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Kim S, Park J, Han YK, Son H. FgVAC1 is an Essential Gene Required for Golgi-to-Vacuole Transport and Fungal Development in Fusarium graminearum. J Microbiol 2024; 62:649-660. [PMID: 39080148 PMCID: PMC11379736 DOI: 10.1007/s12275-024-00160-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2024] [Revised: 07/11/2024] [Accepted: 07/14/2024] [Indexed: 09/07/2024]
Abstract
Fusarium graminearum is an important plant pathogen that causes head blight in cereal crops such as wheat, barley, and rice worldwide. In this study, we identified and functionally characterized FgVAC1, an essential gene in F. graminearum that encodes a Rab5 effector involved in membrane tethering functions. The essentiality of FgVAC1 was confirmed through a conditional promoter replacement strategy using the zearalenone-inducible promoter (PZEAR). Cytological analyses revealed that FgVac1 colocalizes with FgRab51 on early endosomes and regulates the proper transport of the vacuolar hydrolase FgCpy1 to the vacuole. Suppression of FgVAC1 led to inhibited vegetative growth, reduced asexual and sexual reproduction, decreased deoxynivalenol (DON) biosynthesis, and diminished pathogenicity. Our findings highlight the significant role of FgVac1 in vacuolar protein sorting, fungal development, and plant infection in F. graminearum.
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Affiliation(s)
- Sieun Kim
- Horticultural and Herbal Crop Environment Division, National Institute of Horticultural & Herbal Science, Rural Development Administration, Wanju, 55365, Republic of Korea
| | - Jiyeun Park
- Institute for Plant Sciences, University of Cologne, 50923, Cologne, Germany
| | - You-Kyoung Han
- Horticultural and Herbal Crop Environment Division, National Institute of Horticultural & Herbal Science, Rural Development Administration, Wanju, 55365, Republic of Korea.
| | - Hokyoung Son
- Department of Agricultural Biotechnology, Seoul National University, Seoul, 08826, Republic of Korea.
- Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea.
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2
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Liu Y, Wang R, Liu J, Fan M, Ye Z, Hao Y, Xie F, Wang T, Jiang Y, Liu N, Cui X, Lv Q, Yan L. The vacuolar fusion regulated by HOPS complex promotes hyphal initiation and penetration in Candida albicans. Nat Commun 2024; 15:4131. [PMID: 38755250 PMCID: PMC11099166 DOI: 10.1038/s41467-024-48525-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 05/02/2024] [Indexed: 05/18/2024] Open
Abstract
The transition between yeast and hyphae is crucial for regulating the commensalism and pathogenicity in Candida albicans. The mechanisms that affect the invasion of hyphae in solid media, whose deficiency is more related to the pathogenicity of C. albicans, have not been elucidated. Here, we found that the disruption of VAM6 or VPS41 which are components of the homotypic vacuolar fusion and protein sorting (HOPS) complex, or the Rab GTPase YPT72, all responsible for vacuole fusion, led to defects in hyphal growth in both liquid and solid media, but more pronounced on solid agar. The phenotypes of vac8Δ/Δ and GTR1OE-vam6Δ/Δ mutants indicated that these deficiencies are mainly caused by the reduced mechanical forces that drive agar and organs penetration, and confirmed that large vacuoles are required for hyphal mechanical penetration. In summary, our study revealed that large vacuoles generated by vacuolar fusion support hyphal penetration and provided a perspective to refocus attention on the role of solid agar in evaluating C. albicans invasion.
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Affiliation(s)
- Yu Liu
- Center for Basic Research and Innovation of Medicine and Pharmacy (MOE), School of Pharmacy, Naval Medical University, Shanghai, 200433, PR China
| | - Ruina Wang
- Center for Basic Research and Innovation of Medicine and Pharmacy (MOE), School of Pharmacy, Naval Medical University, Shanghai, 200433, PR China
| | - Jiacun Liu
- Center for Basic Research and Innovation of Medicine and Pharmacy (MOE), School of Pharmacy, Naval Medical University, Shanghai, 200433, PR China
| | - Mengting Fan
- School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200241, PR China
| | - Zi Ye
- Center for Basic Research and Innovation of Medicine and Pharmacy (MOE), School of Pharmacy, Naval Medical University, Shanghai, 200433, PR China
| | - Yumeng Hao
- Center for Basic Research and Innovation of Medicine and Pharmacy (MOE), School of Pharmacy, Naval Medical University, Shanghai, 200433, PR China
| | - Fei Xie
- Center for Basic Research and Innovation of Medicine and Pharmacy (MOE), School of Pharmacy, Naval Medical University, Shanghai, 200433, PR China
| | - Ting Wang
- Center for Basic Research and Innovation of Medicine and Pharmacy (MOE), School of Pharmacy, Naval Medical University, Shanghai, 200433, PR China
| | - Yuanying Jiang
- School of Medicine, Tongji University, Shanghai, 200092, PR China
| | - Ningning Liu
- State Key Laboratory of Systems Medicine for Cancer, Center for Single-Cell Omics, School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, PR China.
| | - Xiaoyan Cui
- School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200241, PR China.
| | - Quanzhen Lv
- Center for Basic Research and Innovation of Medicine and Pharmacy (MOE), School of Pharmacy, Naval Medical University, Shanghai, 200433, PR China.
| | - Lan Yan
- Center for Basic Research and Innovation of Medicine and Pharmacy (MOE), School of Pharmacy, Naval Medical University, Shanghai, 200433, PR China.
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3
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Chen SY, Chang CK, Lan CY. Antimicrobial peptide LL-37 disrupts plasma membrane and calcium homeostasis in Candida albicans via the Rim101 pathway. Microbiol Spectr 2023; 11:e0255123. [PMID: 37888991 PMCID: PMC10715129 DOI: 10.1128/spectrum.02551-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Accepted: 09/19/2023] [Indexed: 10/28/2023] Open
Abstract
IMPORTANCE Candida albicans is a major human fungal pathogen, and antimicrobial peptides are key components of innate immunity. Studying the interplay between C. albicans and human antimicrobial peptides would enhance a better understanding of pathogen-host interactions. Moreover, potential applications of antimicrobial peptides in antifungal therapy have aroused great interest. This work explores new mechanisms of LL-37 against C. albicans and reveals the complex connection among calcium homeostasis, oxidative stress, signaling, and possibly organelle interaction. Notably, these findings support the possible use of antimicrobial peptides to prevent and treat fungal infections.
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Affiliation(s)
- Sheng-Yuan Chen
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan
| | - Che-Kang Chang
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan
| | - Chung-Yu Lan
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan
- Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan
- School of Medicine, National Tsing Hua University, Hsinchu, Taiwan
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4
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Acuna E, Ndlovu E, Molaeitabari A, Shahina Z, Dahms TES. Carvacrol-Induced Vacuole Dysfunction and Morphological Consequences in Nakaseomyces glabratus and Candida albicans. Microorganisms 2023; 11:2915. [PMID: 38138059 PMCID: PMC10745442 DOI: 10.3390/microorganisms11122915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 11/27/2023] [Accepted: 11/28/2023] [Indexed: 12/24/2023] Open
Abstract
With the prevalence of systemic fungal infections caused by Candida albicans and non-albicans species and their resistance to classical antifungals, there is an urgent need to explore alternatives. Herein, we evaluate the impact of the monoterpene carvacrol, a major component of oregano and thyme oils, on clinical and laboratory strains of C. albicans and Nakaseomyces glabratus. Carvacrol induces a wide range of antifungal effects, including the inhibition of growth and hyphal and biofilm formation. Using biochemical and microscopic approaches, we elucidate carvacrol-induced hyphal inhibition. The significantly reduced survival rates following exposure to carvacrol were accompanied by dose-dependent vacuolar acidification, disrupted membrane integrity, and aberrant morphology. Germ tube assays, used to elucidate the relationship between vacuolar dysfunction and hyphal inhibition, showed that carvacrol significantly reduced hyphal formation, which was accompanied by a defective C. albicans morphology. Thus, we show a link between vacuolar acidification/disrupted vacuole membrane integrity and compromised candidal morphology/morphogenesis, demonstrating that carvacrol exerts its anti-hyphal activity by altering vacuole integrity.
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Affiliation(s)
| | | | | | - Zinnat Shahina
- Department of Chemistry and Biochemistry, University of Regina, Regina, SK S4S 1P4, Canada; (E.A.)
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5
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Ma D, Yu M, Eszterhas S, Rollenhagen C, Lee SA. A C. albicans TRAPP Complex-Associated Gene Contributes to Cell Wall Integrity, Hyphal and Biofilm Formation, and Tissue Invasion. Microbiol Spectr 2023; 11:e0536122. [PMID: 37222596 PMCID: PMC10269527 DOI: 10.1128/spectrum.05361-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 05/08/2023] [Indexed: 05/25/2023] Open
Abstract
While endocytic and secretory pathways are well-studied cellular processes in the model yeast Saccharomyces cerevisiae, they remain understudied in the opportunistic fungal pathogen Candida albicans. We previously found that null mutants of C. albicans homologs of the S. cerevisiae early endocytosis genes ENT2 and END3 not only exhibited delayed endocytosis but also had defects in cell wall integrity, filamentation, biofilm formation, extracellular protease activity, and tissue invasion in an in vitro model. In this study, we focused on a potential C. albicans homolog to S. cerevisiae TCA17, which was discovered in our whole-genome bioinformatics approach aimed at identifying genes involved in endocytosis. In S. cerevisiae, TCA17 encodes a transport protein particle (TRAPP) complex-associated protein. Using a reverse genetics approach with CRISPR-Cas9-mediated gene deletion, we analyzed the function of the TCA17 homolog in C. albicans. Although the C. albicans tca17Δ/Δ null mutant did not have defects in endocytosis, it displayed an enlarged cell and vacuole morphology, impaired filamentation, and reduced biofilm formation. Moreover, the mutant exhibited altered sensitivity to cell wall stressors and antifungal agents. When assayed using an in vitro keratinocyte infection model, virulence properties were also diminished. Our findings indicate that C. albicans TCA17 may be involved in secretion-related vesicle transport and plays a role in cell wall and vacuolar integrity, hyphal and biofilm formation, and virulence. IMPORTANCE The fungal pathogen Candida albicans causes serious opportunistic infections in immunocompromised patients and has become a major cause of hospital-acquired bloodstream infections, catheter-associated infections, and invasive disease. However, due to a limited understanding of Candida molecular pathogenesis, clinical approaches for the prevention, diagnosis, and treatment of invasive candidiasis need significant improvement. In this study, we focus on identifying and characterizing a gene potentially involved in the C. albicans secretory pathway, as intracellular transport is critical for C. albicans virulence. We specifically investigated the role of this gene in filamentation, biofilm formation, and tissue invasion. Ultimately, these findings advance our current understanding of C. albicans biology and may have implications for the diagnosis and treatment of candidiasis.
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Affiliation(s)
- Dakota Ma
- Medicine Service, White River Junction VA Medical Center, Hartford, Vermont, USA
- Dartmouth College, Hanover, New Hampshire, USA
| | - Miranda Yu
- Medicine Service, White River Junction VA Medical Center, Hartford, Vermont, USA
- Dartmouth College, Hanover, New Hampshire, USA
| | - Susan Eszterhas
- Medicine Service, White River Junction VA Medical Center, Hartford, Vermont, USA
- Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Christiane Rollenhagen
- Medicine Service, White River Junction VA Medical Center, Hartford, Vermont, USA
- Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Samuel A. Lee
- Medicine Service, White River Junction VA Medical Center, Hartford, Vermont, USA
- Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
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6
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Rosemary essential oil and its components 1,8-cineole and α-pinene induce ROS-dependent lethality and ROS-independent virulence inhibition in Candida albicans. PLoS One 2022; 17:e0277097. [DOI: 10.1371/journal.pone.0277097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 10/18/2022] [Indexed: 11/17/2022] Open
Abstract
The essential oil from Rosmarinus officinalis L., a composite mixture of plant-derived secondary metabolites, exhibits antifungal activity against virulent candidal species. Here we report the impact of rosemary oil and two of its components, the monoterpene α-pinene and the monoterpenoid 1,8-cineole, against Candida albicans, which induce ROS-dependent cell death at high concentrations and inhibit hyphal morphogenesis and biofilm formation at lower concentrations. The minimum inhibitory concentrations (100% inhibition) for both rosemary oil and 1,8-cineole were 4500 μg/ml and 3125 μg/ml for α-pinene, with the two components exhibiting partial synergy (FICI = 0.55 ± 0.07). At MIC and 1/2 MIC, rosemary oil and its components induced a generalized cell wall stress response, causing damage to cellular and organelle membranes, along with elevated chitin production and increased cell surface adhesion and elasticity, leading to complete vacuolar segregation, mitochondrial depolarization, elevated reactive oxygen species, microtubule dysfunction, and cell cycle arrest mainly at the G1/S phase, consequently triggering cell death. Interestingly, the same oils at lower fractional MIC (1/8-1/4) inhibited virulence traits, including reduction of mycelium (up to 2-fold) and biofilm (up to 4-fold) formation, through a ROS-independent mechanism.
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7
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Yang M, Zhu Z, Bai Y, Zhuang Z, Ge F, Li M, Wang S. A novel phosphoinositide kinase Fab1 regulates biosynthesis of pathogenic aflatoxin in Aspergillus flavus. Virulence 2020; 12:96-113. [PMID: 33315533 PMCID: PMC7781676 DOI: 10.1080/21505594.2020.1859820] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Aspergillus flavus (A. flavus) is one of the most important model environmental fungi which can produce a potent toxin and carcinogen known as aflatoxin. Aflatoxin contamination causes massive agricultural economic loss and a critical human health issue each year. Although a functional vacuole has been highlighted for its fundamental importance in fungal virulence, the molecular mechanisms of the vacuole in regulating the virulence of A. flavus remain largely unknown. Here, we identified a novel vacuole-related protein in A. flavus, the ortholog of phosphatidylinositol-3-phosphate-5-kinase (Fab1) in Saccharomyces cerevisiae. This kinase was located at the vacuolar membrane, and loss of fab1 function was found to affect the growth, conidia and sclerotial development, cellular acidification and metal ion homeostasis, aflatoxin production and pathogenicity of A. flavus. Further functional analysis revealed that Fab1 was required to maintain the vacuole size and cell morphology. Additional quantitative proteomic analysis suggested that Fab1 was likely to play an important role in maintaining vacuolar/cellular homeostasis, with vacuolar dysregulation upon fab1 deletion leading to impaired aflatoxin synthesis in this fungus. Together, these results provide insight into the molecular mechanisms by which this pathogen produces aflatoxin and mediates its pathogenicity, and may facilitate dissection of the vacuole-mediated regulatory network in A. flavus.
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Affiliation(s)
- Mingkun Yang
- School of Life Sciences, and Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Fujian Agriculture and Forestry University , Fuzhou, China.,State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences , Wuhan, China
| | - Zhuo Zhu
- School of Life Sciences, and Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Fujian Agriculture and Forestry University , Fuzhou, China
| | - Youhuang Bai
- School of Life Sciences, and Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Fujian Agriculture and Forestry University , Fuzhou, China
| | - Zhenhong Zhuang
- School of Life Sciences, and Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Fujian Agriculture and Forestry University , Fuzhou, China
| | - Feng Ge
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences , Wuhan, China
| | - Mingzhu Li
- School of Life Sciences, and Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Fujian Agriculture and Forestry University , Fuzhou, China
| | - Shihua Wang
- School of Life Sciences, and Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Fujian Agriculture and Forestry University , Fuzhou, China
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8
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The Ndr/LATS Kinase Cbk1 Regulates a Specific Subset of Ace2 Functions and Suppresses the Hypha-to-Yeast Transition in Candida albicans. mBio 2020; 11:mBio.01900-20. [PMID: 32817109 PMCID: PMC7439482 DOI: 10.1128/mbio.01900-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The regulation of Ace2 and morphogenesis (RAM) pathway is a key regulatory network that plays a role in many aspects of C. albicans pathobiology. In addition to characterizing the transcriptional effects of this pathway, we discovered that Cbk1 and Ace2, a key RAM pathway regulator-effector pair, mediate a specific set of the overall functions of the RAM pathway. We have also discovered a new function for the Cbk1-Ace2 axis: suppression of the hypha-to-yeast transition. Very few regulators of this transition have been described, and our data indicate that maintenance of hyphal morphogenesis requires suppression of yeast phase growth by Cbk1-regulated Ace2. The regulation of Ace2 and morphogenesis (RAM) pathway is an important regulatory network in the human fungal pathogen Candida albicans. The RAM pathway’s two most well-studied components, the NDR/Lats kinase Cbk1 and its putative substrate, the transcription factor Ace2, have a wide range of phenotypes and functions. It is not clear, however, which of these functions are specifically due to the phosphorylation of Ace2 by Cbk1. To address this question, we first compared the transcriptional profiles of CBK1 and ACE2 deletion mutants. This analysis indicates that, of the large number of genes whose expression is affected by deletion of CBK1 and ACE2, only 5.5% of those genes are concordantly regulated. Our data also suggest that Ace2 directly or indirectly represses a large set of genes during hyphal morphogenesis. Second, we generated strains containing ACE2 alleles with alanine mutations at the Cbk1 phosphorylation sites. Phenotypic and transcriptional analysis of these ace2 mutants indicates that, as in Saccharomyces cerevisiae, Cbk1 regulation is important for daughter cell localization of Ace2 and cell separation during yeast-phase growth. In contrast, Cbk1 phosphorylation of Ace2 plays a minor role in C. albicans yeast-to-hypha transition. We have, however, discovered a new function for the Cbk1-Ace2 axis. Specifically, Cbk1 phosphorylation of Ace2 prevents the hypha-to-yeast transition. To our knowledge, this is one of the first regulators of the C. albicans hypha-to-yeast transition to be described. Finally, we present an integrated model for the role of Cbk1 in the regulation of hyphal morphogenesis in C. albicans.
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9
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Shi HB, Chen N, Zhu XM, Su ZZ, Wang JY, Lu JP, Liu XH, Lin FC. The casein kinase MoYck1 regulates development, autophagy, and virulence in the rice blast fungus. Virulence 2020; 10:719-733. [PMID: 31392921 PMCID: PMC8647852 DOI: 10.1080/21505594.2019.1649588] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Casein kinases are serine/threonine protein kinases that are evolutionarily conserved in yeast and humans and are involved in a range of important cellular processes. However, the biological functions of casein kinases in the fungus Magnaporthe oryzae, the causal agent of destructive rice blast disease, are not characterized. Here, two casein kinases, MoYCK1 and MoHRR25, were identified and targeted for replacement, but only MoYCK1 was further characterized due to the possible nonviability of the MoHRR25 deletion mutant. Disruption of MoYCK1 caused pleiotropic defects in growth, conidiation, conidial germination, and appressorium formation and penetration, therefore resulting in reduced virulence in rice seedlings and barley leaves. Notably, the MoYCK1 deletion triggered quick lipidation of MoAtg8 and degradation of the autophagic marker protein GFP-MoAtg8 under nitrogen starvation conditions, in contrast to the wild type, indicating that autophagy activity was negatively regulated by MoYck1. Furthermore, we found that HOPS (homotypic fusion and vacuolar protein sorting) subunit MoVps41, a putative substrate of MoYck1, was co-located with MoAtg8 and positively required for the degradation of MoAtg8-PE and GFP-MoAtg8. In addition, MoYCK1 is also involved in the response to ionic hyperosmotic and heavy metal cation stresses. Taken together, our results revealed crucial roles of the casein kinase MoYck1 in regulating development, autophagy and virulence in M. oryzae.
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Affiliation(s)
- Huan-Bin Shi
- a State Key Laboratory of Rice Biology, Biotechnology Institute, Zhejiang University , Hangzhou , China.,b State Key Laboratory of Rice Biology, China National Rice Research Institute , Hangzhou , China
| | - Nan Chen
- a State Key Laboratory of Rice Biology, Biotechnology Institute, Zhejiang University , Hangzhou , China
| | - Xue-Ming Zhu
- a State Key Laboratory of Rice Biology, Biotechnology Institute, Zhejiang University , Hangzhou , China
| | - Zhen-Zhu Su
- a State Key Laboratory of Rice Biology, Biotechnology Institute, Zhejiang University , Hangzhou , China
| | - Jiao-Yu Wang
- c State Key Laboratory for Quality and Safety of Agro-products, Institute of Plant Protection Microbiology, Zhejiang Academy of Agricultural Science , Hangzhou , China
| | - Jian-Ping Lu
- d College of Life Sciences, Zhejiang University , Hangzhou , China
| | - Xiao-Hong Liu
- a State Key Laboratory of Rice Biology, Biotechnology Institute, Zhejiang University , Hangzhou , China
| | - Fu-Cheng Lin
- a State Key Laboratory of Rice Biology, Biotechnology Institute, Zhejiang University , Hangzhou , China
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10
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The Role of Secretory Pathways in Candida albicans Pathogenesis. J Fungi (Basel) 2020; 6:jof6010026. [PMID: 32102426 PMCID: PMC7151058 DOI: 10.3390/jof6010026] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2020] [Revised: 02/19/2020] [Accepted: 02/20/2020] [Indexed: 12/17/2022] Open
Abstract
Candida albicans is a fungus that is a commensal organism and a member of the normal human microbiota. It has the ability to transition into an opportunistic invasive pathogen. Attributes that support pathogenesis include secretion of virulence-associated proteins, hyphal formation, and biofilm formation. These processes are supported by secretion, as defined in the broad context of membrane trafficking. In this review, we examine the role of secretory pathways in Candida virulence, with a focus on the model opportunistic fungal pathogen, Candida albicans.
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11
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Ishchuk OP, Sterner O, Ellervik U, Manner S. Simple Carbohydrate Derivatives Diminish the Formation of Biofilm of the Pathogenic Yeast Candida albicans. Antibiotics (Basel) 2019; 9:antibiotics9010010. [PMID: 31905828 PMCID: PMC7167926 DOI: 10.3390/antibiotics9010010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 12/04/2019] [Accepted: 12/24/2019] [Indexed: 11/30/2022] Open
Abstract
The opportunistic human fungal pathogen Candida albicans relies on cell morphological transitions to develop biofilm and invade the host. In the current study, we developed new regulatory molecules, which inhibit the morphological transition of C. albicans from yeast-form cells to cells forming hyphae. These compounds, benzyl α-l-fucopyranoside and benzyl β-d-xylopyranoside, inhibit the hyphae formation and adhesion of C. albicans to a polystyrene surface, resulting in a reduced biofilm formation. The addition of cAMP to cells treated with α-l-fucopyranoside restored the yeast-hyphae switch and the biofilm level to that of the untreated control. In the β-d-xylopyranoside treated cells, the biofilm level was only partially restored by the addition of cAMP, and these cells remained mainly as yeast-form cells.
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Affiliation(s)
- Olena P. Ishchuk
- Department of Biology, Lund University, Sölvegatan 35, SE-223 62 Lund, Sweden;
- Centre for Analysis and Synthesis, Centre for Chemistry and Chemical Engineering, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden; (O.S.); (U.E.)
| | - Olov Sterner
- Centre for Analysis and Synthesis, Centre for Chemistry and Chemical Engineering, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden; (O.S.); (U.E.)
| | - Ulf Ellervik
- Centre for Analysis and Synthesis, Centre for Chemistry and Chemical Engineering, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden; (O.S.); (U.E.)
| | - Sophie Manner
- Centre for Analysis and Synthesis, Centre for Chemistry and Chemical Engineering, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden; (O.S.); (U.E.)
- Correspondence:
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12
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Kim SW, Park YK, Joo YJ, Chun YJ, Hwang JY, Baek JH, Kim J. Subunits of the vacuolar H+-ATPase complex, Vma4 and Vma10, are essential for virulence and represent potential drug targets in Candida albicans. Fungal Biol 2019; 123:709-722. [DOI: 10.1016/j.funbio.2019.06.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 05/20/2019] [Accepted: 06/03/2019] [Indexed: 01/26/2023]
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13
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Ellepola K, Truong T, Liu Y, Lin Q, Lim TK, Lee YM, Cao T, Koo H, Seneviratne CJ. Multi-omics Analyses Reveal Synergistic Carbohydrate Metabolism in Streptococcus mutans-Candida albicans Mixed-Species Biofilms. Infect Immun 2019; 87:e00339-19. [PMID: 31383746 PMCID: PMC6759298 DOI: 10.1128/iai.00339-19] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 07/26/2019] [Indexed: 12/25/2022] Open
Abstract
Candida albicans, a major opportunistic fungal pathogen, is frequently found together with Streptococcus mutans in dental biofilms associated with severe childhood caries (tooth decay), a prevalent pediatric oral disease. However, the impact of this cross-kingdom relationship on C. albicans remains largely uncharacterized. Here, we employed a novel quantitative proteomics approach in conjunction with transcriptomic profiling to unravel molecular pathways of C. albicans when cocultured with S. mutans in mixed biofilms. RNA sequencing and iTRAQ (isobaric tags for relative and absolute quantitation)-based quantitative proteomics revealed that C. albicans genes and proteins associated with carbohydrate metabolism were significantly enhanced, including sugar transport, aerobic respiration, pyruvate breakdown, and the glyoxylate cycle. Other C. albicans genes and proteins directly and indirectly related to cell morphogenesis and cell wall components such as mannan and glucan were also upregulated, indicating enhanced fungal activity in mixed-species biofilm. Further analyses revealed that S. mutans-derived exoenzyme glucosyltransferase B (GtfB), which binds to the fungal cell surface to promote coadhesion, can break down sucrose into glucose and fructose that can be readily metabolized by C. albicans, enhancing growth and acid production. Altogether, we identified key pathways used by C. albicans in the mixed biofilm, indicating an active fungal role in the sugar metabolism and environmental acidification (key virulence traits associated with caries onset) when interacting with S. mutans, and a new cross-feeding mechanism mediated by GtfB that enhances C. albicans carbohydrate utilization. In addition, we demonstrate that comprehensive transcriptomics and quantitative proteomics can be powerful tools to study microbial contributions which remain underexplored in cross-kingdom biofilms.
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Affiliation(s)
- K Ellepola
- Oral Sciences, Faculty of Dentistry, National University of Singapore, Singapore
- Center of Oral and Craniofacial Biology, School of Dentistry, Louisiana State University Health Sciences Center, New Orleans, Louisiana, USA
| | - T Truong
- Oral Sciences, Faculty of Dentistry, National University of Singapore, Singapore
| | - Y Liu
- Biofilm Research Labs, Levy Center for Oral Health, Department of Orthodontics and Divisions of Pediatric Dentistry & Community Oral Health, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Q Lin
- Protein and Proteomic Centre, Department of Biological Sciences, National University of Singapore, Singapore
| | - T K Lim
- Protein and Proteomic Centre, Department of Biological Sciences, National University of Singapore, Singapore
| | - Y M Lee
- Protein and Proteomic Centre, Department of Biological Sciences, National University of Singapore, Singapore
| | - T Cao
- Oral Sciences, Faculty of Dentistry, National University of Singapore, Singapore
| | - H Koo
- Biofilm Research Labs, Levy Center for Oral Health, Department of Orthodontics and Divisions of Pediatric Dentistry & Community Oral Health, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - C J Seneviratne
- National Dental Centre Singapore, Oral Health ACP, SingHealth Duke NUS, Singapore
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Zhang X, Wang G, Yang C, Huang J, Chen X, Zhou J, Li G, Norvienyeku J, Wang Z. A HOPS Protein, MoVps41, Is Crucially Important for Vacuolar Morphogenesis, Vegetative Growth, Reproduction and Virulence in Magnaporthe oryzae. FRONTIERS IN PLANT SCIENCE 2017; 8:1091. [PMID: 28713398 PMCID: PMC5492488 DOI: 10.3389/fpls.2017.01091] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 06/06/2017] [Indexed: 05/02/2023]
Abstract
The homotypic fusion and protein sorting protein complex (HOPS) is the first known tether complex identified in the endocytic system that plays a key role in promoting homotypic vacuolar fusion, vacuolar biogenesis and trafficking in a wide range of organisms, including plant and fungi. However, the exact influence of the HOPS complex on growth, reproduction and pathogenicity of the economically destructive rice blast fungus has not been investigated. In this study, we identified M. oryzae vacuolar protein sorting 41 (MoVps41) an accessory subunit of HOPS complex and used targeted gene deletion approach to evaluate its contribution to growth, reproduction and infectious life cycle of the rice blast fungus. Corresponding results obtained from this study showed that MoVps41 is required for optimum vegetative development of M. oryzae and observed that MoVps41 deletion mutant displayed defective vegetative growth. Our investigation further showed that MoVps41 deletion triggered vacuolar fragmentation, compromised membrane integrity and pathogenesis of the ΔMovps41 mutant. Our studies also showed for the first time that MoVps41 plays an essential role in the regulation of sexual and asexual reproduction of M. oryzae. In summary, our study provides insight into how MoVps41 mediated vacuolar fusion and biogenesis influences reproduction, pathogenesis, and vacuolar integrity in M. oryzae and also underscores the need to holistically investigate the HOPS complex in rice blast pathogen.
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Affiliation(s)
- Xiaojie Zhang
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops and College of Life Science, Fujian Agriculture and Forestry UniversityFuzhou, China
- Fujian University Key Laboratory for Functional Genomics of Plant Fungal Pathogens, Fujian Agriculture and Forestry UniversityFuzhou, China
| | - Guanghui Wang
- Fujian University Key Laboratory for Functional Genomics of Plant Fungal Pathogens, Fujian Agriculture and Forestry UniversityFuzhou, China
| | - Chengdong Yang
- Fujian University Key Laboratory for Functional Genomics of Plant Fungal Pathogens, Fujian Agriculture and Forestry UniversityFuzhou, China
| | - Jun Huang
- Fujian University Key Laboratory for Functional Genomics of Plant Fungal Pathogens, Fujian Agriculture and Forestry UniversityFuzhou, China
| | - Xiaofeng Chen
- Fujian University Key Laboratory for Functional Genomics of Plant Fungal Pathogens, Fujian Agriculture and Forestry UniversityFuzhou, China
| | - Jie Zhou
- Fujian University Key Laboratory for Functional Genomics of Plant Fungal Pathogens, Fujian Agriculture and Forestry UniversityFuzhou, China
| | - Guangpu Li
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma CityOK, United States
| | - Justice Norvienyeku
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops and College of Life Science, Fujian Agriculture and Forestry UniversityFuzhou, China
- Fujian University Key Laboratory for Functional Genomics of Plant Fungal Pathogens, Fujian Agriculture and Forestry UniversityFuzhou, China
- *Correspondence: Justice Norvienyeku, Zonghua Wang,
| | - Zonghua Wang
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops and College of Life Science, Fujian Agriculture and Forestry UniversityFuzhou, China
- Fujian University Key Laboratory for Functional Genomics of Plant Fungal Pathogens, Fujian Agriculture and Forestry UniversityFuzhou, China
- College of Ocean Science, Minjiang UniversityFuzhou, China
- *Correspondence: Justice Norvienyeku, Zonghua Wang,
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15
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Calcineurin and Calcium Channel CchA Coordinate the Salt Stress Response by Regulating Cytoplasmic Ca2+ Homeostasis in Aspergillus nidulans. Appl Environ Microbiol 2016; 82:3420-3430. [PMID: 27037124 DOI: 10.1128/aem.00330-16] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 03/28/2016] [Indexed: 11/20/2022] Open
Abstract
The eukaryotic calcium/calmodulin-dependent protein phosphatase calcineurin is crucial for the environmental adaption of fungi. However, the mechanism of coordinate regulation of the response to salt stress by calcineurin and the high-affinity calcium channel CchA in fungi is not well understood. Here we show that the deletion of cchA suppresses the hyphal growth defects caused by the loss of calcineurin under salt stress in Aspergillus nidulans Additionally, the hypersensitivity of the ΔcnaA strain to extracellular calcium and cell-wall-damaging agents can be suppressed by cchA deletion. Using the calcium-sensitive photoprotein aequorin to monitor the cytoplasmic Ca(2+) concentration ([Ca(2+)]c) in living cells, we found that calcineurin negatively regulates CchA on calcium uptake in response to external calcium in normally cultured cells. However, in salt-stress-pretreated cells, loss of either cnaA or cchA significantly decreased the [Ca(2+)]c, but a deficiency in both cnaA and cchA switches the [Ca(2+)]c to the reference strain level, indicating that calcineurin and CchA synergistically coordinate calcium influx under salt stress. Moreover, real-time PCR results showed that the dysfunction of cchA in the ΔcnaA strain dramatically restored the expression of enaA (a major determinant for sodium detoxification), which was abolished in the ΔcnaA strain under salt stress. These results suggest that double deficiencies of cnaA and cchA could bypass the requirement of calcineurin to induce enaA expression under salt stress. Finally, YvcA, a member of the transient receptor potential channel (TRPC) protein family of vacuolar Ca(2+) channels, was proven to compensate for calcineurin-CchA in fungal salt stress adaption.IMPORTANCE The feedback inhibition relationship between calcineurin and the calcium channel Cch1/Mid1 has been well recognized from yeast. Interestingly, our previous study (S. Wang et al., PLoS One 7:e46564, 2012, http://dx.doi.org/10.1371/journal.pone.0046564) showed that the deletion of cchA could suppress the hyphal growth defects caused by the loss of calcineurin under salt stress in Aspergillus nidulans In this study, our findings suggest that fungi are able to develop a unique mechanism for adapting to environmental salt stress. Compared to cells cultured normally, the NaCl-pretreated cells had a remarkable increase in transient [Ca(2+)]c Furthermore, we show that calcineurin and CchA are required to modulate cellular calcium levels and synergistically coordinate calcium influx under salt stress. Finally, YvcA, a member of of the TRPC family of vacuolar Ca(2+) channels, was proven to compensate for calcineurin-CchA in fungal salt stress adaption. The findings in this study provide insights into the complex regulatory links between calcineurin and CchA to maintain cytoplasmic Ca(2+) homeostasis in response to different environments.
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16
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Douglas LM, Konopka JB. Plasma membrane organization promotes virulence of the human fungal pathogen Candida albicans. J Microbiol 2016; 54:178-91. [PMID: 26920878 DOI: 10.1007/s12275-016-5621-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 01/15/2016] [Accepted: 01/15/2016] [Indexed: 12/21/2022]
Abstract
Candida albicans is a human fungal pathogen capable of causing lethal systemic infections. The plasma membrane plays key roles in virulence because it not only functions as a protective barrier, it also mediates dynamic functions including secretion of virulence factors, cell wall synthesis, invasive hyphal morphogenesis, endocytosis, and nutrient uptake. Consistent with this functional complexity, the plasma membrane is composed of a wide array of lipids and proteins. These components are organized into distinct domains that will be the topic of this review. Some of the plasma membrane domains that will be described are known to act as scaffolds or barriers to diffusion, such as MCC/eisosomes, septins, and sites of contact with the endoplasmic reticulum. Other zones mediate dynamic processes, including secretion, endocytosis, and a special region at hyphal tips that facilitates rapid growth. The highly organized architecture of the plasma membrane facilitates the coordination of diverse functions and promotes the pathogenesis of C. albicans.
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Affiliation(s)
- Lois M Douglas
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY, 11794-5222, USA
| | - James B Konopka
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY, 11794-5222, USA.
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17
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Thomson DD, Berman J, Brand AC. High frame-rate resolution of cell division during Candida albicans filamentation. Fungal Genet Biol 2016; 88:54-8. [PMID: 26854071 PMCID: PMC4767323 DOI: 10.1016/j.fgb.2016.02.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 02/02/2016] [Accepted: 02/03/2016] [Indexed: 11/17/2022]
Abstract
The commensal yeast, Candida albicans, is an opportunistic pathogen in humans and forms filaments called hyphae and pseudohyphae, in which cell division requires precise temporal and spatial control to produce mononuclear cell compartments. High-frame-rate live-cell imaging (1 frame/min) revealed that nuclear division did not occur across the septal plane. We detected the presence of nucleolar fragments that may be extrachromosomal molecules carrying the ribosomal RNA genes. Cells occasionally maintained multiple nucleoli, suggesting either polyploidy, multiple nuclei and/or aneuploidy of ChrR., while the migration pattern of sister nuclei differed between unbranched and branched hyphae. The presented movie challenges and extends previous concepts of C. albicans cell division.
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Affiliation(s)
- Darren D Thomson
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, University of Manchester, CTF Building, Grafton Street, Manchester M13 9NT, UK
| | - Judith Berman
- Department of Microbiology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv 69978, Israel
| | - Alexandra C Brand
- School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK.
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18
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Canonico B, Candiracci M, Citterio B, Curci R, Squarzoni S, Mazzoni A, Papa S, Piatti E. Honey flavonoids inhibit Candida albicans morphogenesis by affecting DNA behavior and mitochondrial function. Future Microbiol 2014; 9:445-56. [PMID: 24810344 DOI: 10.2217/fmb.14.17] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
AIM Candida albicans is a pathogenic yeast, which forms a range of polarized and expanded cell shapes. We aimed to determine the correlation between honey extract (HFE) activity and changes in C. albicans cell cycle, morphology and subcellular organelles. MATERIALS & METHODS HFE anticandidal properties were investigated using flow cytometry and scanning electron microscopy. RESULTS Flow cytometry and scanning electron microscopy analyses indicated that HFE may inhibit the growth of the three phenotypes displayed by C. albicans and reduce infection by affecting membrane integrity. HFE affects hyphal transition by reducing the G0/G1 phase and increasing the G2/M phase. Conversely, yeast and pseudohyphae do not appear to be affected. Modifications of vacuolization and mitochondrial activity, during yeast-hypha transition establish the involvement of vacuole and mitochondria. CONCLUSION HFE improved mitochondrial functionality and reduced the vacuolization, modifying the branching process associated with virulence. It is hypothesized that HFE induces changes in cell cycle progress, membrane integrity, mitochondrial function and biogenesis.
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Affiliation(s)
- Barbara Canonico
- Department of Earth, Life & Environmental Sciences, Urbino, Italy
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19
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Sharma M, Pandey A, Pandey GK. β-catenin in plants and animals: common players but different pathways. FRONTIERS IN PLANT SCIENCE 2014; 5:143. [PMID: 24782881 PMCID: PMC3989760 DOI: 10.3389/fpls.2014.00143] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 03/25/2014] [Indexed: 05/24/2023]
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20
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Distinct roles of Candida albicans-specific genes in host-pathogen interactions. EUKARYOTIC CELL 2014; 13:977-89. [PMID: 24610660 DOI: 10.1128/ec.00051-14] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Human fungal pathogens are distributed throughout their kingdom, suggesting that pathogenic potential evolved independently. Candida albicans is the most virulent member of the CUG clade of yeasts and a common cause of both superficial and invasive infections. We therefore hypothesized that C. albicans possesses distinct pathogenicity mechanisms. In silico genome subtraction and comparative transcriptional analysis identified a total of 65 C. albicans-specific genes (ASGs) expressed during infection. Phenotypic characterization of six ASG-null mutants demonstrated that these genes are dispensable for in vitro growth but play defined roles in host-pathogen interactions. Based on these analyses, we investigated two ASGs in greater detail. An orf19.6688Δ mutant was found to be fully virulent in a mouse model of disseminated candidiasis and to induce higher levels of the proinflammatory cytokine interleukin-1β (IL-1β) following incubation with murine macrophages. A pga16Δ mutant, on the other hand, exhibited attenuated virulence. Moreover, we provide evidence that secondary filamentation events (multiple hyphae emerging from a mother cell and hyphal branching) contribute to pathogenicity: PGA16 deletion did not influence primary hypha formation or extension following contact with epithelial cells; however, multiple hyphae and hyphal branching were strongly reduced. Significantly, these hyphae failed to damage host cells as effectively as the multiple hypha structures formed by wild-type C. albicans cells. Together, our data show that species-specific genes of a eukaryotic pathogen can play important roles in pathogenicity.
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21
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Bal J, Lee HJ, Cheon SA, Lee KJ, Oh DB, Kim JY. Ylpex5 mutation partially suppresses the defective hyphal growth of a Yarrowia lipolytica ceramide synthase mutant, Yllac1, by recovering lipid raft polarization and vacuole morphogenesis. Fungal Genet Biol 2012. [PMID: 23200743 DOI: 10.1016/j.fgb.2012.11.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Sphingolipids are involved in cell differentiation and morphogenesis in eukaryotic cells. In this study, YlLac1p, a ceramide synthase required for glucosylceramide (GlcCer) synthesis, was found to be essential for hyphal growth in Yarrowia lipolytica. Y. lipolytica GlcCer was shown to be composed of a C16:0 fatty acid, which is hydroxylated at C2, and a C18:2 long chain base, which is unsaturated at both C4 and C8 and methylated at C9. Domain swapping analysis revealed that the entire TRAM/Lag1/CLN8 (TLC) domain, not the Lag1 motif, is crucial for the function of YlLac1p. YlDes1p, the C4 desaturase of the ceramide synthesized by YlLac1p, was also required for Y. lipolytica morphogenesis. Both Yllac1Δ and Yldes1Δ mutants neither polarize lipid rafts nor form normal vacuoles. Interestingly, mutation in YlPEX5, which encode a peroxisomal targeting signal receptor, partially suppressed the defective hyphal growth of Yllac1Δ. The Yllac1ΔYlpex5Δ mutant restored the ability to polarize lipid rafts and to form normal vacuoles, although it could not synthesize GlcCer. Taken together, our results suggest that GlcCer or GlcCer derivatives may be involved in hyphal morphogenesis in Y. lipolytica, at least in part, by affecting polarization of lipid rafts and vacuole morphogenesis.
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Affiliation(s)
- Jyotiranjan Bal
- Department of Microbiology and Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon, Republic of Korea
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22
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A Candida albicans temperature-sensitive cdc12-6 mutant identifies roles for septins in selection of sites of germ tube formation and hyphal morphogenesis. EUKARYOTIC CELL 2012; 11:1210-8. [PMID: 22886998 DOI: 10.1128/ec.00216-12] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Septins were identified for their role in septation in Saccharomyces cerevisiae and were subsequently implicated in other morphogenic processes. To study septins in Candida albicans hyphal morphogenesis, a temperature-sensitive mutation was created that altered the C terminus of the essential Cdc12 septin. The cdc12-6 cells grew well at room temperature, but at 37°C they displayed expected defects in septation, nuclear localization, and bud morphogenesis. Although serum stimulated the cdc12-6 cells at 37°C to form germ tube outgrowths, the mutant could not maintain polarized hyphal growth and instead formed chains of elongated cell compartments. Serum also stimulated the cdc12-6 mutant to induce a hyphal reporter gene (HWP1-GFP) and a characteristic zone of filipin staining at the leading edge of growth. Interestingly, cdc12-6 cells shifted to 37°C in the absence of serum gradually displayed enriched filipin staining at the tip, which may be due to the altered cell cycle regulation. A striking difference from the wild type was that the cdc12-6 cells frequently formed a second germ tube in close proximity to the first. The mutant cells also failed to form the diffuse band of septins at the base of germ tubes and hyphae, indicating that this septin band plays a role in preventing proximal formation of germ tubes in a manner analogous to bud site selection. These studies demonstrate that not only are septins important for cytokinesis, but they also promote polarized morphogenesis and selection of germ tube sites that may help disseminate an infection in host tissues.
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23
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Richards A, Gow NAR, Veses V. Identification of vacuole defects in fungi. J Microbiol Methods 2012; 91:155-63. [PMID: 22902527 DOI: 10.1016/j.mimet.2012.08.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2012] [Revised: 07/30/2012] [Accepted: 08/02/2012] [Indexed: 11/25/2022]
Abstract
Fungal vacuoles are involved in a diverse range of cellular functions, participating in cellular homeostasis, degradation of intracellular components, and storage of ions and molecules. In recent years there has been a significant increase in the number of studies linking these organelles with the regulation of growth and control of cellular morphology, particularly in those fungal species able to undergo yeast-hypha morphogenetic transitions. This has contributed to the refinement of previously published protocols and the development of new techniques, particularly in the area of live-cell imaging of membrane trafficking events and vacuolar dynamics. The current review outlines recent advances in the imaging of fungal vacuoles and assays for characterization of trafficking pathways, and other physiological activities of this important cell organelle.
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Affiliation(s)
- Andrea Richards
- The Aberdeen Fungal Group, School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, United Kingdom
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24
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Infection-associated nuclear degeneration in the rice blast fungus Magnaporthe oryzae requires non-selective macro-autophagy. PLoS One 2012; 7:e33270. [PMID: 22448240 PMCID: PMC3308974 DOI: 10.1371/journal.pone.0033270] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Accepted: 02/13/2012] [Indexed: 11/23/2022] Open
Abstract
Background The rice blast fungus Magnaporthe oryzae elaborates a specialized infection structure called an appressorium to breach the rice leaf surface and gain access to plant tissue. Appressorium development is controlled by cell cycle progression, and a single round of nuclear division occurs prior to appressorium formation. Mitosis is always followed by programmed cell death of the spore from which the appressorium develops. Nuclear degeneration in the spore is known to be essential for plant infection, but the precise mechanism by which it occurs is not known. Methodology/Principal Findings In yeast, nuclear breakdown requires a specific form of autophagy, known as piecemeal microautophagy of the nucleus (PMN), and we therefore investigated whether this process occurs in the rice blast fungus. Here, we report that M. oryzae possesses two conserved components of a putative PMN pathway, MoVac8 and MoTsc13, but that both are dispensable for nuclear breakdown during plant infection. MoVAC8 encodes a vacuolar membrane protein and MoTSC13 a peri-nuclear and peripheral ER protein. Conclusions/Significance We show that MoVAC8 is necessary for caffeine resistance, but dispensable for pathogenicity of M. oryzae, while MoTSC13 is involved in cell wall stress responses and is an important virulence determinant. By functional analysis of ΔMoatg1 and ΔMoatg4 mutants, we demonstrate that infection-associated nuclear degeneration in M. oryzae instead occurs by non-selective macroautophagy, which is necessary for rice blast disease.
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25
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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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26
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BARRY D, WILLIAMS G. Microscopic characterisation of filamentous microbes: towards fully automated morphological quantification through image analysis. J Microsc 2011; 244:1-20. [DOI: 10.1111/j.1365-2818.2011.03506.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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27
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Shoji JY, Craven KD. Autophagy in basal hyphal compartments: A green strategy of great recyclers. FUNGAL BIOL REV 2011. [DOI: 10.1016/j.fbr.2011.04.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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28
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Armstrong J. Yeast vacuoles: more than a model lysosome. Trends Cell Biol 2010; 20:580-5. [DOI: 10.1016/j.tcb.2010.06.010] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Revised: 06/30/2010] [Accepted: 06/30/2010] [Indexed: 10/19/2022]
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29
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Peraza-Reyes L, Crider DG, Pon LA. Mitochondrial manoeuvres: latest insights and hypotheses on mitochondrial partitioning during mitosis in Saccharomyces cerevisiae. Bioessays 2010; 32:1040-9. [PMID: 20886527 DOI: 10.1002/bies.201000083] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Revised: 08/19/2010] [Accepted: 08/24/2010] [Indexed: 12/22/2022]
Abstract
Movement and positional control of mitochondria and other organelles are coordinated with cell cycle progression in the budding yeast, Saccharomyces cerevisiae. Recent studies have revealed a checkpoint that inhibits cytokinesis when there are severe defects in mitochondrial inheritance. An established checkpoint signaling pathway, the mitotic exit network (MEN), participates in this process. Here, we describe mitochondrial motility during inheritance in budding yeast, emerging evidence for mitochondrial quality control during inheritance, and organelle inheritance checkpoints for mitochondria and other organelles.
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Affiliation(s)
- Leonardo Peraza-Reyes
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY, USA
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30
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Endosomal and AP-3-dependent vacuolar trafficking routes make additive contributions to Candida albicans hyphal growth and pathogenesis. EUKARYOTIC CELL 2010; 9:1755-65. [PMID: 20870878 DOI: 10.1128/ec.00029-10] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Candida albicans mutants deficient in vacuolar biogenesis are defective in polarized hyphal growth and virulence. However, the specific vacuolar trafficking routes required for hyphal growth and virulence are unknown. In Saccharomyces cerevisiae, two trafficking routes deliver material from the Golgi apparatus to the vacuole. One occurs via the late endosome and is dependent upon Vps21p, while the second bypasses the endosome and requires the AP-3 complex, including Aps3p. To determine the significance of these pathways in C. albicans hyphal growth and virulence, aps3Δ/Δ, vps21Δ/Δ, and aps3Δ/Δ vps21Δ/Δ mutant strains were constructed. Analysis of vacuolar morphology and localization of the vacuolar protein Mlt1p suggests that C. albicans Aps3p and Vps21p mediate two distinct transport pathways. The vps21Δ/Δ mutant has a minor reduction in hyphal elongation, while the aps3Δ/Δ mutant has no defect in hyphal growth. Interestingly, the aps3Δ/Δ vps21Δ/Δ double mutant has dramatically reduced hyphal growth. Overexpression of the Ume6p transcriptional activator resulted in constitutive hyphal growth of wild-type, aps3Δ/Δ, and vps21Δ/Δ strains and formation of highly vacuolated subapical compartments. Thus, Ume6p-dependent transcriptional responses are sufficient to induce subapical vacuolation. However, the aps3Δ/Δ vps21Δ/Δ mutant formed mainly pseudohyphae that lacked vacuolated compartments. The aps3Δ/Δ strain was virulent in a mouse model of disseminated infection; the vps21Δ/Δ mutant failed to kill mice but persisted within kidney tissue, while the double mutant was avirulent and cleared from the kidneys. These results suggest that while the AP-3 pathway alone has little impact on hyphal growth or virulence, it is much more significant when endosomal trafficking is disrupted.
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Armadillo-repeat protein functions: questions for little creatures. Trends Cell Biol 2010; 20:470-81. [PMID: 20688255 DOI: 10.1016/j.tcb.2010.05.003] [Citation(s) in RCA: 184] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2009] [Revised: 05/11/2010] [Accepted: 05/17/2010] [Indexed: 01/24/2023]
Abstract
Armadillo (ARM)-repeat proteins form a large family with diverse and fundamental functions in many eukaryotes. ARM-repeat proteins have largely been characterised in multicellular organisms and much is known about how a subset of these proteins function. The structure of ARM-repeats allows proteins containing them to be functionally very versatile. Are the ARM-repeat proteins in 'little creatures' as multifunctional as their better-studied relatives? The time is now right to start analysing ARM-repeat proteins in these new systems to better understand their cell biology. Here, we review recent advances in understanding the many cellular roles of both well-known and novel ARM-repeat proteins.
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Reijnst P, Jorde S, Wendland J. Candida albicans SH3-domain proteins involved in hyphal growth, cytokinesis, and vacuolar morphology. Curr Genet 2010; 56:309-19. [PMID: 20383711 DOI: 10.1007/s00294-010-0301-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2009] [Revised: 03/22/2010] [Accepted: 03/29/2010] [Indexed: 12/13/2022]
Abstract
This report describes the analyses of three Candida albicans genes that encode Src Homology 3 (SH3)-domain proteins. Homologs in Saccharomyces cerevisiae are encoded by the SLA1, NBP2, and CYK3 genes. Deletion of CYK3 in C. albicans was not feasible, suggesting it is essential. Promoter shutdown experiments of CaCYK3 revealed cytokinesis defects, which are in line with the localization of GFP-tagged Cyk3 at septal sites. Deletion of SLA1 resulted in strains with decreased ability to form hyphal filaments. The number of cortical actin patches was strongly reduced in Deltasla1 strains during all growth stages. Sla1-GFP localizes in patches that are found concentrated at the hyphal tip. Deletion of the first two SH3-domains of Sla1 still resulted in cortical localization of the truncated protein. However, the actin cytoskeleton in this strain was aberrant like in the Deltasla1 deletion mutant indicating a function of these SH3 domains to recruit actin nucleation to sites of endocytosis. Deletion of NBP2 resulted in a defect in vacuolar fusion in hyphae. Germ cells of Deltanbp2 strains lacked a large vacuole but initiated several germ tubes. The mutant phenotypes of Deltanbp2 and Deltasla1 could be corrected by reintegration of the wild-type genes.
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Affiliation(s)
- Patrick Reijnst
- Carlsberg Laboratory, Yeast Biology, Valby, Copenhagen, Denmark
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Reijnst P, Walther A, Wendland J. Functional analysis of Candida albicans genes encoding SH3-domain-containing proteins. FEMS Yeast Res 2010; 10:452-61. [DOI: 10.1111/j.1567-1364.2010.00624.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
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Candida albicans PEP12 is required for biofilm integrity and in vivo virulence. EUKARYOTIC CELL 2009; 9:266-77. [PMID: 20023068 DOI: 10.1128/ec.00295-09] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
To investigate the role of the prevacuolar secretion pathway in biofilm formation and virulence in Candida albicans, we cloned and analyzed the C. albicans homolog of the Saccharomyces cerevisiae prevacuolar trafficking gene PEP12. C. albicans PEP12 encodes a deduced t-SNARE that is 28% identical to S. cerevisiae Pep12p, and plasmids bearing C. albicans PEP12 complemented the abnormal vacuolar morphology and temperature-sensitive growth of an S. cerevisiae pep12 null mutant. The C. albicans pep12 Delta null mutant was defective in endocytosis and vacuolar acidification and accumulated 40- to 60-nm cytoplasmic vesicles near the plasma membrane. Secretory defects included increased extracellular proteolytic activity and absent lipolytic activity. The pep12Delta null mutant was more sensitive to cell wall stresses and antifungal agents than the isogenic complemented strain or the control strain DAY185. Notably, the biofilm formed by the pep12Delta mutant was reduced in overall mass and fragmented completely upon the slightest disturbance. The pep12Delta mutant was markedly reduced in virulence in an in vitro macrophage infection model and an in vivo mouse model of disseminated candidiasis. These results suggest that C. albicans PEP12 plays a key role in biofilm integrity and in vivo virulence.
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Affiliation(s)
- Naomi Attar
- The Henry Wellcome Integrated Signalling Laboratories, Department of Biochemistry, School of Medical Sciences, University of Bristol, Bristol BS8 1TD, UK
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Current awareness on yeast. Yeast 2009. [DOI: 10.1002/yea.1622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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