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du Plooy LM, Telzrow CL, Nichols CB, Probst C, Castro-Lopez N, Wormley FL, Alspaugh JA. A fungal ubiquitin ligase and arrestin binding partner contribute to pathogenesis and survival during cellular stress. mBio 2024:e0098124. [PMID: 39235249 DOI: 10.1128/mbio.00981-24] [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: 04/04/2024] [Accepted: 07/29/2024] [Indexed: 09/06/2024] Open
Abstract
Cellular responses to external stress allow microorganisms to adapt to a vast array of environmental conditions, including infection sites. The molecular mechanisms behind these responses are studied to gain insight into microbial pathogenesis, which could lead to new antimicrobial therapies. Here, we explore a role for arrestin protein-mediated ubiquitination in stress response and pathogenesis in the pathogenic fungus Cryptococcus neoformans. In a previous study, we identified four arrestin-like proteins in C. neoformans and found that one of these is required for efficient membrane synthesis, likely by directing interaction between fatty acid synthases and the Rsp5 E3 ubiquitin ligase. Here, we further explore Cn Rsp5 function and determine that this single Ub ligase is absolutely required for pathogenesis and survival in the presence of cellular stress. Additionally, we show that a second arrestin-like protein, Ali2, similarly facilitates interaction between Rsp5 and some of its protein targets. Of the four postulated C. neoformans arrestin-like proteins, Ali2 appears to contribute the most to C. neoformans pathogenesis, likely by directing Rsp5 to pathogenesis-related ubiquitination targets. A proteomics-based differential ubiquitination screen revealed that several known cell surface proteins are ubiquitinated by Rsp5 and a subset also requires Ali2 for their ubiquitination. Rsp5-mediated ubiquitination alters the stability and the localization of these proteins. A loss of Rsp5-mediated ubiquitination results in cell wall defects that increase susceptibility to external stresses. These findings support a model in which arrestin-like proteins guide Rsp5 to ubiquitinate specific target proteins, some of which are required for survival during stress. IMPORTANCE Microbial proteins involved in human infectious diseases often need to be modified by specific chemical additions to be fully functional. Here, we explore the role of a particular protein modification, ubiquitination, in infections due to the human fungal pathogen Cryptococcus neoformans. We identified a complex of proteins responsible for adding ubiquitin groups to fungal proteins, and this complex is required for virulence. These proteins are fungal specific and might be targets for novel anti-infection therapy.
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Affiliation(s)
- Lukas M du Plooy
- Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Calla L Telzrow
- Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Connie B Nichols
- Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
| | - Corinna Probst
- Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
| | - Natalia Castro-Lopez
- Department of Biology, University of Texas at San Antonio, San Antonio, Texas, USA
- Department of Biology, Texas Christian University, Fort Worth, Texas, USA
| | - Floyd L Wormley
- Department of Biology, University of Texas at San Antonio, San Antonio, Texas, USA
- Department of Biology, Texas Christian University, Fort Worth, Texas, USA
| | - J Andrew Alspaugh
- Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, North Carolina, USA
- Department of Cell Biology, Duke University School of Medicine, Durham, North Carolina, USA
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2
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Flores-Almaraz VS, Truong C, Hernández-Oaxaca D, Reyes-Galindo V, Mastretta-Yanes A, Jaramillo-Correa JP, Salas-Lizana R. Foliar mycobiome remains unaltered under urban air-pollution but differentially express stress-related genes. MICROBIAL ECOLOGY 2024; 87:72. [PMID: 38755460 PMCID: PMC11098924 DOI: 10.1007/s00248-024-02387-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 04/29/2024] [Indexed: 05/18/2024]
Abstract
Air pollution caused by tropospheric ozone contributes to the decline of forest ecosystems; for instance, sacred fir, Abies religiosa (Kunth) Schltdl. & Cham. forests in the peri-urban region of Mexico City. Individual trees within these forests exhibit variation in their response to ozone exposure, including the severity of visible symptoms in needles. Using RNA-Seq metatranscriptomic data and ITS2 metabarcoding, we investigated whether symptom variation correlates with the taxonomic and functional composition of fungal mycobiomes from needles collected in this highly polluted area in the surroundings of Mexico City. Our findings indicate that ozone-related symptoms do not significantly correlate with changes in the taxonomic composition of fungal mycobiomes. However, genes coding for 30 putative proteins were differentially expressed in the mycobiome of asymptomatic needles, including eight genes previously associated with resistance to oxidative stress. These results suggest that fungal communities likely play a role in mitigating the oxidative burst caused by tropospheric ozone in sacred fir. Our study illustrates the feasibility of using RNA-Seq data, accessible from global sequence repositories, for the characterization of fungal communities associated with plant tissues, including their gene expression.
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Affiliation(s)
- Valeria Stephany Flores-Almaraz
- Posgrado en Ciencias Biológicas, Unidad de Posgrado, Edificio A, 1° Piso, Circuito de Posgrados, Ciudad Universitaria, Coyoacán, C.P. 04510, Distrito Federal, México
- Instituto de Biología, Universidad Nacional Autónoma de México, Av. Universidad 3000, 04510, Coyoacán, Ciudad de México, Mexico
| | - Camille Truong
- Royal Botanic Gardens Victoria, Birdwood Ave, Melbourne, VIC 3004, Australia.
| | - Diana Hernández-Oaxaca
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Av. Universidad S/N, 62210, Cuernavaca, Morelos, México
| | - Verónica Reyes-Galindo
- Depto. de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Av. Universidad 3000, 04510, Coyoacán, Ciudad de México, Mexico
| | - Alicia Mastretta-Yanes
- Consejo Nacional de Humanidades Ciencias y Tecnología (CONAHCYT), Avenida Insurgentes Sur 1582, Crédito Constructor, Benito Juárez, Ciudad de México, 03940, México.
- Departamento de Ecología de la Biodiversidad, Instituto de Ecología, Universidad Nacional Autónoma de México, Av. Universidad 3000, 04510, Coyoacán, Ciudad de México, Mexico.
| | - Juan Pablo Jaramillo-Correa
- Depto. de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Av. Universidad 3000, 04510, Coyoacán, Ciudad de México, Mexico
| | - Rodolfo Salas-Lizana
- Laboratorios de Micología. Depto. de Biología Comparada, Facultad de Ciencias., Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, Coyoacán, 04510, Ciudad de México, México.
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3
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Nagy L, Vonk P, Künzler M, Földi C, Virágh M, Ohm R, Hennicke F, Bálint B, Csernetics Á, Hegedüs B, Hou Z, Liu X, Nan S, Pareek M, Sahu N, Szathmári B, Varga T, Wu H, Yang X, Merényi Z. Lessons on fruiting body morphogenesis from genomes and transcriptomes of Agaricomycetes. Stud Mycol 2023; 104:1-85. [PMID: 37351542 PMCID: PMC10282164 DOI: 10.3114/sim.2022.104.01] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 12/02/2022] [Indexed: 01/09/2024] Open
Abstract
Fruiting bodies (sporocarps, sporophores or basidiomata) of mushroom-forming fungi (Agaricomycetes) are among the most complex structures produced by fungi. Unlike vegetative hyphae, fruiting bodies grow determinately and follow a genetically encoded developmental program that orchestrates their growth, tissue differentiation and sexual sporulation. In spite of more than a century of research, our understanding of the molecular details of fruiting body morphogenesis is still limited and a general synthesis on the genetics of this complex process is lacking. In this paper, we aim at a comprehensive identification of conserved genes related to fruiting body morphogenesis and distil novel functional hypotheses for functionally poorly characterised ones. As a result of this analysis, we report 921 conserved developmentally expressed gene families, only a few dozens of which have previously been reported to be involved in fruiting body development. Based on literature data, conserved expression patterns and functional annotations, we provide hypotheses on the potential role of these gene families in fruiting body development, yielding the most complete description of molecular processes in fruiting body morphogenesis to date. We discuss genes related to the initiation of fruiting, differentiation, growth, cell surface and cell wall, defence, transcriptional regulation as well as signal transduction. Based on these data we derive a general model of fruiting body development, which includes an early, proliferative phase that is mostly concerned with laying out the mushroom body plan (via cell division and differentiation), and a second phase of growth via cell expansion as well as meiotic events and sporulation. Altogether, our discussions cover 1 480 genes of Coprinopsis cinerea, and their orthologs in Agaricus bisporus, Cyclocybe aegerita, Armillaria ostoyae, Auriculariopsis ampla, Laccaria bicolor, Lentinula edodes, Lentinus tigrinus, Mycena kentingensis, Phanerochaete chrysosporium, Pleurotus ostreatus, and Schizophyllum commune, providing functional hypotheses for ~10 % of genes in the genomes of these species. Although experimental evidence for the role of these genes will need to be established in the future, our data provide a roadmap for guiding functional analyses of fruiting related genes in the Agaricomycetes. We anticipate that the gene compendium presented here, combined with developments in functional genomics approaches will contribute to uncovering the genetic bases of one of the most spectacular multicellular developmental processes in fungi. Citation: Nagy LG, Vonk PJ, Künzler M, Földi C, Virágh M, Ohm RA, Hennicke F, Bálint B, Csernetics Á, Hegedüs B, Hou Z, Liu XB, Nan S, M. Pareek M, Sahu N, Szathmári B, Varga T, Wu W, Yang X, Merényi Z (2023). Lessons on fruiting body morphogenesis from genomes and transcriptomes of Agaricomycetes. Studies in Mycology 104: 1-85. doi: 10.3114/sim.2022.104.01.
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Affiliation(s)
- L.G. Nagy
- Synthetic and Systems Biology Unit, Biological Research Center, Szeged, 6726, Hungary;
| | - P.J. Vonk
- Microbiology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands;
| | - M. Künzler
- Institute of Microbiology, Department of Biology, Eidgenössische Technische Hochschule (ETH) Zürich, Zürich, Switzerland;
| | - C. Földi
- Synthetic and Systems Biology Unit, Biological Research Center, Szeged, 6726, Hungary;
| | - M. Virágh
- Synthetic and Systems Biology Unit, Biological Research Center, Szeged, 6726, Hungary;
| | - R.A. Ohm
- Microbiology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands;
| | - F. Hennicke
- Project Group Genetics and Genomics of Fungi, Chair Evolution of Plants and Fungi, Ruhr-University Bochum, 44780, Bochum, North Rhine-Westphalia, Germany;
| | - B. Bálint
- Synthetic and Systems Biology Unit, Biological Research Center, Szeged, 6726, Hungary;
| | - Á. Csernetics
- Synthetic and Systems Biology Unit, Biological Research Center, Szeged, 6726, Hungary;
| | - B. Hegedüs
- Synthetic and Systems Biology Unit, Biological Research Center, Szeged, 6726, Hungary;
| | - Z. Hou
- Synthetic and Systems Biology Unit, Biological Research Center, Szeged, 6726, Hungary;
| | - X.B. Liu
- Synthetic and Systems Biology Unit, Biological Research Center, Szeged, 6726, Hungary;
| | - S. Nan
- Institute of Applied Mycology, Huazhong Agricultural University, 430070 Hubei Province, PR China
| | - M. Pareek
- Synthetic and Systems Biology Unit, Biological Research Center, Szeged, 6726, Hungary;
| | - N. Sahu
- Synthetic and Systems Biology Unit, Biological Research Center, Szeged, 6726, Hungary;
| | - B. Szathmári
- Synthetic and Systems Biology Unit, Biological Research Center, Szeged, 6726, Hungary;
| | - T. Varga
- Synthetic and Systems Biology Unit, Biological Research Center, Szeged, 6726, Hungary;
| | - H. Wu
- Synthetic and Systems Biology Unit, Biological Research Center, Szeged, 6726, Hungary;
| | - X. Yang
- Institute of Applied Mycology, Huazhong Agricultural University, 430070 Hubei Province, PR China
| | - Z. Merényi
- Synthetic and Systems Biology Unit, Biological Research Center, Szeged, 6726, Hungary;
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Stempinski PR, Goughenour KD, du Plooy LM, Alspaugh JA, Olszewski MA, Kozubowski L. The Cryptococcus neoformans Flc1 Homologue Controls Calcium Homeostasis and Confers Fungal Pathogenicity in the Infected Hosts. mBio 2022; 13:e0225322. [PMID: 36169198 PMCID: PMC9600462 DOI: 10.1128/mbio.02253-22] [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: 08/08/2022] [Accepted: 09/12/2022] [Indexed: 01/30/2023] Open
Abstract
Cryptococcus neoformans, an opportunistic yeast pathogen, relies on a complex network of stress response pathways that allow for proliferation in the host. In Saccharomyces cerevisiae, stress responses are regulated by integral membrane proteins containing a transient receptor potential (TRP) domain, including the flavin carrier protein 1 (Flc1), which regulates calcium homeostasis and flavin transport. Here, we report that deletion of C. neoformans FLC1 results in cytosolic calcium elevation and increased nuclear content of calcineurin-dependent transcription factor Crz1, which is associated with an aberrant cell wall chitin overaccumulation observed in the flc1Δ mutant. Absence of Flc1 or inhibition of calcineurin with cyclosporine A prevents vacuolar fusion under conditions of combined osmotic and temperature stress, which is reversed in the flc1Δ mutant by the inhibition of TORC1 kinase with rapamycin. Flc1-deficient yeasts exhibit compromised vacuolar fusion under starvation conditions, including conditions that stimulate formation of carbohydrate capsule. Consequently, the flc1Δ mutant fails to proliferate under low nutrient conditions and displays a defect in capsule formation. Consistent with the previously uncharacterized role of Flc1 in vacuolar biogenesis, we find that Flc1 localizes to the vacuole. The flc1Δ mutant presents a survival defect in J774A.1 macrophage cell-line and profound virulence attenuation in both the Galleria mellonella and mouse pulmonary infection models, demonstrating that Flc1 is essential for pathogenicity. Thus, cryptococcal Flc1 functions in calcium homeostasis and links calcineurin and TOR signaling with vacuolar biogenesis to promote survival under conditions associated with vacuolar fusion required for this pathogen's fitness and virulence. IMPORTANCE Cryptococcosis is a highly lethal infection with limited drug choices, most of which are highly toxic or complicated by emerging antifungal resistance. There is a great need for new drug targets that are unique to the fungus. Here, we identify such a potential target, the Flc1 protein, which we show is crucial for C. neoformans stress response and virulence. Importantly, homologues of Flc1 exist in other fungal pathogens, such as Candida albicans and Aspergillus fumigatus, and are poorly conserved in humans, which could translate into wider spectrum therapy associated with minimal toxicity. Thus, Flc1 could be an "Achille's heel" of C. neoformans to be leveraged therapeutically in cryptococcosis and possibly other fungal infections.
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Affiliation(s)
- Piotr R. Stempinski
- Department of Genetics and Biochemistry, Eukaryotic Pathogens Innovation Center (EPIC), Clemson University, Clemson, South Carolina, USA
| | - Kristie D. Goughenour
- LTC Charles S. Kettles VA Medical Center, Ann Arbor, Michigan, USA
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School
| | - Lukas M. du Plooy
- Departments of Medicine and Molecular Genetics/Microbiology, Duke University Medical Center, Durham, North Carolina, USA
| | - J. Andrew Alspaugh
- Departments of Medicine and Molecular Genetics/Microbiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Michal A. Olszewski
- LTC Charles S. Kettles VA Medical Center, Ann Arbor, Michigan, USA
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School
| | - Lukasz Kozubowski
- Department of Genetics and Biochemistry, Eukaryotic Pathogens Innovation Center (EPIC), Clemson University, Clemson, South Carolina, USA
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5
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Zhou L, Li M, Cui P, Tian M, Xu Y, Zheng X, Zhang K, Li G, Wang X. Arrestin-Coding Genes Regulate Endocytosis, Sporulation, Pathogenicity, and Stress Resistance in Arthrobotrys oligospora. Front Cell Infect Microbiol 2022; 12:754333. [PMID: 35252023 PMCID: PMC8890662 DOI: 10.3389/fcimb.2022.754333] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 01/20/2022] [Indexed: 12/12/2022] Open
Abstract
Arrestins are a family of scaffold proteins that play a crucial role in regulating numerous cellular processes, such as GPCR signaling. The Arthrobotrys oligospora arrestin family contains 12 members, which have highly conserved N-terminal and C-terminal domains. In the presence of ammonia, A. oligospora can change its lifestyle from saprotrophic to carnivorous. During this transition, the expression pattern of arrestin-coding (AoArc) genes was markedly upregulated. Therefore, we disrupted seven AoArc genes from A. oligospora to identify their functions. Although individual arrestin mutant strains display similar pathogenesis, phenotypes, and stress resistance, the fundamental data on the roles of AoArc genes in A. oligospora are obtained in this study. Membrane endocytosis in AoArc mutants was significantly reduced. Meanwhile, the capacity of trap device formation against nematodes and ammonia was impaired due to AoArc deletions. We also found that AoArc genes could regulate conidial phenotypes, cell nuclear distribution, pH response, and stress resistance. Results of qRT-PCR assays revealed that sporulation-regulated genes were affected after the deletion of AoArc genes. In particular, among the 12 arrestins, AoArc2 mediates pH signaling in the fungus A. oligospora. Notably, combined with the classical paradigm of arrestin–GPCR signal transduction, we suggest that arrestin-regulated trap formation in A. oligospora may be directly linked to the receptor endocytosis pathway.
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Affiliation(s)
- Liang Zhou
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming, China
- Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, China
| | - Mengfei Li
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming, China
- Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, China
| | - Peijie Cui
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming, China
- Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, China
| | - Mengqing Tian
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming, China
- Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, China
| | - Ya Xu
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming, China
- Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, China
| | - Xi Zheng
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming, China
- Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, China
| | - Keqin Zhang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming, China
- Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, China
| | - Guohong Li
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming, China
- Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, China
- *Correspondence: Xin Wang, ; Guohong Li,
| | - Xin Wang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming, China
- Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, China
- *Correspondence: Xin Wang, ; Guohong Li,
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6
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Abstract
The ability for cells to maintain homeostasis in the presence of extracellular stress is essential for their survival. Stress adaptations are especially important for microbial pathogens to respond to rapidly changing conditions, such as those encountered during the transition from the environment to the infected host. Many fungal pathogens have acquired the ability to quickly adapt to changes in extracellular pH to promote their survival in the various microenvironments encountered during a host infection. For example, the fungus-specific Rim/Pal alkaline response pathway has been well characterized in many fungal pathogens, including Cryptococcus neoformans However, alternative mechanisms for sensing and responding to host pH have yet to be extensively studied. Recent observations from a genetic screen suggest that the C. neoformans sterol homeostasis pathway is required for growth at elevated pH. This work explores interactions among mechanisms of membrane homeostasis, alkaline pH tolerance, and Rim pathway activation. We find that the sterol homeostasis pathway is necessary for growth in an alkaline environment and that an elevated pH is sufficient to induce Sre1 activation. This pH-mediated activation of the Sre1 transcription factor is linked to the biosynthesis of ergosterol but is not dependent on Rim pathway signaling, suggesting that these two pathways are responding to alkaline pH independently. Furthermore, we discover that C. neoformans is more susceptible to membrane-targeting antifungals under alkaline conditions, highlighting the impact of microenvironmental pH on the treatment of invasive fungal infections. Together, these findings further connect membrane integrity and composition with the fungal pH response and pathogenesis.IMPORTANCE The work described here further elucidates how microorganisms sense and adapt to changes in their environment to establish infections in the human host. Specifically, we uncover a novel mechanism by which an opportunistic human fungal pathogen, Cryptococcus neoformans, responds to increases in extracellular pH in order to survive and thrive within the relatively alkaline environment of the human lung. This mechanism, which is intimately linked with fungal membrane sterol homeostasis, is independent of the previously well-studied alkaline response Rim pathway. Furthermore, this ergosterol-dependent alkaline pH response is present in Candida albicans, indicating that this mechanism spans diverse fungal species. These results are also relevant for novel antimicrobial drug development as we show that currently used ergosterol-targeting antifungals are more active in alkaline environments.
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