.)
| | - Maria Cojocaru-Toma
- Faculty of Pharmacy, Nicolae Testemițanu State University of Medicine and Pharmacy, 2025 Chisinau, Moldova
| | - Adriana-Iuliana Anghel
- Faculty of Pharmacy, Carol Davila University of Medicine and Pharmacy, 020956 Bucharest, Romania
| | - Mihaela Dinu
- Faculty of Pharmacy, Carol Davila University of Medicine and Pharmacy, 020956 Bucharest, Romania
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Hoy MJ, Park E, Lee H, Lim WY, Cole DC, DeBouver ND, Bobay BG, Pierce PG, Fox D, Ciofani M, Juvvadi PR, Steinbach W, Hong J, Heitman J. Structure-Guided Synthesis of FK506 and FK520 Analogs with Increased Selectivity Exhibit In Vivo Therapeutic Efficacy against Cryptococcus. mBio 2022; 13:e0104922. [PMID: 35604094 PMCID: PMC9239059 DOI: 10.1128/mbio.01049-22] [Citation(s) in RCA: 1] [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: 04/18/2022] [Accepted: 04/21/2022] [Indexed: 01/04/2023] Open
Abstract
Calcineurin is an essential virulence factor that is conserved across human fungal pathogens, including Cryptococcus neoformans, Aspergillus fumigatus, and Candida albicans. Although an excellent target for antifungal drug development, the serine-threonine phosphatase activity of calcineurin is conserved in mammals, and inhibition of this activity results in immunosuppression. FK506 (tacrolimus) is a naturally produced macrocyclic compound that inhibits calcineurin by binding to the immunophilin FKBP12. Previously, our fungal calcineurin-FK506-FKBP12 structure-based approaches identified a nonconserved region of FKBP12 that can be exploited for fungus-specific targeting. These studies led to the design of an FK506 analog, APX879, modified at the C-22 position, which was less immunosuppressive yet maintained antifungal activity. We now report high-resolution protein crystal structures of fungal FKBP12 and a human truncated calcineurin-FKBP12 bound to a natural FK506 analog, FK520 (ascomycin). Based on information from these structures and the success of APX879, we synthesized and screened a novel panel of C-22-modified compounds derived from both FK506 and FK520. One compound, JH-FK-05, demonstrates broad-spectrum antifungal activity in vitro and is nonimmunosuppressive in vivo. In murine models of pulmonary and disseminated C. neoformans infection, JH-FK-05 treatment significantly reduced fungal burden and extended animal survival alone and in combination with fluconazole. Furthermore, molecular dynamic simulations performed with JH-FK-05 binding to fungal and human FKBP12 identified additional residues outside the C-22 and C-21 positions that could be modified to generate novel FK506 analogs with improved antifungal activity. IMPORTANCE Due to rising rates of antifungal drug resistance and a limited armamentarium of antifungal treatments, there is a paramount need for novel antifungal drugs to treat systemic fungal infections. Calcineurin has been established as an essential and conserved virulence factor in several fungi, making it an attractive antifungal target. However, due to the immunosuppressive action of calcineurin inhibitors, they have not been successfully utilized clinically for antifungal treatment in humans. Recent availability of crystal structures of fungal calcineurin-bound inhibitor complexes has enabled the structure-guided design of FK506 analogs and led to a breakthrough in the development of a compound with increased fungal specificity. The development of a calcineurin inhibitor with reduced immunosuppressive activity and maintained therapeutic antifungal activity would add a significant tool to the treatment options for these invasive fungal infections with exceedingly high rates of mortality.
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Affiliation(s)
- Michael J. Hoy
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Eunchong Park
- Department of Immunology, Duke University Medical Center, Durham, North Carolina, USA
| | - Hyunji Lee
- Department of Chemistry, Duke University, Durham, North Carolina, USA
| | - Won Young Lim
- Department of Chemistry, Duke University, Durham, North Carolina, USA
| | - D. Christopher Cole
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, USA
| | - Nicholas D. DeBouver
- UCB Biosciences, Bainbridge Island, Washington, USA
- Seattle Structural Genomics Center for Infectious Disease (SSGCID), Seattle, Washington, USA
| | | | - Phillip G. Pierce
- UCB Biosciences, Bainbridge Island, Washington, USA
- Seattle Structural Genomics Center for Infectious Disease (SSGCID), Seattle, Washington, USA
| | - David Fox
- UCB Biosciences, Bainbridge Island, Washington, USA
- Seattle Structural Genomics Center for Infectious Disease (SSGCID), Seattle, Washington, USA
| | - Maria Ciofani
- Department of Immunology, Duke University Medical Center, Durham, North Carolina, USA
| | - Praveen R. Juvvadi
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, USA
| | - William Steinbach
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, USA
| | - Jiyong Hong
- Department of Chemistry, Duke University, Durham, North Carolina, USA
| | - Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA
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10
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Shwab EK, Juvvadi PR, Shaheen SK, Allen J, Waitt G, Soderblom EJ, Asfaw YG, Moseley MA, Steinbach WJ. Protein Kinase A Regulates Autophagy-Associated Proteins Impacting Growth and Virulence of Aspergillus fumigatus. J Fungi (Basel) 2022; 8:jof8040354. [PMID: 35448585 PMCID: PMC9029100 DOI: 10.3390/jof8040354] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/14/2022] [Accepted: 03/28/2022] [Indexed: 01/07/2023] Open
Abstract
Cellular recycling via autophagy-associated proteins is a key catabolic pathway critical to invasive fungal pathogen growth and virulence in the nutrient-limited host environment. Protein kinase A (PKA) is vital for the growth and virulence of numerous fungal pathogens. However, the underlying basis for its regulation of pathogenesis remains poorly understood in any species. Our Aspergillus fumigatus PKA-dependent whole proteome and phosphoproteome studies employing advanced mass spectroscopic approaches identified numerous previously undefined PKA-regulated proteins in catabolic pathways. Here, we demonstrate reciprocal inhibition of autophagy and PKA activity, and identify 16 autophagy-associated proteins as likely novel PKA-regulated effectors. We characterize the novel PKA-phosphoregulated sorting nexin Atg20, and demonstrate its importance for growth, cell wall stress response, and virulence of A. fumigatus in a murine infection model. Additionally, we identify physical and functional interaction of Atg20 with previously characterized sorting nexin Atg24. Furthermore, we demonstrate the importance of additional uncharacterized PKA-regulated putative autophagy-associated proteins to hyphal growth. Our data presented here indicate that PKA regulates the autophagy pathway much more extensively than previously known, including targeting of novel effector proteins with fungal-specific functions important for invasive disease.
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Affiliation(s)
- E. Keats Shwab
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Duke University Medical Center, Durham, NC 27710, USA; (E.K.S.); (P.R.J.); (S.K.S.); (J.A.IV)
| | - Praveen R. Juvvadi
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Duke University Medical Center, Durham, NC 27710, USA; (E.K.S.); (P.R.J.); (S.K.S.); (J.A.IV)
| | - Shareef K. Shaheen
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Duke University Medical Center, Durham, NC 27710, USA; (E.K.S.); (P.R.J.); (S.K.S.); (J.A.IV)
| | - John Allen
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Duke University Medical Center, Durham, NC 27710, USA; (E.K.S.); (P.R.J.); (S.K.S.); (J.A.IV)
| | - Greg Waitt
- Duke Proteomics Core Facility, Institute for Genome Sciences and Policy, Duke University, Durham, NC 27701, USA; (G.W.); (E.J.S.); (M.A.M.)
| | - Erik J. Soderblom
- Duke Proteomics Core Facility, Institute for Genome Sciences and Policy, Duke University, Durham, NC 27701, USA; (G.W.); (E.J.S.); (M.A.M.)
| | - Yohannes G. Asfaw
- Department of Laboratory Animal Resources, Duke University Medical Center, Durham, NC 27710, USA;
| | - M. Arthur Moseley
- Duke Proteomics Core Facility, Institute for Genome Sciences and Policy, Duke University, Durham, NC 27701, USA; (G.W.); (E.J.S.); (M.A.M.)
| | - William J. Steinbach
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Duke University Medical Center, Durham, NC 27710, USA; (E.K.S.); (P.R.J.); (S.K.S.); (J.A.IV)
- Department of Molecular Genetics & Microbiology, Duke University Medical Center, Durham, NC 27710, USA
- Correspondence:
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11
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The Heterotrimeric Transcription Factor CCAAT-Binding Complex and Ca 2+-CrzA Signaling Reversely Regulate the Transition between Fungal Hyphal Growth and Asexual Reproduction. mBio 2021; 12:e0300721. [PMID: 34781745 PMCID: PMC8593669 DOI: 10.1128/mbio.03007-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The life cycle of filamentous fungi generally comprises hyphal growth and asexual reproduction. Both growth and propagation processes are critical for invasion growth, spore dissemination, and virulence in fungal pathogens and for the production of secondary metabolites or for biomass accumulation in industrial filamentous fungi. The CCAAT-binding complex (CBC) is a heterotrimeric transcription factor comprising three subunits, HapB, HapC, and HapE, and is highly conserved in fungi. Previous studies revealed that CBC regulates sterol metabolism by repressing several genes in the ergosterol biosynthetic pathway in the human fungal pathogen Aspergillus fumigatus. In the present study, we found dysfunction of CBC caused the abnormal asexual reproduction (conidiation) in submerged liquid culture. CBC suppresses the activation of the brlA gene in the central regulatory pathway for conidiation combined with its upstream regulators fluG, flbD, and flbC by binding to the 5'-CCAAT-3' motif within conidiation gene promoters, and lack of CBC member HapB results in the upregulation of these genes. Furthermore, when the expression of brlA or flbC is repressed, the submerged conidiation does not happen in the hapB mutant. Interestingly, deletion of HapB leads to enhanced transient cytosolic Ca2+ levels and activates conidiation-positive inducer Ca2+-CrzA modules to enhance submerged conidiation, demonstrating that CrzA works with CBC as a reverse regulator of fungal conidiation. To the best of our knowledge, the finding of this study is the first report for the molecular switch mechanism between vegetative hyphal growth and asexual development regulated by CBC, in concert with Ca2+-CrzA signaling in A. fumigatus. IMPORTANCE A precisely timed switch between vegetative hyphal growth and asexual development is a crucial process for the filamentous fungal long-term survival, dissemination, biomass production, and virulence. However, under the submerged culture condition, filamentous fungi would undergo constant vegetative growth whereas asexual conidiation rarely occurs. Knowledge about possible regulators is scarce, and how they could inhibit conidiation in liquid culture is poorly understood. Here, we demonstrated that the transcription factor heterotrimeric CBC dominantly maintains vegetative growth in liquid-submerged cultures by directly suppressing the conidiation-inductive signal. In contrast, calcium and the transcription factor CrzA, are positive inducers of conidiation. Our new insights into the CBC and Ca2+-CrzA regulatory system for transition control in the submerged conidiation of A. fumigatus may have broad repercussions for all filamentous fungi. Moreover, our elucidation of the molecular mechanism for submerged conidiation may support new strategies to precisely control vegetative growth and asexual conidiation in aspergilli used in industry.
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Valero C, Colabardini AC, de Castro PA, Silva LP, Ries LNA, Pardeshi L, Wang F, Rocha MC, Malavazi I, Silva RN, Martins C, Domingos P, Pereira-Silva C, Bromley MJ, Wong KH, Goldman GH. Aspergillus Fumigatus ZnfA, a Novel Zinc Finger Transcription Factor Involved in Calcium Metabolism and Caspofungin Tolerance. FRONTIERS IN FUNGAL BIOLOGY 2021; 2:689900. [PMID: 37744107 PMCID: PMC10512341 DOI: 10.3389/ffunb.2021.689900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 07/16/2021] [Indexed: 09/26/2023]
Abstract
Invasive pulmonary aspergillosis is a life-threatening fungal infection especially in the immunocompromised patients. The low diversity of available antifungal drugs coupled with the emergence of antifungal resistance has become a worldwide clinical concern. The echinocandin Caspofungin (CSP) is recommended as a second-line therapy but resistance and tolerance mechanisms have been reported. However, how the fungal cell articulates the response to CSP is not completely understood. This work provides a detailed characterization of ZnfA, a transcription factor (TF) identified in previous screening studies that is involved in the A. fumigatus responses to calcium and CSP. This TF plays an important role in the regulation of iron homeostasis and cell wall organization in response to high CSP concentrations as revealed by Chromatin Immunoprecipitation coupled to DNA sequencing (ChIP-seq) analysis. Furthermore, ZnfA acts collaboratively with the key TF CrzA in modulating the response to calcium as well as cell wall and osmotic stresses. This study therefore describes the existence of an additional, previously unknown TF that bridges calcium signaling and the CSP cellular response and further exposes the complex connections that exist among different pathways which govern stress sensing and signaling in A. fumigatus.
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Affiliation(s)
- Clara Valero
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Ana Cristina Colabardini
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Patrícia Alves de Castro
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Lilian Pereira Silva
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | | | - Lakhansing Pardeshi
- Faculty of Health Sciences, University of Macau, Macau, China
- Genomics and Bioinformatics Core, Faculty of Health Sciences, University of Macau, Macau, China
| | - Fang Wang
- Faculty of Health Sciences, University of Macau, Macau, China
- Genomics and Bioinformatics Core, Faculty of Health Sciences, University of Macau, Macau, China
| | - Marina Campos Rocha
- Departamento de Genética e Evolução, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Paulo, Brazil
| | - Iran Malavazi
- Departamento de Genética e Evolução, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Paulo, Brazil
| | | | - Celso Martins
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), Oeiras, Portugal
| | - Patrícia Domingos
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), Oeiras, Portugal
| | - Cristina Pereira-Silva
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), Oeiras, Portugal
| | - Michael J. Bromley
- Manchester Fungal Infection Group, Core Technology Facility, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester, United Kingdom
- Manchester Academic Health Science Centre, Lydia Becker Institute of Immunology and Inflammation, Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
| | - Koon Ho Wong
- Faculty of Health Sciences, University of Macau, Macau, China
- Faculty of Health Sciences, Institute of Translational Medicine, University of Macau, Macau, China
| | - Gustavo H. Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
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The Transcription Factor SomA Synchronously Regulates Biofilm Formation and Cell Wall Homeostasis in Aspergillus fumigatus. mBio 2020; 11:mBio.02329-20. [PMID: 33173002 PMCID: PMC7667024 DOI: 10.1128/mbio.02329-20] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The cell wall is essential for fungal viability and is absent from human hosts; thus, drugs disrupting cell wall biosynthesis have gained more attention. Caspofungin is a member of a new class of clinically approved echinocandin drugs to treat invasive aspergillosis by blocking β-1,3-glucan synthase, thus damaging the fungal cell wall. Here, we demonstrate that caspofungin and other cell wall stressors can induce galactosaminogalactan (GAG)-dependent biofilm formation in the human pathogen Aspergillus fumigatus. We further identified SomA as a master transcription factor playing a dual role in both biofilm formation and cell wall homeostasis. SomA plays this dual role by direct binding to a conserved motif upstream of GAG biosynthetic genes and genes involved in cell wall stress sensors, chitin synthases, and β-1,3-glucan synthase. Collectively, these findings reveal a transcriptional control pathway that integrates biofilm formation and cell wall homeostasis and suggest SomA as an attractive target for antifungal drug development. Polysaccharides are key components of both the fungal cell wall and biofilm matrix. Despite having distinct assembly and regulation pathways, matrix exopolysaccharide and cell wall polysaccharides share common substrates and intermediates in their biosynthetic pathways. It is not clear, however, if the biosynthetic pathways governing the production of these polysaccharides are cooperatively regulated. Here, we demonstrate that cell wall stress promotes production of the exopolysaccharide galactosaminogalactan (GAG)-depend biofilm formation in the major fungal pathogen of humans Aspergillus fumigatus and that the transcription factor SomA plays a crucial role in mediating this process. A core set of SomA target genes were identified by transcriptome sequencing and chromatin immunoprecipitation coupled to sequencing (ChIP-Seq). We identified a novel SomA-binding site in the promoter regions of GAG biosynthetic genes agd3 and ega3, as well as its regulators medA and stuA. Strikingly, this SomA-binding site was also found in the upstream regions of genes encoding the cell wall stress sensors, chitin synthases, and β-1,3-glucan synthase. Thus, SomA plays a direct regulation of both GAG and cell wall polysaccharide biosynthesis. Consistent with these findings, SomA is required for the maintenance of normal cell wall architecture and compositions in addition to its function in biofilm development. Moreover, SomA was found to globally regulate glucose uptake and utilization, as well as amino sugar and nucleotide sugar metabolism, which provides precursors for polysaccharide synthesis. Collectively, our work provides insight into fungal adaptive mechanisms in response to cell wall stress where biofilm formation and cell wall homeostasis were synchronously regulated.
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Martins-Santana L, Paula RGD, Silva AG, Lopes DCB, Silva RDN, Silva-Rocha R. CRZ1 regulator and calcium cooperatively modulate holocellulases gene expression in Trichoderma reesei QM6a. Genet Mol Biol 2020; 43:e20190244. [PMID: 32384133 PMCID: PMC7212764 DOI: 10.1590/1678-4685-gmb-2019-0244] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 12/22/2019] [Indexed: 02/06/2023] Open
Abstract
Trichoderma reesei is the main filamentous fungus used in industry to produce cellulases. Here we investigated the role of CRZ1 and Ca2+signaling in the fungus T. reesei QM6a concerning holocellulases production. For this, we first searched for potential CRZ1 binding sites in promoter regions of key genes coding holocellulases, as well as transcriptional regulators and sugar and calcium transporters. Using a nearly constructed T. reeseiAcrz1 strain, we demonstrated that most of the genes expected to be regulated by CRZ1 were affected in the mutant strain induced with sugarcane bagasse (SCB) and cellulose. In particular, our data demonstrate that Ca2+ acts synergistically with CRZ1 to modulate gene expression, but also exerts CRZ1-independent regulatory role in gene expression in T. reesei, highlighting the role of the major regulator Ca2+ on the signaling for holocellulases transcriptional control in the most part of cellulases genes here investigated. This work presents new evidence on the regulatory role of CRZ1 and Ca2+ sensing in the regulation of cellulolytic enzymes in T. reesei, evidencing significant and previously unknown function of this Ca2+sensing system in the control key transcriptional regulators (XYR1 and CRE1) and on the expression of genes related to sugar and Ca2+ transport.
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Affiliation(s)
- Leonardo Martins-Santana
- Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Laboratório de Biologia Sistêmica e Sintética, Ribeirão Preto, SP, Brazil.,Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Bioquímica e Imunologia, Ribeirão Preto, SP, Brazil
| | - Renato Graciano de Paula
- Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Bioquímica e Imunologia, Ribeirão Preto, SP, Brazil.,Universidade Federal do Espírito Santo, Centro de Ciências da Saúde, Departamento de Ciências Fisiológicas, Vitória, ES, Brazil
| | - Adriano Gomes Silva
- Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Laboratório de Biologia Sistêmica e Sintética, Ribeirão Preto, SP, Brazil
| | - Douglas Christian Borges Lopes
- Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Bioquímica e Imunologia, Ribeirão Preto, SP, Brazil
| | - Roberto do Nascimento Silva
- Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Bioquímica e Imunologia, Ribeirão Preto, SP, Brazil
| | - Rafael Silva-Rocha
- Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Laboratório de Biologia Sistêmica e Sintética, Ribeirão Preto, SP, Brazil
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Zheng YQ, Pan KS, Latgé JP, Andrianopoulos A, Luo H, Yan RF, Wei JY, Huang CY, Cao CW. Calcineurin A Is Essential in the Regulation of Asexual Development, Stress Responses and Pathogenesis in Talaromyces marneffei. Front Microbiol 2020; 10:3094. [PMID: 32038542 PMCID: PMC6985273 DOI: 10.3389/fmicb.2019.03094] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Accepted: 12/20/2019] [Indexed: 11/27/2022] Open
Abstract
Talaromyces marneffei is a common cause of infection in immunocompromised patients in Southeast Asia and Southern China. The pathogenicity of T. marneffei depends on the ability of the fungus to survive the cytotoxic processes of the host immune system and grow inside host macrophages. These mechanisms that allow T. marneffei to survive macrophage-induced death are poorly understood. In this study, we examined the role of a calcineurin homolog (cnaA) from T. marneffei during growth, morphogenesis and infection. Deletion of the cnaA gene in T. marneffei resulted in a strain with significant defects in conidiation, germination, morphogenesis, cell wall integrity, and resistance to various stressors. The ΔcnaA mutant showed a lower minimal inhibitory concentration (MIC) against caspofungin (16 μg/ml to 2 μg/ml) and micafungin (from 32 μg/ml to 4 μg/ml) compared with the wild-type. These results suggest that targeting calcineurin in combination with echinocandin treatment may be effective for life-threatening systemic T. marneffei infection. Importantly, the cnaA mutant was incapable of adapting to the macrophage environment in vitro and displayed virulence defects in a mouse model of invasive talaromycosis. For the first time, a role has been shown for cnaA in the morphology and pathogenicity of a dimorphic pathogenic filamentous fungus.
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Affiliation(s)
- Yan-Qing Zheng
- Department of Dermatology and Venereology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Kai-Su Pan
- Department of Dermatology and Venereology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | | | - Alex Andrianopoulos
- School of Biosciences, The University of Melbourne, Parkville, VIC, Australia
| | - Hong Luo
- Department of Dermatology and Venereology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Ru-Fan Yan
- Department of Dermatology and Venereology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Jin-Ying Wei
- Department of Dermatology and Venereology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Chun-Yang Huang
- Department of Dermatology and Venereology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Cun-Wei Cao
- Department of Dermatology and Venereology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
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Function of crzA in Fungal Development and Aflatoxin Production in Aspergillus flavus. Toxins (Basel) 2019; 11:toxins11100567. [PMID: 31569747 PMCID: PMC6832762 DOI: 10.3390/toxins11100567] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 09/26/2019] [Accepted: 09/27/2019] [Indexed: 12/11/2022] Open
Abstract
The calcineurin pathway is an important signaling cascade for growth, sexual development, stress response, and pathogenicity in fungi. In this study, we investigated the function of CrzA, a key transcription factor of the calcineurin pathway, in an aflatoxin-producing fungus Aspergillus flavus (A. flavus). To examine the role of the crzA gene, crzA deletion mutant strains in A. flavus were constructed and their phenotypes, including fungal growth, spore formation, and sclerotial formation, were examined. Absence of crzA results in decreased colony growth, the number of conidia, and sclerocia production. The crzA-deficient mutant strains were more susceptible to osmotic pressure and cell wall stress than control or complemented strains. Moreover, deletion of crzA results in a reduction in aflatoxin production. Taken together, these results demonstrate that CrzA is important for differentiation and mycotoxin production in A. flavus.
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