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Mediator Subunit Med15 Regulates Cell Morphology and Mating in Candida lusitaniae. J Fungi (Basel) 2023; 9:jof9030333. [PMID: 36983501 PMCID: PMC10053558 DOI: 10.3390/jof9030333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 02/26/2023] [Accepted: 02/27/2023] [Indexed: 03/12/2023] Open
Abstract
Candida lusitaniae is an emerging opportunistic pathogenic yeast capable of shifting from yeast to pseudohyphae form, and it is one of the few Candida species with the ability to reproduce sexually. In this study, we showed that a dpp3Δ mutant, inactivated for a putative pyrophosphatase, is impaired in cell separation, pseudohyphal growth and mating. The defective phenotypes were not restored after the reconstruction of a wild-type DPP3 locus, reinforcing the hypothesis of the presence of an additional mutation that we suspected in our previous study. Genetic crosses and genome sequencing identified an additional mutation in MED15, encoding a subunit of the mediator complex that functions as a general transcriptional co-activator in Eukaryotes. We confirmed that inactivation of MED15 was responsible for the defective phenotypes by rescuing the dpp3Δ mutant with a wild-type copy of MED15 and constructing a med15Δ knockout mutant that mimics the phenotypes of dpp3Δ in vitro. Proteomic analyses revealed the biological processes under the control of Med15 and involved in hyphal growth, cell separation and mating. This is the first description of the functions of MED15 in the regulation of hyphal growth, cell separation and mating, and the pathways involved in C. lusitaniae.
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Li G, Liu S, Wu L, Wang X, Cuan R, Zheng Y, Liu D, Yuan Y. Characterization and Functional Analysis of a New Calcium/Calmodulin-Dependent Protein Kinase (CaMK1) in the Citrus Pathogenic Fungus Penicillium italicum. J Fungi (Basel) 2022; 8:jof8070667. [PMID: 35887424 PMCID: PMC9323541 DOI: 10.3390/jof8070667] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 06/21/2022] [Accepted: 06/23/2022] [Indexed: 12/30/2022] Open
Abstract
Calcium (Ca2+)/calmodulin-dependent protein kinases (CaMKs) act as a class of crucial elements in Ca2+-signal transduction pathways that regulate fungal growth, sporulation, virulence, and environmental stress tolerance. However, little is known about the function of such protein kinase in phytopathogenic Penicillium species. In the present study, a new CaMK gene from the citrus pathogenic fungus P. italicum, designated PiCaMK1, was cloned and functionally characterized by gene knockout and transcriptome analysis. The open reading frame of PiCaMK1 is 1209 bp in full length, which encodes 402 amino acid residues (putative molecular weight ~45.2 KD) with the highest homologous (~96.3%) to the P. expansum CaMK. The knockout mutant ΔPiCaMK1 showed a significant reduction in vegetative growth, conidiation, and virulence (i.e., to induce blue mold decay on citrus fruit). ΔPiCaMK1 was less sensitive to NaCl- or KCl-induced salinity stress and less resistant to mannitol-induced osmotic stress, indicating the functional involvement of PiCaMK1 in such environmental stress tolerance. In contrast, the PiCaMK1-complemented strain ΔPiCaMK1COM can restore all the defective phenotypes. Transcriptome analysis revealed that knockout of PiCaMK1 down-regulated expression of the genes involved in DNA replication and repair, cell cycle, meiosis, pyrimidine and purine metabolisms, and MAPK signaling pathway. Our results suggested the critical role of PiCaMK1 in regulating multiple physical and cellular processes of citrus postharvest pathogen P. italicum, including growth, conidiation, virulence, and environmental stress tolerance.
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Affiliation(s)
- Guoqi Li
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, China; (G.L.); (L.W.); (X.W.); (R.C.); (D.L.)
| | - Shaoting Liu
- School of Public Administration, Central China Normal University, Wuhan 430079, China;
| | - Lijuan Wu
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, China; (G.L.); (L.W.); (X.W.); (R.C.); (D.L.)
| | - Xiao Wang
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, China; (G.L.); (L.W.); (X.W.); (R.C.); (D.L.)
| | - Rongrong Cuan
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, China; (G.L.); (L.W.); (X.W.); (R.C.); (D.L.)
| | - Yongliang Zheng
- Hubei Key Laboratory of Economic Forest Germplasm Improvement and Resources Comprehensive Utilization, Hubei Collaborative Innovation Center for the Characteristic Resources Exploitation of Dabie Mountains, College of Biology and Agricultural Resources, Huanggang Normal University, Huanggang 438000, China;
| | - Deli Liu
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, China; (G.L.); (L.W.); (X.W.); (R.C.); (D.L.)
| | - Yongze Yuan
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, China; (G.L.); (L.W.); (X.W.); (R.C.); (D.L.)
- Correspondence:
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Das S, Goswami AM, Saha T. An insight into the role of protein kinases as virulent factors, regulating pathogenic attributes in Candida albicans. Microb Pathog 2022; 164:105418. [DOI: 10.1016/j.micpath.2022.105418] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 01/21/2022] [Accepted: 01/21/2022] [Indexed: 11/26/2022]
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Lin L, Cao J, Du A, An Q, Chen X, Yuan S, Batool W, Shabbir A, Zhang D, Wang Z, Norvienyeku J. eIF3k Domain-Containing Protein Regulates Conidiogenesis, Appressorium Turgor, Virulence, Stress Tolerance, and Physiological and Pathogenic Development of Magnaporthe oryzae Oryzae. FRONTIERS IN PLANT SCIENCE 2021; 12:748120. [PMID: 34733303 PMCID: PMC8558559 DOI: 10.3389/fpls.2021.748120] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 09/22/2021] [Indexed: 05/05/2023]
Abstract
The eukaryotic translation initiation factor 3 (eIF3) complex consists of essential and non-essential sub-complexes. Non-essential eIF3 complex subunits, such as eIF3e, eIF3j, eIF3k, and eIF3l, modulate stress tolerance and enhance the lifespan of Neurospora crassa and Caenorhabditis elegans. However, there is limited knowledge of the role of the non-essential eIF3 sub-complex in the pathophysiological development of plant fungal pathogens. Here, we deployed genetic and biochemical techniques to explore the influence of a hypothetical protein containing eIF3k domain in Magnaporthe oryzae Oryzae (MoOeIF3k) on reproduction, hyphae morphogenesis, stress tolerance, and pathogenesis. Also, the targeted disruption of MoOeIF3k suppressed vegetative growth and asexual sporulation in ΔMoOeif3k strains significantly. We demonstrated that MoOeIF3k promotes the initiation and development of the rice blast disease by positively regulating the mobilization and degradation of glycogen, appressorium integrity, host penetration, and colonization during host-pathogen interaction. For the first time, we demonstrated that the eIF3k subunit supports the survival of the blast fungus by suppressing vegetative growth and possibly regulating the conversions and utilization of stored cellular energy reserves under starvation conditions. We also observed that the deletion of MoOeIF3k accelerated ribosomal RNA (rRNA) generation in the ΔMoOeif3k strains with a corresponding increase in total protein output. In summary, this study unravels the pathophysiological significance of eIF3k filamentous fungi. The findings also underscored the need to systematically evaluate the individual subunits of the non-essential eIF3 sub-complex during host-pathogen interaction. Further studies are required to unravel the influence of synergetic coordination between translation and transcriptional regulatory machinery on the pathogenesis of filamentous fungi pathogens.
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Affiliation(s)
- Lili Lin
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, China
- Fujian University Key Laboratory for Plant-Microbe Interaction, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Jiaying Cao
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, China
- Fujian University Key Laboratory for Plant-Microbe Interaction, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Anqiang Du
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, China
- Fujian University Key Laboratory for Plant-Microbe Interaction, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Qiuli An
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, China
- Fujian University Key Laboratory for Plant-Microbe Interaction, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Xiaomin Chen
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, China
- Fujian University Key Laboratory for Plant-Microbe Interaction, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Shuangshuang Yuan
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, China
- Fujian University Key Laboratory for Plant-Microbe Interaction, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Wajjiha Batool
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, China
- Fujian University Key Laboratory for Plant-Microbe Interaction, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Ammarah Shabbir
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, China
- Fujian University Key Laboratory for Plant-Microbe Interaction, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Dongmei Zhang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, China
- Fujian University Key Laboratory for Plant-Microbe Interaction, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Zonghua Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, China
- Fujian University Key Laboratory for Plant-Microbe Interaction, Fujian Agriculture and Forestry University, Fuzhou, China
- Institute of Oceanography, Minjiang University, Fuzhou, China
- Zonghua Wang,
| | - Justice Norvienyeku
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, China
- Fujian University Key Laboratory for Plant-Microbe Interaction, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education, College of Plant Protection, Hainan University, Haikou, China
- *Correspondence: Justice Norvienyeku,
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Kanashiro AM, Akiyama DY, Kupper KC, Fill TP. Penicillium italicum: An Underexplored Postharvest Pathogen. Front Microbiol 2020; 11:606852. [PMID: 33343551 PMCID: PMC7746842 DOI: 10.3389/fmicb.2020.606852] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 11/06/2020] [Indexed: 11/13/2022] Open
Abstract
In the agricultural sector, citrus is one of the most important fruit genus in the world. In this scenario, Brazil is the largest producer of oranges; 34% of the global production, and exporter of concentrated orange juice; 76% of the juice consumed in the planet, summing up US$ 6.5 billion to Brazilian GDP. However, the orange production has been considerable decreasing due to unfavorable weather conditions in recent years and the increasing number of pathogen infections. One of the main citrus post-harvest phytopathogen is Penicillium italicum, responsible for the blue mold disease, which is currently controlled by pesticides, such as Imazalil, Pyrimethanil, Fludioxonil, and Tiabendazole, which are toxic chemicals harmful to the environment and also to human health. In addition, P. italicum has developed considerable resistance to these chemicals as a result of widespread applications. To address this growing problem, the search for new control methods of citrus post-harvest phytopathogens is being extensively explored, resulting in promising new approaches such as biocontrol methods as “killer” yeasts, application of essential oils, and antimicrobial volatile substances. The alternative methodologies to control P. italicum are reviewed here, as well as the fungal virulence factors and infection strategies. Therefore, this review will focus on a general overview of recent research carried out regarding the phytopathological interaction of P. italicum and its citrus host.
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Affiliation(s)
| | | | - Katia Cristina Kupper
- Advanced Citrus Research Center, Sylvio Moreira/Campinas Agronomic Institute, São Paulo, Brazil
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Zhang T, Cao Q, Li N, Liu D, Yuan Y. Transcriptome analysis of fungicide-responsive gene expression profiles in two Penicillium italicum strains with different response to the sterol demethylation inhibitor (DMI) fungicide prochloraz. BMC Genomics 2020; 21:156. [PMID: 32050894 PMCID: PMC7017498 DOI: 10.1186/s12864-020-6564-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Accepted: 02/07/2020] [Indexed: 12/19/2022] Open
Abstract
Background Penicillium italicum (blue mold) is one of citrus pathogens causing undesirable citrus fruit decay even at strictly-controlled low temperatures (< 10 °C) during shipping and storage. P. italicum isolates with considerably high resistance to sterol demethylation inhibitor (DMI) fungicides have emerged; however, mechanism(s) underlying such DMI-resistance remains unclear. In contrast to available elucidation on anti-DMI mechanism for P. digitatum (green mold), how P. italicum DMI-resistance develops has not yet been clarified. Results The present study prepared RNA-sequencing (RNA-seq) libraries for two P. italicum strains (highly resistant (Pi-R) versus highly sensitive (Pi-S) to DMI fungicides), with and without prochloraz treatment, to identify prochloraz-responsive genes facilitating DMI-resistance. After 6 h prochloraz-treatment, comparative transcriptome profiling showed more differentially expressed genes (DEGs) in Pi-R than Pi-S. Functional enrichments identified 15 DEGs in the prochloraz-induced Pi-R transcriptome, simultaneously up-regulated in P. italicum resistance. These included ATP-binding cassette (ABC) transporter-encoding genes, major facilitator superfamily (MFS) transporter-encoding genes, ergosterol (ERG) anabolism component genes ERG2, ERG6 and EGR11 (CYP51A), mitogen-activated protein kinase (MAPK) signaling-inducer genes Mkk1 and Hog1, and Ca2+/calmodulin-dependent kinase (CaMK) signaling-inducer genes CaMK1 and CaMK2. Fragments Per Kilobase per Million mapped reads (FPKM) analysis of Pi-R transcrtiptome showed that prochloraz induced mRNA increase of additional 4 unigenes, including the other two ERG11 isoforms CYP51B and CYP51C and the remaining kinase-encoding genes (i.e., Bck1 and Slt2) required for Slt2-MAPK signaling. The expression patterns of all the 19 prochloraz-responsive genes, obtained in our RNA-seq data sets, have been validated by quantitative real-time PCR (qRT-PCR). These lines of evidence in together draw a general portrait of anti-DMI mechanisms for P. italicum species. Intriguingly, some strategies adopted by the present Pi-R were not observed in the previously documented prochloraz-resistant P. digitatum transcrtiptomes. These included simultaneous induction of all major EGR11 isoforms (CYP51A/B/C), over-expression of ERG2 and ERG6 to modulate ergosterol anabolism, and concurrent mobilization of Slt2-MAPK and CaMK signaling processes to overcome fungicide-induced stresses. Conclusions The present findings provided transcriptomic evidence on P. italicum DMI-resistance mechanisms and revealed some diversity in anti-DMI strategies between P. italicum and P. digitatum species, contributing to our knowledge on P. italicum DMI-resistance mechanisms.
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Affiliation(s)
- Tingfu Zhang
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China
| | - Qianwen Cao
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China
| | - Na Li
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China.,Yunnan Higher Education Institutions, College of Life Science and Technology, Honghe University, Mengzi, 661199, China
| | - Deli Liu
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China.
| | - Yongze Yuan
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China.
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Abstract
Candida albicans is a commensal as well as a pathogen of humans. C. albicans is able to mount a cellular response to a diverse range of external stimuli in the host and switch reversibly between the yeast and hyphal growth forms. Hyphal development is a key virulence determinant. Here, we studied how C. albicans senses different environmental signals to control its growth forms. Our study results suggest that robust hyphal development requires downregulation of two transcriptional repressors, Nrg1 and Sfl1. Acidic pH or cationic stress inhibits hyphal formation via stress-responsive kinases and Sfl1. Candida albicans is an important human pathogen responsible for causing both superficial and systemic infections. Its ability to switch from the yeast form to the hyphal growth form is required for its pathogenicity. Acidic pH inhibits hyphal initiation, but the nature of the mechanism for this inhibition is not completely clear. We show that acidic pH represses hyphal initiation independently of the temperature- and farnesol-mediated Nrg1 downregulation. Using a collection of transcription factor deletion mutants, we observed that the sfl1 mutant induced hyphae in acidic pH but not in farnesol at 37°C. Furthermore, transcription of hyphal regulators BRG1 and UME6 was not induced in wild-type (WT) cells but was induced in the sfl1 mutant during hyphal induction in acidic pH. Using the same screening conditions with the collection of kinase mutants, we found that deletions of the core stress response mitogen-activated protein (MAP) kinase HOG1 and its kinase PBS2, the cell wall stress MAP kinase MKC1, and the calcium/calmodulin-dependent kinase CMK1 allowed hyphal initiation in acidic pH. Furthermore, Hog1 phosphorylation induced by high osmotic stress also retarded hyphal initiation, and the effect was abolished in the sfl1 and three kinase mutants but was enhanced in the phosphatase mutant ptp2 ptp3. We also found functional associations among Cmk1, Hog1, and Sfl1 for cation stress. Our study results suggest that robust hyphal initiation requires downregulation of both Nrg1 and Sfl1 transcriptional repressors as well as timely BRG1 expression. Acidic pH and cationic stress retard hyphal initiation via the stress-responsive kinases and Sfl1. IMPORTANCECandida albicans is a commensal as well as a pathogen of humans. C. albicans is able to mount a cellular response to a diverse range of external stimuli in the host and switch reversibly between the yeast and hyphal growth forms. Hyphal development is a key virulence determinant. Here, we studied how C. albicans senses different environmental signals to control its growth forms. Our study results suggest that robust hyphal development requires downregulation of two transcriptional repressors, Nrg1 and Sfl1. Acidic pH or cationic stress inhibits hyphal formation via stress-responsive kinases and Sfl1.
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Seifbarghi S, Borhan MH, Wei Y, Coutu C, Robinson SJ, Hegedus DD. Changes in the Sclerotinia sclerotiorum transcriptome during infection of Brassica napus. BMC Genomics 2017; 18:266. [PMID: 28356071 PMCID: PMC5372324 DOI: 10.1186/s12864-017-3642-5] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 03/18/2017] [Indexed: 11/17/2022] Open
Abstract
Background Sclerotinia sclerotiorum causes stem rot in Brassica napus, which leads to lodging and severe yield losses. Although recent studies have explored significant progress in the characterization of individual S. sclerotiorum pathogenicity factors, a gap exists in profiling gene expression throughout the course of S. sclerotiorum infection on a host plant. In this study, RNA-Seq analysis was performed with focus on the events occurring through the early (1 h) to the middle (48 h) stages of infection. Results Transcript analysis revealed the temporal pattern and amplitude of the deployment of genes associated with aspects of pathogenicity or virulence during the course of S. sclerotiorum infection on Brassica napus. These genes were categorized into eight functional groups: hydrolytic enzymes, secondary metabolites, detoxification, signaling, development, secreted effectors, oxalic acid and reactive oxygen species production. The induction patterns of nearly all of these genes agreed with their predicted functions. Principal component analysis delineated gene expression patterns that signified transitions between pathogenic phases, namely host penetration, ramification and necrotic stages, and provided evidence for the occurrence of a brief biotrophic phase soon after host penetration. Conclusions The current observations support the notion that S. sclerotiorum deploys an array of factors and complex strategies to facilitate host colonization and mitigate host defenses. This investigation provides a broad overview of the sequential expression of virulence/pathogenicity-associated genes during infection of B. napus by S. sclerotiorum and provides information for further characterization of genes involved in the S. sclerotiorum-host plant interactions. Electronic supplementary material The online version of this article (doi:10.1186/s12864-017-3642-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Shirin Seifbarghi
- Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK, S7N 0X2, Canada.,Department of Biology, University of Saskatchewan, Saskatoon, Canada
| | - M Hossein Borhan
- Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK, S7N 0X2, Canada
| | - Yangdou Wei
- Department of Biology, University of Saskatchewan, Saskatoon, Canada
| | - Cathy Coutu
- Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK, S7N 0X2, Canada
| | - Stephen J Robinson
- Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK, S7N 0X2, Canada
| | - Dwayne D Hegedus
- Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK, S7N 0X2, Canada. .,Department of Food and Bioproduct Sciences, University of Saskatchewan, Saskatoon, Canada.
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Woolford CA, Lagree K, Xu W, Aleynikov T, Adhikari H, Sanchez H, Cullen PJ, Lanni F, Andes DR, Mitchell AP. Bypass of Candida albicans Filamentation/Biofilm Regulators through Diminished Expression of Protein Kinase Cak1. PLoS Genet 2016; 12:e1006487. [PMID: 27935965 PMCID: PMC5147786 DOI: 10.1371/journal.pgen.1006487] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 11/15/2016] [Indexed: 12/17/2022] Open
Abstract
Biofilm formation on implanted medical devices is a major source of lethal invasive infection by Candida albicans. Filamentous growth of this fungus is tied to biofilm formation because many filamentation-associated genes are required for surface adherence. Cell cycle or cell growth defects can induce filamentation, but we have limited information about the coupling between filamentation and filamentation-associated gene expression after cell cycle/cell growth inhibition. Here we identified the CDK activating protein kinase Cak1 as a determinant of filamentation and filamentation-associated gene expression through a screen of mutations that diminish expression of protein kinase-related genes implicated in cell cycle/cell growth control. A cak1diminished expression (DX) strain displays filamentous growth and expresses filamentation-associated genes in the absence of typical inducing signals. In a wild-type background, expression of filamentation-associated genes depends upon the transcription factors Bcr1, Brg1, Efg1, Tec1, and Ume6. In the cak1 DX background, the dependence of filamentation-associated gene expression on each transcription factor is substantially relieved. The unexpected bypass of filamentation-associated gene expression activators has the functional consequence of enabling biofilm formation in the absence of Bcr1, Brg1, Tec1, Ume6, or in the absence of both Brg1 and Ume6. It also enables filamentous cell morphogenesis, though not biofilm formation, in the absence of Efg1. Because these transcription factors are known to have shared target genes, we suggest that cell cycle/cell growth limitation leads to activation of several transcription factors, thus relieving dependence on any one. The ability of the pathogen Candida albicans to grow on surfaces as biofilms is a determinant of infection ability, because biofilms on implanted medical devices seed infections. Biofilm formation by this organism requires growth in the form of filamentous cells and the expression of filamentation-associated genes. Inhibition of cell proliferation can induce filamentous cell formation, as we find here for strains that express greatly reduced levels of the cell cycle regulator Cak1. Surprisingly, biofilm formation occurs independently of many central biofilm regulatory genes when Cak1 levels are reduced. This response to proliferation inhibition may reflect the activation of numerous biofilm regulators, thus relieving the dependence on any one regulator. The stimulation of biofilm formation by proliferation inhibition, a property of many bacterial pathogens as well, may contribute to the limited effectiveness of antimicrobials against biofilms.
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Affiliation(s)
- Carol A. Woolford
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Katherine Lagree
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Wenjie Xu
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Tatyana Aleynikov
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Hema Adhikari
- Department of Biological Sciences at the University at Buffalo, Buffalo, New York, United States of America
| | - Hiram Sanchez
- Departments of Medicine and Medical Microbiology and Immunology, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Paul J. Cullen
- Department of Biological Sciences at the University at Buffalo, Buffalo, New York, United States of America
| | - Frederick Lanni
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - David R. Andes
- Departments of Medicine and Medical Microbiology and Immunology, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Aaron P. Mitchell
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
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Zinc Cluster Transcription Factors Alter Virulence in Candida albicans. Genetics 2016; 205:559-576. [PMID: 27932543 DOI: 10.1534/genetics.116.195024] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 11/16/2016] [Indexed: 11/18/2022] Open
Abstract
Almost all humans are colonized with Candida albicans However, in immunocompromised individuals, this benign commensal organism becomes a serious, life-threatening pathogen. Here, we describe and analyze the regulatory networks that modulate innate responses in the host niches. We identified Zcf15 and Zcf29, two Zinc Cluster transcription Factors (ZCF) that are required for C. albicans virulence. Previous sequence analysis of clinical C. albicans isolates from immunocompromised patients indicates that both ZCF genes diverged during clonal evolution. Using in vivo animal models, ex vivo cell culture methods, and in vitro sensitivity assays, we demonstrate that knockout mutants of both ZCF15 and ZCF29 are hypersensitive to reactive oxygen species (ROS), suggesting they help neutralize the host-derived ROS produced by phagocytes, as well as establish a sustained infection in vivo Transcriptomic analysis of mutants under resting conditions where cells were not experiencing oxidative stress revealed a large network that control macro and micronutrient homeostasis, which likely contributes to overall pathogen fitness in host niches. Under oxidative stress, both transcription factors regulate a separate set of genes involved in detoxification of ROS and down-regulating ribosome biogenesis. ChIP-seq analysis, which reveals vastly different binding partners for each transcription factor (TF) before and after oxidative stress, further confirms these results. Furthermore, the absence of a dominant binding motif likely facilitates their mobility, and supports the notion that they represent a recent expansion of the ZCF family in the pathogenic Candida species. Our analyses provide a framework for understanding new aspects of the interface between C. albicans and host defense response, and extends our understanding of how complex cell behaviors are linked to the evolution of TFs.
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11
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Ma L, Wang H, Wang C, Su J, Xie Q, Xu L, Yu Y, Liu S, Li S, Xu Y, Li Z. Failure of Elevating Calcium Induces Oxidative Stress Tolerance and Imparts Cisplatin Resistance in Ovarian Cancer Cells. Aging Dis 2016; 7:254-66. [PMID: 27330840 PMCID: PMC4898922 DOI: 10.14336/ad.2016.0118] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2015] [Accepted: 01/17/2016] [Indexed: 12/14/2022] Open
Abstract
Cisplatin is a commonly used chemotherapeutic drug, used for the treatment of malignant ovarian cancer, but acquired resistance limits its application. There is therefore an overwhelming need to understand the mechanism of cisplatin resistance in ovarian cancer, that is, ovarian cancer cells are insensitive to cisplatin treatment. Here, we show that failure of elevating calcium and oxidative stress tolerance play key roles in cisplatin resistance in ovarian cancer cell lines. Cisplatin induces an increase in oxidative stress and alters intracellular Ca(2+) concentration, including cytosolic and mitochondrial Ca(2+) in cisplatin-sensitive SKOV3 cells, but not in cisplatin-resistant SKOV3/DDP cells. Cisplatin induces mitochondrial damage and triggers the mitochondrial apoptotic pathway in cisplatin-sensitive SKOV3 cells, but rarely in cisplatin-resistant SKOV3/DDP cells. Inhibition of calcium signaling attenuates cisplatin-induced oxidative stress and intracellular Ca(2+) overload in cisplatin-sensitive SKOV3 cells. Moreover, in vivo xenograft models of nude mouse, cisplatin significantly reduced the growth rates of tumors originating from SKOV3 cells, but not that of SKOV3/DDP cells. Collectively, our data indicate that failure of calcium up-regulation mediates cisplatin resistance by alleviating oxidative stress in ovarian cancer cells. Our results highlight potential therapeutic strategies to improve cisplatin resistance.
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Affiliation(s)
- Liwei Ma
- 1Medical Research Laboratory, Jilin Medical University, Jilin 132013, China
| | - Hongjun Wang
- 1Medical Research Laboratory, Jilin Medical University, Jilin 132013, China; 2Department of Histology and Embryology, Jilin Medical University, Jilin 132013, China
| | - Chunyan Wang
- 1Medical Research Laboratory, Jilin Medical University, Jilin 132013, China
| | - Jing Su
- 3Department of Pathophysiology, Basic College of Medicine, Jilin University, Changchun, 130021, China
| | - Qi Xie
- 3Department of Pathophysiology, Basic College of Medicine, Jilin University, Changchun, 130021, China
| | - Lu Xu
- 1Medical Research Laboratory, Jilin Medical University, Jilin 132013, China
| | - Yang Yu
- 1Medical Research Laboratory, Jilin Medical University, Jilin 132013, China
| | - Shibing Liu
- 1Medical Research Laboratory, Jilin Medical University, Jilin 132013, China
| | - Songyan Li
- 1Medical Research Laboratory, Jilin Medical University, Jilin 132013, China
| | - Ye Xu
- 1Medical Research Laboratory, Jilin Medical University, Jilin 132013, China
| | - Zhixin Li
- 2Department of Histology and Embryology, Jilin Medical University, Jilin 132013, China
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12
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Hegedus DD, Gerbrandt K, Coutu C. The eukaryotic protein kinase superfamily of the necrotrophic fungal plant pathogen, Sclerotinia sclerotiorum. MOLECULAR PLANT PATHOLOGY 2016; 17:634-647. [PMID: 26395470 PMCID: PMC6638376 DOI: 10.1111/mpp.12321] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Protein kinases have been implicated in the regulation of many processes that guide pathogen development throughout the course of infection. A survey of the Sclerotinia sclerotiorum genome for genes encoding proteins containing the highly conserved eukaryotic protein kinase (ePK) domain, the largest protein kinase superfamily, revealed 92 S. sclerotiorum ePKs. This review examines the composition of the S. sclerotiorum ePKs based on conserved motifs within the ePK domain family, and relates this to orthologues found in other filamentous fungi and yeasts. The ePKs are also discussed in terms of their proposed role(s) in aspects of host pathogenesis, including the coordination of mycelial growth/development and deployment of pathogenicity determinants in response to environmental stimuli, nutrients and stress.
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Affiliation(s)
- Dwayne D Hegedus
- Agriculture and Agri-Food Canada, Saskatoon, SK, Canada, S7N 0X2
- Department of Food and Bioproduct Sciences, University of Saskatchewan, Saskatoon, SK, Canada, S7N 5A9
| | - Kelsey Gerbrandt
- Agriculture and Agri-Food Canada, Saskatoon, SK, Canada, S7N 0X2
| | - Cathy Coutu
- Agriculture and Agri-Food Canada, Saskatoon, SK, Canada, S7N 0X2
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13
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Muñoz A, Bertuzzi M, Bettgenhaeuser J, Iakobachvili N, Bignell EM, Read ND. Different Stress-Induced Calcium Signatures Are Reported by Aequorin-Mediated Calcium Measurements in Living Cells of Aspergillus fumigatus. PLoS One 2015; 10:e0138008. [PMID: 26402916 PMCID: PMC4581630 DOI: 10.1371/journal.pone.0138008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 08/24/2015] [Indexed: 11/18/2022] Open
Abstract
Aspergillus fumigatus is an inhaled fungal pathogen of human lungs, the developmental growth of which is reliant upon Ca2+-mediated signalling. Ca2+ signalling has regulatory significance in all eukaryotic cells but how A. fumigatus uses intracellular Ca2+ signals to respond to stresses imposed by the mammalian lung is poorly understood. In this work, A. fumigatus strains derived from the clinical isolate CEA10, and a non-homologous recombination mutant ΔakuBKU80, were engineered to express the bioluminescent Ca2+-reporter aequorin. An aequorin-mediated method for routine Ca2+ measurements during the early stages of colony initiation was successfully developed and dynamic changes in cytosolic free calcium ([Ca2+]c) in response to extracellular stimuli were measured. The response to extracellular challenges (hypo- and hyper-osmotic shock, mechanical perturbation, high extracellular Ca2+, oxidative stress or exposure to human serum) that the fungus might be exposed to during infection, were analysed in living conidial germlings. The 'signatures' of the transient [Ca2+]c responses to extracellular stimuli were found to be dose- and age-dependent. Moreover, Ca2+-signatures associated with each physico-chemical treatment were found to be unique, suggesting the involvement of heterogeneous combinations of Ca2+-signalling components in each stress response. Concordant with the involvement of Ca2+-calmodulin complexes in these Ca2+-mediated responses, the calmodulin inhibitor trifluoperazine (TFP) induced changes in the Ca2+-signatures to all the challenges. The Ca2+-chelator BAPTA potently inhibited the initial responses to most stressors in accordance with a critical role for extracellular Ca2+ in initiating the stress responses.
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Affiliation(s)
- Alberto Muñoz
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, University of Manchester, Manchester, United Kingdom
- Fungal Cell Biology Group, Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Margherita Bertuzzi
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, University of Manchester, Manchester, United Kingdom
- Centre for Molecular Bacteriology and Infection, Department of Medicine, Imperial College London, London, United Kingdom
| | - Jan Bettgenhaeuser
- Fungal Cell Biology Group, Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Nino Iakobachvili
- Centre for Molecular Bacteriology and Infection, Department of Medicine, Imperial College London, London, United Kingdom
| | - Elaine M. Bignell
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, University of Manchester, Manchester, United Kingdom
- Centre for Molecular Bacteriology and Infection, Department of Medicine, Imperial College London, London, United Kingdom
- * E-mail: (NDR); (EMB)
| | - Nick D. Read
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, University of Manchester, Manchester, United Kingdom
- Fungal Cell Biology Group, Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
- * E-mail: (NDR); (EMB)
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14
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She X, Khamooshi K, Gao Y, Shen Y, Lv Y, Calderone R, Fonzi W, Liu W, Li D. Fungal-specific subunits of the Candida albicans mitochondrial complex I drive diverse cell functions including cell wall synthesis. Cell Microbiol 2015; 17:1350-64. [PMID: 25801605 PMCID: PMC4677794 DOI: 10.1111/cmi.12438] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 02/05/2015] [Accepted: 03/10/2015] [Indexed: 12/11/2022]
Abstract
Our published research has focused on the role of Goa1p, an apparent regulator of the Candida albicans mitochondrial complex I (CI). Lack of Goa1p affects optimum cell growth, CI activity and virulence. Eukaryotic CI is composed of a core of 14 alpha-proteobacterial subunit proteins and a variable number of supernumerary subunit proteins. Of the latter group of proteins, one (NUZM) is fungal specific and the other (NUXM) is found in fungi, algae and plants, but is not a mammalian CI subunit protein. We have established that NUXM is orf19.6607 and NUZM is orf19.287 in C. albicans. Herein, we validate both subunit proteins as NADH:ubiquinone oxidoreductases (NUO) and annotate their gene functions. To accomplish these objectives, we compared null mutants of each with wild type (WT) and gene-reconstituted strains. Genetic mutants of genes NUO1 (orf19.6607) and NUO2 (orf19.287), not surprisingly, each had reduced oxygen consumption, decreased mitochondrial redox potential, decreased CI activity, increased reactive oxidant species (ROS) and decreased chronological ageing in vitro. Loss of either gene results in disassembly of CI. Transcriptional profiling of both mutants indicated significant down-regulation of genes of carbon metabolism, as well as up-regulation of mitochondrial-associated gene families that may occur to compensate for the loss of CI activity. Profiling of both mutants also demonstrated a loss of cell wall β-mannosylation but not in a conserved CI subunit (ndh51Δ). The profiling data may indicate specific functions driven by the enzymatic activity of Nuo1p and Nuo2p. Of importance, each mutant is also avirulent in a murine blood-borne, invasive model of candidiasis associated with their reduced colonization of tissues. Based on their fungal specificity and roles in virulence, we suggest both as drug targets for antifungal drug discovery.
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Affiliation(s)
- Xiaodong She
- Georgetown University Medical Center, Department of Microbiology & Immunology, Washington, DC, 20057
- Institute of Dermatology, Chinese Academy of Medical Sciences (CAMS) & Jiangsu Key Laboratory of Molecular Biology for Skin Disease and STIs, Nanjing, China
| | - Kasra Khamooshi
- Georgetown University Medical Center, Department of Microbiology & Immunology, Washington, DC, 20057
| | - Yin Gao
- Institute of Dermatology, Chinese Academy of Medical Sciences (CAMS) & Jiangsu Key Laboratory of Molecular Biology for Skin Disease and STIs, Nanjing, China
| | - Yongnian Shen
- Institute of Dermatology, Chinese Academy of Medical Sciences (CAMS) & Jiangsu Key Laboratory of Molecular Biology for Skin Disease and STIs, Nanjing, China
| | - Yuxia Lv
- Institute of Dermatology, Chinese Academy of Medical Sciences (CAMS) & Jiangsu Key Laboratory of Molecular Biology for Skin Disease and STIs, Nanjing, China
| | - Richard Calderone
- Georgetown University Medical Center, Department of Microbiology & Immunology, Washington, DC, 20057
| | - William Fonzi
- Georgetown University Medical Center, Department of Microbiology & Immunology, Washington, DC, 20057
| | - Weida Liu
- Institute of Dermatology, Chinese Academy of Medical Sciences (CAMS) & Jiangsu Key Laboratory of Molecular Biology for Skin Disease and STIs, Nanjing, China
| | - Dongmei Li
- Georgetown University Medical Center, Department of Microbiology & Immunology, Washington, DC, 20057
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