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Dladla M, Gyzenhout M, Marias G, Ghosh S. Azole resistance in Aspergillus fumigatus- comprehensive review. Arch Microbiol 2024; 206:305. [PMID: 38878211 DOI: 10.1007/s00203-024-04026-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Revised: 05/28/2024] [Accepted: 05/31/2024] [Indexed: 06/23/2024]
Abstract
Aspergillus fumigatus is a ubiquitous filamentous fungus commonly found in the environment. It is also an opportunistic human pathogen known to cause a range of respiratory infections, such as invasive aspergillosis, particularly in immunocompromised individuals. Azole antifungal agents are widely used for the treatment and prophylaxis of Aspergillus infections due to their efficacy and tolerability. However, the emergence of azole resistance in A. fumigatus has become a major concern in recent years due to their association with increased treatment failures and mortality rates. The development of azole resistance in A. fumigatus can occur through both acquired and intrinsic mechanisms. Acquired resistance typically arises from mutations in the target enzyme, lanosterol 14-α-demethylase (Cyp51A), reduces the affinity of azole antifungal agents for the enzyme, rendering them less effective, while intrinsic resistance refers to a natural resistance of certain A. fumigatus isolates to azole antifungals due to inherent genetic characteristics. The current review aims to provide a comprehensive overview of azole antifungal resistance in A. fumigatus, discusses underlying resistance mechanisms, including alterations in the target enzyme, Cyp51A, and the involvement of efflux pumps in drug efflux. Impact of azole fungicide uses in the environment and the spread of resistant strains is also explored.
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Affiliation(s)
- Mthokozisi Dladla
- Department of Genetics, Faculty of Natural and Agricultural Sciences, University of the Free State, Bloemfontein, 9301, South Africa
| | - Marieka Gyzenhout
- Department of Genetics, Faculty of Natural and Agricultural Sciences, University of the Free State, Bloemfontein, 9301, South Africa.
| | - Gert Marias
- Department of Plant Sciences, Division of Plant Pathology, Faculty of Natural and Agricultural Sciences, University of the Free State, Bloemfontein, South Africa
| | - Soumya Ghosh
- Department of Genetics, Faculty of Natural and Agricultural Sciences, University of the Free State, Bloemfontein, 9301, South Africa.
- Natural and Medical Sciences Research Center, University of Nizwa, Nizwa 616, Birkat Al Mawz, Oman.
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de Matos Silva S, Echeverri CR, Mendes-Giannini MJS, Fusco-Almeida AM, Gonzalez A. Common virulence factors between Histoplasma and Paracoccidioides: Recognition of Hsp60 and Enolase by CR3 and plasmin receptors in host cells. CURRENT RESEARCH IN MICROBIAL SCIENCES 2024; 7:100246. [PMID: 39022313 PMCID: PMC11253281 DOI: 10.1016/j.crmicr.2024.100246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2024] Open
Abstract
Over the last two decades, the incidence of Invasive Fungal Infections (IFIs) globally has risen, posing a considerable challenge despite available antifungal therapies. Addressing this, the World Health Organization (WHO) prioritized research on specific fungi, notably Histoplasma spp. and Paracoccidioides spp. These dimorphic fungi have a mycelial life cycle in soil and a yeast phase associated with tissues of mammalian hosts. Inhalation of conidia and mycelial fragments initiates the infection, crucially transforming into the yeast form within the host, influenced by factors like temperature, host immunity, and hormonal status. Survival and multiplication within alveolar macrophages are crucial for disease progression, where innate immune responses play a pivotal role in overcoming physical barriers. The transition to pathogenic yeast, triggered by increased temperature, involves yeast phase-specific gene expression, closely linked to infection establishment and pathogenicity. Cell adhesion mechanisms during host-pathogen interactions are intricately linked to fungal virulence, which is critical for tissue colonization and disease development. Yeast replication within macrophages leads to their rupture, aiding pathogen dissemination. Immune cells, especially macrophages, dendritic cells, and neutrophils, are key players during infection control, with macrophages crucial for defense, tissue integrity, and pathogen elimination. Recognition of common virulence molecules such as heat- shock protein-60 (Hsp60) and enolase by pattern recognition receptors (PRRs), mainly via the complement receptor 3 (CR3) and plasmin receptor pathways, respectively, could be pivotal in host-pathogen interactions for Histoplasma spp. and Paracoccidioides spp., influencing adhesion, phagocytosis, and inflammatory regulation. This review provides a comprehensive overview of the dynamic of these two IFIs between host and pathogen. Further research into these fungi's virulence factors promises insights into pathogenic mechanisms, potentially guiding the development of effective treatment strategies.
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Affiliation(s)
- Samanta de Matos Silva
- Laboratory of Mycology, Department of Clinical Analysis, School of Pharmaceutical Science, Paulista State University (UNESP), Araraquara, Brazil
- Nucleous of Proteomics, Department of Clinical Analysis, School of Pharmaceutical Science, Paulista State University (UNESP), Araraquara, Brazil
- Basic and Applied Microbiology Group (MICROBA), School of Microbiology, Universidad de Antioquia (UdeA), Medellín, Colombia
| | - Carolina Rodriguez Echeverri
- Laboratory of Mycology, Department of Clinical Analysis, School of Pharmaceutical Science, Paulista State University (UNESP), Araraquara, Brazil
- Nucleous of Proteomics, Department of Clinical Analysis, School of Pharmaceutical Science, Paulista State University (UNESP), Araraquara, Brazil
- Basic and Applied Microbiology Group (MICROBA), School of Microbiology, Universidad de Antioquia (UdeA), Medellín, Colombia
| | - Maria José Soares Mendes-Giannini
- Laboratory of Mycology, Department of Clinical Analysis, School of Pharmaceutical Science, Paulista State University (UNESP), Araraquara, Brazil
- Nucleous of Proteomics, Department of Clinical Analysis, School of Pharmaceutical Science, Paulista State University (UNESP), Araraquara, Brazil
| | - Ana Marisa Fusco-Almeida
- Laboratory of Mycology, Department of Clinical Analysis, School of Pharmaceutical Science, Paulista State University (UNESP), Araraquara, Brazil
- Nucleous of Proteomics, Department of Clinical Analysis, School of Pharmaceutical Science, Paulista State University (UNESP), Araraquara, Brazil
| | - Angel Gonzalez
- Basic and Applied Microbiology Group (MICROBA), School of Microbiology, Universidad de Antioquia (UdeA), Medellín, Colombia
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Wang K, Wen S, Shang L, Li Y, Li Z, Chen W, Li Y, Jian H, Lyu D. Rapid Identification of High-Temperature Responsive Genes Using Large-Scale Yeast Functional Screening System in Potato. PLANTS (BASEL, SWITZERLAND) 2023; 12:3712. [PMID: 37960068 PMCID: PMC10650283 DOI: 10.3390/plants12213712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 10/19/2023] [Accepted: 10/26/2023] [Indexed: 11/15/2023]
Abstract
As the third largest global food crop, potato plays an important role in ensuring food security. However, it is particularly sensitive to high temperatures, which seriously inhibits its growth and development, thereby reducing yield and quality and severely limiting its planting area. Therefore, rapid, and high-throughput screening for high-temperature response genes is highly significant for analyzing potato high-temperature tolerance molecular mechanisms and cultivating new high-temperature-tolerant potato varieties. We screened genes that respond to high temperature by constructing a potato cDNA yeast library. After high-temperature treatment at 39 °C, the yeast library was subjected to high-throughput sequencing, and a total of 1931 heat resistance candidate genes were screened. Through GO and KEGG analysis, we found they were mainly enriched in "photosynthesis" and "response to stimuli" pathways. Subsequently, 12 randomly selected genes were validated under high temperature, drought, and salt stress using qRT-PCR. All genes were responsive to high temperature, and most were also induced by drought and salt stress. Among them, five genes ectopically expressed in yeast enhance yeast's tolerance to high temperatures. We provide numerous candidate genes for potato response to high temperature stress, laying the foundation for subsequent analysis of the molecular mechanism of potato response to high temperature.
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Affiliation(s)
- Ke Wang
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Southwest University, Chongqing 400715, China
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China
| | - Shiqi Wen
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Southwest University, Chongqing 400715, China
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China
| | - Lina Shang
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Southwest University, Chongqing 400715, China
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China
| | - Yang Li
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Southwest University, Chongqing 400715, China
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China
| | - Ziyan Li
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Southwest University, Chongqing 400715, China
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China
| | - Weixi Chen
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Southwest University, Chongqing 400715, China
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China
| | - Yong Li
- Agriculture College, Anshun University, Anshun 561000, China
| | - Hongju Jian
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Southwest University, Chongqing 400715, China
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China
- State Cultivation Base of Crop Stress Biology for Southern Mountainous Land, Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Biology and Genetic Breeding for Tuber and Root Crops, Chongqing 400715, China
| | - Dianqiu Lyu
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Southwest University, Chongqing 400715, China
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China
- State Cultivation Base of Crop Stress Biology for Southern Mountainous Land, Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Biology and Genetic Breeding for Tuber and Root Crops, Chongqing 400715, China
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Wasana WP, Senevirathne A, Nikapitiya C, Lee JS, Kang DH, Kwon KK, Oh C, De Zoysa M. Probiotic effects of Pseudoalteromonas ruthenica: Antibacterial, immune stimulation and modulation of gut microbiota composition. FISH & SHELLFISH IMMUNOLOGY 2022; 131:229-243. [PMID: 36210003 DOI: 10.1016/j.fsi.2022.09.070] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 09/27/2022] [Accepted: 09/29/2022] [Indexed: 06/16/2023]
Abstract
This study aimed to characterise and evaluate the probiotic properties of a newly isolated marine bacterium, strain S6031. The isolated strain was identified as Pseudoalteromonas ruthenica. In vivo experiments were conducted with P. ruthenica-immersed larvae and P. ruthenica-enriched Artemia fed to adult zebrafish. Disease tolerance of larval zebrafish against Edwardsiella piscicida was demonstrated by 66.34% cumulative per cent survival (CPS) in the P. ruthenica-exposed group, which was higher than the CPS of the control (46.67%) at 72 h post challenge (hpc). Heat-stressed larvae had 55% CPS in the P. ruthenica-immersed group, while the control had 30% CPS at 60 hpc. Immune-stress response gene transcripts (muc5.1, muc5.2, muc5.3, alpi2, alpi3, hsp70, and hsp90a) were induced, while pro-inflammatory genes (tnfα, il1b, and il6) were downregulated in P. ruthenica-immersed larvae compared to the control. This trend was confirmed by low pro-inflammatory and high stress-responsive protein expression levels in P. ruthenica-exposed larvae. Adult zebrafish had higher CPS (27.2%) in the P. ruthenica-fed group than the control (9.52%) upon E. piscicida challenge, suggesting increased disease tolerance. Histological analysis demonstrated modulation of goblet cell density and average villus height in the P. ruthenica-supplemented group. Metagenomics analysis clearly indicated modulation of alpha diversity indices and the relative abundance of Proteobacteria in the P. ruthenica-supplemented zebrafish gut. Furthermore, increased Firmicutes colonisation and reduced Bacteroidetes abundance in the gut were observed upon P. ruthenica supplementation. Additionally, this study confirmed the concentration-dependent increase of colony dispersion and macrophage uptake upon mucin treatment. In summary, P. ruthenica possesses remarkable functional properties as a probiotic that enhances host defence against diseases and thermal stress.
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Affiliation(s)
- Withanage Prasadini Wasana
- College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungnam National University, Yuseong-gu, Daejeon 34134, Republic of Korea
| | - Amal Senevirathne
- College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungnam National University, Yuseong-gu, Daejeon 34134, Republic of Korea
| | - Chamilani Nikapitiya
- College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungnam National University, Yuseong-gu, Daejeon 34134, Republic of Korea
| | - Jong-Soo Lee
- College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungnam National University, Yuseong-gu, Daejeon 34134, Republic of Korea
| | - Do-Hyung Kang
- Jeju Marine Research Center, Korea Institute of Ocean Science and Technology (KIOST), Gujwa‑eup, Jeju Special Self-Governing Province 63349, Republic of Korea; Department of Ocean Science, University of Science and Technology, 217, Gajeong-ro, Yuseong-gu, Daejeon 34113, Republic of Korea
| | - Kae Kyoung Kwon
- Marine Biotechnology Research Center, Korea Institute of Ocean Science and Technology (KIOST), Busan, Republic of Korea; Department of Ocean Science, University of Science and Technology, 217, Gajeong-ro, Yuseong-gu, Daejeon 34113, Republic of Korea
| | - Chulhong Oh
- Jeju Marine Research Center, Korea Institute of Ocean Science and Technology (KIOST), Gujwa‑eup, Jeju Special Self-Governing Province 63349, Republic of Korea; Department of Ocean Science, University of Science and Technology, 217, Gajeong-ro, Yuseong-gu, Daejeon 34113, Republic of Korea.
| | - Mahanama De Zoysa
- College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungnam National University, Yuseong-gu, Daejeon 34134, Republic of Korea.
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Regulation of Hsp80 involved in the acquisition of induced thermotolerance, and NCA-2 involved in calcium stress tolerance by the calcineurin-CRZ-1 signaling pathway in Neurospora crassa. Mycol Prog 2022. [DOI: 10.1007/s11557-022-01833-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Millson SH, Truman AW, Piper PW. Hsp90 and phosphorylation of the Slt2(Mpk1) MAP kinase activation loop are essential for catalytic, but not non-catalytic, Slt2-mediated transcription in yeast. Cell Stress Chaperones 2022; 27:295-304. [PMID: 35420390 PMCID: PMC9106771 DOI: 10.1007/s12192-022-01274-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/01/2022] [Accepted: 04/05/2022] [Indexed: 11/18/2022] Open
Abstract
In yeast, the Slt2(Mpk1) stress-activated protein kinase directs the activation of two transcription factors, Rlm1 and Swi4/Swi6, in response to cell wall stress. Rlm1 is activated through a phosphorylation by Slt2, whereas the Swi4/Swi6 activation is noncatalytic and triggered by the binding of phosphorylated forms of both Slt2 and a catalytically inactive pseudokinase (Mlp1). Previous studies have delineated a role for the molecular chaperone Hsp90 in the activation of Slt2, but the involvement of Hsp90 in these events of catalytic versus non-catalytic cell integrity signaling has remained elusive. In cells lacking Mlp1, the Hsp90 inhibitor radicicol was found to inhibit the Slt2-mediated catalytic activation of Rlm1, but not the noncatalytic activation of Swi4/Swi6. Mutation of residues in the TEY motif of the Slt2 activation loop strongly impacted both Hsp90 binding and Rlm1-mediated transcription. In contrast, many of these same mutations had only modest effects on Swi4/6 (Slt2-mediated, non-catalytic) transcription, although one that blocked both the Slt2:Hsp90 interaction and Rlm1-mediated transcription (E191G) triggered a hyperactivation of Swi4/6. Taken together, our results cement the importance of the Slt2 activation loop for both the binding of Hsp90 by Slt2 and the catalytic activation of cell integrity signaling.
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Affiliation(s)
- Stefan H Millson
- School of Life Sciences, University of Lincoln, Brayford Pool, Lincoln, LN6 7DL, UK
| | - Andrew W Truman
- Department of Biological Sciences, The University of North Carolina at Charlotte, Charlotte, NC, 28223, USA
| | - Peter W Piper
- Department of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK.
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A Novel Pseudoalteromonas xiamenensis Marine Isolate as a Potential Probiotic: Anti-Inflammatory and Innate Immune Modulatory Effects against Thermal and Pathogenic Stresses. Mar Drugs 2021; 19:md19120707. [PMID: 34940706 PMCID: PMC8707914 DOI: 10.3390/md19120707] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 12/11/2021] [Accepted: 12/12/2021] [Indexed: 11/16/2022] Open
Abstract
A marine bacterial strain was isolated from seawater and characterized for it beneficial probiotic effects using zebrafish as a model system. The strain was identified by morphological, physiological, biochemical, and phylogenetic analyses. The strain was most closely related to Pseudoalteromonas xiamenensis Y2, with 99.66% similarity; thus, we named it Pseudoalteromonas xiamenensis S1131. Improvement of host disease tolerance for the P. xiamenensis isolate was adapted in a zebrafish model using Edwardsiella piscicida challenge. The larvae were pre-exposed to P. xiamenensis prior to E. piscicida challenge, resulting in a 73.3% survival rate compared to a 46.6% survival for the control. The treated larvae tolerated elevated temperatures at 38 °C, with 85% survival, compared to 60% survival for the control. Assessment of immunomodulatory responses at the mRNA level demonstrated the suppression of pro-inflammatory markers tnfα and il6, and upregulation of heat shock protein hsp90 and mucin genes. The same effect was corroborated by immunoblot analysis, revealing significant inhibition of Tnfα and an enhanced expression of the Hsp90 protein. The antibacterial activity of P. xiamenensis may be related to mucin overexpression, which can suppress bacterial biofilm formation and enhance macrophage uptake. This phenomenon was evaluated using nonstimulated macrophage RAW264.7 cells. Further studies may be warranted to elucidate a complete profile of the probiotic effects, to expand the potential applications of the present P. xiamenensis isolate.
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Abu Bakar N, Karsani SA, Alias SA. Fungal survival under temperature stress: a proteomic perspective. PeerJ 2020; 8:e10423. [PMID: 33362961 PMCID: PMC7747687 DOI: 10.7717/peerj.10423] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 11/03/2020] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Increases in knowledge of climate change generally, and its impact on agricultural industries specifically, have led to a greater research effort aimed at improving understanding of the role of fungi in various fields. Fungi play a key role in soil ecosystems as the primary agent of decomposition, recycling of organic nutrients. Fungi also include important pathogens of plants, insects, bacteria, domestic animals and humans, thus highlighting their importance in many contexts. Temperature directly affects fungal growth and protein dynamics, which ultimately will cascade through to affect crop performance. To study changes in the global protein complement of fungi, proteomic approaches have been used to examine links between temperature stress and fungal proteomic profiles. SURVEY METHODOLOGY AND OBJECTIVES A traditional rather than a systematic review approach was taken to focus on fungal responses to temperature stress elucidated using proteomic approaches. The effects of temperature stress on fungal metabolic pathways and, in particular, heat shock proteins (HSPs) are discussed. The objective of this review is to provide an overview of the effects of temperature stress on fungal proteomes. CONCLUDING REMARKS Elucidating fungal proteomic response under temperature stress is useful in the context of increasing understanding of fungal sensitivity and resilience to the challenges posed by contemporary climate change processes. Although useful, a more thorough work is needed such as combining data from multiple -omics platforms in order to develop deeper understanding of the factor influencing and controlling cell physiology. This information can be beneficial to identify potential biomarkers for monitoring environmental changes in soil, including the agricultural ecosystems vital to human society and economy.
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Affiliation(s)
- Nurlizah Abu Bakar
- Institute of Ocean and Earth Sciences, Universiti Malaya, Kuala Lumpur, Malaysia
- National Antarctic Research Centre, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Saiful Anuar Karsani
- Institute of Biological Sciences, Faculty of Science, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Siti Aisyah Alias
- Institute of Ocean and Earth Sciences, Universiti Malaya, Kuala Lumpur, Malaysia
- National Antarctic Research Centre, Universiti Malaya, Kuala Lumpur, Malaysia
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Zhang X, Cao S, Li W, Sun H, Deng Y, Zhang A, Chen H. Functional Characterization of Calcineurin-Responsive Transcription Factors Fg01341 and Fg01350 in Fusarium graminearum. Front Microbiol 2020; 11:597998. [PMID: 33324378 PMCID: PMC7726117 DOI: 10.3389/fmicb.2020.597998] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 11/05/2020] [Indexed: 11/13/2022] Open
Abstract
Ca2 +/calmodulin-dependent phosphatase calcineurin is one of the important regulators of intracellular calcium homeostasis and has been investigated extensively in Saccharomyces cerevisiae. However, only a few reports have explored the function of the Crz1 homolog in filamentous fungi, especially in Fusarium graminearum. In this study, we identified Fg01341 as a potential ortholog of yeast Crz1. Fg01341 could interact with calcineurin and initiate nuclear transport in a calcineurin-dependent manner. The ΔFg01341 mutant exhibited normal hyphal growth on basic medium and conidia formation, but sexual reproduction was partially blocked. Pathogenicity assays showed that the virulence of the ΔFg01341 mutant in flowering wheat heads and corn silks dramatically decreased and was thus consistent with the reduction in deoxynivalenol production. Unexpectedly, the sensitivity to osmotic stress of the deletion mutant and that of the wild-type strain did not present any differences. The deletion mutant showed higher sensitivity to tebuconazole than the wild-type strain. Results also showed that the transcription factor Fg01350 might be the calcineurin target and was independent of Crz1. Furthermore, ΔFg01350 showed defects in hyphal growth, sexual production, virulence, and deoxynivalenol production. Collectively, the results indicate that these two proteins functionally redundant and that the calcineurin-Crz1-independent pathway is particularly important in F. graminearum.
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Affiliation(s)
- Xiangxiang Zhang
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China.,The Management of Scientific Research, Jiangsu Coastal Area Institute of Agricultural Sciences, Yancheng, China
| | - Shulin Cao
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Wei Li
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Haiyan Sun
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Yuanyu Deng
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Aixiang Zhang
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Huaigu Chen
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
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Molecular insights into information processing and developmental and immune regulation of Eriocheir sinensis megalopa under hyposaline stress. Genomics 2020; 112:4647-4656. [PMID: 32798716 DOI: 10.1016/j.ygeno.2020.07.037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 07/22/2020] [Accepted: 07/24/2020] [Indexed: 11/23/2022]
Abstract
Eriocheir sinensis is an important euryhaline catadromous crustacean of the Yangtze River and an important commercial species for breeding in China. However, wild E. sinensis have suffered serious damage attributed to overfishing, climate change, etc. The Ministry of Agriculture of China issued a notice banning the commercial fishing of wild E. sinensis. E. sinensis megalopa migrates upriver into fresh water for growth and fattening, which creates optimal conditions to experimentally explore its hyposaline osmoregulation mechanism. We performed comparative transcriptome analyses of E. sinensis megalopae under hyposaline stress. The results suggest that KEGG pathways and genes related to genetic information processing, developmental regulation, immune and anti-stress responses were differentially expressed. The present study reveals the most significantly enriched pathways and functional gene groups, and explores the hyposaline osmoregulation mode of E. sinensis megalopae. This study lays a theoretical foundation for further studies on the osmoregulation and developmental mechanisms of E. sinensis.
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11
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LeBlanc EV, Polvi EJ, Veri AO, Privé GG, Cowen LE. Structure-guided approaches to targeting stress responses in human fungal pathogens. J Biol Chem 2020; 295:14458-14472. [PMID: 32796038 DOI: 10.1074/jbc.rev120.013731] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 08/11/2020] [Indexed: 11/06/2022] Open
Abstract
Fungi inhabit extraordinarily diverse ecological niches, including the human body. Invasive fungal infections have a devastating impact on human health worldwide, killing ∼1.5 million individuals annually. The majority of these deaths are attributable to species of Candida, Cryptococcus, and Aspergillus Treating fungal infections is challenging, in part due to the emergence of resistance to our limited arsenal of antifungal agents, necessitating the development of novel therapeutic options. Whereas conventional antifungal strategies target proteins or cellular components essential for fungal growth, an attractive alternative strategy involves targeting proteins that regulate fungal virulence or antifungal drug resistance, such as regulators of fungal stress responses. Stress response networks enable fungi to adapt, grow, and cause disease in humans and include regulators that are highly conserved across eukaryotes as well as those that are fungal-specific. This review highlights recent developments in elucidating crystal structures of fungal stress response regulators and emphasizes how this knowledge can guide the design of fungal-selective inhibitors. We focus on the progress that has been made with highly conserved regulators, including the molecular chaperone Hsp90, the protein phosphatase calcineurin, and the small GTPase Ras1, as well as with divergent stress response regulators, including the cell wall kinase Yck2 and trehalose synthases. Exploring structures of these important fungal stress regulators will accelerate the design of selective antifungals that can be deployed to combat life-threatening fungal diseases.
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Affiliation(s)
- Emmanuelle V LeBlanc
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Elizabeth J Polvi
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Amanda O Veri
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Gilbert G Privé
- Departments of Medical Biophysics and Biochemistry, University of Toronto, Toronto, Ontario, Canada.,Princess Margaret Cancer Centre, Toronto, Ontario, Canada
| | - Leah E Cowen
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
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Dominant mutants of the calcineurin catalytic subunit (CNA-1) showed developmental defects, increased sensitivity to stress conditions, and CNA-1 interacts with CaM and CRZ-1 in Neurospora crassa. Arch Microbiol 2019; 202:921-934. [DOI: 10.1007/s00203-019-01768-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 10/12/2019] [Accepted: 10/31/2019] [Indexed: 12/20/2022]
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13
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Echinocandins for the Treatment of Invasive Aspergillosis: from Laboratory to Bedside. Antimicrob Agents Chemother 2019; 63:AAC.00399-19. [PMID: 31138565 DOI: 10.1128/aac.00399-19] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Echinocandins (caspofungin, micafungin, anidulafungin), targeting β-1,3-glucan synthesis of the cell wall, represent one of the three currently available antifungal drug classes for the treatment of invasive fungal infections. Despite their limited antifungal activity against Aspergillus spp., echinocandins are considered an alternative option for the treatment of invasive aspergillosis (IA). This drug class exhibits several advantages, such as excellent tolerability and its potential for synergistic interactions with some other antifungals. The objective of this review is to discuss the in vitro and clinical efficacy of echinocandins against Aspergillus spp., considering the complex interactions between the drug, the mold, and the host. The antifungal effect of echinocandins is not limited to direct inhibition of hyphal growth but also induces an immunomodulatory effect on the host's response. Moreover, Aspergillus spp. have developed important adaptive mechanisms of tolerance to survive and overcome the action of echinocandins, such as paradoxical growth at increased concentrations. This stress response can be abolished by several compounds that potentiate the activity of echinocandins, such as drugs targeting the heat shock protein 90 (Hsp90)-calcineurin axis, opening perspectives for adjuvant therapies. Finally, the present and future places of echinocandins as prophylaxis, monotherapy, or combination therapy of IA are discussed in view of the emergence of pan-azole resistance among Aspergillus fumigatus isolates, the occurrence of breakthrough IA, and the advent of new long-lasting echinocandins (rezafungin) or other β-1,3-glucan synthase inhibitors (ibrexafungerp).
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Wang W, Xu Y, Chen T, Xing L, Xu K, Xu Y, Ji D, Chen C, Xie C. Regulatory mechanisms underlying the maintenance of homeostasis in Pyropia haitanensis under hypersaline stress conditions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 662:168-179. [PMID: 30690352 DOI: 10.1016/j.scitotenv.2019.01.214] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 01/04/2019] [Accepted: 01/18/2019] [Indexed: 05/10/2023]
Abstract
Intertidal macroalgae are highly resistant to hypersaline stress conditions. However, the underlying mechanism remains unknown. In the present study, the mechanism behind Pyropia haitanensis responses to two hypersaline stress conditions [100‰ (HSS_100) and 110‰ (HSS_110)] was investigated via analyses of physiological and transcriptomic changes. We observed that the differences between the responses of Py. haitanensis to HSS_100 and HSS_110 conditions involved the following three aspects: osmotic regulation, ionic homeostasis, and adjustment to secondary stresses. First, the water retention of Py. haitanensis was maintained through increased expansin production under HSS_100 conditions, while cell wall pectin needed to be protected from hydrolysis via the increased abundance of a pectin methylesterase inhibitor under HSS_110 conditions. Meanwhile, Py. haitanensis achieved stable and rapid osmotic adjustments because of the coordinated accumulation of inorganic ions (K+, Na+, and Cl-) and organic osmolytes (glycine betaine and trehalose) under HSS_100 conditions, but not under HSS_110 conditions. Second, Py. haitanensis maintained a higher K+/Na+ ratio under HSS_100 conditions than under HSS_110 conditions, mainly via the export of Na+ into the apoplast rather than compartmentalizing it into the vacuoles, and the enhanced uptake and retention of K+. However, K+/Na+ homeostasis was not completely disrupted during a short-term exposure to HSS_110 conditions. Finally, the Py. haitanensis antioxidant system scavenged more ROS and synthesized more heat shock proteins under HSS_100 conditions than under HSS_110 conditions, although thalli may have been able to maintain a certain redox balance during a short-term exposure to HSS_110 conditions. These differences may explain why Py. haitanensis can adapt to HSS_100 conditions rather than HSS_110 conditions, and also why the thalli exposed to HSS_110 conditions can recover after being transferred to normal seawater. Thus, the data presented herein may elucidate the mechanisms enabling Pyropia species to tolerate the sudden and periodic changes in salinity typical of intertidal systems.
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Affiliation(s)
- Wenlei Wang
- Fisheries College, Jimei University, Xiamen 361021, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Xiamen 361021, China
| | - Yan Xu
- Fisheries College, Jimei University, Xiamen 361021, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Xiamen 361021, China
| | - TianXiang Chen
- Fisheries College, Jimei University, Xiamen 361021, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Xiamen 361021, China
| | - Lei Xing
- Fisheries College, Jimei University, Xiamen 361021, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Xiamen 361021, China
| | - Kai Xu
- Fisheries College, Jimei University, Xiamen 361021, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Xiamen 361021, China
| | - Yan Xu
- Fisheries College, Jimei University, Xiamen 361021, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Xiamen 361021, China
| | - Dehua Ji
- Fisheries College, Jimei University, Xiamen 361021, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Xiamen 361021, China
| | - Changsheng Chen
- Fisheries College, Jimei University, Xiamen 361021, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Xiamen 361021, China
| | - Chaotian Xie
- Fisheries College, Jimei University, Xiamen 361021, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Xiamen 361021, China.
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Koubkova-Yu TCT, Chao JC, Leu JY. Heterologous Hsp90 promotes phenotypic diversity through network evolution. PLoS Biol 2018; 16:e2006450. [PMID: 30439936 PMCID: PMC6264905 DOI: 10.1371/journal.pbio.2006450] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 11/29/2018] [Accepted: 10/30/2018] [Indexed: 12/24/2022] Open
Abstract
Biological processes in living cells are often carried out by gene networks in which signals and reactions are integrated through network hubs. Despite their functional importance, it remains unclear to what extent network hubs are evolvable and how alterations impact long-term evolution. We investigated these issues using heat shock protein 90 (Hsp90), a central hub of proteostasis networks. When native Hsp90 in Saccharomyces cerevisiae cells was replaced by the ortholog from hypersaline-tolerant Yarrowia lipolytica that diverged from S. cerevisiae about 270 million years ago, the cells exhibited improved growth in hypersaline environments but compromised growth in others, indicating functional divergence in Hsp90 between the two yeasts. Laboratory evolution shows that evolved Y. lipolytica-HSP90–carrying S. cerevisiae cells exhibit a wider range of phenotypic variation than cells carrying native Hsp90. Identified beneficial mutations are involved in multiple pathways and are often pleiotropic. Our results show that cells adapt to a heterologous Hsp90 by modifying different subnetworks, facilitating the evolution of phenotypic diversity inaccessible to wild-type cells. Biological processes in living cells are often carried out by gene networks. Hubs are highly connected network components important for integrating signal inputs and generating responsive functional outputs. Heat shock protein 90 (Hsp90), a versatile hub in the protein homeostasis network, is a molecular chaperone essential for cell viability in all tested eukaryotic cells. In yeast, about a quarter of the expressed proteins are profoundly influenced when Hsp90 activity is reduced. Despite its pivotal role, we found that the function of Hsp90 has diverged between two yeast species, Yarrowia lipolytica and Saccharomyces cerevisiae, which split about 270 million years ago. To understand the impacts and adaptive strategies in cells with an altered network hub, we conducted laboratory evolution experiments using a S. cerevisiae strain in which native Hsp90 is replaced by its counterpart in Y. lipolytica. We observed different fitness gain or loss under various stress conditions in individual evolved clones, suggesting that cells adapted via different evolutionary paths. Genome sequencing and mutation reconstitution experiments show that beneficial mutations occurred in multiple Hsp90-related pathways that interact with each other. Our results show that a perturbed network allows cells to evolve a broader range of phenotypic diversity unavailable to wild-type cells.
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Affiliation(s)
- Tracy Chih-Ting Koubkova-Yu
- Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, National Chung-Hsing University and Academia Sinica, Taipei, Taiwan
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
- Graduate Institute of Biotechnology, National Chung-Hsing University, Taichung, Taiwan
| | - Jung-Chi Chao
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Jun-Yi Leu
- Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, National Chung-Hsing University and Academia Sinica, Taipei, Taiwan
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
- Biotechnology Center, National Chung-Hsing University, Taichung, Taiwan
- * E-mail:
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Traewachiwiphak S, Yokthongwattana C, Ves-Urai P, Charoensawan V, Yokthongwattana K. Gene expression and promoter characterization of heat-shock protein 90B gene (HSP90B) in the model unicellular green alga Chlamydomonas reinhardtii. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2018; 272:107-116. [PMID: 29807581 DOI: 10.1016/j.plantsci.2018.04.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 03/11/2018] [Accepted: 04/12/2018] [Indexed: 06/08/2023]
Abstract
Molecular chaperones or heat shock proteins are a large protein family with important functions in every cellular organism. Among all types of the heat shock proteins, information on the ER-localized HSP90 protein (HSP90B) and its encoding gene is relatively scarce in the literature, especially in photosynthetic organisms. In this study, expression profiles as well as promoter sequence of the HSP90B gene were investigated in the model green alga Chlamydomonas reinhardtii. We have found that HSP90B is strongly induced by heat and ER stresses, while other short-term exposure to abiotic stresses, such as salinity, dark-to-light transition or light stress does not appear to affect the expression. Promoter truncation analysis as well as chromatin immunoprecipitation using the antibodies recognizing histone H3 and acetylated histone H3, revealed a putative core constitutive promoter sequence between -1 to -253 bp from the transcription start site. Our results also suggested that the nucleotides upstream of the core promoter may contain repressive elements such as putative repressor binding site(s).
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Affiliation(s)
- Somchoke Traewachiwiphak
- Department of Biochemistry, Faculty of Science, Mahidol University, 272 Rama 6 Rd., Bangkok 10400, Thailand; Center for Excellence in Protein and Enzyme Technology, Faculty of Science, Mahidol University, 272 Rama 6 Rd., Bangkok 10400, Thailand
| | - Chotika Yokthongwattana
- Department of Biochemistry, Faculty of Science, Kasetsart University, 50 Ngamwongwan Rd., Bangkok 10900, Thailand
| | - Parthompong Ves-Urai
- Department of Biochemistry, Faculty of Science, Mahidol University, 272 Rama 6 Rd., Bangkok 10400, Thailand
| | - Varodom Charoensawan
- Department of Biochemistry, Faculty of Science, Mahidol University, 272 Rama 6 Rd., Bangkok 10400, Thailand; Integrative Computational BioScience (ICBS) Center, Mahidol University, Nakhon Pathom, Thailand; Systems Biology of Diseases Research Unit, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Kittisak Yokthongwattana
- Department of Biochemistry, Faculty of Science, Mahidol University, 272 Rama 6 Rd., Bangkok 10400, Thailand; Center for Excellence in Protein and Enzyme Technology, Faculty of Science, Mahidol University, 272 Rama 6 Rd., Bangkok 10400, Thailand.
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Calcineurin Regulatory Subunit Calcium-Binding Domains Differentially Contribute to Calcineurin Signaling in Saccharomyces cerevisiae. Genetics 2018; 209:801-813. [PMID: 29735720 DOI: 10.1534/genetics.118.300911] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 05/02/2018] [Indexed: 12/22/2022] Open
Abstract
The protein phosphatase calcineurin is central to Ca2+ signaling pathways from yeast to humans. Full activation of calcineurin requires Ca2+ binding to the regulatory subunit CNB, comprised of four Ca2+-binding EF hand domains, and recruitment of Ca2+-calmodulin. Here we report the consequences of disrupting Ca2+ binding to individual Cnb1 EF hand domains on calcineurin function in Saccharomyces cerevisiae Calcineurin activity was monitored via quantitation of the calcineurin-dependent reporter gene, CDRE-lacZ, and calcineurin-dependent growth under conditions of environmental stress. Mutation of EF2 dramatically reduced CDRE-lacZ expression and failed to support calcineurin-dependent growth. In contrast, Ca2+ binding to EF4 was largely dispensable for calcineurin function. Mutation of EF1 and EF3 exerted intermediate phenotypes. Reduced activity of EF1, EF2, or EF3 mutant calcineurin was also observed in yeast lacking functional calmodulin and could not be rescued by expression of a truncated catalytic subunit lacking the C-terminal autoinhibitory domain either alone or in conjunction with the calmodulin binding and autoinhibitory segment domains. Ca2+ binding to EF1, EF2, and EF3 in response to intracellular Ca2+ signals therefore has functions in phosphatase activation beyond calmodulin recruitment and displacement of known autoinhibitory domains. Disruption of Ca2+ binding to EF1, EF2, or EF3 reduced Ca2+ responsiveness of calcineurin, but increased the sensitivity of calcineurin to immunophilin-immunosuppressant inhibition. Mutation of EF2 also increased the susceptibility of calcineurin to hydrogen peroxide inactivation. Our observations indicate that distinct Cnb1 EF hand domains differentially affect calcineurin function in vivo, and that EF4 is not essential despite conservation across taxa.
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18
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Molecular Chaperones: Structure-Function Relationship and their Role in Protein Folding. REGULATION OF HEAT SHOCK PROTEIN RESPONSES 2018. [DOI: 10.1007/978-3-319-74715-6_8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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19
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Khandelwal NK, Chauhan N, Sarkar P, Esquivel BD, Coccetti P, Singh A, Coste AT, Gupta M, Sanglard D, White TC, Chauvel M, d'Enfert C, Chattopadhyay A, Gaur NA, Mondal AK, Prasad R. Azole resistance in a Candida albicans mutant lacking the ABC transporter CDR6/ROA1 depends on TOR signaling. J Biol Chem 2017; 293:412-432. [PMID: 29158264 DOI: 10.1074/jbc.m117.807032] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2017] [Revised: 11/17/2017] [Indexed: 12/12/2022] Open
Abstract
ATP-binding cassette (ABC) transporters help export various substrates across the cell membrane and significantly contribute to drug resistance. However, a recent study reported an unusual case in which the loss of an ABC transporter in Candida albicans, orf19.4531 (previously named ROA1), increases resistance against antifungal azoles, which was attributed to an altered membrane potential in the mutant strain. To obtain further mechanistic insights into this phenomenon, here we confirmed that the plasma membrane-localized transporter (renamed CDR6/ROA1 for consistency with C. albicans nomenclature) could efflux xenobiotics such as berberine, rhodamine 123, and paraquat. Moreover, a CDR6/ROA1 null mutant, NKKY101, displayed increased susceptibility to these xenobiotics. Interestingly, fluorescence recovery after photobleaching (FRAP) results indicated that NKKY101 mutant cells exhibited increased plasma membrane rigidity, resulting in reduced azole accumulation and contributing to azole resistance. Transcriptional profiling revealed that ribosome biogenesis genes were significantly up-regulated in the NKKY101 mutant. As ribosome biogenesis is a well-known downstream phenomenon of target of rapamycin (TOR1) signaling, we suspected a link between ribosome biogenesis and TOR1 signaling in NKKY101. Therefore, we grew NKKY101 cells on rapamycin and observed TOR1 hyperactivation, which leads to Hsp90-dependent calcineurin stabilization and thereby increased azole resistance. This in vitro finding was supported by in vivo data from a mouse model of systemic infection in which NKKY101 cells led to higher fungal load after fluconazole challenge than wild-type cells. Taken together, our study uncovers a mechanism of azole resistance in C. albicans, involving increased membrane rigidity and TOR signaling.
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Affiliation(s)
- Nitesh Kumar Khandelwal
- From the School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India.,the International Centre for Genetic Engineering and Biotechnology, New Delhi 110067, India, and
| | - Neeraj Chauhan
- Department of Microbiology, Biochemistry, and Molecular Genetics, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey 07103
| | - Parijat Sarkar
- the CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500007, India
| | - Brooke D Esquivel
- the School of Biological Sciences, Cell Biology, and Biophysics, University of Missouri, Kansas City, Missouri 64110
| | - Paola Coccetti
- the Department of Biotechnology and Biosciences, University of Milano-Bicocca, 20126 Milan, Italy.,SYSBIO, Centre of Systems Biology, 20126 Milan, Italy
| | - Ashutosh Singh
- From the School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India.,the Department of Biochemistry, Lucknow University, Lucknow 226024, Uttar Pradesh, India
| | - Alix T Coste
- the Institute of Microbiology, University of Lausanne and University Hospital Center, Rue du Bugnon 48, Lausanne, CH-1011, Switzerland
| | - Meghna Gupta
- From the School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India.,the Department of Biochemistry and Biophysics, University of California, San Francisco, California 94158
| | - Dominique Sanglard
- the Institute of Microbiology, University of Lausanne and University Hospital Center, Rue du Bugnon 48, Lausanne, CH-1011, Switzerland
| | - Theodore C White
- the School of Biological Sciences, Cell Biology, and Biophysics, University of Missouri, Kansas City, Missouri 64110
| | - Murielle Chauvel
- the Département Génomes et Génétique, Unité Biologie et Pathogénicité Fongiques, Institut Pasteur, INRA, 75015 Paris, France
| | - Christophe d'Enfert
- the Département Génomes et Génétique, Unité Biologie et Pathogénicité Fongiques, Institut Pasteur, INRA, 75015 Paris, France
| | | | - Naseem A Gaur
- the International Centre for Genetic Engineering and Biotechnology, New Delhi 110067, India, and
| | - Alok Kumar Mondal
- From the School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Rajendra Prasad
- From the School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India, .,the Amity Institute of Integrative Sciences and Health, Amity University Haryana, Amity Education Valley Gurgaon-122413, India
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Addition of 17-(allylamino)-17-demethoxygeldanamycin to a suboptimal caspofungin treatment regimen in neutropenic rats with invasive pulmonary aspergillosis delays the time to death but does not enhance the overall therapeutic efficacy. PLoS One 2017; 12:e0180961. [PMID: 28742113 PMCID: PMC5524388 DOI: 10.1371/journal.pone.0180961] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 06/23/2017] [Indexed: 12/31/2022] Open
Abstract
Caspofungin (CAS) which is used as salvage therapy in patients with invasive pulmonary aspergillosis (IPA) inhibits the 1,3-β-D-glucan synthesis in Aspergillus fumigatus. Inhibiting 1,3-β-D-glucan synthesis induces a stress response and in an invertebrate model it was demonstrated that inhibiting this response with geldamycin enhanced the therapeutic efficacy of CAS. Since geldamycin itself is toxic to mammalians, the therapeutic efficacy of combining geldamycin with CAS was not studied in rodent models. Therefore in this study we investigated if the geldamycin derivate 17-(allylamino)-17-demethoxygeldanamycin (17-AAG) was able to enhance the therapeutic efficacy of CAS in vitro and in our IPA model in transiently neutropenic rats. In vitro we confirmed the earlier demonstrated synergy between 17-AAG and CAS in ten A. fumigatus isolates. In vivo we treated A. fumigatus infected neutropenic rats with a sub-optimal dose of 0.75 mg/kg/day CAS and 1 mg/kg/day 17-AAG for ten days. Survival was monitored for 21 days after fungal inoculation. It appeared that the addition 17-AAG delayed death but did not improve overall survival of rats with IPA. Increasing the doses of 17-AAG was not possible due to hepatic toxicity. This study underlines the need to develop less toxic and more fungal specific geldamycin derivatives and the need to test such drugs not only in invertebrate models but also in mammalian models.
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Sun H, Zhuo X, Zhao X, Yang Y, Chen X, Yao C, Du A. The heat shock protein 90 of Toxoplasma gondii is essential for invasion of host cells and tachyzoite growth. ACTA ACUST UNITED AC 2017. [PMID: 28627357 PMCID: PMC5479401 DOI: 10.1051/parasite/2017023] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Toxoplasma gondii is an obligate intracellular apicomplexan parasite that infects almost all warm-blooded vertebrates. Heat shock proteins (HSP) regulate key signal transduction events in many organisms, and heat shock protein 90 (Hsp90) plays an important role in growth, development, and virulence in several parasitic protozoa. Here, we discovered increased transcription of the Hsp90 gene under conditions for bradyzoite differentiation, i.e. alkaline and heat shock conditions in vitro, suggesting that Hsp90 may be connected with bradyzoite development in T. gondii. A knockout of the TgHsp90 strain (ΔHsp90) and a complementation strain were constructed. The TgHsp90 knockout cells were found to be defective in host-cell invasion, were not able to proliferate in vitro in Vero cells, and did not show long-time survival in mice in vivo. These inabilities of the knockout parasites were restored upon complementation of TgHsp90. These data unequivocally show that TgHsp90 contributes to bradyzoite development, and to invasion and replication of T. gondii in host cells.
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Affiliation(s)
- Hongchao Sun
- Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou 310058, PR China
| | - Xunhui Zhuo
- Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou 310058, PR China
| | - Xianfeng Zhao
- Shenzhen Entry-exit Inspection and Quarantine Bureau, Shenzhen 518045, PR China
| | - Yi Yang
- Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou 310058, PR China
| | - Xueqiu Chen
- Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou 310058, PR China
| | - Chaoqun Yao
- Department of Biomedical Sciences and One Health Center for Zoonoses and Tropical Veterinary Medicine, Ross University School of Veterinary Medicine, P.O. Box 334, Basseterre, St. Kitts, West Indies
| | - Aifang Du
- Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou 310058, PR China
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O'Meara TR, Robbins N, Cowen LE. The Hsp90 Chaperone Network Modulates Candida Virulence Traits. Trends Microbiol 2017; 25:809-819. [PMID: 28549824 DOI: 10.1016/j.tim.2017.05.003] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 04/28/2017] [Accepted: 05/02/2017] [Indexed: 11/30/2022]
Abstract
Hsp90 is a conserved molecular chaperone that facilitates the folding and function of client proteins. Hsp90 function is dynamically regulated by interactions with co-chaperones and by post-translational modifications. In the fungal pathogen Candida albicans, Hsp90 enables drug resistance and virulence by stabilizing diverse signal transducers. Here, we review studies that have unveiled regulators of Hsp90 function, as well as downstream effectors that govern the key virulence traits of morphogenesis and drug resistance. We highlight recent work mapping the Hsp90 genetic network in C. albicans under diverse environmental conditions, and how these interactions provide insight into circuitry important for drug resistance, morphogenesis, and virulence. Ultimately, elucidating the Hsp90 chaperone network will aid in the development of therapeutics to treat fungal disease.
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Affiliation(s)
- Teresa R O'Meara
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5G 1M1, Canada
| | - Nicole Robbins
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5G 1M1, Canada
| | - Leah E Cowen
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5G 1M1, Canada.
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Song J, Zhai P, Lu L. Damage resistance protein (Dap) contributes to azole resistance in a sterol-regulatory-element-binding protein SrbA-dependent way. Appl Microbiol Biotechnol 2017; 101:3729-3741. [DOI: 10.1007/s00253-016-8072-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 11/23/2016] [Accepted: 12/07/2016] [Indexed: 02/06/2023]
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Gu X, Xue W, Yin Y, Liu H, Li S, Sun X. The Hsp90 Co-chaperones Sti1, Aha1, and P23 Regulate Adaptive Responses to Antifungal Azoles. Front Microbiol 2016; 7:1571. [PMID: 27761133 PMCID: PMC5050212 DOI: 10.3389/fmicb.2016.01571] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 09/20/2016] [Indexed: 12/26/2022] Open
Abstract
Heat Shock Protein 90 (Hsp90) is essential for tumor progression in humans and drug resistance in fungi. However, the roles of its many co-chaperones in antifungal resistance are unknown. In this study, by susceptibility test of Neurospora crassa mutants lacking each of 18 Hsp90/Calcineurin system member genes (including 8 Hsp90 co-chaperone genes) to antifungal drugs and other stresses, we demonstrate that the Hsp90 co-chaperones Sti1 (Hop1 in yeast), Aha1, and P23 (Sba1 in yeast) were required for the basal resistance to antifungal azoles and heat stress. Deletion of any of them resulted in hypersensitivity to azoles and heat. Liquid chromatography-mass spectrometry (LC-MS) analysis showed that the toxic sterols eburicol and 14α-methyl-3,6-diol were significantly accumulated in the sti1 and p23 deletion mutants after ketoconazole treatment, which has been shown before to led to cell membrane stress. At the transcriptional level, Aha1, Sti1, and P23 positively regulate responses to ketoconazole stress by erg11 and erg6, key genes in the ergosterol biosynthetic pathway. Aha1, Sti1, and P23 are highly conserved in fungi, and sti1 and p23 deletion also increased the susceptibility to azoles in Fusarium verticillioides. These results indicate that Hsp90-cochaperones Aha1, Sti1, and P23 are critical for the basal azole resistance and could be potential targets for developing new antifungal agents.
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Affiliation(s)
- Xiaokui Gu
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of SciencesBeijing, China; College of Life Sciences, University of Chinese Academy of SciencesBeijing, China
| | - Wei Xue
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of SciencesBeijing, China; College of Life Sciences, University of Chinese Academy of SciencesBeijing, China
| | - Yajing Yin
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of SciencesBeijing, China; College of Life Sciences, University of Chinese Academy of SciencesBeijing, China
| | - Hongwei Liu
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences Beijing, China
| | - Shaojie Li
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences Beijing, China
| | - Xianyun Sun
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences Beijing, China
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Bui DC, Lee Y, Lim JY, Fu M, Kim JC, Choi GJ, Son H, Lee YW. Heat shock protein 90 is required for sexual and asexual development, virulence, and heat shock response in Fusarium graminearum. Sci Rep 2016; 6:28154. [PMID: 27306495 PMCID: PMC4910114 DOI: 10.1038/srep28154] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Accepted: 05/27/2016] [Indexed: 12/29/2022] Open
Abstract
Eukaryotic cells repress global translation and selectively upregulate stress response proteins by altering multiple steps in gene expression. In this study, genome-wide transcriptome analysis of cellular adaptation to thermal stress was performed on the plant pathogenic fungus Fusarium graminearum. The results revealed that profound alterations in gene expression were required for heat shock responses in F. graminearum. Among these proteins, heat shock protein 90 (FgHsp90) was revealed to play a central role in heat shock stress responses in this fungus. FgHsp90 was highly expressed and exclusively localised to nuclei in response to heat stress. Moreover, our comprehensive functional characterisation of FgHsp90 provides clear genetic evidence supporting its crucial roles in the vegetative growth, reproduction, and virulence of F. graminearum. In particular, FgHsp90 performs multiple functions as a transcriptional regulator of conidiation. Our findings provide new insight into the mechanisms underlying adaptation to heat shock and the roles of Hsp90 in fungal development.
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Affiliation(s)
- Duc-Cuong Bui
- Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, Republic of Korea
| | - Yoonji Lee
- Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, Republic of Korea
| | - Jae Yun Lim
- Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, Republic of Korea
| | - Minmin Fu
- Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, Republic of Korea
| | - Jin-Cheol Kim
- Division of Applied Bioscience and Biotechnology, Institute of Environmentally Friendly Agriculture, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Gyung Ja Choi
- Eco-friendly New Materials Research Group, Research Centre for Biobased Chemistry, Division of Convergence Chemistry, Korea Research Institute of Chemical Technology, Daejeon 34114, Republic of Korea
| | - Hokyoung Son
- Centre for Food and Bioconvergence, Seoul National University, Seoul 08826, Republic of Korea
| | - Yin-Won Lee
- Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, Republic of Korea
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de Oliveira HC, Assato PA, Marcos CM, Scorzoni L, de Paula E Silva ACA, Da Silva JDF, Singulani JDL, Alarcon KM, Fusco-Almeida AM, Mendes-Giannini MJS. Paracoccidioides-host Interaction: An Overview on Recent Advances in the Paracoccidioidomycosis. Front Microbiol 2015; 6:1319. [PMID: 26635779 PMCID: PMC4658449 DOI: 10.3389/fmicb.2015.01319] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 11/09/2015] [Indexed: 11/13/2022] Open
Abstract
Paracoccidioides brasiliensis and P. lutzii are etiologic agents of paracoccidioidomycosis (PCM), an important endemic mycosis in Latin America. During its evolution, these fungi have developed characteristics and mechanisms that allow their growth in adverse conditions within their host through which they efficiently cause disease. This process is multi-factorial and involves host-pathogen interactions (adaptation, adhesion, and invasion), as well as fungal virulence and host immune response. In this review, we demonstrated the glycoproteins and polysaccharides network, which composes the cell wall of Paracoccidioides spp. These are important for the change of conidia or mycelial (26°C) to parasitic yeast (37°C). The morphological switch, a mechanism for the pathogen to adapt and thrive inside the host, is obligatory for the establishment of the infection and seems to be related to pathogenicity. For these fungi, one of the most important steps during the interaction with the host is the adhesion. Cell surface proteins called adhesins, responsible for the first contact with host cells, contribute to host colonization and invasion by mediating this process. These fungi also present the capacity to form biofilm and through which they may evade the host's immune system. During infection, Paracoccidioides spp. can interact with different host cell types and has the ability to modulate the host's adaptive and/or innate immune response. In addition, it participates and interferes in the coagulation system and phenomena like cytoskeletal rearrangement and apoptosis. In recent years, Paracoccidioides spp. have had their endemic areas expanding in correlation with the expansion of agriculture. In response, several studies were developed to understand the infection using in vitro and in vivo systems, including alternative non-mammal models. Moreover, new advances were made in treating these infections using both well-established and new antifungal agents. These included natural and/or derivate synthetic substances as well as vaccines, peptides, and anti-adhesins sera. Because of all the advances in the PCM study, this review has the objective to summarize all of the recent discoveries on Paracoccidioides-host interaction, with particular emphasis on fungi surface proteins (molecules that play a fundamental role in the adhesion and/or dissemination of the fungi to host-cells), as well as advances in the treatment of PCM with new and well-established antifungal agents and approaches.
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Affiliation(s)
- Haroldo C de Oliveira
- Faculdade de Ciências Farmacêuticas, UNESP - Universidade Estadual Paulista, Campus Araraquara, Departamento de Análises Clínicas, Laboratório de Micologia Clínica São Paulo, Brazil
| | - Patrícia A Assato
- Faculdade de Ciências Farmacêuticas, UNESP - Universidade Estadual Paulista, Campus Araraquara, Departamento de Análises Clínicas, Laboratório de Micologia Clínica São Paulo, Brazil
| | - Caroline M Marcos
- Faculdade de Ciências Farmacêuticas, UNESP - Universidade Estadual Paulista, Campus Araraquara, Departamento de Análises Clínicas, Laboratório de Micologia Clínica São Paulo, Brazil
| | - Liliana Scorzoni
- Faculdade de Ciências Farmacêuticas, UNESP - Universidade Estadual Paulista, Campus Araraquara, Departamento de Análises Clínicas, Laboratório de Micologia Clínica São Paulo, Brazil
| | - Ana C A de Paula E Silva
- Faculdade de Ciências Farmacêuticas, UNESP - Universidade Estadual Paulista, Campus Araraquara, Departamento de Análises Clínicas, Laboratório de Micologia Clínica São Paulo, Brazil
| | - Julhiany De Fátima Da Silva
- Faculdade de Ciências Farmacêuticas, UNESP - Universidade Estadual Paulista, Campus Araraquara, Departamento de Análises Clínicas, Laboratório de Micologia Clínica São Paulo, Brazil
| | - Junya de Lacorte Singulani
- Faculdade de Ciências Farmacêuticas, UNESP - Universidade Estadual Paulista, Campus Araraquara, Departamento de Análises Clínicas, Laboratório de Micologia Clínica São Paulo, Brazil
| | - Kaila M Alarcon
- Faculdade de Ciências Farmacêuticas, UNESP - Universidade Estadual Paulista, Campus Araraquara, Departamento de Análises Clínicas, Laboratório de Micologia Clínica São Paulo, Brazil
| | - Ana M Fusco-Almeida
- Faculdade de Ciências Farmacêuticas, UNESP - Universidade Estadual Paulista, Campus Araraquara, Departamento de Análises Clínicas, Laboratório de Micologia Clínica São Paulo, Brazil
| | - Maria J S Mendes-Giannini
- Faculdade de Ciências Farmacêuticas, UNESP - Universidade Estadual Paulista, Campus Araraquara, Departamento de Análises Clínicas, Laboratório de Micologia Clínica São Paulo, Brazil
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Synergistic regulatory networks mediated by microRNAs and transcription factors under drought, heat and salt stresses in Oryza Sativa spp. Gene 2015; 555:127-39. [DOI: 10.1016/j.gene.2014.10.054] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Revised: 09/12/2014] [Accepted: 10/26/2014] [Indexed: 01/16/2023]
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Xu D, Sun L, Liu S, Zhang L, Yang H. Polymorphisms of heat shock protein 90 (Hsp90) in the sea cucumber Apostichopus japonicus and their association with heat-resistance. FISH & SHELLFISH IMMUNOLOGY 2014; 41:428-436. [PMID: 25270529 DOI: 10.1016/j.fsi.2014.09.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 09/09/2014] [Accepted: 09/20/2014] [Indexed: 06/03/2023]
Abstract
Heat shock protein 90 (Hsp90) functions as a molecular chaperone and plays an important role in the resistance of organisms to stress, particularly heat-stress. In our study, 12 exons and 11 introns of hsp90 were identified in the sea cucumber Apostichopus japonicus. Twenty-two single nucleotide polymorphisms (SNPs), including three non-synonymous mutations, were detected in the exons. Susceptible and resistant individuals were distinguished using a high-temperature (32 °C) challenge experiment. Three blocks with high linkage disequilibrium were detected among these SNPs. Five of the twenty-two SNPs were shown to be significantly associated with susceptibility/resistance to high temperature by correlation analysis (chi-square test, P < 0.05). To confirm the importance of these five SNPs, a heat-resistance strain (HRS) was selected through three generations. Using the common population as the control group, it was shown that the distributions of genotypes and alleles of SNP e10-1 and e11-6 were significantly different between the two groups (P < 0.05). SNP e10-1 was trimorphic, with three alleles (A, C and T) and five genotypes (AA, CC, AT, CT and AC). The allele frequency of SNP e2-3 was also significantly associated with this trait (P < 0.05). This is the first demonstration of SNPs related to heat-resistance in A. japonicus and supports the use of SNP markers in the selective breeding of sea cucumbers.
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Affiliation(s)
- Dongxue Xu
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, PR China; University of Chinese Academy of Sciences, Beijing, PR China
| | - Lina Sun
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, PR China
| | - Shilin Liu
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, PR China
| | - Libin Zhang
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, PR China
| | - Hongsheng Yang
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, PR China.
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Abstract
The epigenetic writer Sir2 maintains the heterochromatin state of chromosome in three chromosomal regions, namely, the silent mating type loci, telomeres, and the ribosomal DNA (rDNA). In this study, we demonstrated the mechanism by which Sir2 is regulated under heat stress. Our study reveals that a transient heat shock causes a drastic reduction in the SIR2 transcript which results in sustained failure to initiate silencing for as long as 90 generations. Hsp82 overexpression, which is the usual outcome of heat shock treatment, leads to a similar downregulation of SIR2 transcription. Using a series of genetic experiments, we have established that heat shock or Hsp82 overexpression causes upregulation of CUP9 that, in turn, represses SIR2 transcription by binding to its upstream activator sequence. We have mapped the cis regulatory element of SIR2. Our study shows that the deletion of cup9 causes reversal of the Hsp82 overexpression phenotype and upregulation of SIR2 expression in heat-induced Hsp82-overexpressing cells. On the other hand, we found that Cup9 overexpression represses SIR2 transcription and leads to a failure in the establishment of heterochromatin. The results of our study highlight the mechanism by which environmental factors amend the epigenetic configuration of chromatin.
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Juvvadi PR, Lamoth F, Steinbach WJ. Calcineurin as a Multifunctional Regulator: Unraveling Novel Functions in Fungal Stress Responses, Hyphal Growth, Drug Resistance, and Pathogenesis. FUNGAL BIOL REV 2014; 28:56-69. [PMID: 25383089 DOI: 10.1016/j.fbr.2014.02.004] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Calcineurin signaling plays diverse roles in fungi in regulating stress responses, morphogenesis and pathogenesis. Although calcineurin signaling is conserved among fungi, recent studies indicate important divergences in calcineurin-dependent cellular functions among different human fungal pathogens. Fungal pathogens utilize the calcineurin pathway to effectively survive the host environment and cause life-threatening infections. The immunosuppressive calcineurin inhibitors (FK506 and cyclosporine A) are active against fungi, making targeting calcineurin a promising antifungal drug development strategy. Here we summarize current knowledge on calcineurin in yeasts and filamentous fungi, and review the importance of understanding fungal-specific attributes of calcineurin to decipher fungal pathogenesis and develop novel antifungal therapeutic approaches.
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Affiliation(s)
- Praveen R Juvvadi
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Duke University Medical Center, Durham NC, USA
| | - Frédéric Lamoth
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Duke University Medical Center, Durham NC, USA ; Infectious Diseases Service, Department of Medicine, Lausanne University Hospital, Lausanne, Switzerland ; Institute of Microbiology, Lausanne University Hospital, Lausanne, Switzerland
| | - William J Steinbach
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Duke University Medical Center, Durham NC, USA ; Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham NC, USA
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31
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Lamoth F, Juvvadi PR, Steinbach WJ. Heat shock protein 90 (Hsp90): A novel antifungal target against Aspergillus fumigatus. Crit Rev Microbiol 2014; 42:310-21. [PMID: 25243616 DOI: 10.3109/1040841x.2014.947239] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Invasive aspergillosis is a life-threatening and difficult to treat infection in immunosuppressed patients. The efficacy of current anti-Aspergillus therapies, targeting the cell wall or membrane, is limited by toxicity (polyenes), fungistatic activity and some level of basal resistance (echinocandins), or the emergence of acquired resistance (triazoles). The heat shock protein 90 (Hsp90) is a conserved molecular chaperone involved in the rapid development of antifungal resistance in the yeast Candida albicans. Few studies have addressed its role in filamentous fungi such as Aspergillus fumigatus, in which mechanisms of resistance may differ substantially. Hsp90 is at the center of a complex network involving calcineurin, lysine deacetylases (KDAC) and other client proteins, which orchestrate compensatory repair mechanisms of the cell wall in response to the stress induced by antifungals. In A. fumigatus, Hsp90 is a trigger for resistance to high concentrations of caspofungin, known as the paradoxical effect. Disrupting Hsp90 circuitry by different means (Hsp90 inhibitors, KDAC inhibitors and anti-calcineurin drugs) potentiates the antifungal activity of caspofungin, thus representing a promising novel antifungal approach. This review will discuss the specific features of A. fumigatus Hsp90 and the potential for antifungal strategies of invasive aspergillosis targeting this essential chaperone.
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Affiliation(s)
- Frédéric Lamoth
- a Division of Pediatric Infectious Diseases, Department of Pediatrics , Duke University Medical Center , Durham , NC , USA .,b Infectious Diseases Service, Department of Medicine , Lausanne University Hospital , Lausanne , Switzerland .,c Institute of Microbiology, Lausanne University Hospital , Lausanne , Switzerland , and
| | - Praveen R Juvvadi
- a Division of Pediatric Infectious Diseases, Department of Pediatrics , Duke University Medical Center , Durham , NC , USA
| | - William J Steinbach
- a Division of Pediatric Infectious Diseases, Department of Pediatrics , Duke University Medical Center , Durham , NC , USA .,d Department of Molecular Genetics and Microbiology , Duke University Medical Center , Durham , NC , USA
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32
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Hayes BME, Anderson MA, Traven A, van der Weerden NL, Bleackley MR. Activation of stress signalling pathways enhances tolerance of fungi to chemical fungicides and antifungal proteins. Cell Mol Life Sci 2014; 71:2651-66. [PMID: 24526056 PMCID: PMC11113482 DOI: 10.1007/s00018-014-1573-8] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 12/17/2013] [Accepted: 01/20/2014] [Indexed: 10/25/2022]
Abstract
Fungal disease is an increasing problem in both agriculture and human health. Treatment of human fungal disease involves the use of chemical fungicides, which generally target the integrity of the fungal plasma membrane or cell wall. Chemical fungicides used for the treatment of plant disease, have more diverse mechanisms of action including inhibition of sterol biosynthesis, microtubule assembly and the mitochondrial respiratory chain. However, these treatments have limitations, including toxicity and the emergence of resistance. This has led to increased interest in the use of antimicrobial peptides for the treatment of fungal disease in both plants and humans. Antimicrobial peptides are a diverse group of molecules with differing mechanisms of action, many of which remain poorly understood. Furthermore, it is becoming increasingly apparent that stress response pathways are involved in the tolerance of fungi to both chemical fungicides and antimicrobial peptides. These signalling pathways such as the cell wall integrity and high-osmolarity glycerol pathway are triggered by stimuli, such as cell wall instability, changes in osmolarity and production of reactive oxygen species. Here we review stress signalling induced by treatment of fungi with chemical fungicides and antifungal peptides. Study of these pathways gives insight into how these molecules exert their antifungal effect and also into the mechanisms used by fungi to tolerate sub-lethal treatment by these molecules. Inactivation of stress response pathways represents a potential method of increasing the efficacy of antifungal molecules.
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Affiliation(s)
- Brigitte M. E. Hayes
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3086 Australia
| | - Marilyn A. Anderson
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3086 Australia
| | - Ana Traven
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC 3800 Australia
| | | | - Mark R. Bleackley
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3086 Australia
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33
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Tsai HC, Chung KR. Calcineurin phosphatase and phospholipase C are required for developmental and pathological functions in the citrus fungal pathogen Alternaria alternata. MICROBIOLOGY-SGM 2014; 160:1453-1465. [PMID: 24763426 DOI: 10.1099/mic.0.077818-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Excessive Ca(2+) or compounds interfering with phosphoinositide cycling have been found to inhibit the growth of the tangerine pathotype of Alternaria alternata, suggesting a crucial role of Ca(2+) homeostasis in this pathotype. The roles of PLC1, a phospholipase C-coding gene and CAL1, a calcineurin phosphatase-coding gene were investigated. Targeted gene disruption showed that both PLC1 and CAL1 were required for vegetative growth, conidial formation and pathogenesis in citrus. Fungal strains lacking PLC1 or CAL1 exhibited extremely slow growth and induced small lesions on calamondin leaves. Δplc1 mutants produced fewer conidia, which germinated at slower rates than wild-type. Δcal1 mutants produced abnormal hyphae and failed to produce any mature conidia, but instead produced highly melanized bulbous hyphae with distinct septae. Fluorescence microscopy using Fluo-3 dye as a Ca(2+) indicator revealed that the Δplc1 mutant hyphae emitted stronger cytosolic fluorescence, and the Δcal1 mutant hyphae emitted less cytosolic fluorescence, than those of wild-type. Infection assessed on detached calamondin leaves revealed that application of CaCl2 or neomycin 24 h prior to inoculation provided protection against Alt. alternata. These data indicate that a dynamic equilibrium of cellular Ca(2+) is critical for developmental and pathological processes of Alt. alternata.
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Affiliation(s)
- Hsieh-Chin Tsai
- Citrus Research and Education Center, Institute of Food and Agricultural Sciences (IFAS), University of Florida, 700 Experiment Station Road, Lake Alfred, FL 33850, USA
| | - Kuang-Ren Chung
- Department of Plant Pathology, IFAS, University of Florida, Gainesville, FL 32611, USA.,Citrus Research and Education Center, Institute of Food and Agricultural Sciences (IFAS), University of Florida, 700 Experiment Station Road, Lake Alfred, FL 33850, USA
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Abstract
Calcium ions are ubiquitous intracellular messengers. An increase in the cytosolic Ca(2+) concentration activates many proteins, including calmodulin and the Ca(2+)/calmodulin-dependent protein phosphatase calcineurin. The phosphatase is conserved from yeast to humans (except in plants), and many target proteins of calcineurin have been identified. The most prominent and best-investigated targets, however, are the transcription factors NFAT (nuclear factor of activated T cells) in mammals and Crz1 (calcineurin-responsive zinc finger 1) in yeast. In recent years, many orthologues of Crz1 have been identified and characterized in various species of fungi, amoebae, and other lower eukaryotes. It has been shown that the functions of calcineurin-Crz1 signaling, ranging from ion homeostasis through cell wall biogenesis to the building of filamentous structures, are conserved in the different organisms. Furthermore, frequency-modulated gene expression through Crz1 has been discovered as a striking new mechanism by which cells can coordinate their response to a signal. In this review, I focus on the latest findings concerning calcineurin-Crz1 signaling in fungi, amoebae and other lower eukaryotes. I discuss the potential of Crz1 and its orthologues as putative drug targets, and I also discuss possible parallels with calcineurin-NFAT signaling in mammals.
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Abstract
SummaryFungal pathogens pose a major threat to human health worldwide. They infect billions of people each year, leading to at least 1·5 million deaths. Treatment of fungal infections is difficult due to the limited number of clinically useful antifungal drugs, and the emergence of drug resistance. A promising new strategy to enhance the efficacy of antifungal drugs and block the evolution of drug resistance is to target the molecular chaperone Hsp90. Pharmacological inhibitors of Hsp90 function that are in development as anticancer agents have potential to be repurposed as agents for combination antifungal therapy for some applications, such as biofilm infections. For systemic infections, however, effective combination therapy regimens may require Hsp90 inhibitors that can selectively target Hsp90 in the pathogen, or alternate strategies to compromise function of the Hsp90 chaperone machine. Selectively impairing Hsp90 function in the pathogen could in principle be achieved by targeting Hsp90 co-chaperones or regulators of Hsp90 function that are more divergent between pathogen and host than Hsp90. Antifungal combination therapies could also exploit downstream effectors of Hsp90 that are critical for fungal drug resistance and virulence. Here, we discuss the progress and prospects for establishing Hsp90 as an important therapeutic target for life-threatening fungal infections.
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O'Meara TR, Cowen LE. Hsp90-dependent regulatory circuitry controlling temperature-dependent fungal development and virulence. Cell Microbiol 2014; 16:473-81. [PMID: 24438186 DOI: 10.1111/cmi.12266] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 01/09/2014] [Accepted: 01/13/2014] [Indexed: 11/28/2022]
Abstract
The pathogenic fungi Candida albicans, Aspergillus fumigatus, and Cryptococcus neoformans are an increasing cause of human mortality, especially in immunocompromised populations. During colonization and adaptation to various host environments, these fungi undergo morphogenetic alterations that allow for survival within the host. One key environmental cue driving morphological changes is external temperature. The Hsp90 chaperone protein provides one mechanism to link temperature with the signalling cascades that regulate morphogenesis, fungal development and virulence. Candida albicans is a model system for understanding the connections between morphogenesis and Hsp90. Due to the high degree of conservation in Hsp90, many of the connections in C. albicans may be extrapolated to other fungal pathogens or parasites. Examining the role of Hsp90 during development and morphogenesis in these three major fungal pathogens may provide insight into key aspects of adaptation to the host, leading to additional avenues for therapy.
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Affiliation(s)
- Teresa R O'Meara
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
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Hill JA, Ammar R, Torti D, Nislow C, Cowen LE. Genetic and genomic architecture of the evolution of resistance to antifungal drug combinations. PLoS Genet 2013; 9:e1003390. [PMID: 23593013 PMCID: PMC3617151 DOI: 10.1371/journal.pgen.1003390] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Accepted: 01/30/2013] [Indexed: 12/19/2022] Open
Abstract
The evolution of drug resistance in fungal pathogens compromises the efficacy of the limited number of antifungal drugs. Drug combinations have emerged as a powerful strategy to enhance antifungal efficacy and abrogate drug resistance, but the impact on the evolution of drug resistance remains largely unexplored. Targeting the molecular chaperone Hsp90 or its downstream effector, the protein phosphatase calcineurin, abrogates resistance to the most widely deployed antifungals, the azoles, which inhibit ergosterol biosynthesis. Here, we evolved experimental populations of the model yeast Saccharomyces cerevisiae and the leading human fungal pathogen Candida albicans with azole and an inhibitor of Hsp90, geldanamycin, or calcineurin, FK506. To recapitulate a clinical context where Hsp90 or calcineurin inhibitors could be utilized in combination with azoles to render resistant pathogens responsive to treatment, the evolution experiment was initiated with strains that are resistant to azoles in a manner that depends on Hsp90 and calcineurin. Of the 290 lineages initiated, most went extinct, yet 14 evolved resistance to the drug combination. Drug target mutations that conferred resistance to geldanamycin or FK506 were identified and validated in five evolved lineages. Whole-genome sequencing identified mutations in a gene encoding a transcriptional activator of drug efflux pumps, PDR1, and a gene encoding a transcriptional repressor of ergosterol biosynthesis genes, MOT3, that transformed azole resistance of two lineages from dependent on calcineurin to independent of this regulator. Resistance also arose by mutation that truncated the catalytic subunit of calcineurin, and by mutation in LCB1, encoding a sphingolipid biosynthetic enzyme. Genome analysis revealed extensive aneuploidy in four of the C. albicans lineages. Thus, we identify molecular determinants of the transition of azole resistance from calcineurin dependence to independence and establish multiple mechanisms by which resistance to drug combinations evolves, providing a foundation for predicting and preventing the evolution of drug resistance. Fungal infections are a leading cause of mortality worldwide and are difficult to treat due to the limited number of antifungal drugs, whose effectiveness is compromised by the emergence of drug resistance. A powerful strategy to combat drug resistance is combination therapy. Inhibiting the molecular chaperone Hsp90 or its downstream effector calcineurin cripples fungal stress responses and abrogates drug resistance. Here we provide the first analysis of the genetic and genomic changes that underpin the evolution of resistance to antifungal drug combinations in the leading human fungal pathogen, Candida albicans, and model yeast, Saccharomyces cerevisiae. We evolved experimental populations with combinations of inhibitors of Hsp90 or calcineurin and the most widely used antifungal in the clinic, the azoles, which inhibit ergosterol biosynthesis. We harnessed whole-genome sequencing to identify diverse resistance mutations among the 14 lineages that evolved resistance to the drug combination. These included mutations in genes encoding the drug targets, a transcriptional regulator of multidrug transporters, a transcriptional repressor of ergosterol biosynthesis enzymes, and a regulator of sphingolipid biosynthesis. We also identified extensive aneuploidies in several C. albicans lineages. Our study reveals multiple mechanisms by which resistance to drug combination can evolve, suggesting new strategies to combat drug resistance.
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Affiliation(s)
- Jessica A. Hill
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Ron Ammar
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
| | - Dax Torti
- Donnelly Sequencing Centre, University of Toronto, Toronto, Ontario, Canada
| | - Corey Nislow
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
| | - Leah E. Cowen
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- * E-mail:
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38
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Leach MD, Klipp E, Cowen LE, Brown AJP. Fungal Hsp90: a biological transistor that tunes cellular outputs to thermal inputs. Nat Rev Microbiol 2012; 10:693-704. [PMID: 22976491 DOI: 10.1038/nrmicro2875] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Heat shock protein 90 (HSP90) is an essential, abundant and ubiquitous eukaryotic chaperone that has crucial roles in protein folding and modulates the activities of key regulators. The fungal Hsp90 interactome, which includes numerous client proteins such as receptors, protein kinases and transcription factors, displays a surprisingly high degree of plasticity that depends on environmental conditions. Furthermore, although fungal Hsp90 levels increase following environmental challenges, Hsp90 activity is tightly controlled via post-translational regulation and an autoregulatory loop involving heat shock transcription factor 1 (Hsf1). In this Review, we discuss the roles and regulation of fungal Hsp90. We propose that Hsp90 acts as a biological transistor that modulates the activity of fungal signalling networks in response to environmental cues via this Hsf1-Hsp90 autoregulatory loop.
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Affiliation(s)
- Michelle D Leach
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
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Biology of the heat shock response and protein chaperones: budding yeast (Saccharomyces cerevisiae) as a model system. Microbiol Mol Biol Rev 2012; 76:115-58. [PMID: 22688810 DOI: 10.1128/mmbr.05018-11] [Citation(s) in RCA: 362] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The eukaryotic heat shock response is an ancient and highly conserved transcriptional program that results in the immediate synthesis of a battery of cytoprotective genes in the presence of thermal and other environmental stresses. Many of these genes encode molecular chaperones, powerful protein remodelers with the capacity to shield, fold, or unfold substrates in a context-dependent manner. The budding yeast Saccharomyces cerevisiae continues to be an invaluable model for driving the discovery of regulatory features of this fundamental stress response. In addition, budding yeast has been an outstanding model system to elucidate the cell biology of protein chaperones and their organization into functional networks. In this review, we evaluate our understanding of the multifaceted response to heat shock. In addition, the chaperone complement of the cytosol is compared to those of mitochondria and the endoplasmic reticulum, organelles with their own unique protein homeostasis milieus. Finally, we examine recent advances in the understanding of the roles of protein chaperones and the heat shock response in pathogenic fungi, which is being accelerated by the wealth of information gained for budding yeast.
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Robbins N, Leach MD, Cowen LE. Lysine deacetylases Hda1 and Rpd3 regulate Hsp90 function thereby governing fungal drug resistance. Cell Rep 2012; 2:878-88. [PMID: 23041319 PMCID: PMC3607219 DOI: 10.1016/j.celrep.2012.08.035] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Revised: 06/26/2012] [Accepted: 08/30/2012] [Indexed: 12/03/2022] Open
Abstract
The molecular chaperone Hsp90 is a hub of protein homeostasis and regulatory circuitry. Hsp90 function is regulated by posttranslational modifications including acetylation in mammals; however, whether this regulation is conserved remains unknown. In fungi, Hsp90 governs the evolution of drug resistance by stabilizing signal transducers. Here, we establish that pharmacological inhibition of lysine deacetylases (KDACs) blocks the emergence and maintenance of Hsp90-dependent resistance to the most widely deployed antifungals, the azoles, in the human fungal pathogen Candida albicans and the model yeast Saccharomyces cerevisiae. S. cerevisiae Hsp90 is acetylated on lysine 27 and 270, and key KDACs for drug resistance are Hda1 and Rpd3. Compromising KDACs alters stability and function of Hsp90 client proteins, including the drug-resistance regulator calcineurin. Thus, we establish acetylation as a mechanism of posttranslational control of Hsp90 function in fungi, functional redundancy between KDACs Hda1 and Rpd3, as well as a mechanism governing fungal drug resistance with broad therapeutic potential.
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Affiliation(s)
- Nicole Robbins
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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Matos TGF, Morais FV, Campos CBL. Hsp90 regulates Paracoccidioides brasiliensis proliferation and ROS levels under thermal stress and cooperates with calcineurin to control yeast to mycelium dimorphism. Med Mycol 2012; 51:413-21. [PMID: 23013413 DOI: 10.3109/13693786.2012.725481] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Paracoccidioidomycosis is a systemic human mycosis in Latin America caused by Paracoccidioides brasiliensis, a dimorphic pathogenic fungus that lives as a mold in the environment and as yeast during infections of human lungs. In this work, we provide evidence that the inhibition of Hsp90 by geldanamycin (GDA) impairs the proliferation of the yeast, but has no effect on mycelial development. Treatment with cyclosporin A (CsA), an inhibitor of the Hsp90 client protein calcineurin, did not increase the effect of GDA. In contrast, GDA prevented mycelial to yeast differentiation through a mechanism partially dependent on calcineurin, whereas differentiation from yeast to mycelia occurred independent of GDA or CsA. A significant increase in reactive oxygen species (ROS) levels was detected in GDA-treated yeast at 42°C. However, the levels of ROS remained unchanged in GDA-treated yeast or mycelia incubated at 37°C, suggesting that Hsp90 plays different roles under normal and thermal stress conditions. We propose that Hsp90 strengthens the stress response of P. brasiliensis at 37°C through a mechanism that does not involve ROS. Moreover, we suggest that Hsp90 has calcineurin-dependent functions in this organism.
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Affiliation(s)
- Tatiana G F Matos
- Instituto de Pesquisa e Desenvolvimento , Universidade do Vale do ParaiIba UNIVAP, São Jose dos Campos, São Paulo, Brazil
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Heat shock protein 90 is required for conidiation and cell wall integrity in Aspergillus fumigatus. EUKARYOTIC CELL 2012; 11:1324-32. [PMID: 22822234 DOI: 10.1128/ec.00032-12] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Heat shock protein 90 (Hsp90) is a eukaryotic molecular chaperone. Its involvement in the resistance of Candida albicans to azole and echinocandin antifungals is well established. However, little is known about Hsp90's function in the filamentous fungal pathogen Aspergillus fumigatus. We investigated the role of Hsp90 in A. fumigatus by genetic repression and examined its cellular localization under various stress conditions. Failure to generate a deletion strain of hsp90 suggested that it is essential. Genetic repression of Hsp90 was achieved by an inducible nitrogen-dependent promoter (pniiA-Hsp90) and led to decreased spore viability, decreased hyphal growth, and severe defects in germination and conidiation concomitant with the downregulation of the conidiation-specific transcription factors brlA, wetA, and abaA. Hsp90 repression potentiated the effect of cell wall inhibitors affecting the β-glucan structure of the cell wall (caspofungin, Congo red) and of the calcineurin inhibitor FK506, supporting a role in regulating cell wall integrity pathways. Moreover, compromising Hsp90 abolished the paradoxical effect of caspofungin. Pharmacological inhibition of Hsp90 by geldanamycin and its derivatives (17-AAG and 17-DMAG) resulted in similar effects. C-terminal green fluorescent protein (GFP) tagging of Hsp90 revealed mainly cytosolic distribution under standard growth conditions. However, treatment with caspofungin resulted in Hsp90 accumulation at the cell wall and at sites of septum formation, further highlighting its role in cell wall stress compensatory mechanisms. Targeting Hsp90 with fungal-specific inhibitors to cripple stress response compensatory pathways represents an attractive new antifungal strategy.
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Singh-Babak SD, Babak T, Diezmann S, Hill JA, Xie JL, Chen YL, Poutanen SM, Rennie RP, Heitman J, Cowen LE. Global analysis of the evolution and mechanism of echinocandin resistance in Candida glabrata. PLoS Pathog 2012; 8:e1002718. [PMID: 22615574 PMCID: PMC3355103 DOI: 10.1371/journal.ppat.1002718] [Citation(s) in RCA: 136] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Accepted: 04/10/2012] [Indexed: 12/24/2022] Open
Abstract
The evolution of drug resistance has a profound impact on human health. Candida glabrata is a leading human fungal pathogen that can rapidly evolve resistance to echinocandins, which target cell wall biosynthesis and are front-line therapeutics for Candida infections. Here, we provide the first global analysis of mutations accompanying the evolution of fungal drug resistance in a human host utilizing a series of C. glabrata isolates that evolved echinocandin resistance in a patient treated with the echinocandin caspofungin for recurring bloodstream candidemia. Whole genome sequencing identified a mutation in the drug target, FKS2, accompanying a major resistance increase, and 8 additional non-synonymous mutations. The FKS2-T1987C mutation was sufficient for echinocandin resistance, and associated with a fitness cost that was mitigated with further evolution, observed in vitro and in a murine model of systemic candidemia. A CDC6-A511G(K171E) mutation acquired before FKS2-T1987C(S663P), conferred a small resistance increase. Elevated dosage of CDC55, which acquired a C463T(P155S) mutation after FKS2-T1987C(S663P), ameliorated fitness. To discover strategies to abrogate echinocandin resistance, we focused on the molecular chaperone Hsp90 and downstream effector calcineurin. Genetic or pharmacological compromise of Hsp90 or calcineurin function reduced basal tolerance and resistance. Hsp90 and calcineurin were required for caspofungin-dependent FKS2 induction, providing a mechanism governing echinocandin resistance. A mitochondrial respiration-defective petite mutant in the series revealed that the petite phenotype does not confer echinocandin resistance, but renders strains refractory to synergy between echinocandins and Hsp90 or calcineurin inhibitors. The kidneys of mice infected with the petite mutant were sterile, while those infected with the HSP90-repressible strain had reduced fungal burden. We provide the first global view of mutations accompanying the evolution of fungal drug resistance in a human host, implicate the premier compensatory mutation mitigating the cost of echinocandin resistance, and suggest a new mechanism of echinocandin resistance with broad therapeutic potential. The evolution of drug resistance poses a severe threat to human health. Candida glabrata is a leading cause of mortality due to fungal infections worldwide. It can rapidly evolve resistance to drugs such as echinocandins, which target the fungal cell wall and are front-line therapeutics for Candida infections. We harness whole genome sequencing to provide a global view of mutations that accumulate in C. glabrata during the evolution of echinocandin resistance in a human host. Nine non-synonymous mutations were identified, including one in the echinocandin target. A mutation in an additional gene conferred a small resistance increase and another was in a gene whose dosage mitigated the fitness cost of resistance. We further discovered that compromising function of the molecular chaperone Hsp90 abrogates drug resistance and reduces kidney fungal burden in a mouse model of infection. Hsp90 and its downstream effector calcineurin are required for induction of the drug target in response to drug. Thus, we reveal the first global portrait of antifungal resistance mutations that evolve in a human host, identify the first compensatory mutation that mitigates the cost of echinocandin resistance, and suggest a new mechanism of echinocandin resistance that can be exploited to treat life-threatening fungal infections.
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Affiliation(s)
| | - Tomas Babak
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Stephanie Diezmann
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Jessica A. Hill
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Jinglin Lucy Xie
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Ying-Lien Chen
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Susan M. Poutanen
- University Health Network/Mount Sinai Hospital, Department of Microbiology, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
- Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Robert P. Rennie
- Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, Canada
| | - Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Leah E. Cowen
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- * E-mail:
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Dimopoulos MA, Mitsiades CS, Anderson KC, Richardson PG. Tanespimycin as antitumor therapy. CLINICAL LYMPHOMA MYELOMA & LEUKEMIA 2011; 11:17-22. [PMID: 21454186 DOI: 10.3816/clml.2011.n.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
BACKGROUND The 90 kDa heat shock protein (HSP90), which facilitates proper folding and stability of numerous signaling molecules involved in growth control, cell survival, and development, has been implicated in malignant processes. Like its parent compound geldanamycin, tanespimycin binds to HSP90 and causes antineoplastic effects in vitro and in vivo. MATERIALS AND METHODS All relevant published papers identified through searches of PubMed and abstracts from major recent hematology and oncology meetings were reviewed as of October 2009. RESULTS Different formulations and schedules of tanespimycin monotherapy and combination therapy have been tested in several phase I studies in patients with solid tumors or multiple myeloma (MM). No responses have been reported in studies of tanespimycin monotherapy in patients with metastatic melanoma. Tanespimycin given in combination with trastuzumab in patients with metastatic breast cancer induced a partial response in 24% of patients. Single-agent tanespimycin showed activity in MM and in combination with bortezomib, 27% of patients achieved minor response or better (48% bortezomib-naive patients, 22% bortezomib-pretreated patients, 13% bortezomib-refractory patients). CONCLUSION Tanespimycin represents a promising new agent for the treatment of relapsed/refractory MM. Results of ongoing and future trials will determine the role of tanespimycin both in MM and other malignancies, including breast cancer.
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Shapiro RS, Robbins N, Cowen LE. Regulatory circuitry governing fungal development, drug resistance, and disease. Microbiol Mol Biol Rev 2011; 75:213-67. [PMID: 21646428 PMCID: PMC3122626 DOI: 10.1128/mmbr.00045-10] [Citation(s) in RCA: 384] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Pathogenic fungi have become a leading cause of human mortality due to the increasing frequency of fungal infections in immunocompromised populations and the limited armamentarium of clinically useful antifungal drugs. Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus are the leading causes of opportunistic fungal infections. In these diverse pathogenic fungi, complex signal transduction cascades are critical for sensing environmental changes and mediating appropriate cellular responses. For C. albicans, several environmental cues regulate a morphogenetic switch from yeast to filamentous growth, a reversible transition important for virulence. Many of the signaling cascades regulating morphogenesis are also required for cells to adapt and survive the cellular stresses imposed by antifungal drugs. Many of these signaling networks are conserved in C. neoformans and A. fumigatus, which undergo distinct morphogenetic programs during specific phases of their life cycles. Furthermore, the key mechanisms of fungal drug resistance, including alterations of the drug target, overexpression of drug efflux transporters, and alteration of cellular stress responses, are conserved between these species. This review focuses on the circuitry regulating fungal morphogenesis and drug resistance and the impact of these pathways on virulence. Although the three human-pathogenic fungi highlighted in this review are those most frequently encountered in the clinic, they represent a minute fraction of fungal diversity. Exploration of the conservation and divergence of core signal transduction pathways across C. albicans, C. neoformans, and A. fumigatus provides a foundation for the study of a broader diversity of pathogenic fungi and a platform for the development of new therapeutic strategies for fungal disease.
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Affiliation(s)
| | | | - Leah E. Cowen
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
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Gu L, Xu D, You T, Li X, Yao S, Chen S, Zhao J, Lan H, Zhang F. Analysis of gene expression by ESTs from suppression subtractive hybridization library in Chenopodium album L. under salt stress. Mol Biol Rep 2011; 38:5285-95. [PMID: 21246286 DOI: 10.1007/s11033-011-0678-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2010] [Accepted: 01/10/2011] [Indexed: 11/29/2022]
Abstract
To identify genes expression in Chenopodium album exposed to NaCl stress and screen ESTs related to salt stress, a subtractive suppression hybridization (SSH) library of C. album under salt stress was constructed in the present study. Random EST sequencing produced 825 high-quality ESTs with GenBank ID GE746311-GE747007, which had 301 bp of average size and were clustered into 88 contigs and 550 singletons. They were classified into 12 categories according to their function annotations. 635 ESTs (76.97%) showed similarities to gene sequences in the non-redundancy database, while 190 ESTs (23.03%) showed low or no similarities. The transcriptional profiles of 56 ESTs randomly selected from 347 unknown or novel ESTs of SSH library under varying NaCl concentration and at different time points were analyzed. The results indicated that a high proportion of tested ESTs were activated by salt stress. Four in 56 ESTs responded to NaCl were also enhanced in expression level when exposed to ABA and PEG stresses. The above four ESTs were validated by northern blotting which was consistent with the results of RT-PCR. The results suggested that genes corresponded to these ESTs might be involved in stress response or regulation. The complete sequences and detailed function of these ESTs need to be further studied.
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Affiliation(s)
- Lili Gu
- Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi 830046, China
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Jarosz DF, Taipale M, Lindquist S. Protein homeostasis and the phenotypic manifestation of genetic diversity: principles and mechanisms. Annu Rev Genet 2011; 44:189-216. [PMID: 21047258 DOI: 10.1146/annurev.genet.40.110405.090412] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Changing a single nucleotide in a genome can have profound consequences under some conditions, but the same change can have no consequences under others. Indeed, organisms can be surprisingly robust to environmental and genetic perturbations. Yet, the mechanisms underlying such robustness are controversial. Moreover, how they might affect evolutionary change remains enigmatic. Here, we review the recently appreciated central role of protein homeostasis in buffering and potentiating genetic variation and discuss how these processes mediate the critical influence of the environment on the relationship between genotype and phenotype. Deciphering how robustness emerges from biological organization and the mechanisms by which it is overcome in changing environments will lead to a more complete understanding of both fundamental evolutionary processes and diverse human diseases.
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Affiliation(s)
- Daniel F Jarosz
- Whitehead Institute for Biomedical Research and Howard Hughes Medical Institute, Cambridge, Massachusetts 02142, USA.
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Kim IS, Jin I, Yoon HS. Decarbonylated cyclophilin A Cpr1 protein protects Saccharomyces cerevisiae KNU5377Y when exposed to stress induced by menadione. Cell Stress Chaperones 2011; 16:1-14. [PMID: 20680535 PMCID: PMC3024093 DOI: 10.1007/s12192-010-0215-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2010] [Revised: 07/16/2010] [Accepted: 07/19/2010] [Indexed: 01/20/2023] Open
Abstract
Cyclophilins are conserved cis-trans peptidyl-prolyl isomerase that are implicated in protein folding and function as molecular chaperones. The accumulation of Cpr1 protein to menadione in Saccharomyces cerevisiae KNU5377Y suggests a possibility that this protein may participate in the mechanism of stress tolerance. Stress response of S. cerevisiae KNU5377Y cpr1Δ mutant strain was investigated in the presence of menadione (MD). The growth ability of the strain was confirmed in an oxidant-supplemented medium, and a relationship was established between diminishing levels of cell rescue enzymes and MD sensitivity. The results demonstrate the significant effect of CPR1 disruption in the cellular growth rate, cell viability and morphology, and redox state in the presence of MD and suggest the possible role of Cpr1p in acquiring sensitivity to MD and its physiological role in cellular stress tolerance. The in vivo importance of Cpr1p for antioxidant-mediated reactive oxygen species (ROS) neutralization and chaperone-mediated protein folding was confirmed by analyzing the expression changes of a variety of cell rescue proteins in a CPR1-disrupted strain. The cpr1Δ to the exogenous MD showed reduced expression level of antioxidant enzymes, molecular chaperones, and metabolic enzymes such as nicotinamide adenine dinucleotide phosphate (NADPH)- or adenosine triphosphate (ATP)-generating systems. More importantly, it was shown that cpr1Δ mutant caused imbalance in the cellular redox homeostasis and increased ROS levels in the cytosol as well as mitochondria and elevated iron concentrations. As a result of excess ROS production, the cpr1Δ mutant provoked an increase in oxidative damage and a reduction in antioxidant activity and free radical scavenger ability. However, there was no difference in the stress responses between the wild-type and the cpr1Δ mutant strains derived from S. cerevisiae BY4741 as a control strain under the same stress. Unlike BY4741, KNU5377Y Cpr1 protein was decarbonylated during MD stress. Decarbonylation of Cpr1 protein in KNU5377Y strain seems to be caused by a rapid and efficient gene expression program via stress response factors Hsf1, Yap1, and Msn2. Hence, the decarbonylated Cpr1 protein may be critical in cellular redox homeostasis and may be a potential chaperone to menadione.
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Affiliation(s)
- Il-Sup Kim
- Department of Microbiology, Kyungpook National University, Daegu, 702-701, Republic of Korea.
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Identification of a cell death pathway in Candida albicans during the response to pheromone. EUKARYOTIC CELL 2010; 9:1690-701. [PMID: 20870881 DOI: 10.1128/ec.00155-10] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Mating in hemiascomycete yeasts involves the secretion of pheromones that induce sexual differentiation in cells of the opposite mating type. Studies in Saccharomyces cerevisiae have revealed that a subpopulation of cells experiences cell death during exposure to pheromone. In this work, we tested whether the phenomenon of pheromone-induced death (PID) also occurs in the opportunistic pathogen Candida albicans. Mating in C. albicans is uniquely regulated by white-opaque phenotypic switching; both cell types respond to pheromone, but only opaque cells undergo the morphological transition and cell conjugation. We show that approximately 20% of opaque cells, but not white cells, of laboratory strain SC5314 experience pheromone-induced death. Furthermore, analysis of mutant strains revealed that PID was significantly reduced in strains lacking Fig1 or Fus1 transmembrane proteins that are induced during the mating process and, we now show, are necessary for efficient mating in C. albicans. The level of PID was also Ca(2+) dependent, as chelation of Ca(2+) ions increased cell death to almost 50% of the population. However, in contrast to S. cerevisiae PID, pheromone-induced killing of C. albicans cells was largely independent of signaling via the Ca(2+)-dependent protein phosphatase calcineurin, even when combined with the loss of Cmk1 and Cmk2 proteins. Finally, we demonstrate that levels of PID vary widely between clinical isolates of C. albicans, with some strains experiencing close to 70% cell death. We discuss these findings in light of the role of prodeath and prosurvival pathways operating in yeast cells undergoing the morphological response to pheromone.
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Bhaganna P, Volkers RJM, Bell ANW, Kluge K, Timson DJ, McGrath JW, Ruijssenaars HJ, Hallsworth JE. Hydrophobic substances induce water stress in microbial cells. Microb Biotechnol 2010; 3:701-16. [PMID: 21255365 PMCID: PMC3815343 DOI: 10.1111/j.1751-7915.2010.00203.x] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Ubiquitous noxious hydrophobic substances, such as hydrocarbons, pesticides and diverse industrial chemicals, stress biological systems and thereby affect their ability to mediate biosphere functions like element and energy cycling vital to biosphere health. Such chemically diverse compounds may have distinct toxic activities for cellular systems; they may also share a common mechanism of stress induction mediated by their hydrophobicity. We hypothesized that the stressful effects of, and cellular adaptations to, hydrophobic stressors operate at the level of water : macromolecule interactions. Here, we present evidence that: (i) hydrocarbons reduce structural interactions within and between cellular macromolecules, (ii) organic compatible solutes – metabolites that protect against osmotic and chaotrope‐induced stresses – ameliorate this effect, (iii) toxic hydrophobic substances induce a potent form of water stress in macromolecular and cellular systems, and (iv) the stress mechanism of, and cellular responses to, hydrophobic substances are remarkably similar to those associated with chaotrope‐induced water stress. These findings suggest that it may be possible to devise new interventions for microbial processes in both natural environments and industrial reactors to expand microbial tolerance of hydrophobic substances, and hence the biotic windows for such processes.
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Affiliation(s)
- Prashanth Bhaganna
- Department of Biological Sciences, University of Essex, Colchester CO4 3SQ, UK
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