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Fong JL, Ong Eng Yong V, Yeo C, Adamson C, Li L, Zhang D, Qiao Y. Biochemical Characterization of Recombinant Enterococcus faecalis EntV Peptide to Elucidate Its Antihyphal and Antifungal Mechanisms against Candida albicans. ACS Infect Dis 2024; 10:3408-3418. [PMID: 39137394 DOI: 10.1021/acsinfecdis.4c00515] [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] [Indexed: 08/15/2024]
Abstract
Candida albicans is a common opportunistic fungus in humans, whose morphological switch between yeast and hyphae forms represents a key virulence trait. Developing strategies to inhibit C. albicans hyphal growth may provide insights into designs of novel antivirulent therapeutics. Importantly, the gut commensal bacterium, Enterococcus faecalis, secretes a bacteriocin EntV which has potent antivirulent and antifungal effects against C. albicans in infection models; however, hampered by the challenges to access large quantities of bioactive EntV, the detailed understanding of its mechanisms on C. albicans has remained elusive. In this work, we biochemically reconstituted the proteolytic cleavage reaction to obtain recombinant EntV88-His6 on a large preparative scale, providing facile access to the C-terminal EntV construct. Under in vitro C. albicans hyphal assay with specific inducers, we demonstrated that EntV88-His6 exhibits potent bioactivity against GlcNAc-triggered hyphal growth. Moreover, with fluorescent FITC-EntV88-His6, we revealed that EntV88-His6 enters C. albicans via endocytosis and perturbs the proper localization of the polarisome scaffolding Spa2 protein. Our findings provide important clues on EntV's mechanism of action. Surprisingly, we showed that EntV88-His6 does not affect C. albicans yeast cell growth but potently exerts cytotoxicity against C. albicans under hyphal-inducing conditions in vitro. The combination of EntV88-His6 and GlcNAc displays rapid killing of C. albicans, rendering it a promising antivirulent and antifungal agent.
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Affiliation(s)
- Jia Li Fong
- School of Chemistry, Chemical Engineering and Biotechnology (CCEB), Nanyang Technological University (NTU), 21 Nanyang Link, Singapore 637371, Singapore
| | - Victor Ong Eng Yong
- Temasek Life Sciences Laboratory, 1 Research Link, Singapore 117604, Singapore
| | - Claresta Yeo
- School of Chemistry, Chemical Engineering and Biotechnology (CCEB), Nanyang Technological University (NTU), 21 Nanyang Link, Singapore 637371, Singapore
| | - Christopher Adamson
- School of Chemistry, Chemical Engineering and Biotechnology (CCEB), Nanyang Technological University (NTU), 21 Nanyang Link, Singapore 637371, Singapore
| | - Lanxin Li
- School of Chemistry, Chemical Engineering and Biotechnology (CCEB), Nanyang Technological University (NTU), 21 Nanyang Link, Singapore 637371, Singapore
| | - Dan Zhang
- Temasek Life Sciences Laboratory, 1 Research Link, Singapore 117604, Singapore
| | - Yuan Qiao
- School of Chemistry, Chemical Engineering and Biotechnology (CCEB), Nanyang Technological University (NTU), 21 Nanyang Link, Singapore 637371, Singapore
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2
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Song S, Zhao S, Sun X, Meng L, Wang Z, Tan H, Liu J, Zhang M, Deng Y. Anti-virulence strategy of diaryl chalcogenide compounds against Candida albicans infection. Virulence 2023; 14:2265012. [PMID: 37771181 PMCID: PMC10549196 DOI: 10.1080/21505594.2023.2265012] [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: 10/12/2022] [Accepted: 09/25/2023] [Indexed: 09/30/2023] Open
Abstract
Candida albicans is an important opportunistic pathogenic fungus that frequently causes serious systemic infection in humans. Due to the vital roles of biofilm formation and the yeast-to-hypha transition in the infection process, we have selected a series of diaryl chalcogenides and tested their efficacy against C. albicans SC5314 pathogenicity by the inhibition of biofilm formation and the yeast-to-hypha transition. The compounds 5-sulfenylindole and 5-selenylindole were found to have excellent abilities to inhibit both biofilm formation and hyphal formation in C. albicans SC5314. Intriguingly, the two leading compounds also markedly attenuated C. albicans SC5314 virulence in human cell lines and mouse infection models at micromolar levels. Furthermore, our results showed that the presence of the compounds at 100 µM resulted in a marked decrease in the expression of genes involved in the cAMP-PKA and MAPK pathways in C. albicans SC5314. Intriguingly, the compounds 5-sulfenylindole and 5-selenylindole not only attenuated the cytotoxicity of Candida species strains but also showed excellent synergistic effects with antifungal agents against the clinical drug-resistant C. albicans strain HCH12. The compound 5-sulfenylindole showed an obvious advantage over fluconazole as it could also restore the composition and richness of the intestinal microbiota in mice infected by C. albicans. Together, these results suggest that diaryl chalcogenides can potentially be designed as novel clinical therapeutic agents against C. albicans infection. The diaryl chalcogenides of 5-sulfenylindole and 5-selenylindole discovered in this study can provide new direction for developing antifungal agents against C. albicans infection.
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Affiliation(s)
- Shihao Song
- Key Laboratory of Tropical Biological Resources of Ministry of Education, School of Pharmaceutical Sciences, Hainan University, Haikou, China
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Shuo Zhao
- School of Basic Medicine, Zunyi Medical University, Zunyi, China
| | - Xiuyun Sun
- Key Laboratory of Tropical Biological Resources of Ministry of Education, School of Pharmaceutical Sciences, Hainan University, Haikou, China
| | - Lili Meng
- Integrative Microbiology Research Center, College of Plant Protection, South China Agricultural University, Guangzhou, China
| | - Zijie Wang
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
- Hunan Children’s Hospital, Changsha, China
| | - Huihui Tan
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Jingyun Liu
- Integrative Microbiology Research Center, College of Plant Protection, South China Agricultural University, Guangzhou, China
- Zhengzhou Shuqing Medical College, Zhengzhou, China
| | - Min Zhang
- Key Laboratory of Functional Molecular Engineering of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, China
| | - Yinyue Deng
- Key Laboratory of Tropical Biological Resources of Ministry of Education, School of Pharmaceutical Sciences, Hainan University, Haikou, China
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
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3
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Kakizaki T, Abe H, Kotouge Y, Matsubuchi M, Sugou M, Honma C, Tsukuta K, Satoh S, Shioya T, Nakamura H, Cannon KS, Woods BL, Gladfelter A, Takeshita N, Muraguchi H. Live-cell imaging of septins and cell polarity proteins in the growing dikaryotic vegetative hypha of the model mushroom Coprinopsis cinerea. Sci Rep 2023; 13:10132. [PMID: 37349479 PMCID: PMC10287680 DOI: 10.1038/s41598-023-37115-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 06/15/2023] [Indexed: 06/24/2023] Open
Abstract
The developmental biology underlying the morphogenesis of mushrooms remains poorly understood despite the essential role of fungi in the terrestrial environment and global carbon cycle. The mushroom Coprinopsis cinerea is a leading model system for the molecular and cellular basis of fungal morphogenesis. The dikaryotic vegetative hyphae of this fungus grow by tip growth with clamp cell formation, conjugate nuclear division, septation, subapical peg formation, and fusion of the clamp cell to the peg. Studying these processes provides many opportunities to gain insights into fungal cell morphogenesis. Here, we report the dynamics of five septins, as well as the regulators CcCla4, CcSpa2, and F-actin, visualized by tagging with fluorescent proteins, EGFP, PA-GFP or mCherry, in the growing dikaryotic vegetative hyphae. We also observed the nuclei using tagged Sumo proteins and histone H1. The five septins colocalized at the hyphal tip in the shape of a dome with a hole (DwH). CcSpa2-EGFP signals were observed in the hole, while CcCla4 signals were observed as the fluctuating dome at the hyphal tip. Before septation, CcCla4-EGFP was also occasionally recruited transiently around the future septum site. Fluorescent protein-tagged septins and F-actin together formed a contractile ring at the septum site. These distinct specialized growth machineries at different sites of dikaryotic vegetative hyphae provide a foundation to explore the differentiation program of various types of cells required for fruiting body formation.
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Affiliation(s)
- Tetsuya Kakizaki
- Department of Biotechnology, Faculty of Bioresource Sciences, Akita Prefectural University, Shimoshinjo-nakano, Akita, 010-0195, Japan
| | - Haruki Abe
- Department of Biotechnology, Faculty of Bioresource Sciences, Akita Prefectural University, Shimoshinjo-nakano, Akita, 010-0195, Japan
| | - Yuuka Kotouge
- Department of Biotechnology, Faculty of Bioresource Sciences, Akita Prefectural University, Shimoshinjo-nakano, Akita, 010-0195, Japan
| | - Mitsuki Matsubuchi
- Department of Biotechnology, Faculty of Bioresource Sciences, Akita Prefectural University, Shimoshinjo-nakano, Akita, 010-0195, Japan
| | - Mayu Sugou
- Department of Biotechnology, Faculty of Bioresource Sciences, Akita Prefectural University, Shimoshinjo-nakano, Akita, 010-0195, Japan
| | - Chiharu Honma
- Department of Biotechnology, Faculty of Bioresource Sciences, Akita Prefectural University, Shimoshinjo-nakano, Akita, 010-0195, Japan
| | - Kouki Tsukuta
- Department of Biotechnology, Faculty of Bioresource Sciences, Akita Prefectural University, Shimoshinjo-nakano, Akita, 010-0195, Japan
| | - Souichi Satoh
- Department of Biotechnology, Faculty of Bioresource Sciences, Akita Prefectural University, Shimoshinjo-nakano, Akita, 010-0195, Japan
| | - Tatsuhiro Shioya
- Department of Biotechnology, Faculty of Bioresource Sciences, Akita Prefectural University, Shimoshinjo-nakano, Akita, 010-0195, Japan
| | - Hiroe Nakamura
- Department of Biotechnology, Faculty of Bioresource Sciences, Akita Prefectural University, Shimoshinjo-nakano, Akita, 010-0195, Japan
| | - Kevin S Cannon
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Benjamin L Woods
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Amy Gladfelter
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Cell Biology, Duke University, Durham, USA
| | - Norio Takeshita
- Microbiology Research Center for Sustainability (MiCS), Faculty of Life and Environmental Sciences, University of Tsukuba, Tennodai 1-1-1, Tsukuba, 305-8572, Japan
| | - Hajime Muraguchi
- Department of Biotechnology, Faculty of Bioresource Sciences, Akita Prefectural University, Shimoshinjo-nakano, Akita, 010-0195, Japan.
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Zhu Y, Fang C, Shi Y, Shan Y, Liu X, Liang Y, Huang L, Liu X, Liu C, Zhao Y, Fan S, Zhang X. Candida albicans Multilocus Sequence Typing Clade I Contributes to the Clinical Phenotype of Vulvovaginal Candidiasis Patients. Front Med (Lausanne) 2022; 9:837536. [PMID: 35433756 PMCID: PMC9010739 DOI: 10.3389/fmed.2022.837536] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 02/18/2022] [Indexed: 01/12/2023] Open
Abstract
Candida albicans is the most frequent fungal species responsible for vulvovaginal candidiasis (VVC), which exhibits distinct genetic diversity that is linked with the clinical phenotype. This study aimed to assess the genotypes and clinical characteristics of different C. albicans isolates from VVC patients. Based on multilocus sequence typing (MLST), clade 1 was identified as the largest C. albicans group, which appeared most frequently in recurrent VVC and treatment failure cases. Further study of antifungal susceptibility demonstrated that MLST clade 1 strains presented significantly higher drug resistance ability than non-clade 1 strains, which result from the overexpression of MDR1. The mRNA and protein expression levels of virulence-related genes were also significantly higher in clade 1 isolates than in non-clade 1 isolates. Proteomic analysis indicated that the protein stabilization pathway was significantly enriched in clade 1 strains and that RPS4 was a central regulator of proteins involved in stress resistance, adherence, and DNA repair, which all contribute to the resistance and virulence of MLST clade 1 strains. This study was the first attempt to compare the correlation mechanisms between C. albicans MLST clade 1 and non-clade 1 strains and the clinical phenotype, which is of great significance for VVC classification and treatment.
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Affiliation(s)
- Yuxia Zhu
- Department of Obstetrics and Gynecology, Peking University Shenzhen Hospital, Shenzhen, China
- Shenzhen PKU-HKUST Medical Center, Institute of Obstetrics and Gynecology, Shenzhen, China
- Shenzhen Key Laboratory on Technology for Early Diagnosis of Major Gynecological Disease, Shenzhen, China
| | | | - Yu Shi
- Clinical College of Peking University Shenzhen Hospital, Anhui Medical University, Hefei, China
| | - Yingying Shan
- Department of Obstetrics and Gynecology, Peking University Shenzhen Hospital, Shenzhen, China
- Shenzhen PKU-HKUST Medical Center, Institute of Obstetrics and Gynecology, Shenzhen, China
- Shenzhen Key Laboratory on Technology for Early Diagnosis of Major Gynecological Disease, Shenzhen, China
| | - Xiaoping Liu
- Department of Laboratory Science, Peking University Shenzhen Hospital, Shenzhen, China
| | - Yiheng Liang
- Department of Obstetrics and Gynecology, Peking University Shenzhen Hospital, Shenzhen, China
- Shenzhen PKU-HKUST Medical Center, Institute of Obstetrics and Gynecology, Shenzhen, China
- Shenzhen Key Laboratory on Technology for Early Diagnosis of Major Gynecological Disease, Shenzhen, China
| | - Liting Huang
- Department of Obstetrics and Gynecology, Peking University Shenzhen Hospital, Shenzhen, China
- Shenzhen PKU-HKUST Medical Center, Institute of Obstetrics and Gynecology, Shenzhen, China
- Shenzhen Key Laboratory on Technology for Early Diagnosis of Major Gynecological Disease, Shenzhen, China
| | - Xinyang Liu
- Department of Obstetrics and Gynecology, Peking University Shenzhen Hospital, Shenzhen, China
- Shenzhen PKU-HKUST Medical Center, Institute of Obstetrics and Gynecology, Shenzhen, China
- Shenzhen Key Laboratory on Technology for Early Diagnosis of Major Gynecological Disease, Shenzhen, China
| | - Chunfeng Liu
- Department of Obstetrics and Gynecology, Peking University Shenzhen Hospital, Shenzhen, China
- Shenzhen PKU-HKUST Medical Center, Institute of Obstetrics and Gynecology, Shenzhen, China
- Shenzhen Key Laboratory on Technology for Early Diagnosis of Major Gynecological Disease, Shenzhen, China
| | - Yin Zhao
- Research Institute of Huazhong University of Science and Technology in Shenzhen, Shenzhen, China
| | - Shangrong Fan
- Department of Obstetrics and Gynecology, Peking University Shenzhen Hospital, Shenzhen, China
- Shenzhen PKU-HKUST Medical Center, Institute of Obstetrics and Gynecology, Shenzhen, China
- Shenzhen Key Laboratory on Technology for Early Diagnosis of Major Gynecological Disease, Shenzhen, China
- Shangrong Fan
| | - Xiaowei Zhang
- Department of Obstetrics and Gynecology, Peking University Shenzhen Hospital, Shenzhen, China
- Shenzhen PKU-HKUST Medical Center, Institute of Obstetrics and Gynecology, Shenzhen, China
- Shenzhen Key Laboratory on Technology for Early Diagnosis of Major Gynecological Disease, Shenzhen, China
- *Correspondence: Xiaowei Zhang
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5
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Chow EWL, Pang LM, Wang Y. From Jekyll to Hyde: The Yeast-Hyphal Transition of Candida albicans. Pathogens 2021; 10:pathogens10070859. [PMID: 34358008 PMCID: PMC8308684 DOI: 10.3390/pathogens10070859] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 06/30/2021] [Accepted: 07/05/2021] [Indexed: 12/22/2022] Open
Abstract
Candida albicans is a major fungal pathogen of humans, accounting for 15% of nosocomial infections with an estimated attributable mortality of 47%. C. albicans is usually a benign member of the human microbiome in healthy people. Under constant exposure to highly dynamic environmental cues in diverse host niches, C. albicans has successfully evolved to adapt to both commensal and pathogenic lifestyles. The ability of C. albicans to undergo a reversible morphological transition from yeast to filamentous forms is a well-established virulent trait. Over the past few decades, a significant amount of research has been carried out to understand the underlying regulatory mechanisms, signaling pathways, and transcription factors that govern the C. albicans yeast-to-hyphal transition. This review will summarize our current understanding of well-elucidated signal transduction pathways that activate C. albicans hyphal morphogenesis in response to various environmental cues and the cell cycle machinery involved in the subsequent regulation and maintenance of hyphal morphogenesis.
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Affiliation(s)
- Eve Wai Ling Chow
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore 138673, Singapore;
| | - Li Mei Pang
- National Dental Centre Singapore, National Dental Research Institute Singapore (NDRIS), 5 Second Hospital Ave, Singapore 168938, Singapore;
| | - Yue Wang
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore 138673, Singapore;
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 10 Medical Drive, Singapore 117597, Singapore
- Correspondence:
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Mamouei Z, Singh S, Lemire B, Gu Y, Alqarihi A, Nabeela S, Li D, Ibrahim A, Uppuluri P. An evolutionarily diverged mitochondrial protein controls biofilm growth and virulence in Candida albicans. PLoS Biol 2021; 19:e3000957. [PMID: 33720927 PMCID: PMC8007014 DOI: 10.1371/journal.pbio.3000957] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 03/29/2021] [Accepted: 01/29/2021] [Indexed: 11/19/2022] Open
Abstract
A forward genetic screening approach identified orf19.2500 as a gene controlling Candida albicans biofilm dispersal and biofilm detachment. Three-dimensional (3D) protein modeling and bioinformatics revealed that orf19.2500 is a conserved mitochondrial protein, structurally similar to, but functionally diverged from, the squalene/phytoene synthases family. The C. albicans orf19.2500 is distinguished by 3 evolutionarily acquired stretches of amino acid inserts, absent from all other eukaryotes except a small number of ascomycete fungi. Biochemical assays showed that orf19.2500 is required for the assembly and activity of the NADH ubiquinone oxidoreductase Complex I (CI) of the respiratory electron transport chain (ETC) and was thereby named NDU1. NDU1 is essential for respiration and growth on alternative carbon sources, important for immune evasion, required for virulence in a mouse model of hematogenously disseminated candidiasis, and for potentiating resistance to antifungal drugs. Our study is the first report on a protein that sets the Candida-like fungi phylogenetically apart from all other eukaryotes, based solely on evolutionary "gain" of new amino acid inserts that are also the functional hub of the protein.
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Affiliation(s)
- Zeinab Mamouei
- David Geffen School of Medicine, University of California (UCLA), Los Angeles, California, United States of America
| | - Shakti Singh
- Division of Infectious Disease, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, United States of America
| | - Bernard Lemire
- Department of Biochemistry, University of Alberta, Alberta, Canada
| | - Yiyou Gu
- Division of Infectious Disease, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, United States of America
| | - Abdullah Alqarihi
- Division of Infectious Disease, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, United States of America
| | - Sunna Nabeela
- Division of Infectious Disease, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, United States of America
| | - Dongmei Li
- Department of Microbiology and Immunology, Georgetown University Medical Center, Washington, DC, United States of America
| | - Ashraf Ibrahim
- David Geffen School of Medicine, University of California (UCLA), Los Angeles, California, United States of America
- Division of Infectious Disease, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, United States of America
| | - Priya Uppuluri
- David Geffen School of Medicine, University of California (UCLA), Los Angeles, California, United States of America
- Division of Infectious Disease, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, United States of America
- * E-mail:
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Zheng H, Li L, Yu Z, Yuan Y, Zheng Q, Xie Q, Li G, Abubakar YS, Zhou J, Wang Z, Zheng W. FgSpa2 recruits FgMsb3, a Rab8 GAP, to the polarisome to regulate polarized trafficking, growth and pathogenicity in Fusarium graminearum. THE NEW PHYTOLOGIST 2021; 229:1665-1683. [PMID: 32978966 DOI: 10.1111/nph.16935] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 09/01/2020] [Indexed: 06/11/2023]
Abstract
In filamentous fungi, hyphal growth depends on the continuous delivery of vesicles to the growing tips. It is unclear how fast-growing hyphae coordinate simultaneous cell extension and expansion in the tip cells. We have functionally characterized 12 TBC (Tre-2/Bub2/Cdc16) domain-containing proteins in Fusarium graminearum. Among them, FgMsb3 is found to regulate hyphal tip expansion and to be required for pathogenicity. The regulatory mechanism of FgMsb3 has been further investigated by genetic, high-resolution microscopy and high-throughput co-immunoprecipitation strategies. The FgMsb3 protein localizes at the polarisome and the hyphal apical dome (HAD) where it acts as a GTPase-activating protein for FgRab8 which is required for apical secretion-mediated growth and pathogenicity. Deletion of FgMSB3 causes excessive polarized trafficking but blocks the fusion of FgSnc1-associated vesicles to the plasma membrane. Moreover, we establish that FgSpa2 interacts with FgMsb3, enabling FgMsb3 tethering to the polarisome. Loss of FgSpa2 or other polarisome components (FgBud6 and FgPea2) causes complete shifting of FgMsb3 to the HAD and this affects the polarized growth and pathogenicity of the fungus. In summary, we conclude that FgSpa2 regulates FgMsb3-FgRab8 cascade and this is crucial for creating a steady-state equilibrium that maintains continuous polarized growth and contributes to the pathogenicity of F. graminearum.
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Affiliation(s)
- Huawei Zheng
- Marine and Agricultural Biotechnology Laboratory, Institute of Oceanography, Minjiang University, Fuzhou, 350108, China
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Lingping Li
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Zhi Yu
- Marine and Agricultural Biotechnology Laboratory, Institute of Oceanography, Minjiang University, Fuzhou, 350108, China
- Fujian Province Key Laboratory of Pathogenic Fungi and Mycotoxins, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Yanping Yuan
- Fujian Province Key Laboratory of Pathogenic Fungi and Mycotoxins, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Qiaojia Zheng
- Marine and Agricultural Biotechnology Laboratory, Institute of Oceanography, Minjiang University, Fuzhou, 350108, China
| | - Qiurong Xie
- Fujian Key Laboratory of Integrative Medicine on Geriatric, Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, 350122, China
| | - Guangpu Li
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Yakubu Saddeeq Abubakar
- Department of Biochemistry, Faculty of Life Sciences, Ahmadu Bello University, Zaria, 810211, Nigeria
| | - Jie Zhou
- Fujian Province Key Laboratory of Pathogenic Fungi and Mycotoxins, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Zonghua Wang
- Marine and Agricultural Biotechnology Laboratory, Institute of Oceanography, Minjiang University, Fuzhou, 350108, China
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- Fujian Province Key Laboratory of Pathogenic Fungi and Mycotoxins, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Wenhui Zheng
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- Fujian Province Key Laboratory of Pathogenic Fungi and Mycotoxins, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
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8
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Xie Y, Loh ZY, Xue J, Zhou F, Sun J, Qiao Z, Jin S, Deng Y, Li H, Wang Y, Lu L, Gao Y, Miao Y. Orchestrated actin nucleation by the Candida albicans polarisome complex enables filamentous growth. J Biol Chem 2020; 295:14840-14854. [PMID: 32848016 DOI: 10.1074/jbc.ra120.013890] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 08/09/2020] [Indexed: 12/29/2022] Open
Abstract
Candida albicans is a dimorphic fungus that converts from a yeast form to a hyphae form during infection. This switch requires the formation of actin cable to coordinate polarized cell growth. It's known that nucleation of this cable requires a multiprotein complex localized at the tip called the polarisome, but the mechanisms underpinning this process were unclear. Here, we found that C. albicans Aip5, a homolog of polarisome component ScAip5 in Saccharomyces cerevisiae that nucleates actin polymerization and synergizes with the formin ScBni1, regulates actin assembly and hyphae growth synergistically with other polarisome proteins Bni1, Bud6, and Spa2. The C terminus of Aip5 binds directly to G-actin, Bni1, and the C-terminal of Bud6, which form the core of the nucleation complex to polymerize F-actin. Based on insights from structural biology and molecular dynamic simulations, we propose a possible complex conformation of the actin nucleation core, which provides cooperative positioning and supports the synergistic actin nucleation activity of a tri-protein complex Bni1-Bud6-Aip5. Together with known interactions of Bni1 with Bud6 and Aip5 in S. cerevisiae, our findings unravel molecular mechanisms of C. albicans by which the tri-protein complex coordinates the actin nucleation in actin cable assembly and hyphal growth, which is likely a conserved mechanism in different filamentous fungi and yeast.
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Affiliation(s)
- Ying Xie
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Zhi Yang Loh
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Jiao Xue
- School of Biological Sciences, Nanyang Technological University, Singapore; College of Life Science and Technology, Jinan University, Guangzhou, China; The College of Life Sciences, Northwest University, Xi'an, China
| | - Feng Zhou
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Jialin Sun
- School of Biological Sciences, Nanyang Technological University, Singapore; Institute of Molecular and Cell Biology, A*STAR, Singapore
| | - Zhu Qiao
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Shengyang Jin
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Yinyue Deng
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-sen University, Guangzhou, China
| | - Hongye Li
- College of Life Science and Technology, Jinan University, Guangzhou, China
| | - Yue Wang
- Institute of Molecular and Cell Biology, A*STAR, Singapore
| | - Lanyuan Lu
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Yonggui Gao
- School of Biological Sciences, Nanyang Technological University, Singapore; Institute of Molecular and Cell Biology, A*STAR, Singapore; NTU Institute of Structural Biology, Nanyang Technological University, Nanyang Drive, Singapore
| | - Yansong Miao
- School of Biological Sciences, Nanyang Technological University, Singapore.
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9
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Song S, Sun X, Meng L, Wu Q, Wang K, Deng Y. Antifungal activity of hypocrellin compounds and their synergistic effects with antimicrobial agents against Candida albicans. Microb Biotechnol 2020; 14:430-443. [PMID: 32510867 PMCID: PMC7936304 DOI: 10.1111/1751-7915.13601] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 05/08/2020] [Indexed: 12/12/2022] Open
Abstract
Candida albicans is a common human fungal pathogen. The previous study revealed that quinone compounds showed antimicrobial activity against C. albicans by inhibiting cell growth. However, it was unclear whether quinones have other antifungal effects against C. albicans in addition to fungicidal effects. In this study, we assessed the inhibitory activity of a total of 25 quinone compounds against C. albicans morphological transition, which is essential for the pathogenicity of C. albicans. Several quinones exhibited strong inhibition of mycelium formation by C. albicans SC5314. Three leading compounds, namely hypocrellins A, B and C, also exhibited marked attenuation of C. albicans SC5314 virulence in both human cell lines and mouse infection models. These three compounds significantly suppressed the proliferation of C. albicans SC5314 cells in a mouse mucosal infection model. Intriguingly, hypocrellins not only attenuated the cytotoxicity of a nystatin-resistant C. albicans strain but also showed excellent synergistic effects with antifungal agents against both wild-type C. albicans SC5314 and the drug-resistant mutant strains. In addition, hypocrellins A, B and C interfered with the biological functions and virulence of various clinical Candida species, suggesting the promising potential of these compounds for development as new therapeutic agents against infections caused by Candida pathogens.
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Affiliation(s)
- Shihao Song
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-sen University, Guangzhou, 510275, China.,College of Agriculture, South China Agricultural University, Guangzhou, 510642, China
| | - Xiuyun Sun
- College of Agriculture, South China Agricultural University, Guangzhou, 510642, China
| | - Lili Meng
- College of Agriculture, South China Agricultural University, Guangzhou, 510642, China
| | - Qianhua Wu
- College of Agriculture, South China Agricultural University, Guangzhou, 510642, China
| | - Ke Wang
- Pulmonary and Critical Care Medicine Ward, The First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, China
| | - Yinyue Deng
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-sen University, Guangzhou, 510275, China.,College of Agriculture, South China Agricultural University, Guangzhou, 510642, China
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10
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Yang T, Li W, Li Y, Liu X, Yang D. The ESCRT System Plays an Important Role in the Germination in Candida albicans by Regulating the Expression of Hyphal-Specific Genes and the Localization of Polarity-Related Proteins. Mycopathologia 2020; 185:439-454. [PMID: 32279163 DOI: 10.1007/s11046-020-00442-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 03/12/2020] [Indexed: 11/30/2022]
Abstract
Candida albicans is an important opportunistic fungal pathogen, and its pathogenicity is closely related to its ability to form hyphae. ESCRT system was initially discovered as a membrane-budding machinery involved in the formation of multivesicular bodies. More recently, the role of ESCRT is vastly expanded. Early reports showed that the ESCRT system is involved in inducing hyphae under neutral-alkaline environment via the Rim101 pathway. We previously found that in the environment that contains serum, one ESCRT protein, Vps4, is essential for polarity maintenance during hyphal formation, as its deletion causes the formation of multiple hyphae. In this study, we found that Vps4 is also essential for the proper localization of Cdc42 and Cdc3, which may be related to its role in polarity maintenance. We also discovered that deletions of the ESCRT proteins significantly delay germination and cause downregulation of hyphal-specific genes, most prominent of which is HGC1. Since Hgc1 is essential for many aspects of hyphal growth, its downregulation could explain our observed phenotypes. Our further studies show that ESCRT proteins are involved in the dynamics of Ras1. Deletions of VPS4 or SNF7 significantly decrease the recovery rate of GFP-Ras1 in the fluorescence recovery after photobleaching experiment. The decreased Ras1 dynamics may disrupt the signaling pathway and lead to downregulation of hyphal-specific genes. Therefore, in this study we discovered a novel and Rim101 independent mechanism used by the ESCRT system to regulate hyphal induction and polarity maintenance, which could provide insights on the pathogenicity mechanism of Candia albicans.
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Affiliation(s)
- Tianran Yang
- Gene Engineering and Biotechnology Beijing Key Laboratory, College of Life Sciences, Beijing Normal University, Beijing, 100875, China.,Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing, 100875, China
| | - Wanjie Li
- Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing, 100875, China
| | - Yi Li
- Gene Engineering and Biotechnology Beijing Key Laboratory, College of Life Sciences, Beijing Normal University, Beijing, 100875, China.,Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing, 100875, China
| | - Xin Liu
- Gene Engineering and Biotechnology Beijing Key Laboratory, College of Life Sciences, Beijing Normal University, Beijing, 100875, China.,Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing, 100875, China
| | - Dong Yang
- Gene Engineering and Biotechnology Beijing Key Laboratory, College of Life Sciences, Beijing Normal University, Beijing, 100875, China. .,Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing, 100875, China.
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11
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Zhang J, Yun Y, Lou Y, Abubakar YS, Guo P, Wang S, Li C, Feng Y, Adnan M, Zhou J, Lu G, Zheng W. FgAP‐2 complex is essential for pathogenicity and polarised growth and regulates the apical localisation of membrane lipid flippases in
Fusarium graminearum. Cell Microbiol 2019; 21:e13041. [DOI: 10.1111/cmi.13041] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 04/11/2019] [Accepted: 05/12/2019] [Indexed: 12/20/2022]
Affiliation(s)
- Jing Zhang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant ProtectionFujian Agriculture and Forestry University Fuzhou China
| | - Yingzi Yun
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant ProtectionFujian Agriculture and Forestry University Fuzhou China
| | - Yi Lou
- Fujian Province Key Laboratory of Pathogenic Fungi and Mycotoxins, College of Life SciencesFujian Agriculture and Forestry University Fuzhou China
| | | | - Pusheng Guo
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant ProtectionFujian Agriculture and Forestry University Fuzhou China
| | - Shumin Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant ProtectionFujian Agriculture and Forestry University Fuzhou China
| | - Chunling Li
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant ProtectionFujian Agriculture and Forestry University Fuzhou China
| | - Yuan Feng
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant ProtectionFujian Agriculture and Forestry University Fuzhou China
| | - Muhammad Adnan
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant ProtectionFujian Agriculture and Forestry University Fuzhou China
| | - Jie Zhou
- Fujian Province Key Laboratory of Pathogenic Fungi and Mycotoxins, College of Life SciencesFujian Agriculture and Forestry University Fuzhou China
| | - Guo‐dong Lu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant ProtectionFujian Agriculture and Forestry University Fuzhou China
| | - Wenhui Zheng
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant ProtectionFujian Agriculture and Forestry University Fuzhou China
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12
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Randhawa A, Kundu D, Sharma A, Prasad R, Mondal AK. Overexpression of the CORVET complex alleviates the fungicidal effects of fludioxonil on the yeast Saccharomyces cerevisiae expressing hybrid histidine kinase 3. J Biol Chem 2018; 294:461-475. [PMID: 30446623 DOI: 10.1074/jbc.ra118.004736] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 10/25/2018] [Indexed: 11/06/2022] Open
Abstract
The hybrid histidine kinase 3 (HHK3) is a highly conserved sensor kinase in fungi that regulates the downstream HOG/p38 mitogen-activated protein kinase (MAPK). In addition to its role in osmoadaptation, HHK3 is involved in hyphal morphogenesis, conidiation, virulence, and cellular adaptation to oxidative stress. However, the molecular mechanisms by which it controls these processes remain obscure. Moreover, HHK3 is a molecular target for antifungal agents such as fludioxonil, which thereby interferes with the HOG/p38 pathway, leading to the abnormal accumulation of glycerol and subsequent cell lysis. Here, we used a chemical genomics approach with the yeast Saccharomyces cerevisiae to better understand the fungicidal action of fludioxonil and the role of HHK3 in fungal growth and physiology. Our results indicated that the abnormal accumulation of glycerol is not the primary cause of fludioxonil toxicity. Fludioxonil appears to impair endosomal trafficking in the fungal cells. We found that the components of class C core vacuole/endosome tethering (CORVET) complex are essential for yeast viability in the presence of a subthreshold dose of fludioxonil and that their overexpression alleviates fludioxonil toxicity. We also noted that by impeding secretory vesicle trafficking, fludioxonil inhibits hyphal growth in the opportunistic fungal pathogen Candida albicans Our results suggest that HHK3 regulates fungal hyphal growth by affecting vesicle trafficking. Together, our results reveal an important role of CORVET complex in the fungicidal action of fludioxonil downstream of HHK3.
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Affiliation(s)
- Anmoldeep Randhawa
- From the Council of Scientific and Industrial Research (CSIR)-Institute of Microbial Technology, Sector 39A, Chandigarh 160036, India
| | - Debasree Kundu
- From the Council of Scientific and Industrial Research (CSIR)-Institute of Microbial Technology, Sector 39A, Chandigarh 160036, India.,School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India, and
| | - Anupam Sharma
- From the Council of Scientific and Industrial Research (CSIR)-Institute of Microbial Technology, Sector 39A, Chandigarh 160036, India
| | - Rajendra Prasad
- Amity Institute of Integrative Sciences and Health, Amity University, Gurgaon 122413, India
| | - Alok K Mondal
- School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India, and
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13
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Zhao S, Huang J, Sun X, Huang X, Fu S, Yang L, Liu X, He F, Deng Y. (1-aryloxy-2-hydroxypropyl)-phenylpiperazine derivatives suppress Candida albicans virulence by interfering with morphological transition. Microb Biotechnol 2018; 11:1080-1089. [PMID: 30221456 PMCID: PMC6196381 DOI: 10.1111/1751-7915.13307] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 07/14/2018] [Accepted: 07/31/2018] [Indexed: 11/30/2022] Open
Abstract
Clinical treatment of Candida albicans infections has become more difficult due to the limited development of antifungal agents and the rapid emergence of drug resistance. In this study, we demonstrate the synthesis of a series of piperazine derivatives and the evaluation of their inhibitory activity against C. albicans virulence. Thirty-four (1-aryloxy-2-hydroxypropyl)-phenylpiperazine derivatives, including 25 new compounds, were synthesized and assessed for their efficacy against the physiology and pathogenesis of C. albicans. Several compounds strongly inhibited the morphological transition and virulence of C. albicans cells, although they did not influence the growth rate of the fungal pathogen. A leading novel compound, (1-(4-ethoxyphenyl)-4-(1-biphenylol-2-hydroxypropyl)-piperazine), significantly attenuated C. albicans virulence by interfering with the process of hyphal development, but it showed no cytotoxicity against human cells at a micromolar level. These findings suggest that (1-aryloxy-2-hydroxypropyl)-phenylpiperazine derivatives could potentially be developed as novel therapeutic agents for the clinical treatment of C. albicans infections by interfering with morphological transition and virulence.
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Affiliation(s)
- Shuo Zhao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐BioresourcesSouth China Agricultural UniversityGuangzhou510642China
- Guangdong Innovative Research Team of SociomicrobiologyCollege of AgricultureSouth China Agricultural UniversityGuangzhou510642China
- Integrative Microbiology Research CentreSouth China Agricultural UniversityGuangzhou510642China
| | - Jun‐Jun Huang
- Pharmaceutical Research CenterSchool of PharmacologyGuangzhou Medical UniversityGuangzhou510182China
| | - Xiuyun Sun
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐BioresourcesSouth China Agricultural UniversityGuangzhou510642China
- Guangdong Innovative Research Team of SociomicrobiologyCollege of AgricultureSouth China Agricultural UniversityGuangzhou510642China
- Integrative Microbiology Research CentreSouth China Agricultural UniversityGuangzhou510642China
| | - Xiaorong Huang
- Guangdong Innovative Research Team of SociomicrobiologyCollege of AgricultureSouth China Agricultural UniversityGuangzhou510642China
| | - Shuna Fu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐BioresourcesSouth China Agricultural UniversityGuangzhou510642China
- Guangdong Innovative Research Team of SociomicrobiologyCollege of AgricultureSouth China Agricultural UniversityGuangzhou510642China
- Integrative Microbiology Research CentreSouth China Agricultural UniversityGuangzhou510642China
| | - Liang Yang
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE)Nanyang Technological UniversitySingapore637551Singapore
| | - Xue‐Wei Liu
- Division of Chemistry and Biological ChemistrySchool of Physical and Mathematical SciencesNanyang Technological University21 Nanyang LinkSingapore637371Singapore
| | - Fei He
- Integrative Microbiology Research CentreSouth China Agricultural UniversityGuangzhou510642China
| | - Yinyue Deng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐BioresourcesSouth China Agricultural UniversityGuangzhou510642China
- Guangdong Innovative Research Team of SociomicrobiologyCollege of AgricultureSouth China Agricultural UniversityGuangzhou510642China
- Integrative Microbiology Research CentreSouth China Agricultural UniversityGuangzhou510642China
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14
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Mamouei Z, Zeng G, Wang YM, Wang Y. Candida albicanspossess a highly versatile and dynamic high-affinity iron transport system important for its commensal-pathogenic lifestyle. Mol Microbiol 2017; 106:986-998. [DOI: 10.1111/mmi.13864] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/11/2017] [Indexed: 02/02/2023]
Affiliation(s)
- Zeinab Mamouei
- Multi-Modal Molecular (M3) Biology; Institute of Molecular and Cell Biology, Agency for Science, Technology, and Research; Singapore
| | - Guisheng Zeng
- Multi-Modal Molecular (M3) Biology; Institute of Molecular and Cell Biology, Agency for Science, Technology, and Research; Singapore
| | - Yan-Ming Wang
- Multi-Modal Molecular (M3) Biology; Institute of Molecular and Cell Biology, Agency for Science, Technology, and Research; Singapore
| | - Yue Wang
- Multi-Modal Molecular (M3) Biology; Institute of Molecular and Cell Biology, Agency for Science, Technology, and Research; Singapore
- Department of Biochemistry, Yong Loo Lin School of Medicine; National University of Singapore; Singapore
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15
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Guo PP, Yong JYA, Wang YM, Li CR. Sec15 links bud site selection to polarised cell growth and exocytosis in Candida albicans. Sci Rep 2016; 6:26464. [PMID: 27225289 PMCID: PMC4881018 DOI: 10.1038/srep26464] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 05/04/2016] [Indexed: 01/17/2023] Open
Abstract
The exocyst plays a crucial role in the targeting of secretory vesicles to the plasma membrane during exocytosis. It has been shown to be involved in diverse cellular processes including yeast budding. However, the mechanism of the exocyst regulating yeast budding has not been fully elucidated. Here we report a novel interaction between the exocyst component Sec15 and the Ras-family GTPase Rsr1, a master regulator of bud-site-selection system, in the fungus Candida albicans. We present several lines of evidence indicating physical and genetic interaction of Sec15 with Rsr1. In vitro binding assays and co-immunoprecipitation studies showed that Sec15 associated physically with Rsr1. Deletion of RSR1 completely abolished the polarised localisation of Sec15 as well as all the other exocyst components in both yeast and hyphal cells, suggesting a functional interaction between Sec15 and Rsr1. We also show that C. albicans Sec15 interacts directly with the polarity determinant Bem1 and the type V myosin, Myo2. Disruption of the interaction by shutting off SEC15 results in mislocaliztion of Bem1-GFP. These findings highlight the important role of Sec15 in polarised cell growth by providing a direct functional link between bud-site-selection and exocytosis.
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Affiliation(s)
- Pan Pan Guo
- Institute of Health Sciences, Anhui University, Hefei 230601, China
| | - Jie Ying Au Yong
- Institute of Molecular and Cell Biology, A*STAR, 61 Biopolis Drive, 138673 Singapore
| | - Yan Ming Wang
- Institute of Molecular and Cell Biology, A*STAR, 61 Biopolis Drive, 138673 Singapore
| | - Chang Run Li
- Institute of Health Sciences, Anhui University, Hefei 230601, China
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16
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Au Yong JY, Wang YM, Wang Y. The Nim1 kinase Gin4 has distinct domains crucial for septin assembly, phospholipid binding and mitotic exit. J Cell Sci 2016; 129:2744-56. [PMID: 27231094 PMCID: PMC4958294 DOI: 10.1242/jcs.183160] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 05/20/2016] [Indexed: 12/29/2022] Open
Abstract
In fungi, the Nim1 protein kinases, such as Gin4, are important regulators of multiple cell cycle events, including the G2–M transition, septin assembly, polarized growth and cytokinesis. Compelling evidence has linked some key functions of Gin4 with the large C-terminal non-kinase region which, however, is poorly defined. By systematically dissecting and functionally characterizing the non-kinase region of Gin4 in the human fungal pathogen Candida albicans, we report the identification of three new domains with distinct functions: a lipid-binding domain (LBD), a septin-binding domain (SBD) and a nucleolus-associating domain (NAD). The LBD and SBD are indispensable for the function of Gin4, and they alone could sufficiently restore septin ring assembly in GIN4-null mutants. The NAD localizes to the periphery of the nucleolus and physically associates with Cdc14, the ultimate effector of the mitotic exit network. Gin4 mutants that lack the NAD are defective in spindle orientation and exit mitosis prematurely. Furthermore, we show that Gin4 is a substrate of Cdc14. These findings provide novel insights into the roles and mechanisms of Nim1 kinases in the regulation of some crucial cell cycle events. Summary: Systematic dissection of the Gin4 kinase in the human pathogenic fungus Candida albicans uncovers three new functional domains that interact with distinct cellular components.
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Affiliation(s)
- Jie Ying Au Yong
- Institute of Molecular and Cell Biology, Agency for Science, Technology, and Research, Singapore 138673
| | - Yan-Ming Wang
- Institute of Molecular and Cell Biology, Agency for Science, Technology, and Research, Singapore 138673
| | - Yue Wang
- Institute of Molecular and Cell Biology, Agency for Science, Technology, and Research, Singapore 138673 Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597
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17
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Wang H, Huang ZX, Au Yong JY, Zou H, Zeng G, Gao J, Wang Y, Wong AHH, Wang Y. CDK phosphorylates the polarisome scaffold Spa2 to maintain its localization at the site of cell growth. Mol Microbiol 2016; 101:250-64. [DOI: 10.1111/mmi.13386] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Haitao Wang
- Institute of Molecular and Cell Biology, Agency for Science, Technology, and Research; Singapore
- Faculty of Health Sciences; University of Macau; Macau China
| | - Zhen-Xing Huang
- Institute of Molecular and Cell Biology, Agency for Science, Technology, and Research; Singapore
| | - Jie Ying Au Yong
- Institute of Molecular and Cell Biology, Agency for Science, Technology, and Research; Singapore
| | - Hao Zou
- Institute of Molecular and Cell Biology, Agency for Science, Technology, and Research; Singapore
| | - Guisheng Zeng
- Institute of Molecular and Cell Biology, Agency for Science, Technology, and Research; Singapore
| | - Jiaxin Gao
- Institute of Molecular and Cell Biology, Agency for Science, Technology, and Research; Singapore
| | - Yanming Wang
- Institute of Molecular and Cell Biology, Agency for Science, Technology, and Research; Singapore
| | | | - Yue Wang
- Institute of Molecular and Cell Biology, Agency for Science, Technology, and Research; Singapore
- Department of Biochemistry, Yong Loo Lin School of Medicine; National University of Singapore; Singapore
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18
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Guo M, Kilaru S, Schuster M, Latz M, Steinberg G. Fluorescent markers for the Spitzenkörper and exocytosis in Zymoseptoria tritici. Fungal Genet Biol 2016; 79:158-65. [PMID: 26092802 PMCID: PMC4502456 DOI: 10.1016/j.fgb.2015.04.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 04/10/2015] [Accepted: 04/13/2015] [Indexed: 11/25/2022]
Abstract
We establish Z. tritici polarity markers ZtSec4, ZtMlc1, ZtRab11, ZtExo70 and ZtSpa2. All markers localize correctly, labeling the Spitzenkörper and sites of polar exocytosis. We provide 5 carboxin-resistance conveying vectors for integration of all markers into the sdi1 locus. We provide 5 hygromycin B-resistance conveying vectors for random integration of all markers.
Fungal hyphae are highly polarized cells that invade their substrate by tip growth. In plant pathogenic fungi, hyphal growth is essential for host invasion. This makes polarity factors and secretion regulators potential new targets for novel fungicides. Polarization requires delivery of secretory vesicles to the apical Spitzenkörper, followed by polarized exocytosis at the expanding cell tip. Here, we introduce fluorescent markers to visualize the apical Spitzenkörper and the apical site of exocytosis in hyphae of the wheat pathogen Zymoseptoria tritici. We fused green fluorescent protein to the small GTPase ZtSec4, the myosin light chain ZtMlc1 and the small GTPase ZtRab11 and co-localize the fusion proteins with the dye FM4-64 in the hyphal apex, suggesting that the markers label the hyphal Spitzenkörper in Z. tritici. In addition, we localize GFP-fusions to the exocyst protein ZtExo70, the polarisome protein ZtSpa2. Consistent with results in the ascomycete Neurospora crassa, these markers did localize near the plasma membrane at the hyphal tip and only partially co-localize with FM4-64. Thus, these fluorescent markers are useful molecular tools that allow phenotypic analysis of mutants in Z. tritici. These tools will help develop new avenues of research in our quest to control STB infection in wheat.
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Affiliation(s)
- M Guo
- School of Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - S Kilaru
- School of Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - M Schuster
- School of Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - M Latz
- School of Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - G Steinberg
- School of Biosciences, University of Exeter, Exeter EX4 4QD, UK.
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19
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Trapping toxins within lipid droplets is a resistance mechanism in fungi. Sci Rep 2015; 5:15133. [PMID: 26463663 PMCID: PMC4604559 DOI: 10.1038/srep15133] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 09/17/2015] [Indexed: 01/11/2023] Open
Abstract
Lipid droplets (LDs) act as intracellular storage organelles in most types of cells and are principally involved in energy homeostasis and lipid metabolism. However, the role of LDs in resistance to toxins in fungi remains largely unknown. Here, we show that the trapping of endogenous toxins by LDs is a self-resistance mechanism in the toxin producer, while absorbing external lipophilic toxins is a resistance mechanism in the toxin recipient that acts to quench the production of reactive oxygen species. We found that an endolichenic fungus that generates phototoxic perylenequinones (PQs) trapped the PQs inside LDs. Using a model that incorporates the fungicidal action of hypocrellin A (HA), a PQ derivative, we showed that yeast cells escaped killing by trapping toxins inside LDs. Furthermore, LD-deficient mutants were hypersusceptible to HA-mediated phototoxins and other fungicides. Our study identified a previously unrecognised function of LDs in fungi that has implications for our understanding of environmental adaptation strategies for fungi and antifungal drug discovery.
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20
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Analysis of the Candida albicans Phosphoproteome. EUKARYOTIC CELL 2015; 14:474-85. [PMID: 25750214 DOI: 10.1128/ec.00011-15] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 03/04/2015] [Indexed: 01/19/2023]
Abstract
Candida albicans is an important human fungal pathogen in both immunocompetent and immunocompromised individuals. C. albicans regulation has been studied in many contexts, including morphological transitions, mating competence, biofilm formation, stress resistance, and cell wall synthesis. Analysis of kinase- and phosphatase-deficient mutants has made it clear that protein phosphorylation plays an important role in the regulation of these pathways. In this study, to further our understanding of phosphorylation in C. albicans regulation, we performed a deep analysis of the phosphoproteome in C. albicans. We identified 19,590 unique peptides that corresponded to 15,906 unique phosphosites on 2,896 proteins. The ratios of serine, threonine, and tyrosine phosphosites were 80.01%, 18.11%, and 1.81%, respectively. The majority of proteins (2,111) contained at least two detected phosphorylation sites. Consistent with findings in other fungi, cytoskeletal proteins were among the most highly phosphorylated proteins, and there were differences in Gene Ontology (GO) terms for proteins with serine and threonine versus tyrosine phosphorylation sites. This large-scale analysis identified phosphosites in protein components of Mediator, an important transcriptional coregulatory protein complex. A targeted analysis of the phosphosites in Mediator complex proteins confirmed the large-scale studies, and further in vitro assays identified a subset of these phosphorylations that were catalyzed by Cdk8 (Ssn3), a kinase within the Mediator complex. These data represent the deepest single analysis of a fungal phosphoproteome and lay the groundwork for future analyses of the C. albicans phosphoproteome and specific phosphoproteins.
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21
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Ren L, Willet AH, Roberts-Galbraith RH, McDonald NA, Feoktistova A, Chen JS, Huang H, Guillen R, Boone C, Sidhu SS, Beckley JR, Gould KL. The Cdc15 and Imp2 SH3 domains cooperatively scaffold a network of proteins that redundantly ensure efficient cell division in fission yeast. Mol Biol Cell 2014; 26:256-69. [PMID: 25428987 PMCID: PMC4294673 DOI: 10.1091/mbc.e14-10-1451] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The fission yeast F-BAR proteins Cdc15 and Imp2 and their combined SH3-domain partners appear to act as “molecular glue” to stabilize the interaction between the plasma membrane and a complex network of proteins at the division site that mediates cell division. Schizosaccharomyces pombe cdc15 homology (PCH) family members participate in numerous biological processes, including cytokinesis, typically by bridging the plasma membrane via their F-BAR domains to the actin cytoskeleton. Two SH3 domain–containing PCH family members, Cdc15 and Imp2, play critical roles in S. pombe cytokinesis. Although both proteins localize to the contractile ring, with Cdc15 preceding Imp2, only cdc15 is an essential gene. Despite these distinct roles, the SH3 domains of Cdc15 and Imp2 cooperate in the essential process of recruiting other proteins to stabilize the contractile ring. To better understand the connectivity of this SH3 domain–based protein network at the CR and its function, we used a biochemical approach coupled to proteomics to identify additional proteins (Rgf3, Art1, Spa2, and Pos1) that are integrated into this network. Cell biological and genetic analyses of these SH3 partners implicate them in a range of activities that ensure the fidelity of cell division, including promoting cell wall metabolism and influencing cell morphogenesis.
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Affiliation(s)
- Liping Ren
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232
| | - Alaina H Willet
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232
| | - Rachel H Roberts-Galbraith
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232
| | - Nathan A McDonald
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232
| | - Anna Feoktistova
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232
| | - Jun-Song Chen
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232
| | - Haiming Huang
- Terrence Donnelly Center for Cellular and Biomolecular Research, Banting and Best Department of Medical Research, University of Toronto, Toronto, ON M5G 1L6, Canada
| | - Rodrigo Guillen
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232
| | - Charles Boone
- Terrence Donnelly Center for Cellular and Biomolecular Research, Banting and Best Department of Medical Research, University of Toronto, Toronto, ON M5G 1L6, Canada
| | - Sachdev S Sidhu
- Terrence Donnelly Center for Cellular and Biomolecular Research, Banting and Best Department of Medical Research, University of Toronto, Toronto, ON M5G 1L6, Canada
| | - Janel R Beckley
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232
| | - Kathleen L Gould
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232
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22
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Thomson DD, Wehmeier S, Byfield FJ, Janmey PA, Caballero-Lima D, Crossley A, Brand AC. Contact-induced apical asymmetry drives the thigmotropic responses of Candida albicans hyphae. Cell Microbiol 2014; 17:342-54. [PMID: 25262778 PMCID: PMC4371639 DOI: 10.1111/cmi.12369] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 09/02/2014] [Accepted: 09/08/2014] [Indexed: 11/30/2022]
Abstract
Filamentous hyphae of the human pathogen, Candida albicans, invade mucosal layers and medical silicones. In vitro, hyphal tips reorient thigmotropically on contact with small obstacles. It is not known how surface topography is sensed but hyphae lacking the cortical marker, Rsr1/Bud1, are unresponsive. We show that, on surfaces, the morphology of hyphal tips and the position of internal polarity protein complexes are asymmetrically skewed towards the substratum and biased towards the softer of two surfaces. In nano-fabricated chambers, the Spitzenkörper (Spk) responded to touch by translocating across the apex towards the point of contact, where its stable maintenance correlated with contour-following growth. In the rsr1Δ mutant, the position of the Spk meandered and these responses were attenuated. Perpendicular collision caused lateral Spk oscillation within the tip until after establishment of a new growth axis, suggesting Spk position does not predict the direction of growth in C. albicans. Acute tip reorientation occurred only in cells where forward growth was countered by hyphal friction sufficient to generate a tip force of ∼ 8.7 μN (1.2 MPa), more than that required to penetrate host cell membranes. These findings suggest mechanisms through which the organization of hyphal tip growth in C. albicans facilitates the probing, penetration and invasion of host tissue.
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Affiliation(s)
- Darren D Thomson
- School of Medical Sciences, University of Aberdeen, Aberdeen, AB25 2ZD, UK; Institute for Biology Valrose, University of Nice-Sophia Antipolis, Nice, France
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23
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A spindle pole antigen gene MoSPA2 is important for polar cell growth of vegetative hyphae and conidia, but is dispensable for pathogenicity in Magnaporthe oryzae. Curr Genet 2014; 60:255-63. [DOI: 10.1007/s00294-014-0431-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 04/24/2014] [Accepted: 05/05/2014] [Indexed: 10/25/2022]
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24
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Wang M, Wang F, Yang J, Zhao D, Wang H, Shao F, Wang W, Sun R, Ling M, Zhai J, Song S. Mannan-binding lectin inhibits Candida albicans-induced cellular responses in PMA-activated THP-1 cells through Toll-like receptor 2 and Toll-like receptor 4. PLoS One 2013; 8:e83517. [PMID: 24391778 PMCID: PMC3877063 DOI: 10.1371/journal.pone.0083517] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 11/04/2013] [Indexed: 11/29/2022] Open
Abstract
Background Candida albicans (C. albicans), the most common human fungal pathogen, can cause fatal systemic infections under certain circumstances. Mannan-binding lectin (MBL),a member of the collectin family in the C-type lectin superfamily, is an important serum component associated with innate immunity. Toll-like receptors (TLRs) are expressed extensively, and have been shown to be involved in C. albicans-induced cellular responses. We first examined whether MBL modulated heat-killed (HK) C. albicans-induced cellular responses in phorbol 12-myristate 13-acetate (PMA)-activated human THP-1 macrophages. We then investigated the possible mechanisms of its inhibitory effect. Methodology/Principal Finding Enzyme-linked immunosorbent assay (ELISA) and reverse transcriptasepolymerase chain reaction (RT-PCR) analysis showed that MBL at higher concentrations (10–20 µg/ml) significantly attenuated C. albicans-induced chemokine (e.g., IL-8) and proinflammatory cytokine (e.g., TNF-α) production from PMA-activated THP-1 cells at both protein and mRNA levels. Electrophoretic mobility shift assay (EMSA) and Western blot (WB) analysis showed that MBL could inhibit C. albicans-induced nuclear factor-κB (NF-κB) DNA binding and its translocation in PMA-activated THP-1 cells. MBL could directly bind to PMA-activated THP-1 cells in the presence of Ca2+, and this binding decreased TLR2 and TLR4 expressions in C. albicans-induced THP-1 macrophages. Furthermore, the binding could be partially inhibited by both anti-TLR2 monoclonal antibody (clone TL2.1) and anti-TLR4 monoclonal antibody (clone HTA125). In addition, co-immunoprecipitation experiments and microtiter wells assay showed that MBL could directly bind to the recombinant soluble form of extracellular TLR2 domain (sTLR2) and sTLR4. Conclusions/Significance Our study demonstrates that MBL can affect proinflammatory cytokine and chemokine expressions by modifying C. albicans-/TLR-signaling pathways. This study supports an important role for MBL on the regulation of C. albicans-induced cellular responses.
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Affiliation(s)
- Mingyong Wang
- Department of Laboratory Medicine, Xinxiang Medical University, Xinxiang, China
- * E-mail:
| | - Fanping Wang
- Department of Laboratory Medicine, Xinxiang Medical University, Xinxiang, China
| | - Jianbin Yang
- Department of Clinical Laboratory, The First Affiliated Hospital of Xinxiang Medical University, Xinxiang, China
| | - Dongfang Zhao
- Department of Clinical Laboratory, The First Affiliated Hospital of Xinxiang Medical University, Xinxiang, China
| | - Hongpo Wang
- Department of Clinical Laboratory, The First Affiliated Hospital of Xinxiang Medical University, Xinxiang, China
| | - Feng Shao
- Department of Clinical Laboratory, The Third Affiliated Hospital of Xinxiang Medical University, Xinxiang, China
| | - Wenjun Wang
- Cancer Research Institute, Southern Medical University, Guangzhou, China
| | - Ruili Sun
- Department of Laboratory Medicine, Xinxiang Medical University, Xinxiang, China
| | - Mingzhi Ling
- Department of Laboratory Medicine, Xinxiang Medical University, Xinxiang, China
| | - Jingjing Zhai
- Department of Laboratory Medicine, Xinxiang Medical University, Xinxiang, China
| | - Shijun Song
- Department of Clinical Laboratory, The Third Affiliated Hospital of Xinxiang Medical University, Xinxiang, China
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25
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Vernay A, Schaub S, Guillas I, Bassilana M, Arkowitz RA. A steep phosphoinositide bis-phosphate gradient forms during fungal filamentous growth. ACTA ACUST UNITED AC 2012; 198:711-30. [PMID: 22891265 PMCID: PMC3514036 DOI: 10.1083/jcb.201203099] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
A gradient of PI(4,5)P2 formed by phospholipid synthesis, diffusion,
and regulated turnover is crucial for filamentous growth. Membrane lipids have been implicated in many critical cellular processes, yet
little is known about the role of asymmetric lipid distribution in cell
morphogenesis. The phosphoinositide bis-phosphate PI(4,5)P2 is
essential for polarized growth in a range of organisms. Although an asymmetric
distribution of this phospholipid has been observed in some cells, long-range
gradients of PI(4,5)P2 have not been observed. Here, we show that in
the human pathogenic fungus Candida albicans a steep,
long-range gradient of PI(4,5)P2 occurs concomitant with emergence of
the hyphal filament. Both sufficient PI(4)P synthesis and the actin cytoskeleton
are necessary for this steep PI(4,5)P2 gradient. In contrast, neither
microtubules nor asymmetrically localized mRNAs are critical. Our results
indicate that a gradient of PI(4,5)P2, crucial for filamentous
growth, is generated and maintained by the filament tip–localized
PI(4)P-5-kinase Mss4 and clearing of this lipid at the back of the cell.
Furthermore, we propose that slow membrane diffusion of PI(4,5)P2
contributes to the maintenance of such a gradient.
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Affiliation(s)
- Aurélia Vernay
- Institute of Biology Valrose, Université Nice - Sophia Antipolis, 06108 Nice Cedex 2, France
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26
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Li CR, Au Yong JY, Wang YM, Wang Y. CDK regulates septin organization through cell-cycle-dependent phosphorylation of the Nim1-related kinase Gin4. J Cell Sci 2012; 125:2533-43. [PMID: 22366454 DOI: 10.1242/jcs.104497] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Cyclin-dependent kinases (CDKs) regulate septin organization in a cell-cycle-dependent manner in yeast. However, the mechanism remains unclear. Here, we show that the Candida albicans CDK Cdc28 phosphorylates the Nim1-related kinase Gin4, a known septin regulator, activating its kinase activity, which in turn phosphorylates the Sep7 septin. Gin4 contains a cluster of CDK phosphorylation sites near the kinase domain. Replacing serine/threonine with alanine in these sites prevents Gin4 activation, weakens its association with Sep7, alters Sep7 dynamics and causes morphological and cytokinetic defects. By contrast, phosphomimetic mutation enhances the kinase activity with only moderate deteriorating effects. We also found that Gin4 has both kinase-independent and -dependent functions, acting during G1 phase and mitosis, respectively, with the former being essential for septin ring assembly. Thus, we have identified a previously unknown signaling pathway linking CDKs and the septins that provides new insights into the mechanisms controlling septin organization and function in coordination with cell-cycle phases.
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Affiliation(s)
- Chang-Run Li
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Proteos, 61 Biopolis Drive, 138673, Singapore
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Roles of Ras1 membrane localization during Candida albicans hyphal growth and farnesol response. EUKARYOTIC CELL 2011; 10:1473-84. [PMID: 21908593 DOI: 10.1128/ec.05153-11] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Many Ras GTPases localize to membranes via C-terminal farnesylation and palmitoylation, and localization regulates function. In Candida albicans, a fungal pathogen of humans, Ras1 links environmental cues to morphogenesis. Here, we report the localization and membrane dynamics of Ras1, and we characterize the roles of conserved C-terminal cysteine residues, C287 and C288, which are predicted sites of palmitoylation and farnesylation, respectively. GFP-Ras1 is localized uniformly to plasma membranes in both yeast and hyphae, yet Ras1 plasma membrane mobility was reduced in hyphae compared to that in yeast. Ras1-C288S was mislocalized to the cytoplasm and could not support hyphal development. Ras1-C287S was present primarily on endomembranes, and strains expressing ras1-C287S were delayed or defective in hyphal induction depending on the medium used. Cells bearing constitutively activated Ras1-C287S or Ras1-C288S, due to a G13V substitution, showed increased filamentation, suggesting that lipid modifications are differentially important for Ras1 activation and effector interactions. The C. albicans autoregulatory molecule, farnesol, inhibits Ras1 signaling through adenylate cyclase and bears structural similarities to the farnesyl molecule that modifies Ras1. At lower concentrations of farnesol, hyphal growth was inhibited but Ras1 plasma membrane association was not altered; higher concentrations of farnesol led to mislocalization of Ras1 and another G protein, Rac1. Furthermore, farnesol inhibited hyphal growth mediated by cytosolic Ras1-C288SG13V, suggesting that farnesol does not act through mechanisms that depend on Ras1 farnesylation. Our findings imply that Ras1 is farnesylated and palmitoylated, and that the Ras1 stimulation of adenylate cyclase-dependent phenotypes can occur in the absence of these lipid modifications.
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Arkowitz RA, Bassilana M. Polarized growth in fungi: symmetry breaking and hyphal formation. Semin Cell Dev Biol 2011; 22:806-15. [PMID: 21906692 DOI: 10.1016/j.semcdb.2011.08.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Revised: 08/16/2011] [Accepted: 08/18/2011] [Indexed: 01/12/2023]
Abstract
Cell shape is a critical determinant for function. The baker's yeast Saccharomyces cerevisiae changes shape in response to its environment, growing by budding in rich nutrients, forming invasive pseudohyphal filaments in nutrient poor conditions and pear shaped shmoos for growth towards a partner during mating. The human opportunistic pathogen Candida albicans can switch from budding to hyphal growth, in response to numerous environmental stimuli to colonize and invade its host. Hyphal growth, typical of filamentous fungi, is not observed in S. cerevisiae. A number of internal cues regulate when and where yeast cells break symmetry leading to polarized growth and ultimately distinct cell shapes. This review discusses how cells break symmetry using the yeast S. cerevisiae paradigm and how polarized growth is initiated and maintained to result in dramatic morphological changes during C. albicans hyphal growth.
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Affiliation(s)
- Robert A Arkowitz
- Centre National de la Recherche Scientifique and Université de Nice-Sophia Antipolis, Institute of Developmental Biology and Cancer, CNRS-UMR6543 Faculté des Sciences, Nice, France.
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Gutiérrez-Escribano P, González-Novo A, Suárez MB, Li CR, Wang Y, de Aldana CRV, Correa-Bordes J. CDK-dependent phosphorylation of Mob2 is essential for hyphal development in Candida albicans. Mol Biol Cell 2011; 22:2458-69. [PMID: 21593210 PMCID: PMC3135472 DOI: 10.1091/mbc.e11-03-0205] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
In yeast, CDKs and the NDR kinase Cbk1 are regulators of polarized growth. It is found that the CDK Cdc28 regulates the function of Cbk1 in response to hypha-inducing conditions by direct phosphorylation of Mob2, a conserved regulatory subunit of Cbk1. Nuclear Dbf2-related (NDR) protein kinases are essential components of regulatory pathways involved in cell morphogenesis, cell cycle control, and viability in eukaryotic cells. For their activity and function, these kinases require interaction with Mob proteins. However, little is known about how the Mob proteins are regulated. In Candida albicans, the cyclin-dependent kinase (CDK) Cdc28 and the NDR kinase Cbk1 are required for hyphal growth. Here we demonstrate that Mob2, the Cbk1 activator, undergoes a Cdc28-dependent differential phosphorylation on hyphal induction. Mutations in the four CDK consensus sites in Mob2 to Ala significantly impaired hyphal development. The mutant cells produced short hyphae with enlarged tips that displayed an illicit activation of cell separation. We also show that Cdc28 phosphorylation of Mob2 is essential for the maintenance of polarisome components at hyphal tips but not at bud tips during yeast growth. Thus we have found a novel signaling pathway by which Cdc28 controls Cbk1 through the regulatory phosphorylation of Mob2, which is crucial for normal hyphal development.
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30
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Lettner T, Zeidler U, Gimona M, Hauser M, Breitenbach M, Bito A. Candida albicans AGE3, the ortholog of the S. cerevisiae ARF-GAP-encoding gene GCS1, is required for hyphal growth and drug resistance. PLoS One 2010; 5:e11993. [PMID: 20700541 PMCID: PMC2916835 DOI: 10.1371/journal.pone.0011993] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Accepted: 07/12/2010] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Hyphal growth and multidrug resistance of C. albicans are important features for virulence and antifungal therapy of this pathogenic fungus. METHODOLOGY/PRINCIPAL FINDINGS Here we show by phenotypic complementation analysis that the C. albicans gene AGE3 is the functional ortholog of the yeast ARF-GAP-encoding gene GCS1. The finding that the gene is required for efficient endocytosis points to an important functional role of Age3p in endosomal compartments. Most C. albicans age3Delta mutant cells which grew as cell clusters under yeast growth conditions showed defects in filamentation under different hyphal growth conditions and were almost completely disabled for invasive filamentous growth. Under hyphal growth conditions only a fraction of age3Delta cells shows a wild-type-like polarization pattern of the actin cytoskeleton and lipid rafts. Moreover, age3Delta cells were highly susceptible to several unrelated toxic compounds including antifungal azole drugs. Irrespective of the AGE3 genotype, C-terminal fusions of GFP to the drug efflux pumps Cdr1p and Mdr1p were predominantly localized in the plasma membrane. Moreover, the plasma membranes of wild-type and age3Delta mutant cells contained similar amounts of Cdr1p, Cdr2p and Mdr1p. CONCLUSIONS/SIGNIFICANCE The results indicate that the defect in sustaining filament elongation is probably caused by the failure of age3Delta cells to polarize the actin cytoskeleton and possibly of inefficient endocytosis. The high susceptibility of age3Delta cells to azoles is not caused by inefficient transport of efflux pumps to the cell membrane. A possible role of a vacuolar defect of age3Delta cells in drug susceptibility is proposed and discussed. In conclusion, our study shows that the ARF-GAP Age3p is required for hyphal growth which is an important virulence factor of C. albicans and essential for detoxification of azole drugs which are routinely used for antifungal therapy. Thus, it represents a promising antifungal drug target.
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Affiliation(s)
- Thomas Lettner
- Department of Cell Biology, University of Salzburg, Salzburg, Austria
| | - Ute Zeidler
- Institut Pasteur, Unité Biologie et Pathogénicité Fongiques, Paris, France
| | - Mario Gimona
- Department of Cell Biology, University of Salzburg, Salzburg, Austria
| | - Michael Hauser
- Department of Molecular Biology, University of Salzburg, Salzburg, Austria
| | | | - Arnold Bito
- Department of Cell Biology, University of Salzburg, Salzburg, Austria
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Reconstruction of signaling networks regulating fungal morphogenesis by transcriptomics. EUKARYOTIC CELL 2009; 8:1677-91. [PMID: 19749177 DOI: 10.1128/ec.00050-09] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Coordinated control of hyphal elongation and branching is essential for sustaining mycelial growth of filamentous fungi. In order to study the molecular machinery ensuring polarity control in the industrial fungus Aspergillus niger, we took advantage of the temperature-sensitive (ts) apical-branching ramosa-1 mutant. We show here that this strain serves as an excellent model system to study critical steps of polar growth control during mycelial development and report for the first time a transcriptomic fingerprint of apical branching for a filamentous fungus. This fingerprint indicates that several signal transduction pathways, including TORC2, phospholipid, calcium, and cell wall integrity signaling, concertedly act to control apical branching. We furthermore identified the genetic locus affected in the ramosa-1 mutant by complementation of the ts phenotype. Sequence analyses demonstrated that a single amino acid exchange in the RmsA protein is responsible for induced apical branching of the ramosa-1 mutant. Deletion experiments showed that the corresponding rmsA gene is essential for the growth of A. niger, and complementation analyses with Saccharomyces cerevisiae evidenced that RmsA serves as a functional equivalent of the TORC2 component Avo1p. TORC2 signaling is required for actin polarization and cell wall integrity in S. cerevisiae. Congruently, our microscopic investigations showed that polarized actin organization and chitin deposition are disturbed in the ramosa-1 mutant. The integration of the transcriptomic, genetic, and phenotypic data obtained in this study allowed us to reconstruct a model for cellular events involved in apical branching.
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A histidine kinase PmHHK1 regulates polar growth, sporulation and cell wall composition in the dimorphic fungus Penicillium marneffei. ACTA ACUST UNITED AC 2009; 113:915-23. [DOI: 10.1016/j.mycres.2009.03.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2008] [Revised: 02/10/2009] [Accepted: 03/25/2009] [Indexed: 11/21/2022]
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Araujo-Palomares CL, Riquelme M, Castro-Longoria E. The polarisome component SPA-2 localizes at the apex of Neurospora crassa and partially colocalizes with the Spitzenkörper. Fungal Genet Biol 2009; 46:551-63. [DOI: 10.1016/j.fgb.2009.02.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2008] [Revised: 02/18/2009] [Accepted: 02/19/2009] [Indexed: 01/27/2023]
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Badrane H, Nguyen MH, Cheng S, Kumar V, Derendorf H, Iczkowski KA, Clancy CJ. The Candida albicans phosphatase Inp51p interacts with the EH domain protein Irs4p, regulates phosphatidylinositol-4,5-bisphosphate levels and influences hyphal formation, the cell integrity pathway and virulence. MICROBIOLOGY-SGM 2008; 154:3296-3308. [PMID: 18957583 DOI: 10.1099/mic.0.2008/018002-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
We previously identified Candida albicans Irs4p as an epidermal growth factor substrate 15 homology (EH) domain-containing protein that is reactive with antibodies in the sera of patients with candidiasis and contributes to cell wall integrity, hyphal formation and virulence. In this study, we use a yeast two-hybrid method and co-immunoprecipitation to show that Irs4p physically interacts with the phosphatase Inp51p. Disruption of the Inp51p Asn-Pro-Phe (NPF) motif eliminates the interaction, suggesting that this motif is targeted by Irs4p. Both inp51 and irs4 null mutants exhibit significantly increased levels of phosphatidylinositol-4,5-bisphosphate [PI(4,5)P(2)] without changes in levels of other phosphoinositides. Like the irs4 mutant, the inp51 mutant demonstrates increased susceptibility to cell wall-active agents, impaired hyphal formation and abnormal chitin distribution along hyphal walls during growth within solid agar. Moreover, the inp51 and irs4 mutants overactivate the cell wall integrity pathway as measured by Mkc1p phosphorylation. As anticipated, mortality due to disseminated candidiasis is significantly attenuated among mice infected with the inp51 mutant, and tissue burdens and inflammation within the kidneys are reduced. Hyphal formation and chitin distribution in vivo are also impaired, consistent with observations of embedded growth in vitro. All phenotypes exhibited by the inp51 and irs4 mutants are rescued by complementation with the respective genes. In conclusion, our findings suggest that Irs4p binds and activates Inp51p to negatively regulate PI(4,5)P(2) levels and the cell integrity pathway, and that PI(4,5)P(2) homeostasis is important for coordinating cell wall integrity, hyphal growth and virulence under conditions of cell wall stress.
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Affiliation(s)
- Hassan Badrane
- Department of Medicine, University of Florida College of Medicine, Gainesville, FL, USA
| | - M Hong Nguyen
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL, USA.,North Florida/South Georgia Veterans Health System, Gainesville, FL, USA.,Department of Medicine, University of Florida College of Medicine, Gainesville, FL, USA
| | - Shaoji Cheng
- Department of Medicine, University of Florida College of Medicine, Gainesville, FL, USA
| | - Vipul Kumar
- Department of Pharmaceutics, University of Florida College of Pharmacy, Gainesville, FL, USA
| | - Hartmut Derendorf
- Department of Pharmaceutics, University of Florida College of Pharmacy, Gainesville, FL, USA
| | - Kenneth A Iczkowski
- Department of Pathology, University of Colorado Health Science Center, Aurora, CO, USA
| | - Cornelius J Clancy
- North Florida/South Georgia Veterans Health System, Gainesville, FL, USA.,Department of Medicine, University of Florida College of Medicine, Gainesville, FL, USA
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The antimicrobial peptide histatin-5 causes a spatially restricted disruption on the Candida albicans surface, allowing rapid entry of the peptide into the cytoplasm. PLoS Pathog 2008; 4:e1000190. [PMID: 18974864 PMCID: PMC2568956 DOI: 10.1371/journal.ppat.1000190] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2008] [Accepted: 09/26/2008] [Indexed: 11/19/2022] Open
Abstract
Antimicrobial peptides play an important role in host defense against microbial pathogens. Their high cationic charge and strong amphipathic structure allow them to bind to the anionic microbial cell membrane and disrupt the membrane bilayer by forming pores or channels. In contrast to the classical pore-forming peptides, studies on histatin-5 (Hst-5) have suggested that the peptide is transported into the cytoplasm of Candida albicans in a non-lytic manner, and cytoplasmic Hst-5 exerts its candicidal activities on various intracellular targets, consistent with its weak amphipathic structure. To understand how Hst-5 is internalized, we investigated the localization of FITC-conjugated Hst-5. We find that Hst-5 is internalized into the vacuole through receptor-mediated endocytosis at low extracellular Hst-5 concentrations, whereas under higher physiological concentrations, Hst-5 is translocated into the cytoplasm through a mechanism that requires a high cationic charge on Hst-5. At intermediate concentrations, two cell populations with distinct Hst-5 localizations were observed. By cell sorting, we show that cells with vacuolar localization of Hst-5 survived, while none of the cells with cytoplasmic Hst-5 formed colonies. Surprisingly, extracellular Hst-5, upon cell surface binding, induces a perturbation on the cell surface, as visualized by an immediate and rapid internalization of Hst-5 and propidium iodide or rhodamine B into the cytoplasm from the site using time-lapse microscopy, and a concurrent rapid expansion of the vacuole. Thus, the formation of a spatially restricted site in the plasma membrane causes the initial injury to C. albicans and offers a mechanism for its internalization into the cytoplasm. Our study suggests that, unlike classical channel-forming antimicrobial peptides, action of Hst-5 requires an energized membrane and causes localized disruptions on the plasma membrane of the yeast. This mechanism of cell membrane disruption may provide species-specific killing with minimal damage to microflora and the host and may be used by many other antimicrobial peptides.
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The IQGAP Iqg1 is a regulatory target of CDK for cytokinesis in Candida albicans. EMBO J 2008; 27:2998-3010. [PMID: 18923418 DOI: 10.1038/emboj.2008.219] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2008] [Accepted: 09/23/2008] [Indexed: 01/05/2023] Open
Abstract
Cyclin-dependent kinases (CDKs) drive and coordinate multiple cell-cycle events, including construction and contraction of the actomyosin ring during cytokinesis. However, it remains unclear whether CDKs regulate cytokinesis by directly targeting components of the ring. In a search for proteins containing consensus CDK phosphorylation sites in Candida albicans, we found that the IQGAP Iqg1 contains two dense clusters of 19 such sites flanking the actin-interacting CH domain. Here, we show that Iqg1 is indeed a phosphoprotein that undergoes cell-cycle-dependent phosphorylation and can be phosphorylated by purified Clb-Cdc28 kinases in vitro. Mass spectrometry identified several phosphoserine and phosphothreonine residues among these CDK sites. Mutating 15 of the CDK phosphorylation sites with alanine markedly reduced Iqg1 phosphorylation in vivo. The 15A mutation greatly stabilized Iqg1, caused both premature assembly and delayed disassembly of the actomyosin ring, blocked Iqg1 interaction with the actin-nucleating proteins Bni1 and Bnr1, and resulted in defects in cytokinesis. Our data therefore strongly support the idea that the Cdc28 CDK regulates cytokinesis partly by directly phosphorylating the actomyosin ring component Iqg1.
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Carbó N, Pérez-Martín J. Spa2 is required for morphogenesis but it is dispensable for pathogenicity in the phytopathogenic fungus Ustilago maydis. Fungal Genet Biol 2008; 45:1315-27. [PMID: 18674629 DOI: 10.1016/j.fgb.2008.06.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2008] [Revised: 06/23/2008] [Accepted: 06/29/2008] [Indexed: 01/05/2023]
Abstract
The increasing evidence linking regulation of polar growth and pathogenicity in fungi has elicited a significant effort devoted to produce a better understanding of mechanisms determining polarization in pathogenic fungi. Here we characterize in the phytopathogenic basidiomycete Ustilago maydis, the Spa2 protein, a well-known component of polarisome, firstly described in Saccharomyces cerevisiae. U. maydis display a dimorphic switch between budding growth of hapoid cells and filamentous growth of the dikaryon. During yeast growth, a GFP-tagged Spa2 protein localized to distinct growth sites in a cell cycle-specific manner, while during hyphal growth is persistently located to hyphal tips. Deletion of spa2 gene produces rounder budding cells and thicker filaments than wild-type cells, suggesting a role of Spa2 for the determination of the growth area in U. maydis. We also address the connections between Spa2 and the actin- and microtubule-cytoskeleton. We found that the absence of Spa2 does not affect cytoskeleton organization and strikingly, interference with actin filament or microtubule formation does not affect the polar localization of Spa2. In contrast, defects in the small GTPase Rac1 seems to affect the ability of Spa2 to locate to precise sites at the tip cell. Finally, to our surprise, we found that cells defectives in Spa2 function were as pathogenic as wild-type cells.
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Affiliation(s)
- Natalia Carbó
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología CSIC, Madrid, Spain
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38
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An internal polarity landmark is important for externally induced hyphal behaviors in Candida albicans. EUKARYOTIC CELL 2008; 7:712-20. [PMID: 18281602 PMCID: PMC2292634 DOI: 10.1128/ec.00453-07] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Directional growth is a function of polarized cells such as neurites, pollen tubes, and fungal hyphae. Correct orientation of the extending cell tip depends on signaling pathways and effectors that mediate asymmetric responses to specific environmental cues. In the hyphal form of the eukaryotic fungal pathogen Candida albicans, these responses include thigmotropism and galvanotropism (hyphal turning in response to changes in substrate topography and imposed electrical fields, respectively) and penetration into semisolid substrates. During vegetative growth in C. albicans, as in the model yeast Saccharomyces cerevisiae, the Ras-like GTPase Rsr1 mediates internal cellular cues to position new buds in a prespecified pattern on the mother cell cortex. Here, we demonstrate that Rsr1 is also important for hyphal tip orientation in response to the external environmental cues that induce thigmotropic and galvanotropic growth. In addition, Rsr1 is involved in hyphal interactions with epithelial cells in vitro and its deletion diminishes the hyphal invasion of kidney tissue during systemic infection. Thus, Rsr1, an internal polarity landmark in yeast, is also involved in polarized growth responses to asymmetric environmental signals, a paradigm that is different from that described for the homologous protein in S. cerevisiae. Rsr1 may thereby contribute to the pathogenesis of C. albicans infections by influencing hyphal tip responses triggered by interaction with host tissues.
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Meyer V, Arentshorst M, van den Hondel CAMJJ, Ram AFJ. The polarisome component SpaA localises to hyphal tips of Aspergillus niger and is important for polar growth. Fungal Genet Biol 2008; 45:152-64. [PMID: 17826199 DOI: 10.1016/j.fgb.2007.07.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2007] [Revised: 07/09/2007] [Accepted: 07/11/2007] [Indexed: 11/23/2022]
Abstract
Hyphal tip growth is a key feature of filamentous fungi, however, the molecular mechanism(s) that regulate cell polarity are poorly understood. On the other hand, much more is known about polarised growth in the yeast Saccharomyces cerevisiae. Here, the proteins Spa2p, Bni1p, Bud6p and Pea2p form a protein complex named the polarisome known to be important for the assurance of polar growth. We searched the genome of Aspergillus niger and identified homologues for Spa2p, Bni1p, Bud6p but not for Pea2p. We characterised the function of the Spa2p homologue SpaA by determining its cellular localisation and by constructing deletion and overexpressing mutant strains. SpaA was found to be localised exclusively at the hyphal tip, suggesting that SpaA can be used as marker for polarisation. Deletion and overexpression of spaA resulted in reduced growth rate, increased hyphal diameter and polarity defects, indicating that one of the functions of SpaA is to ensure polarity maintenance. In addition, we could show that SpaA is able to complement the defective haploid invasive growth phenotype of a S. cerevisiae SPA2 null mutant. We suggest that the function of SpaA is to ensure maximal polar growth rate in A. niger.
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Affiliation(s)
- Vera Meyer
- Department of Microbiology and Genetics, Institute of Biotechnology, Berlin University of Technology, Gustav-Meyer-Allee 25, D-13355 Berlin, Germany.
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40
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Abstract
Candida albicans is termed a dimorphic fungus because it proliferates in either a yeast form or a hyphal form. The switch between these forms is the result of a complex interplay of external and internal factors and is coordinated in part by polarity-regulating proteins that are conserved among eukaryotic cells. However, yeast and hyphal cells are not the only morphological states of C. albicans. The opaque form required for mating, the pseudohyphal cell, and the chlamydospore represent distinct cell types that form in response to specific genetic or environmental conditions. In addition, hyperextended buds can form as a result of various cell cycle-related stresses. Recent studies are beginning to shed light on some of the molecular controls regulating the various morphogenetic forms of this fascinating human pathogen.
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Affiliation(s)
- Malcolm Whiteway
- National Research Council of Canada, Biotechnology Research Institute, Montreal, Quebec, H4P 2R2, Canada.
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41
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Boon C, Deng Y, Wang LH, He Y, Xu JL, Fan Y, Pan SQ, Zhang LH. A novel DSF-like signal from Burkholderia cenocepacia interferes with Candida albicans morphological transition. ISME JOURNAL 2007; 2:27-36. [PMID: 18049456 DOI: 10.1038/ismej.2007.76] [Citation(s) in RCA: 205] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
In addition to producing lethal antibiotics, microorganisms may also use a new form of antagonistic mechanism in which signal molecules are exported to influence the gene expression and hence the ecological competence of their competitors. We report here the isolation and characterization of a novel signaling molecule, cis-2-dodecenoic acid (BDSF), from Burkholderia cenocepacia. BDSF is structurally similar to the diffusible signal factor (DSF) that is produced by the RpfF enzyme of Xanthomonas campestris. Deletion analysis demonstrated that Bcam0581, which encodes an RpfF homologue, was essential for BDSF production. The gene is highly conserved and widespread in the Burkholderia cepacia complex. Exogenous addition of BDSF restored the biofilm and extracellular polysaccharide production phenotypes of Xanthomonas campestris pv. campestris DSF-deficient mutants, highlighting its potential role in inter-species signaling. Further analyses showed that Candida albicans germ tube formation was strongly inhibited by either coculture with B. cenocepacia or by exogenous addition of physiological relevant levels of BDSF, whereas deletion of Bcam0581 abrogated the inhibitory ability of the bacterial pathogen. As B. cenocepacia and C. albicans are frequently encountered human pathogens, identification of the BDSF signal and its activity thus provides a new insight into the molecular grounds of their antagonistic interactions whose importance to microbial ecology and pathogenesis is now becoming evident.
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Affiliation(s)
- Calvin Boon
- Institute of Molecular and Cell Biology, Singapore
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42
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Zheng XD, Lee RTH, Wang YM, Lin QS, Wang Y. Phosphorylation of Rga2, a Cdc42 GAP, by CDK/Hgc1 is crucial for Candida albicans hyphal growth. EMBO J 2007; 26:3760-9. [PMID: 17673907 PMCID: PMC1952229 DOI: 10.1038/sj.emboj.7601814] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2007] [Accepted: 07/05/2007] [Indexed: 11/08/2022] Open
Abstract
Cyclin-dependent kinases (CDKs) control yeast morphogenesis, although how they regulate the polarity machinery remains unclear. The dimorphic fungus Candida albicans uses Cdc28/Hgc1, a CDK/cyclin complex, to promote persistent actin polarization for hyphal growth. Here, we report that Rga2, a GTPase-activating protein (GAP) of the central polarity regulator Cdc42, undergoes Hgc1-dependent hyperphosphorylation. Using the analog-sensitive Cdc28as mutant, we confirmed that Cdc28 controls Rga2 phosphorylation in vitro and in vivo. Deleting RGA2 produced elongated yeast cells without apparent effect on hyphal morphogenesis. However, deleting it or inactivating its GAP activity restored hyphal growth in hgc1Delta mutants, suggesting that Rga2 represses hyphal development and Cdc28/Hgc1 inactivates it upon hyphal induction. We provide evidence that Cdc28/Hgc1 may act to prevent Rga2 from localizing to hyphal tips, leading to localized Cdc42 activation for hyphal extension. Rga2 also undergoes transient Cdc28-dependent hyperphosphorylation at bud emergence, suggesting that regulating a GAP(s) of Cdc42 by CDKs may play an important role in governing different forms of polarized morphogenesis in yeast. This study reveals a direct molecular link between CDKs and the polarity machinery.
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Affiliation(s)
- Xin-De Zheng
- Laboratory of Candida albicans, Institute of Molecular and Cell Biology, Singapore, Singapore
| | - Raymond Teck Ho Lee
- Laboratory of Candida albicans, Institute of Molecular and Cell Biology, Singapore, Singapore
| | - Yan-Ming Wang
- Laboratory of Candida albicans, Institute of Molecular and Cell Biology, Singapore, Singapore
| | - Qi-Shan Lin
- Proteomics Core Facility, Center for Functional Genomics, University at Albany, Rensselaer, NY, USA
| | - Yue Wang
- Laboratory of Candida albicans, Institute of Molecular and Cell Biology, Singapore, Singapore
- Laboratory of Candida albicans, Institute of Molecular and Cell Biology, 61 Biopolis Drive, Singapore 138673, Singapore. Tel.: +65 658 69521; Fax: +65 677 91117; E-mail:
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Li CR, Lee RTH, Wang YM, Zheng XD, Wang Y. Candida albicans hyphal morphogenesis occurs in Sec3p-independent and Sec3p-dependent phases separated by septin ring formation. J Cell Sci 2007; 120:1898-907. [PMID: 17504812 DOI: 10.1242/jcs.002931] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The growing tips of Candida albicans hyphae are sites of polarized exocytosis. Mammalian septins have been implicated in regulating exocytosis and C. albicans septins are known to localize at hyphal tips, although their function here is unknown. Here, we report that C. albicans cells deleted of the exocyst subunit gene SEC3 can grow normal germ tubes, but are unable to maintain tip growth after assembly of the first septin ring, resulting in isotropic expansion of the tip. Deleting either of the septin genes CDC10 or CDC11 caused Sec3p mislocalization and surprisingly, also restored hyphal development in the sec3Δ mutant without rescuing the temperature sensitivity. Co-immunoprecipitation experiments detected association of the septin Cdc3p with the exocyst subunits Sec3p and Sec5p. Our results reveal that C. albicans hyphal development occurs through Sec3p-independent and dependent phases, and provide strong genetic and biochemical evidence for a role of septins in polarized exocytosis.
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Affiliation(s)
- Chang-Run Li
- Candida albicans Molecular and Cell Biology Laboratory, Institute of Molecular and Cell Biology, 61 Biopolis Drive, 138673, Singapore
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44
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Li WJ, Wang YM, Zheng XD, Shi QM, Zhang TT, Bai C, Li D, Sang JL, Wang Y. The F-box protein Grr1 regulates the stability of Ccn1, Cln3 and Hof1 and cell morphogenesis in Candida albicans. Mol Microbiol 2007; 62:212-26. [PMID: 16987179 DOI: 10.1111/j.1365-2958.2006.05361.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Both G1 and mitotic cyclins have been implicated in regulating Candida albicans filamentous growth. We have investigated the functions of Grr1 whose orthologue in Saccharomyces cerevisiae is known to mediate ubiquitin-dependent degradation of the G1 cyclins Cln1 and Cln2. Here, we report that deleting C. albicans GRR1 causes significant stabilization of two G1 cyclins Ccn1 and Cln3 and pseudohyphal growth. grr1Delta cells are highly heterogeneous in length and many of them fail to separate after cytokinesis. Interestingly, some isolated rod-like G1 cells of similar sizes are present in the grr1Delta culture. Time-lapse microscopy revealed that the rod-shaped G1 cells first grew exclusively in width before budding and then the bud grew exclusively by apical extension until after cytokinesis, yielding rod-like daughter cells. Consistently, actin patches persistently localize to the bud tip until around the time of cytokinesis. Despite the pseudohyphal phenotype, grr1Delta cells respond normally to hyphal induction. Hyperphosphorylated Cln3 isoforms accumulate in grr1Delta cells, indicating that Grr1 selectively mediates their degradation in wild-type cells. grr1Delta pseudohyphal growth requires neither Hgc1 nor Swel, two important regulators of cell morphogenesis. Furthermore, the cellular level of Hof1, a protein having a role in cytokinesis, is also significantly increased in grr1Delta cells.
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Affiliation(s)
- Wan Jie Li
- Institute of Life Sciences, Beijing Normal University, Beijing 100875, China
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45
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Martin R, Hellwig D, Schaub Y, Bauer J, Walther A, Wendland J. Functional analysis ofCandida albicans genes whoseSaccharomyces cerevisiae homologues are involved in endocytosis. Yeast 2007; 24:511-22. [PMID: 17431925 DOI: 10.1002/yea.1489] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
PCR-based techniques for directed gene alterations have become standard tools in Candida albicans. To help to increase the speed of functional analysis of Candida albicans genes, we previously constructed and updated a modular set of pFA-plasmid vectors for PCR-based gene targeting in C. albicans. Here we report the functional analyses of C. albicans ORFs whose homologues in S. cerevisiae are involved in endocytosis, to explore their potential involvement in polarized cell growth. Three C. albicans genes, ABP1, BZZ1 and EDE1, were found to be non-essential. Yeast and hyphal morphogenesis were not affected by the individual deletions and the mutant strains appeared wild-type-like under the different growth conditions tested. On the other hand, deletion of both alleles of the C. albicans PAN1 homologue was not feasible. Promoter shut-down experiments using a MET3p-PAN1/pan1 strain indicated severe growth defects and abolished endocytosis, indicating that PAN1 is an essential gene. Subcellular distribution of CaAbp1 and CaPan1 was analysed via GFP-tagged proteins. Both proteins were found to localize at the cortex and at hyphal tips in a patch-like manner, supporting their role in endocytosis. Localization patterns of Abp1 and Pan1, however, were distinct from that of the FM4-64 stained Spitzenkörper.
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Affiliation(s)
- Ronny Martin
- Department of Microbiology, Friedrich-Schiller-University, Jena, Germany
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46
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Shi QM, Wang YM, Zheng XD, Teck Ho Lee R, Wang Y. Critical role of DNA checkpoints in mediating genotoxic-stress-induced filamentous growth in Candida albicans. Mol Biol Cell 2006; 18:815-26. [PMID: 17182857 PMCID: PMC1805102 DOI: 10.1091/mbc.e06-05-0442] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The polymorphic fungus Candida albicans switches from yeast to filamentous growth in response to a range of genotoxic insults, including inhibition of DNA synthesis by hydroxyurea (HU) or aphidicolin (AC), depletion of the ribonucleotide-reductase subunit Rnr2p, and DNA damage induced by methylmethane sulfonate (MMS) or UV light (UV). Deleting RAD53, which encodes a downstream effector kinase for both the DNA-replication and DNA-damage checkpoint pathways, completely abolished the filamentous growth caused by all the genotoxins tested. Deleting RAD9, which encodes a signal transducer of the DNA-damage checkpoint, specifically blocked the filamentous growth induced by MMS or UV but not that induced by HU or AC. Deleting MRC1, the counterpart of RAD9 in the DNA-replication checkpoint, impaired DNA synthesis and caused cell elongation even in the absence of external genotoxic insults. Together, the results indicate that the DNA-replication/damage checkpoints are critically required for the induction of filamentous growth by genotoxic stress. In addition, either of two mutations in the FHA1 domain of Rad53p, G65A, and N104A, nearly completely blocked the filamentous-growth response but had no significant deleterious effect on cell-cycle arrest. These results suggest that the FHA domain, known for its ability to bind phosphopeptides, has an important role in mediating genotoxic-stress-induced filamentous growth and that such growth is a specific, Rad53p-regulated cellular response in C. albicans.
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Affiliation(s)
- Qing-Mei Shi
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research Biological Sciences Institutes, Singapore 138673
| | - Yan-Ming Wang
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research Biological Sciences Institutes, Singapore 138673
| | - Xin-De Zheng
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research Biological Sciences Institutes, Singapore 138673
| | - Raymond Teck Ho Lee
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research Biological Sciences Institutes, Singapore 138673
| | - Yue Wang
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research Biological Sciences Institutes, Singapore 138673
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47
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Wang A, Lane S, Tian Z, Sharon A, Hazan I, Liu H. Temporal and spatial control of HGC1 expression results in Hgc1 localization to the apical cells of hyphae in Candida albicans. EUKARYOTIC CELL 2006; 6:253-61. [PMID: 17172437 PMCID: PMC1797949 DOI: 10.1128/ec.00380-06] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The human fungal pathogen Candida albicans can undergo a morphological transition from a unicellular yeast growth form to a multicellular hyphal growth form. During hyphal growth, cell division is asymmetric. Only the apical cell divides, whereas subapical cells remain in G(1), and cell surface growth is highly restricted to the tip of the apical cell. Hgc1, a hypha-specific, G(1) cyclin-like protein, is essential for hyphal development. Here, we report, using indirect immunofluorescence, that Hgc1 is preferentially localized to the dividing apical cells of hyphae. Hgc1 protein is rapidly degraded in a cell cycle-independent manner, and the protein turnover likely occurs in both the apical and the subapical cells of hyphae. In addition to rapid protein turnover, the HGC1 transcript is also dynamically regulated during cell cycle progression in hyphal growth. It is induced upon germ tube formation in early G(1); the transcript level is reduced during the G(1)/S transition and peaks again around the G(2)/M phase in the subsequent cell cycles. Transcription from the HGC1 promoter is essential for its apical cell localization, as Hgc1 no longer exhibits preferential apical localization when expressed under the MAL2 promoter. Using fluorescence in situ hybridization, the HGC1 transcript is detected only in the apical cells of hyphae, suggesting that HGC1 is transcribed in the apical cell. Therefore, the preferential localization of Hgc1 to the apical cells of hyphae results from the dynamic temporal and spatial control of HGC1 expression.
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Affiliation(s)
- Allen Wang
- Department of Biological Chemistry, University of California, Irvine, CA 92697-1700, USA
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48
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Fang HM, Wang Y. RA domain-mediated interaction of Cdc35 with Ras1 is essential for increasing cellular cAMP level for Candida albicans hyphal development. Mol Microbiol 2006; 61:484-96. [PMID: 16856944 DOI: 10.1111/j.1365-2958.2006.05248.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Many Ras GTPases activate their effectors through binding at a conserved Ras association (RA) domain. An example is the activation of the budding yeast adenylate cyclase Cyr1 by Ras1 and Ras2. Candida albicans Ras1 is speculated to similarly activate Cdc35, the orthologue of Cyr1, for hyphal development. Here, we have investigated whether the RA domain mediates Ras1-Cdc35 interaction and how this interaction regulates cAMP levels and morphogenesis. Yeast two-hybrid assays suggested that Ras1 interacts only with the RA but not any other identifiable domains of Cdc35. The Ras1-RA interaction was further confirmed by in vitro binding assays of purified RA domain and Ras1 and by co-immunoprecipitation of Ras1 and Cdc35 from cell lysates. Substituting Ala for the conserved residue K(338) or L(349) in the RA domain or deleting the RA domain abolished the Ras1-RA or Ras1-Cdc35 interactions. cdc35 mutants with the RA domain deleted or carrying K388A or L349A mutation exhibited rather normal yeast growth but were completely defective in hyphal morphogenesis. Further, the mutants contained nearly wild-type levels of cAMP during yeast growth but were unable to increase it upon hyphal induction. These results suggest an essential role for the RA-mediated Ras1-Cdc35 interaction in raising cellular cAMP levels for hyphal morphogenesis.
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Affiliation(s)
- Hao-Ming Fang
- Institute of Molecular and Cell Biology, ASTAR Biomedical Sciences Institutes, Proteos, 61 Biopolis Drive, Singapore 138673, Singapore
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49
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Rida PC, Nishikawa A, Won GY, Dean N. Yeast-to-hyphal transition triggers formin-dependent Golgi localization to the growing tip in Candida albicans. Mol Biol Cell 2006; 17:4364-78. [PMID: 16855023 PMCID: PMC1635370 DOI: 10.1091/mbc.e06-02-0143] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Rapid and long-distance secretion of membrane components is critical for hyphal formation in filamentous fungi, but the mechanisms responsible for polarized trafficking are not well understood. Here, we demonstrate that in Candida albicans, the majority of the Golgi complex is redistributed to the distal region during hyphal formation. Randomly distributed Golgi puncta in yeast cells cluster toward the growing tip during hyphal formation, remain associated with the distal portion of the filament during its extension, and are almost absent from the cell body. This restricted Golgi localization pattern is distinct from other organelles, including the endoplasmic reticulum, vacuole and mitochondria, which remain distributed throughout the cell body and hypha. Hyphal-induced positioning of the Golgi and the maintenance of its structural integrity requires actin cytoskeleton, but not microtubules. Absence of the formin Bni1 causes a hyphal-specific dispersal of the Golgi into a haze of finely dispersed vesicles with a sedimentation density no different from that of normal Golgi. These results demonstrate the existence of a hyphal-specific, Bni1-dependent cue for Golgi integrity and positioning at the distal portion of the hyphal tip, and suggest that filamentous fungi have evolved a novel strategy for polarized secretion, involving a redistribution of the Golgi to the growing tip.
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Affiliation(s)
- Padmashree C.G. Rida
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794-5215
| | - Akiko Nishikawa
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794-5215
| | - Gena Y. Won
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794-5215
| | - Neta Dean
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794-5215
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50
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Virag A, Harris SD. Functional characterization of Aspergillus nidulans homologues of Saccharomyces cerevisiae Spa2 and Bud6. EUKARYOTIC CELL 2006; 5:881-95. [PMID: 16757736 PMCID: PMC1489272 DOI: 10.1128/ec.00036-06] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2006] [Accepted: 04/12/2006] [Indexed: 11/20/2022]
Abstract
The importance of polarized growth for fungi has elicited significant effort directed at better understanding underlying mechanisms of polarization, with a focus on yeast systems. At sites of tip growth, multiple protein complexes assemble and coordinate to ensure that incoming building material reaches the appropriate destination sites, and polarized growth is maintained. One of these complexes is the polarisome that consists of Spa2, Bud6, Pea2, and Bni1 in Saccharomyces cerevisiae. Filamentous hyphae differ in their development and life style from yeasts and likely regulate polarized growth in a different way. This is expected to reflect on the composition and presence of protein complexes that assemble at the hyphal tip. In this study we searched for polarisome homologues in the model filamentous fungus Aspergillus nidulans and characterized the S. cerevisiae Spa2 and Bud6 homologues, SpaA and BudA. Compared to the S. cerevisiae Spa2, SpaA lacks domain II but has three additional domains that are conserved within filamentous fungi. Gene replacement strains and localization studies show that SpaA functions exclusively at the hyphal tip, while BudA functions at sites of septum formation and possibly at hyphal tips. We show that SpaA is not required for the assembly or maintenance of the Spitzenkörper. We propose that the core function of the polarisome in polarized growth is maintained but with different contributions of polarisome components to the process.
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Affiliation(s)
- Aleksandra Virag
- Plant Science Initiative, and Department of Plant Pathology, University of Nebraska, Lincoln, NE 68588-0660, USA
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