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Chevalier L, Klingelschmitt F, Mousseron L, Minc N. Mechanical strategies supporting growth and size diversity in Filamentous Fungi. Mol Biol Cell 2024; 35:br17. [PMID: 39046771 DOI: 10.1091/mbc.e24-04-0171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/25/2024] Open
Abstract
The stereotypical tip growth of filamentous fungi supports their lifestyles and functions. It relies on the polarized remodeling and expansion of a protective elastic cell wall (CW) driven by large cytoplasmic turgor pressure. Remarkably, hyphal filament diameters and cell elongation rates can vary extensively among different fungi. To date, however, how fungal cell mechanics may be adapted to support these morphological diversities while ensuring surface integrity remains unknown. Here, we combined super-resolution imaging and deflation assays to measure local CW thickness, elasticity and turgor in a set of fungal species spread on the evolutionary tree that spans a large range in cell size and growth speeds. While CW elasticity exhibited dispersed values, presumably reflecting differences in CW composition, both thickness and turgor scaled in dose-dependence with cell diameter and growth speeds. Notably, larger cells exhibited thinner lateral CWs, and faster cells thinner apical CWs. Counterintuitively, turgor pressure was also inversely scaled with cell diameter and tip growth speed, challenging the idea that turgor is the primary factor dictating tip elongation rates. We propose that fast-growing cells with rapid CW turnover have evolved strategies based on a less turgid cytoplasm and thin walls to safeguard surface integrity and survival.
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Affiliation(s)
- Louis Chevalier
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013 Paris, France
- Equipe Labellisée LIGUE Contre le Cancer, 75013 Paris, France
| | - Flora Klingelschmitt
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013 Paris, France
- Equipe Labellisée LIGUE Contre le Cancer, 75013 Paris, France
| | - Ludovic Mousseron
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013 Paris, France
- Equipe Labellisée LIGUE Contre le Cancer, 75013 Paris, France
| | - Nicolas Minc
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013 Paris, France
- Equipe Labellisée LIGUE Contre le Cancer, 75013 Paris, France
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Zuriegat Q, Abubakar YS, Wang Z, Chen M, Zhang J. Emerging Roles of Exocyst Complex in Fungi: A Review. J Fungi (Basel) 2024; 10:614. [PMID: 39330374 PMCID: PMC11433146 DOI: 10.3390/jof10090614] [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: 07/25/2024] [Revised: 08/19/2024] [Accepted: 08/21/2024] [Indexed: 09/28/2024] Open
Abstract
The exocyst complex, an evolutionarily conserved octameric protein assembly, plays a central role in the targeted binding and fusion of vesicles at the plasma membrane. In fungal cells, this transport system is essential for polarized growth, morphogenesis, cell wall maintenance and virulence. Recent advances have greatly improved our understanding of the role and regulation of the exocyst complex in fungi. This review synthesizes these developments and focuses on the intricate interplay between the exocyst complex, specific fungal cargos and regulatory proteins. Insights into thestructure of the exocyst and its functional dynamics have revealed new dimensions of its architecture and its interactions with the cellular environment. Furthermore, the regulation of exocyst activity involves complex signaling pathways and interactions with cytoskeletal elements that are crucial for its role in vesicle trafficking. By exploring these emerging themes, this review provides a comprehensive overview of the multifaceted functions of the exocyst complex in fungal biology. Understanding these mechanisms offers potential avenues for novel therapeutic strategies against fungal pathogens and insights into the general principles of vesicle trafficking in eukaryotic cells. The review therefore highlights the importance of the exocyst complex in maintaining cellular functions and its broader implications in fungal pathogenicity and cell biology.
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Affiliation(s)
- Qussai Zuriegat
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Q.Z.); (Y.S.A.); (Z.W.)
| | - Yakubu Saddeeq Abubakar
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Q.Z.); (Y.S.A.); (Z.W.)
| | - Zonghua Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Q.Z.); (Y.S.A.); (Z.W.)
- Fujian Key Laboratory on Conservation and Sustainable Utilization of Marine Biodiversity, College of Materials and Chemical Engineering, Minjiang University, Fuzhou 350108, China
| | - Meilian Chen
- Fujian Key Laboratory on Conservation and Sustainable Utilization of Marine Biodiversity, College of Materials and Chemical Engineering, Minjiang University, Fuzhou 350108, China
| | - Jun Zhang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Q.Z.); (Y.S.A.); (Z.W.)
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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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Vasselli JG, Kainer E, Shaw BD. Using fimbrin to quantify the endocytic subapical collar during polarized growth in three filamentous fungi. Mycologia 2023:1-14. [PMID: 37196171 DOI: 10.1080/00275514.2023.2202689] [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: 08/01/2022] [Accepted: 04/09/2023] [Indexed: 05/19/2023]
Abstract
Filamentous fungi produce specialized cells called hyphae. These cells grow by polarized extension at their apex, which is maintained by the balance of endocytosis and exocytosis at the apex. Although endocytosis has been well characterized in other organisms, the details of endocytosis and its role in maintaining polarity during hyphal growth in filamentous fungi is comparatively sparsely studied. In recent years, a concentrated region of protein activity that trails the growing apex of hyphal cells has been discovered. This region, dubbed the "endocytic collar" (EC), is a dynamic 3-dimensional region of concentrated endocytic activity, the disruption of which results in the loss of hyphal polarity. Here, fluorescent protein-tagged fimbrin was used as a marker to map the collar during growth of hyphae in three fungi: Aspergillus nidulans, Colletotrichum graminicola, and Neurospora crassa. Advanced microscopy techniques and novel quantification strategies were then utilized to quantify the spatiotemporal localization and recovery rates of fimbrin in the EC during hyphal growth. Correlating these variables with hyphal growth rate revealed that the strongest observed relationship with hyphal growth is the distance by which the EC trails the apex, and that measured endocytic rate does not correlate strongly with hyphal growth rate. This supports the hypothesis that endocytic influence on hyphal growth rate is better explained by spatiotemporal regulation of the EC than by the raw rate of endocytosis.
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Affiliation(s)
- Joseph G Vasselli
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas 77843
| | - Ellen Kainer
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas 77843
| | - Brian D Shaw
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas 77843
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Cannon KS, Vargas-Muniz JM, Billington N, Seim I, Ekena J, Sellers JR, Gladfelter AS. A gene duplication of a septin reveals a developmentally regulated filament length control mechanism. J Cell Biol 2023; 222:e202204063. [PMID: 36786832 PMCID: PMC9960279 DOI: 10.1083/jcb.202204063] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 11/20/2022] [Accepted: 01/19/2023] [Indexed: 02/15/2023] Open
Abstract
Septins are a family of conserved filament-forming proteins that function in multiple cellular processes. The number of septin genes within an organism varies, and higher eukaryotes express many septin isoforms due to alternative splicing. It is unclear if different combinations of septin proteins in complex alter the polymers' biophysical properties. We report that a duplication event within the CDC11 locus in Ashbya gossypii gave rise to two similar but distinct Cdc11 proteins: Cdc11a and Cdc1b. CDC11b transcription is developmentally regulated, producing different amounts of Cdc11a- and Cdc11b-complexes in the lifecycle of Ashbya gossypii. Deletion of either gene results in distinct cell polarity defects, suggesting non-overlapping functions. Cdc11a and Cdc11b complexes have differences in filament length and membrane-binding ability. Thus, septin subunit composition has functional consequences on filament properties and cell morphogenesis. Small sequence differences elicit distinct biophysical properties and cell functions of septins, illuminating how gene duplication could be a driving force for septin gene expansions seen throughout the tree of life.
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Affiliation(s)
- Kevin S. Cannon
- Biology Department, University of North Carolina, Chapel Hill, NC, USA
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC, USA
| | - Jose M. Vargas-Muniz
- Microbiology Program, School of Biological Sciences, Southern Illinois University, Carbondale, IL, USA
| | - Neil Billington
- Cell Biology and Physiology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Ian Seim
- Biology Department, University of North Carolina, Chapel Hill, NC, USA
- Department of Applied Physical Sciences, University of North Carolina, Chapel Hill, NC, USA
- Curriculum in Bioinformatics and Computational Biology, University of North Carolina, Chapel Hill, NC, USA
| | - Joanne Ekena
- Biology Department, University of North Carolina, Chapel Hill, NC, USA
| | - James R. Sellers
- Cell Biology and Physiology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Amy. S. Gladfelter
- Biology Department, University of North Carolina, Chapel Hill, NC, USA
- Marine Biological Laboratory, Woods Hole, MA, USA
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6
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Cell wall dynamics stabilize tip growth in a filamentous fungus. PLoS Biol 2023; 21:e3001981. [PMID: 36649360 PMCID: PMC9882835 DOI: 10.1371/journal.pbio.3001981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 01/27/2023] [Accepted: 12/22/2022] [Indexed: 01/18/2023] Open
Abstract
Hyphal tip growth allows filamentous fungi to colonize space, reproduce, or infect. It features remarkable morphogenetic plasticity including unusually fast elongation rates, tip turning, branching, or bulging. These shape changes are all driven from the expansion of a protective cell wall (CW) secreted from apical pools of exocytic vesicles. How CW secretion, remodeling, and deformation are modulated in concert to support rapid tip growth and morphogenesis while ensuring surface integrity remains poorly understood. We implemented subresolution imaging to map the dynamics of CW thickness and secretory vesicles in Aspergillus nidulans. We found that tip growth is associated with balanced rates of CW secretion and expansion, which limit temporal fluctuations in CW thickness, elongation speed, and vesicle amount, to less than 10% to 20%. Affecting this balance through modulations of growth or trafficking yield to near-immediate changes in CW thickness, mechanics, and shape. We developed a model with mechanical feedback that accounts for steady states of hyphal growth as well as rapid adaptation of CW mechanics and vesicle recruitment to different perturbations. These data provide unprecedented details on how CW dynamics emerges from material secretion and expansion, to stabilize fungal tip growth as well as promote its morphogenetic plasticity.
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Arakawa S, Kanaseki T, Wagner R, Goodenough U. Ultrastructure of the foliose lichen Myelochroa leucotyliza and its solo fungal and algal (Trebouxia sp.) partners. ALGAL RES 2022. [DOI: 10.1016/j.algal.2021.102571] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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Abstract
In a number of elongated cells, such as fungal hyphae, a vesicle cluster is observed at the growing tip. This cluster, called a Spitzenkörper, has been suggested to act as a vesicle supply center, yet analysis of its function is challenging, as a majority of components identified thus far are essential for growth. Here, we probe the function of the Spitzenkörper in the human fungal pathogen Candida albicans, using genetics and synthetic physical interactions (SPI). We show that the C. albicans Spitzenkörper is comprised principally of secretory vesicles. Mutant strains lacking the Spitzenkörper component myosin light chain 1 (Mlc1) or having a SPI between Mlc1 and either another Spitzenkörper component, the Rab GTPase Sec4, or prenylated green fluorescent protein (GFP), are viable and still exhibit a Spitzenkörper during filamentous growth. Strikingly, all of these mutants formed filaments with increased diameters and extension rates, indicating that Mlc1 negatively regulates myosin V, Myo2, activity. The results of our quantitative studies reveal a strong correlation between filament diameter and extension rate, which is consistent with the vesicle supply center model for fungal tip growth. Together, our results indicate that the Spitzenkörper protein Mlc1 is important for growth robustness and reveal a critical link between filament morphology and extension rate. IMPORTANCE Hyphal tip growth is critical in a range of fungal pathogens, in particular for invasion into animal and plant tissues. In Candida albicans, as in many filamentous fungi, a cluster of vesicles, called a Spitzenkörper, is observed at the tip of growing hyphae that is thought to function as a vesicle supply center. A central prediction of the vesicle supply center model is that the filament diameter is proportional to the extension rate. Here, we show that mutants lacking the Spitzenkörper component myosin light chain 1 (Mlc1) or having synthetic physical interactions between Mlc1 and either another Spitzenkörper component or prenylated GFP, are defective in filamentous growth regulation, exhibiting a range of growth rates and sizes, with a strong correlation between diameter and extension rate. These results suggest that the Spitzenkörper is important for growth robustness and reveal a critical link between filament morphology and extension rate.
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Gerganova V, Lamas I, Rutkowski DM, Vještica A, Castro DG, Vincenzetti V, Vavylonis D, Martin SG. Cell patterning by secretion-induced plasma membrane flows. SCIENCE ADVANCES 2021; 7:eabg6718. [PMID: 34533984 PMCID: PMC8448446 DOI: 10.1126/sciadv.abg6718] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 07/26/2021] [Indexed: 05/20/2023]
Abstract
Cells self-organize using reaction-diffusion and fluid-flow principles. Whether bulk membrane flows contribute to cell patterning has not been established. Here, using mathematical modeling, optogenetics, and synthetic probes, we show that polarized exocytosis causes lateral membrane flows away from regions of membrane insertion. Plasma membrane–associated proteins with sufficiently low diffusion and/or detachment rates couple to the flows and deplete from areas of exocytosis. In rod-shaped fission yeast cells, zones of Cdc42 GTPase activity driving polarized exocytosis are limited by GTPase activating proteins (GAPs). We show that membrane flows pattern the GAP Rga4 distribution and that coupling of a synthetic GAP to membrane flows is sufficient to establish the rod shape. Thus, membrane flows induced by Cdc42-dependent exocytosis form a negative feedback restricting the zone of Cdc42 activity.
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Affiliation(s)
- Veneta Gerganova
- Department of Fundamental Microbiology, University of Lausanne, CH-1015, Switzerland
| | - Iker Lamas
- Department of Fundamental Microbiology, University of Lausanne, CH-1015, Switzerland
| | | | - Aleksandar Vještica
- Department of Fundamental Microbiology, University of Lausanne, CH-1015, Switzerland
| | - Daniela Gallo Castro
- Department of Fundamental Microbiology, University of Lausanne, CH-1015, Switzerland
| | - Vincent Vincenzetti
- Department of Fundamental Microbiology, University of Lausanne, CH-1015, Switzerland
| | - Dimitrios Vavylonis
- Department of Physics, Lehigh University, Bethlehem, PA 18015, USA
- Corresponding author. (S.G.M.); (D.V.)
| | - Sophie G. Martin
- Department of Fundamental Microbiology, University of Lausanne, CH-1015, Switzerland
- Corresponding author. (S.G.M.); (D.V.)
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10
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The Exocyst Regulates Hydrolytic Enzyme Secretion at Hyphal Tips and Septa in the Banana Fusarium Wilt Fungus Fusarium odoratissimum. Appl Environ Microbiol 2021; 87:e0308820. [PMID: 34132587 DOI: 10.1128/aem.03088-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Hyphal polarized growth in filamentous fungi requires tip-directed secretion, while additional evidence suggests that fungal exocytosis for the hydrolytic enzyme secretion can occur at other sites in hyphae, including the septum. In this study, we analyzed the role of the exocyst complex involved in the secretion in the banana wilt fungal pathogen Fusarium odoratissimum. All eight exocyst components in F. odoratissimum not only localized to the tips ahead of the Spitzenkörper in growing hyphae but also localized to the outer edges of septa in mature hyphae. To further analyze the exocyst in F. odoratissimum, we attempted single gene deletion for all the genes encoding the eight exocyst components and only succeeded in constructing the gene deletion mutants for exo70 and sec5; we suspect that the other 6 exocyst components are encoded by essential genes. Deletion of exo70 or sec5 led to defects in vegetative growth, conidiation, and pathogenicity in F. odoratissimum. Notably, the deletion of exo70 resulted in decreased activities for endoglucosidase, filter paper enzymes, and amylase, while the loss of sec5 only led to a slight reduction in amylase activity. Septum-localized α-amylase (AmyB) was identified as the marker for septum-directed secretion, and we found that Exo70 is essential for the localization of AmyB to septa. Meanwhile the loss of Sec5 did not affect AmyB localization to septa but led to a higher accumulation of AmyB in cytoplasm. This suggested that while Exo70 and Sec5 both take part in the septum-directed secretion, the two play different roles in this process. IMPORTANCE The exocyst complex is a multisubunit tethering complex (MTC) for secretory vesicles at the plasma membrane and contains eight subunits, Sec3, Sec5, Sec6, Sec8, Sec10, Sec15, Exo70, and Exo84. While the exocyst complex is well defined in eukaryotes from yeast (Saccharomyces cerevisiae) to humans, the exocyst components in filamentous fungi show different localization patterns in the apical tips of hyphae, which suggests that filamentous fungi have evolved divergent strategies to regulate endomembrane trafficking. In this study, we demonstrated that the exocyst components in Fusarium odoratissimum are localized not only to the tips of growing hyphae but also to the outer edge of the septa in mature hyphae, suggesting that the exocyst complex plays a role in the regulation of septum-directed protein secretion in F. odoratissimum. We further found that Exo70 and Sec5 are required for the septum-directed secretion of α-amylase in F. odoratissimum but with different influences.
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11
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Dünkler A, Leda M, Kromer JM, Neller J, Gronemeyer T, Goryachev AB, Johnsson N. Type V myosin focuses the polarisome and shapes the tip of yeast cells. J Cell Biol 2021; 220:211845. [PMID: 33656555 PMCID: PMC7933982 DOI: 10.1083/jcb.202006193] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 01/25/2021] [Accepted: 02/04/2021] [Indexed: 11/22/2022] Open
Abstract
The polarisome is a cortical proteinaceous microcompartment that organizes the growth of actin filaments and the fusion of secretory vesicles in yeasts and filamentous fungi. Polarisomes are compact, spotlike structures at the growing tips of their respective cells. The molecular forces that control the form and size of this microcompartment are not known. Here we identify a complex between the polarisome subunit Pea2 and the type V Myosin Myo2 that anchors Myo2 at the cortex of yeast cells. We discovered a point mutation in the cargo-binding domain of Myo2 that impairs the interaction with Pea2 and consequently the formation and focused localization of the polarisome. Cells carrying this mutation grow round instead of elongated buds. Further experiments and biophysical modeling suggest that the interactions between polarisome-bound Myo2 motors and dynamic actin filaments spatially focus the polarisome and sustain its compact shape.
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Affiliation(s)
- Alexander Dünkler
- Institute of Molecular Genetics and Cell Biology, Department of Biology, Ulm University, Ulm, Germany
| | - Marcin Leda
- Centre for Synthetic and Systems Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Jan-Michael Kromer
- Institute of Molecular Genetics and Cell Biology, Department of Biology, Ulm University, Ulm, Germany
| | - Joachim Neller
- Institute of Molecular Genetics and Cell Biology, Department of Biology, Ulm University, Ulm, Germany
| | - Thomas Gronemeyer
- Institute of Molecular Genetics and Cell Biology, Department of Biology, Ulm University, Ulm, Germany
| | - Andrew B Goryachev
- Centre for Synthetic and Systems Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Nils Johnsson
- Institute of Molecular Genetics and Cell Biology, Department of Biology, Ulm University, Ulm, Germany
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12
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Pinar M, Peñalva MA. The fungal RABOME: RAB GTPases acting in the endocytic and exocytic pathways of Aspergillus nidulans (with excursions to other filamentous fungi). Mol Microbiol 2021; 116:53-70. [PMID: 33724562 DOI: 10.1111/mmi.14716] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 03/04/2021] [Accepted: 03/11/2021] [Indexed: 10/21/2022]
Abstract
RAB GTPases are major determinants of membrane identity that have been exploited as highly specific reporters to study intracellular traffic in vivo. A score of fungal papers have considered individual RABs, but systematic, integrated studies on the localization and physiological role of these regulators and their effectors have been performed only with Aspergillus nidulans. These studies have influenced the intracellular trafficking field beyond fungal specialists, leading to findings such as the maturation of trans-Golgi (TGN) cisternae into post-Golgi RAB11 secretory vesicles, the concept that these RAB11 secretory carriers are loaded with three molecular nanomotors, the understanding of the role of endocytic recycling mediated by RAB6 and RAB11 in determining the hyphal mode of life, the discovery that early endosome maturation and the ESCRT pathway are essential, the identification of specific adaptors of dynein-dynactin to RAB5 endosomes, the exquisite dependence that autophagy displays on RAB1 activity, the role of TRAPPII as a GEF for RAB11, or the conclusion that the RAB1-to-RAB11 transition is not mediated by TRAPP maturation. A remarkable finding was that the A. nidulans Spitzenkörper contains four RABs: RAB11, Sec4, RAB6, and RAB1. How these RABs cooperate during exocytosis represents an as yet outstanding question.
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Affiliation(s)
- Mario Pinar
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Madrid, Spain
| | - Miguel A Peñalva
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Madrid, Spain
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13
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Baltussen TJH, Coolen JPM, Verweij PE, Dijksterhuis J, Melchers WJG. Identifying Conserved Generic Aspergillus spp. Co-Expressed Gene Modules Associated with Germination Using Cross-Platform and Cross-Species Transcriptomics. J Fungi (Basel) 2021; 7:270. [PMID: 33916245 PMCID: PMC8067318 DOI: 10.3390/jof7040270] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 03/27/2021] [Accepted: 03/29/2021] [Indexed: 12/26/2022] Open
Abstract
Aspergillus spp. is an opportunistic human pathogen that may cause a spectrum of pulmonary diseases. In order to establish infection, inhaled conidia must germinate, whereby they break dormancy, start to swell, and initiate a highly polarized growth process. To identify critical biological processes during germination, we performed a cross-platform, cross-species comparative analysis of germinating A. fumigatus and A. niger conidia using transcriptional data from published RNA-Seq and Affymetrix studies. A consensus co-expression network analysis identified four gene modules associated with stages of germination. These modules showed numerous shared biological processes between A. niger and A. fumigatus during conidial germination. Specifically, the turquoise module was enriched with secondary metabolism, the black module was highly enriched with protein synthesis, the darkgreen module was enriched with protein fate, and the blue module was highly enriched with polarized growth. More specifically, enriched functional categories identified in the blue module were vesicle formation, vesicular transport, tubulin dependent transport, actin-dependent transport, exocytosis, and endocytosis. Genes important for these biological processes showed similar expression patterns in A. fumigatus and A. niger, therefore, they could be potential antifungal targets. Through cross-platform, cross-species comparative analysis, we were able to identify biologically meaningful modules shared by A. fumigatus and A. niger, which underscores the potential of this approach.
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Affiliation(s)
- Tim J. H. Baltussen
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (J.P.M.C.); (P.E.V.); (W.J.G.M.)
- Center of Expertise in Mycology Radboudumc/CWZ, 6532 SZ Nijmegen, The Netherlands
| | - Jordy P. M. Coolen
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (J.P.M.C.); (P.E.V.); (W.J.G.M.)
- Center of Expertise in Mycology Radboudumc/CWZ, 6532 SZ Nijmegen, The Netherlands
| | - Paul E. Verweij
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (J.P.M.C.); (P.E.V.); (W.J.G.M.)
- Center of Expertise in Mycology Radboudumc/CWZ, 6532 SZ Nijmegen, The Netherlands
| | - Jan Dijksterhuis
- Westerdijk Fungal Biodiversity Institute, 3584 CT Utrecht, The Netherlands
| | - Willem J. G. Melchers
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (J.P.M.C.); (P.E.V.); (W.J.G.M.)
- Center of Expertise in Mycology Radboudumc/CWZ, 6532 SZ Nijmegen, The Netherlands
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14
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Cao S, Li W, Li C, Wang G, Jiang W, Sun H, Deng Y, Chen H. The CHY-Type Zinc Finger Protein FgChy1 Regulates Polarized Growth, Pathogenicity, and Microtubule Assembly in Fusarium graminearum. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2021; 34:362-375. [PMID: 33369502 DOI: 10.1094/mpmi-07-20-0206-r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Microtubules (MTs), as transport tracks, play important roles in hyphal-tip growth in filamentous fungi, but MT-associated proteins involved in polarized growth remain unknown. Here, we found that one novel zinc finger protein, FgChy1, is required for MT morphology and polarized growth in Fusarium graminearum. The Fgchy1 mutant presented curved and directionless growth of hyphae. Importantly, the conidia and germ tubes of the Fgchy1 mutant exhibited badly damaged and less-organized beta-tubulin cytoskeletons. Compared with the wild type, the Fgchy1 mutant lost the ability to maintain polarity and was also more sensitive to the anti-MT drugs carbendazim and nocodazole, likely due to the impaired MT cytoskeleton. Indeed, the hyphae of the wild type treated with nocodazole exhibited a morphology consistent with that of the Fgchy1 mutant. Interestingly, the disruption of FgChy1 resulted in the off-center localization of actin patches and the polarity-related polarisome protein FgSpa2 from the hyphal-tip axis. A similar defect in FgSpa2 localization was also observed in the nocodazole-treated wild-type strain. In addition, FgChy1 is also required for conidiogenesis, septation, sexual reproduction, pathogenicity, and deoxynivalenol production. Overall, this study provides the first demonstrations of the functions of the novel zinc finger protein FgChy1 in polarized growth, development, and virulence in filamentous fungi.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Shulin Cao
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, Jiangsu, China
| | - Wei Li
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, Jiangsu, China
| | - Chaohui Li
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, Jiangsu, China
| | - Guanghui Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Wenqiang Jiang
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, Jiangsu, China
- Hubei Collaborative Innovation Center for Grain Industry, Yangtze University, Jingzhou 434025, Hubei, China
| | - Haiyan Sun
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, Jiangsu, China
| | - Yuanyu Deng
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, Jiangsu, China
| | - Huaigu Chen
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, Jiangsu, China
- Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou 225009, Jiangsu, China
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15
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Abstract
Tip-growing fungal cells maintain cell polarity at the apical regions and elongate by de novo synthesis of the cell wall. Cell polarity and tip growth rate affect mycelial morphology. Tip-growing fungal cells maintain cell polarity at the apical regions and elongate by de novo synthesis of the cell wall. Cell polarity and tip growth rate affect mycelial morphology. However, it remains unclear how both features act cooperatively to determine cell shape. Here, we investigated this relationship by analyzing hyphal tip growth of filamentous fungi growing inside extremely narrow 1 μm-width channels of microfluidic devices. Since the channels are much narrower than the diameter of hyphae, any hypha growing through the channel must adapt its morphology. Live-cell imaging analyses revealed that hyphae of some species continued growing through the channels, whereas hyphae of other species often ceased growing when passing through the channels, or had lost apical polarity after emerging from the other end of the channel. Fluorescence live-cell imaging analyses of the Spitzenkörper, a collection of secretory vesicles and polarity-related proteins at the hyphal tip, in Neurospora crassa indicates that hyphal tip growth requires a very delicate balance of ordered exocytosis to maintain polarity in spatially confined environments. We analyzed the mycelial growth of seven fungal species from different lineages, including phytopathogenic fungi. This comparative approach revealed that the growth defects induced by the channels were not correlated with their taxonomic classification or with the width of hyphae, but, rather, correlated with the hyphal elongation rate. This report indicates a trade-off between morphological plasticity and velocity in mycelial growth and serves to help understand fungal invasive growth into substrates or plant/animal cells, with direct impact on fungal biotechnology, ecology, and pathogenicity.
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16
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Xie Y, Miao Y. Polarisome assembly mediates actin remodeling during polarized yeast and fungal growth. J Cell Sci 2021; 134:134/1/jcs247916. [PMID: 33419950 DOI: 10.1242/jcs.247916] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Dynamic assembly and remodeling of actin is critical for many cellular processes during development and stress adaptation. In filamentous fungi and budding yeast, actin cables align in a polarized manner along the mother-to-daughter cell axis, and are essential for the establishment and maintenance of polarity; moreover, they rapidly remodel in response to environmental cues to achieve an optimal system response. A formin at the tip region within a macromolecular complex, called the polarisome, is responsible for driving actin cable polymerization during polarity establishment. This polarisome undergoes dynamic assembly through spatial and temporally regulated interactions between its components. Understanding this process is important to comprehend the tuneable activities of the formin-centered nucleation core, which are regulated through divergent molecular interactions and assembly modes within the polarisome. In this Review, we focus on how intrinsically disordered regions (IDRs) orchestrate the condensation of the polarisome components and the dynamic assembly of the complex. In addition, we address how these components are dynamically distributed in and out of the assembly zone, thereby regulating polarized growth. We also discuss the potential mechanical feedback mechanisms by which the force-induced actin polymerization at the tip of the budding yeast regulates the assembly and function of the polarisome.
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Affiliation(s)
- Ying Xie
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Yansong Miao
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
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17
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Taheraly S, Ershov D, Dmitrieff S, Minc N. An image analysis method to survey the dynamics of polar protein abundance in the regulation of tip growth. J Cell Sci 2020; 133:133/22/jcs252064. [PMID: 33257499 DOI: 10.1242/jcs.252064] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 10/14/2020] [Indexed: 11/20/2022] Open
Abstract
Tip growth is critical for the lifestyle of many walled cells. In yeast and fungi, this process is typically associated with the polarized deposition of conserved tip factors, including landmarks, Rho GTPases, cytoskeleton regulators, and membrane and cell wall remodelers. Because tip growth speeds may vary extensively between life cycles or species, we asked whether the local amount of specific polar elements could determine or limit tip growth speeds. Using the model fission yeast, we developed a quantitative image analysis pipeline to dynamically correlate single tip elongation speeds and polar protein abundance in large data sets. We found that polarity landmarks are typically diluted by growth. In contrast, tip growth speed is positively correlated with the local amount of factors related to actin, secretion or cell wall remodeling, but, surprisingly, exhibits long saturation plateaus above certain concentrations of those factors. Similar saturation observed for Spitzenkörper components in much faster growing fungal hyphae suggests that elements independent of canonical surface remodelers may limit single tip growth. This work provides standardized methods and resources to decipher the complex mechanisms that control cell growth.This article has an associated First Person interview with Sarah Taheraly, joint first author of the paper.
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Affiliation(s)
- Sarah Taheraly
- Université de Paris, CNRS, Institut Jacques Monod, 75013, Paris, France
| | - Dmitry Ershov
- Université de Paris, CNRS, Institut Jacques Monod, 75013, Paris, France
| | - Serge Dmitrieff
- Université de Paris, CNRS, Institut Jacques Monod, 75013, Paris, France
| | - Nicolas Minc
- Université de Paris, CNRS, Institut Jacques Monod, 75013, Paris, France
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18
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Peñalva MA, Moscoso‐Romero E, Hernández‐González M. Tracking exocytosis of aGPI‐anchored protein inAspergillus nidulans. Traffic 2020; 21:675-688. [DOI: 10.1111/tra.12761] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 09/04/2020] [Accepted: 09/07/2020] [Indexed: 12/26/2022]
Affiliation(s)
- Miguel A. Peñalva
- Department of Cellular and Molecular Biology Centro de Investigaciones Biológicas CSIC Madrid Spain
| | - Esteban Moscoso‐Romero
- Department of Cellular and Molecular Biology Centro de Investigaciones Biológicas CSIC Madrid Spain
- Morphogenesis and Cell Polarity Unit Instituto de Biología Funcional y Genómica CSIC‐Universidad de Salamanca Salamanca Spain
| | - Miguel Hernández‐González
- Department of Cellular and Molecular Biology Centro de Investigaciones Biológicas CSIC Madrid Spain
- The Francis Crick Institute London UK
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19
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Silva PM, Puerner C, Seminara A, Bassilana M, Arkowitz RA. Secretory Vesicle Clustering in Fungal Filamentous Cells Does Not Require Directional Growth. Cell Rep 2020; 28:2231-2245.e5. [PMID: 31433995 DOI: 10.1016/j.celrep.2019.07.062] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Revised: 04/22/2019] [Accepted: 07/18/2019] [Indexed: 11/27/2022] Open
Abstract
During symmetry breaking, the highly conserved Rho GTPase Cdc42 becomes stabilized at a defined site via an amplification process. However, little is known about how a new polarity site is established in an already asymmetric cell-a critical process in a changing environment. The human fungal pathogen Candida albicans switches from budding to filamentous growth in response to external cues, a transition controlled by Cdc42. Here, we have used optogenetic manipulation of cell polarity to reset growth in asymmetric filamentous C. albicans cells. We show that increasing the level of active Cdc42 on the plasma membrane results in disruption of the exocyst subunit Sec3 localization and a striking de novo clustering of secretory vesicles. This new cluster of secretory vesicles is highly dynamic, moving by hops and jumps, until a new growth site is established. Our results reveal that secretory vesicle clustering can occur in the absence of directional growth.
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Affiliation(s)
- Patrícia M Silva
- Université Côte d'Azur, CNRS, INSERM, Institute of Biology Valrose (iBV), Parc Valrose, Nice, France
| | - Charles Puerner
- Université Côte d'Azur, CNRS, INSERM, Institute of Biology Valrose (iBV), Parc Valrose, Nice, France
| | - Agnese Seminara
- Université Côte d'Azur, CNRS, Institute Physics of Nice (INPHYNI), Ave. J. Vallot, Nice, France
| | - Martine Bassilana
- Université Côte d'Azur, CNRS, INSERM, Institute of Biology Valrose (iBV), Parc Valrose, Nice, France
| | - Robert A Arkowitz
- Université Côte d'Azur, CNRS, INSERM, Institute of Biology Valrose (iBV), Parc Valrose, Nice, France.
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20
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Sporulation in Ashbya gossypii. J Fungi (Basel) 2020; 6:jof6030157. [PMID: 32872517 PMCID: PMC7558398 DOI: 10.3390/jof6030157] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 08/26/2020] [Accepted: 08/28/2020] [Indexed: 12/28/2022] Open
Abstract
Ashbya gossypii is a filamentous ascomycete belonging to the yeast family of Saccharomycetaceae. At the end of its growth phase Ashbya generates abundant amounts of riboflavin and spores that form within sporangia derived from fragmented cellular compartments of hyphae. The length of spores differs within species of the genus. Needle-shaped Ashbya spores aggregate via terminal filaments. A. gossypii is a homothallic fungus which may possess a and α mating types. However, the solo-MATa type strain is self-fertile and sporulates abundantly apparently without the need of prior mating. The central components required for the regulation of sporulation, encoded by IME1, IME2, IME4, KAR4, are conserved with Saccharomyces cerevisiae. Nutrient depletion generates a strong positive signal for sporulation via the cAMP-PKA pathway and SOK2, which is also essential for sporulation. Strong inhibitors of sporulation besides mutations in the central regulatory genes are the addition of exogenous cAMP or the overexpression of the mating type gene MATα2. Sporulation has been dissected using gene-function analyses and global RNA-seq transcriptomics. This revealed a role of Msn2/4, another potential PKA-target, for spore wall formation and a key dual role of the protein A kinase Tpk2 at the onset of sporulation as well as for breaking the dormancy of spores to initiate germination. Recent work has provided an overview of ascus development, regulation of sporulation and spore maturation. This will be summarized in the current review with a focus on the central regulatory genes. Current research and open questions will also be discussed.
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21
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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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22
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Spitzenkörper assembly mechanisms reveal conserved features of fungal and metazoan polarity scaffolds. Nat Commun 2020; 11:2830. [PMID: 32503980 PMCID: PMC7275032 DOI: 10.1038/s41467-020-16712-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 05/14/2020] [Indexed: 02/08/2023] Open
Abstract
The Spitzenkörper (SPK) constitutes a collection of secretory vesicles and polarity-related proteins intimately associated with polarized growth of fungal hyphae. Many SPK-localized proteins are known, but their assembly and dynamics remain poorly understood. Here, we identify protein-protein interaction cascades leading to assembly of two SPK scaffolds and recruitment of diverse effectors in Neurospora crassa. Both scaffolds are transported to the SPK by the myosin V motor (MYO-5), with the coiled-coil protein SPZ-1 acting as cargo adaptor. Neither scaffold appears to be required for accumulation of SPK secretory vesicles. One scaffold consists of Leashin-2 (LAH-2), which is required for SPK localization of the signalling kinase COT-1 and the glycolysis enzyme GPI-1. The other scaffold comprises a complex of Janus-1 (JNS-1) and the polarisome protein SPA-2. Via its Spa homology domain (SHD), SPA-2 recruits a calponin domain-containing F-actin effector (CCP-1). The SHD NMR structure reveals a conserved surface groove required for effector binding. Similarities between SPA-2/JNS-1 and the metazoan GIT/PIX complex identify foundational features of the cell polarity apparatus that predate the fungal-metazoan divergence. The Spitzenkörper (SPK) is a polarized accumulation of proteins and secretory vesicles associated with tip growth of fungal hyphae. Here, Zheng et al. study SPK assembly and dynamics, identify SPK protein scaffolds and associated proteins, and reveal similarities with other scaffolds from metazoans.
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23
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Callejas-Negrete OA, Castro-Longoria E. The role of GYP-3 in cellular morphogenesis of Neurospora crassa: Analyzing its relationship with the polarisome. Fungal Genet Biol 2019; 128:49-59. [DOI: 10.1016/j.fgb.2019.04.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 04/03/2019] [Accepted: 04/03/2019] [Indexed: 12/18/2022]
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24
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Verdín J, Sánchez-León E, Rico-Ramírez AM, Martínez-Núñez L, Fajardo-Somera RA, Riquelme M. Off the wall: The rhyme and reason of Neurospora crassa hyphal morphogenesis. ACTA ACUST UNITED AC 2019; 5:100020. [PMID: 32743136 PMCID: PMC7389182 DOI: 10.1016/j.tcsw.2019.100020] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 02/07/2019] [Accepted: 02/10/2019] [Indexed: 12/11/2022]
Abstract
Chitin and β-1,3-glucan synthases are transported separately in chitosomes and macrovesicles. Chitin synthases occupy the core of the SPK; β-1,3-glucan synthases the outer layer. CHS-4 arrival to the SPK and septa is CSE-7 dependent. Rabs YPT-1 and YPT-31 localization at the SPK mimics that of chitosomes and macrovesicles. The exocyst acts as a tether between the SPK outer layer vesicles and the apical PM.
The fungal cell wall building processes are the ultimate determinants of hyphal shape. In Neurospora crassa the main cell wall components, β-1,3-glucan and chitin, are synthesized by enzymes conveyed by specialized vesicles to the hyphal tip. These vesicles follow different secretory routes, which are delicately coordinated by cargo-specific Rab GTPases until their accumulation at the Spitzenkörper. From there, the exocyst mediates the docking of secretory vesicles to the plasma membrane, where they ultimately get fused. Although significant progress has been done on the cellular mechanisms that carry cell wall synthesizing enzymes from the endoplasmic reticulum to hyphal tips, a lot of information is still missing. Here, the current knowledge on N. crassa cell wall composition and biosynthesis is presented with an emphasis on the underlying molecular and cellular secretory processes.
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Key Words
- BGT, β-1,3-glucan transferases
- CHS, chitin synthase
- CLSM, confocal laser scanning microscopy
- CWI, cell wall integrity
- CWP, cell wall proteins
- Cell wall
- ER, endoplasmic reticulum
- FRAP, fluorescence recovery after photobleaching
- GEF, guanine nucleotide exchange factor
- GFP, green fluorescent protein
- GH, glycosyl hydrolases
- GPI, glycosylphosphatidylinositol
- GSC, β-1,3-glucan synthase complex
- MMD, myosin-like motor domain
- MS, mass spectrometry
- MT, microtubule
- NEC, network of elongated cisternae
- PM, plasma membrane
- SPK, Spitzenkörper
- Spitzenkörper
- TIRFM, total internal reflection fluorescence microscopy
- TM, transmembrane
- Tip growth
- Vesicles
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Affiliation(s)
- Jorge Verdín
- Industrial Biotechnology, CIATEJ-Jalisco State Scientific Research and Technology Assistance Center, Mexico National Council for Science and Technology, Zapopan, Jalisco, Mexico
| | - Eddy Sánchez-León
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | - Adriana M Rico-Ramírez
- Department of Microbiology, Centro de Investigación Científica y de Educación Superior de Ensenada, CICESE Ensenada, Baja California, Mexico
| | - Leonora Martínez-Núñez
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Rosa A Fajardo-Somera
- Karlsruhe Institute of Technology (KIT) South Campus, Institute for Applied Biosciences, Department of Microbiology, Karlsruhe, Germany
| | - Meritxell Riquelme
- Department of Microbiology, Centro de Investigación Científica y de Educación Superior de Ensenada, CICESE Ensenada, Baja California, Mexico
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25
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Lai H, Chiou JG, Zhurikhina A, Zyla TR, Tsygankov D, Lew DJ. Temporal regulation of morphogenetic events in Saccharomyces cerevisiae. Mol Biol Cell 2018; 29:2069-2083. [PMID: 29927361 PMCID: PMC6232962 DOI: 10.1091/mbc.e18-03-0188] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Tip growth in fungi involves highly polarized secretion and modification of the cell wall at the growing tip. The genetic requirements for initiating polarized growth are perhaps best understood for the model budding yeast Saccharomyces cerevisiae. Once the cell is committed to enter the cell cycle by activation of G1 cyclin/cyclin-dependent kinase (CDK) complexes, the polarity regulator Cdc42 becomes concentrated at the presumptive bud site, actin cables are oriented toward that site, and septin filaments assemble into a ring around the polarity site. Several minutes later, the bud emerges. Here, we investigated the mechanisms that regulate the timing of these events at the single-cell level. Septin recruitment was delayed relative to polarity establishment, and our findings suggest that a CDK-dependent septin “priming” facilitates septin recruitment by Cdc42. Bud emergence was delayed relative to the initiation of polarized secretion, and our findings suggest that the delay reflects the time needed to weaken the cell wall sufficiently for the cell to bud. Rho1 activation by Rom2 occurred at around the time of bud emergence, perhaps in response to local cell-wall weakening. This report reveals regulatory mechanisms underlying the morphogenetic events in the budding yeast.
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Affiliation(s)
- Helen Lai
- Department of Pharmacology and Cancer Biology, Duke University, Durham, NC 27710.,Department of Molecular Genetics and Microbiology, Duke University, Durham, NC 27710
| | - Jian-Geng Chiou
- Department of Pharmacology and Cancer Biology, Duke University, Durham, NC 27710
| | - Anastasia Zhurikhina
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University School of Medicine, Atlanta, GA 30332
| | - Trevin R Zyla
- Department of Pharmacology and Cancer Biology, Duke University, Durham, NC 27710
| | - Denis Tsygankov
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University School of Medicine, Atlanta, GA 30332
| | - Daniel J Lew
- Department of Pharmacology and Cancer Biology, Duke University, Durham, NC 27710.,Department of Molecular Genetics and Microbiology, Duke University, Durham, NC 27710
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Riquelme M, Aguirre J, Bartnicki-García S, Braus GH, Feldbrügge M, Fleig U, Hansberg W, Herrera-Estrella A, Kämper J, Kück U, Mouriño-Pérez RR, Takeshita N, Fischer R. Fungal Morphogenesis, from the Polarized Growth of Hyphae to Complex Reproduction and Infection Structures. Microbiol Mol Biol Rev 2018; 82:e00068-17. [PMID: 29643171 PMCID: PMC5968459 DOI: 10.1128/mmbr.00068-17] [Citation(s) in RCA: 183] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Filamentous fungi constitute a large group of eukaryotic microorganisms that grow by forming simple tube-like hyphae that are capable of differentiating into more-complex morphological structures and distinct cell types. Hyphae form filamentous networks by extending at their tips while branching in subapical regions. Rapid tip elongation requires massive membrane insertion and extension of the rigid chitin-containing cell wall. This process is sustained by a continuous flow of secretory vesicles that depends on the coordinated action of the microtubule and actin cytoskeletons and the corresponding motors and associated proteins. Vesicles transport cell wall-synthesizing enzymes and accumulate in a special structure, the Spitzenkörper, before traveling further and fusing with the tip membrane. The place of vesicle fusion and growth direction are enabled and defined by the position of the Spitzenkörper, the so-called cell end markers, and other proteins involved in the exocytic process. Also important for tip extension is membrane recycling by endocytosis via early endosomes, which function as multipurpose transport vehicles for mRNA, septins, ribosomes, and peroxisomes. Cell integrity, hyphal branching, and morphogenesis are all processes that are largely dependent on vesicle and cytoskeleton dynamics. When hyphae differentiate structures for asexual or sexual reproduction or to mediate interspecies interactions, the hyphal basic cellular machinery may be reprogrammed through the synthesis of new proteins and/or the modification of protein activity. Although some transcriptional networks involved in such reprogramming of hyphae are well studied in several model filamentous fungi, clear connections between these networks and known determinants of hyphal morphogenesis are yet to be established.
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Affiliation(s)
- Meritxell Riquelme
- Department of Microbiology, Centro de Investigación Científica y de Educación Superior de Ensenada, Ensenada, Baja California, Mexico
| | - Jesús Aguirre
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de Mexico, Mexico City, Mexico
| | - Salomon Bartnicki-García
- Department of Microbiology, Centro de Investigación Científica y de Educación Superior de Ensenada, Ensenada, Baja California, Mexico
| | - Gerhard H Braus
- Department of Molecular Microbiology and Genetics and Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, Goettingen, Germany
| | - Michael Feldbrügge
- Institute for Microbiology, Heinrich Heine University Düsseldorf, Cluster of Excellence on Plant Sciences, Düsseldorf, Germany
| | - Ursula Fleig
- Institute for Functional Genomics of Microorganisms, Heinrich Heine University Düsseldorf, Cluster of Excellence on Plant Sciences, Düsseldorf, Germany
| | - Wilhelm Hansberg
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de Mexico, Mexico City, Mexico
| | - Alfredo Herrera-Estrella
- Laboratorio Nacional de Genómica para la Biodiversidad, Centro de Investigación y de Estudios Avanzados del IPN, Irapuato, Mexico
| | - Jörg Kämper
- Karlsruhe Institute of Technology-South Campus, Institute for Applied Biosciences, Karlsruhe, Germany
| | - Ulrich Kück
- Ruhr University Bochum, Lehrstuhl für Allgemeine und Molekulare Botanik, Bochum, Germany
| | - Rosa R Mouriño-Pérez
- Department of Microbiology, Centro de Investigación Científica y de Educación Superior de Ensenada, Ensenada, Baja California, Mexico
| | - Norio Takeshita
- University of Tsukuba, Faculty of Life and Environmental Sciences, Tsukuba, Japan
| | - Reinhard Fischer
- Karlsruhe Institute of Technology-South Campus, Institute for Applied Biosciences, Karlsruhe, Germany
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Zhou L, Evangelinos M, Wernet V, Eckert AF, Ishitsuka Y, Fischer R, Nienhaus GU, Takeshita N. Superresolution and pulse-chase imaging reveal the role of vesicle transport in polar growth of fungal cells. SCIENCE ADVANCES 2018; 4:e1701798. [PMID: 29387789 PMCID: PMC5787382 DOI: 10.1126/sciadv.1701798] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Accepted: 12/27/2017] [Indexed: 06/07/2023]
Abstract
Polarized growth of filamentous fungi requires continuous transport of biomolecules to the hyphal tip. To this end, construction materials are packaged in vesicles and transported by motor proteins along microtubules and actin filaments. We have studied these processes with quantitative superresolution localization microscopy of live Aspergillus nidulans cells expressing the photoconvertible protein mEosFPthermo fused to the chitin synthase ChsB. ChsB is mainly located at the Spitzenkörper near the hyphal tip and produces chitin, a key component of the cell wall. We have visualized the pulsatory dynamics of the Spitzenkörper, reflecting vesicle accumulation before exocytosis and their subsequent fusion with the apical plasma membrane. Furthermore, high-speed pulse-chase imaging after photoconversion of mEosFPthermo in a tightly focused spot revealed that ChsB is transported with two different speeds from the cell body to the hyphal tip and vice versa. Comparative analysis using motor protein deletion mutants allowed us to assign the fast movements (7 to 10 μm s-1) to transport of secretory vesicles by kinesin-1, and the slower ones (2 to 7 μm s-1) to transport by kinesin-3 on early endosomes. Our results show how motor proteins ensure the supply of vesicles to the hyphal tip, where temporally regulated exocytosis results in stepwise tip extension.
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Affiliation(s)
- Lu Zhou
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
- Institute of Nanotechnology, KIT, Karlsruhe, Germany
| | - Minoas Evangelinos
- Department of Microbiology, Institute for Applied Biosciences, KIT, Karlsruhe, Germany
- Faculty of Biology, University of Athens, Athens, Greece
- Institut de Biologie et de Médecine Moléculaires, Université Libre de Bruxelles, Gosselies, Belgium
| | - Valentin Wernet
- Department of Microbiology, Institute for Applied Biosciences, KIT, Karlsruhe, Germany
| | - Antonia F. Eckert
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Yuji Ishitsuka
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Reinhard Fischer
- Department of Microbiology, Institute for Applied Biosciences, KIT, Karlsruhe, Germany
| | - G. Ulrich Nienhaus
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
- Institute of Nanotechnology, KIT, Karlsruhe, Germany
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Institute of Toxicology and Genetics, KIT, Eggenstein-Leopoldshafen, Germany
| | - Norio Takeshita
- Department of Microbiology, Institute for Applied Biosciences, KIT, Karlsruhe, Germany
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
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28
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Xiang X. Nuclear movement in fungi. Semin Cell Dev Biol 2017; 82:3-16. [PMID: 29241689 DOI: 10.1016/j.semcdb.2017.10.024] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 10/17/2017] [Accepted: 10/23/2017] [Indexed: 12/22/2022]
Abstract
Nuclear movement within a cell occurs in a variety of eukaryotic organisms including yeasts and filamentous fungi. Fungal molecular genetic studies identified the minus-end-directed microtubule motor cytoplasmic dynein as a critical protein for nuclear movement or orientation of the mitotic spindle contained in the nucleus. Studies in the budding yeast first indicated that dynein anchored at the cortex via its anchoring protein Num1 exerts pulling force on an astral microtubule to orient the anaphase spindle across the mother-daughter axis before nuclear division. Prior to anaphase, myosin V interacts with the plus end of an astral microtubule via Kar9-Bim1/EB1 and pulls the plus end along the actin cables to move the nucleus/spindle close to the bud neck. In addition, pushing or pulling forces generated from cortex-linked polymerization or depolymerization of microtubules drive nuclear movements in yeasts and possibly also in filamentous fungi. In filamentous fungi, multiple nuclei within a hyphal segment undergo dynein-dependent back-and-forth movements and their positioning is also influenced by cytoplasmic streaming toward the hyphal tip. In addition, nuclear movement occurs at various stages of fungal development and fungal infection of plant tissues. This review discusses our current understanding on the mechanisms of nuclear movement in fungal organisms, the importance of nuclear positioning and the regulatory strategies that ensure the proper positioning of nucleus/spindle.
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Affiliation(s)
- Xin Xiang
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences - F. Edward Hébert School of Medicine, Bethesda, MD, USA.
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29
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Oscarsson T, Walther A, Lengeler KB, Wendland J. An Arf-GAP promotes endocytosis and hyphal growth of Ashbya gossypii. FEMS Microbiol Lett 2017; 364:4600504. [DOI: 10.1093/femsle/fnx240] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 11/06/2017] [Indexed: 12/18/2022] Open
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Evolutionary dynamics in the fungal polarization network, a mechanistic perspective. Biophys Rev 2017; 9:375-387. [PMID: 28812259 PMCID: PMC5578929 DOI: 10.1007/s12551-017-0286-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 07/24/2017] [Indexed: 12/21/2022] Open
Abstract
Polarity establishment underlies proper cell cycle completion across virtually all organisms. Much progress has been made in generating an understanding of the structural and functional components of this process, especially in model species. Here we focus on the evolutionary dynamics of the fungal polarization protein network in order to determine general components and mechanistic principles, species- or lineage-specific adaptations and the evolvability of the network. The currently available genomic and proteomic screens in a variety of fungal species have shown three main characteristics: (1) certain proteins, processes and functions are conserved throughout the fungal clade; (2) orthologous functions can never be assumed, as various cases have been observed of homologous loci with dissimilar functions; (3) species have, typically, various species- or lineage-specific proteins incorporated in their polarization network. Further large-scale comparative and experimental studies, including those on non-model species representing the great fungal diversity, are needed to gain a better understanding of the evolutionary dynamics and generalities of the polarization network in fungi.
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Abstract
The eukaryotic actin cytoskeleton is a highly dynamic framework that is involved in many biological processes, such as cell growth, division, morphology, and motility. G-actin polymerizes into microfilaments that associate into bundles, patches, and networks, which, in turn, organize into higher order structures that are fundamental for the course of important physiological events. Actin rings are an example for such higher order actin entities, but this term represents an actually diverse set of subcellular structures that are involved in various processes. This review especially sheds light on a crucial type of non-constricting ring-like actin networks, and categorizes them under the term 'actin fringe'. These 'actin fringes' are visualized as highly dynamic and yet steady structures in the tip of various polarized growing cells. The present comprehensive overview compares the actin fringe characteristics of rapidly elongating pollen tubes with several related actin arrays in other cell types of diverse species. The current state of knowledge about various actin fringe functions is summarized, and the key role of this structure in the polar growth process is discussed.
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Affiliation(s)
- Octavian O H Stephan
- Department of Biology, Friedrich-Alexander University of Erlangen-Nuremberg, Erlangen, Bavaria 91058, Germany
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32
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Pantazopoulou A. The Golgi apparatus: insights from filamentous fungi. Mycologia 2017; 108:603-22. [DOI: 10.3852/15-309] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 01/01/2016] [Indexed: 02/06/2023]
Affiliation(s)
- Areti Pantazopoulou
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, Madrid 28040, Spain
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33
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Schröter S, Beckmann S, Schmitt HD. ER arrival sites for COPI vesicles localize to hotspots of membrane trafficking. EMBO J 2016; 35:1935-55. [PMID: 27440402 DOI: 10.15252/embj.201592873] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 06/21/2016] [Indexed: 11/09/2022] Open
Abstract
COPI-coated vesicles mediate retrograde membrane traffic from the cis-Golgi to the endoplasmic reticulum (ER) in all eukaryotic cells. However, it is still unknown whether COPI vesicles fuse everywhere or at specific sites with the ER membrane. Taking advantage of the circumstance that the vesicles still carry their coat when they arrive at the ER, we have visualized active ER arrival sites (ERAS) by monitoring contact between COPI coat components and the ER-resident Dsl tethering complex using bimolecular fluorescence complementation (BiFC). ERAS form punctate structures near Golgi compartments, clearly distinct from ER exit sites. Furthermore, ERAS are highly polarized in an actin and myosin V-dependent manner and are localized near hotspots of plasma membrane expansion. Genetic experiments suggest that the COPI•Dsl BiFC complexes recapitulate the physiological interaction between COPI and the Dsl complex and that COPI vesicles are mistargeted in dsl1 mutants. We conclude that the Dsl complex functions in confining COPI vesicle fusion sites.
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Affiliation(s)
- Saskia Schröter
- Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Sabrina Beckmann
- Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Hans Dieter Schmitt
- Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
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34
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Martin-Urdiroz M, Deeks MJ, Horton CG, Dawe HR, Jourdain I. The Exocyst Complex in Health and Disease. Front Cell Dev Biol 2016; 4:24. [PMID: 27148529 PMCID: PMC4828438 DOI: 10.3389/fcell.2016.00024] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Accepted: 03/11/2016] [Indexed: 01/23/2023] Open
Abstract
Exocytosis involves the fusion of intracellular secretory vesicles with the plasma membrane, thereby delivering integral membrane proteins to the cell surface and releasing material into the extracellular space. Importantly, exocytosis also provides a source of lipid moieties for membrane extension. The tethering of the secretory vesicle before docking and fusion with the plasma membrane is mediated by the exocyst complex, an evolutionary conserved octameric complex of proteins. Recent findings indicate that the exocyst complex also takes part in other intra-cellular processes besides secretion. These various functions seem to converge toward defining a direction of membrane growth in a range of systems from fungi to plants and from neurons to cilia. In this review we summarize the current knowledge of exocyst function in cell polarity, signaling and cell-cell communication and discuss implications for plant and animal health and disease.
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Affiliation(s)
| | - Michael J Deeks
- Biosciences, College of Life and Environmental Sciences, University of Exeter Exeter, UK
| | - Connor G Horton
- Biosciences, College of Life and Environmental Sciences, University of Exeter Exeter, UK
| | - Helen R Dawe
- Biosciences, College of Life and Environmental Sciences, University of Exeter Exeter, UK
| | - Isabelle Jourdain
- Biosciences, College of Life and Environmental Sciences, University of Exeter Exeter, UK
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35
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Schultzhaus Z, Quintanilla L, Hilton A, Shaw BD. Live Cell Imaging of Actin Dynamics in the Filamentous Fungus Aspergillus nidulans. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2016; 22:264-274. [PMID: 26879694 DOI: 10.1017/s1431927616000131] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Hyphal cells of filamentous fungi grow at their tips in a method analogous to pollen tube and root hair elongation. This process, generally referred to as tip growth, requires precise regulation of the actin cytoskeleton, and characterizing the various actin structures in these cell types is currently an active area of research. Here, the actin marker Lifeact was used to document actin dynamics in the filamentous fungus Aspergillus nidulans. Contractile double rings were observed at septa, and annular clusters of puncta were seen subtending growing hyphal tips, corresponding to the well-characterized subapical endocytic collar. However, Lifeact also revealed two additional structures. One, an apical array, was dynamic on the face opposite the tip, while a subapical web was dynamic on the apical face and was located several microns behind the growth site. Each was observed turning into the other over time, implying that they could represent different localizations of the same structure, although hyphae with a subapical web grew faster than those exhibiting an apical array. The subapical web has not been documented in any filamentous fungus to date, and is separate from the networks of F-actin seen in other tip-growing organisms surrounding septa or stationary along the plasmalemma.
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Affiliation(s)
- Zachary Schultzhaus
- Department of Plant Pathology and Microbiology,Texas A&M University,College Station,TX 77843,USA
| | - Laura Quintanilla
- Department of Plant Pathology and Microbiology,Texas A&M University,College Station,TX 77843,USA
| | - Angelyn Hilton
- Department of Plant Pathology and Microbiology,Texas A&M University,College Station,TX 77843,USA
| | - Brian D Shaw
- Department of Plant Pathology and Microbiology,Texas A&M University,College Station,TX 77843,USA
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36
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New Insight Into the Roles of Membrane Microdomains in Physiological Activities of Fungal Cells. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 325:119-80. [PMID: 27241220 DOI: 10.1016/bs.ircmb.2016.02.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The organization of biological membranes into structurally and functionally distinct lateral microdomains is generally accepted. From bacteria to mammals, laterally compartmentalized membranes seem to be a vital attribute of life. The crucial fraction of our current knowledge about the membrane microdomains has been gained from studies on fungi. In this review we summarize the evidence of the microdomain organization of membranes from fungal cells, with accent on their enormous diversity in composition, temporal dynamics, modes of formation, and recognized engagement in the cell physiology. A special emphasis is laid on the fact that in addition to their other biological functions, membrane microdomains also mediate the communication among different membranes within a eukaryotic cell and coordinate their functions. Involvement of fungal membrane microdomains in stress sensing, regulation of lipid homeostasis, and cell differentiation is discussed more in detail.
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37
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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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38
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Fisher KE, Roberson RW. Hyphal tip cytoplasmic organization in four zygomycetous fungi. Mycologia 2016; 108:533-42. [PMID: 26908648 DOI: 10.3852/15-226] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 02/11/2016] [Indexed: 11/10/2022]
Abstract
We have examined the hyphal tip structure in four zygomycetous fungi: Mortierella verticillata (Mortierellales), Coemansia reversa (Kickxellales), Mucor indicus and Gilbertella persicaria (Mucorales) using both light and transmission electron microscopy. We have used cryofixation and freeze-substitution methods to preserve fungal hyphae for transmission electron microscopy, which yielded improved preservation of ultrastructural details. Our research has confirmed studies that described the accumulation of secretory vesicles as a crescent at the hyphal apex (i.e. the apical vesicle crescent [AVC]) and provided a more detailed understanding of the vesicle populations. In addition, we have been able to observe the behavior of the AVC during hyphal growth in M. indicus and G. persicaria.
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Affiliation(s)
- Karen E Fisher
- School of Life Sciences, Arizona State University, Tempe, Arizona 85287
| | - Robert W Roberson
- School of Life Sciences, Arizona State University, Tempe, Arizona 85287
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39
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Chen X, Ebbole DJ, Wang Z. The exocyst complex: delivery hub for morphogenesis and pathogenesis in filamentous fungi. CURRENT OPINION IN PLANT BIOLOGY 2015; 28:48-54. [PMID: 26453967 DOI: 10.1016/j.pbi.2015.09.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Revised: 08/30/2015] [Accepted: 09/05/2015] [Indexed: 06/05/2023]
Abstract
Regulated by several small GTPases, the octameric exocyst complex directs the docking and tethering of exocytic vesicles to the destined plasma membrane sites, providing the precise spatiotemporal control of exocytosis. Although the exocyst components are well conserved among various fungal species, the mechanisms for the regulation of its assembly and activity are diverse. Exocytosis is crucial for the generation of cell polarity as well as the delivery of effector proteins in filamentous fungi, and thus plays an important role for fungal morphogenesis and pathogenicity on plant hosts. This review focuses on current findings about the roles of the exocyst complex in the morphogenesis and pathogenesis of filamentous fungi.
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Affiliation(s)
- Xiaofeng Chen
- Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Fujian Province Key Laboratory of Pathogenic Fungi and Mycotoxins, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Daniel J Ebbole
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX 77843, USA
| | - Zonghua Wang
- Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Fujian Province Key Laboratory of Pathogenic Fungi and Mycotoxins, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
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40
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Aguiar TQ, Silva R, Domingues L. Ashbya gossypii beyond industrial riboflavin production: A historical perspective and emerging biotechnological applications. Biotechnol Adv 2015; 33:1774-86. [DOI: 10.1016/j.biotechadv.2015.10.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 09/28/2015] [Accepted: 10/04/2015] [Indexed: 10/22/2022]
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41
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42
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Jose M, Tollis S, Nair D, Mitteau R, Velours C, Massoni-Laporte A, Royou A, Sibarita JB, McCusker D. A quantitative imaging-based screen reveals the exocyst as a network hub connecting endocytosis and exocytosis. Mol Biol Cell 2015; 26:2519-34. [PMID: 25947137 PMCID: PMC4571305 DOI: 10.1091/mbc.e14-11-1527] [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: 11/12/2014] [Accepted: 04/29/2015] [Indexed: 12/15/2022] Open
Abstract
The mechanisms governing the spatial organization of endocytosis and exocytosis are ill defined. A quantitative imaging screen and high-density single-vesicle tracking are used to identify mutants that are defective in endocytic and exocytic vesicle organization. The screen identifies a role for the exocyst complex in connecting the two pathways. The coupling of endocytosis and exocytosis underlies fundamental biological processes ranging from fertilization to neuronal activity and cellular polarity. However, the mechanisms governing the spatial organization of endocytosis and exocytosis require clarification. Using a quantitative imaging-based screen in budding yeast, we identified 89 mutants displaying defects in the localization of either one or both pathways. High-resolution single-vesicle tracking revealed that the endocytic and exocytic mutants she4∆ and bud6∆ alter post-Golgi vesicle dynamics in opposite ways. The endocytic and exocytic pathways display strong interdependence during polarity establishment while being more independent during polarity maintenance. Systems analysis identified the exocyst complex as a key network hub, rich in genetic interactions with endocytic and exocytic components. Exocyst mutants displayed altered endocytic and post-Golgi vesicle dynamics and interspersed endocytic and exocytic domains compared with control cells. These data are consistent with an important role for the exocyst in coordinating endocytosis and exocytosis.
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Affiliation(s)
- Mini Jose
- Dynamics of Cell Growth and Division, European Institute of Chemistry and Biology, F-33607 Bordeaux, France Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, Université Bordeaux, F-33000 Bordeaux, France Centre for Neuroscience, Indian Institute of Science, Bangalore 560012, India
| | - Sylvain Tollis
- Dynamics of Cell Growth and Division, European Institute of Chemistry and Biology, F-33607 Bordeaux, France Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, Université Bordeaux, F-33000 Bordeaux, France
| | - Deepak Nair
- Centre for Neuroscience, Indian Institute of Science, Bangalore 560012, India Institut Interdisciplinaire de Neurosciences, CNRS UMR 5297, Université Bordeaux, F-33000 Bordeaux, France
| | - Romain Mitteau
- Dynamics of Cell Growth and Division, European Institute of Chemistry and Biology, F-33607 Bordeaux, France Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, Université Bordeaux, F-33000 Bordeaux, France
| | - Christophe Velours
- Dynamics of Cell Growth and Division, European Institute of Chemistry and Biology, F-33607 Bordeaux, France Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, Université Bordeaux, F-33000 Bordeaux, France
| | - Aurelie Massoni-Laporte
- Dynamics of Cell Growth and Division, European Institute of Chemistry and Biology, F-33607 Bordeaux, France Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, Université Bordeaux, F-33000 Bordeaux, France
| | - Anne Royou
- Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, Université Bordeaux, F-33000 Bordeaux, France Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, Université Bordeaux, F-33000 Bordeaux, France
| | - Jean-Baptiste Sibarita
- Institut Interdisciplinaire de Neurosciences, CNRS UMR 5297, Université Bordeaux, F-33000 Bordeaux, France
| | - Derek McCusker
- Dynamics of Cell Growth and Division, European Institute of Chemistry and Biology, F-33607 Bordeaux, France Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, Université Bordeaux, F-33000 Bordeaux, France
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Arkowitz RA, Bassilana M. Regulation of hyphal morphogenesis by Ras and Rho small GTPases. FUNGAL BIOL REV 2015. [DOI: 10.1016/j.fbr.2015.02.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Abstract
Morphogenesis in fungi is often induced by extracellular factors and executed by fungal genetic factors. Cell surface changes and alterations of the microenvironment often accompany morphogenetic changes in fungi. In this review, we will first discuss the general traits of yeast and hyphal morphotypes and how morphogenesis affects development and adaptation by fungi to their native niches, including host niches. Then we will focus on the molecular machinery responsible for the two most fundamental growth forms, yeast and hyphae. Last, we will describe how fungi incorporate exogenous environmental and host signals together with genetic factors to determine their morphotype and how morphogenesis, in turn, shapes the fungal microenvironment.
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Affiliation(s)
- Xiaorong Lin
- Department of Biology, Texas A&M University, College Station, Texas 77843-3258
| | - J Andrew Alspaugh
- Department of Medicine, Division of Infectious Diseases, Duke University Medical Center, Durham, North Carolina 27710
| | - Haoping Liu
- Department of Biological Chemistry, University of California, Irvine, California 92697
| | - Steven Harris
- Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, Nebraska 68588
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45
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Perez-Nadales E, Nogueira MFA, Baldin C, Castanheira S, El Ghalid M, Grund E, Lengeler K, Marchegiani E, Mehrotra PV, Moretti M, Naik V, Oses-Ruiz M, Oskarsson T, Schäfer K, Wasserstrom L, Brakhage AA, Gow NAR, Kahmann R, Lebrun MH, Perez-Martin J, Di Pietro A, Talbot NJ, Toquin V, Walther A, Wendland J. Fungal model systems and the elucidation of pathogenicity determinants. Fungal Genet Biol 2014; 70:42-67. [PMID: 25011008 PMCID: PMC4161391 DOI: 10.1016/j.fgb.2014.06.011] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Revised: 06/23/2014] [Accepted: 06/25/2014] [Indexed: 12/05/2022]
Abstract
Fungi have the capacity to cause devastating diseases of both plants and animals, causing significant harvest losses that threaten food security and human mycoses with high mortality rates. As a consequence, there is a critical need to promote development of new antifungal drugs, which requires a comprehensive molecular knowledge of fungal pathogenesis. In this review, we critically evaluate current knowledge of seven fungal organisms used as major research models for fungal pathogenesis. These include pathogens of both animals and plants; Ashbya gossypii, Aspergillus fumigatus, Candida albicans, Fusarium oxysporum, Magnaporthe oryzae, Ustilago maydis and Zymoseptoria tritici. We present key insights into the virulence mechanisms deployed by each species and a comparative overview of key insights obtained from genomic analysis. We then consider current trends and future challenges associated with the study of fungal pathogenicity.
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Affiliation(s)
- Elena Perez-Nadales
- Department of Genetics, Edificio Gregor Mendel, Planta 1. Campus de Rabanales, University of Cordoba, 14071 Cordoba, Spain.
| | | | - Clara Baldin
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (HKI), Beutembergstr. 11a, 07745 Jena, Germany; Department of Microbiology and Molecular Biology, Institute of Microbiology, Friedrich Schiller University Jena, Beutenbergstr. 11a, 07745 Jena, Germany
| | - Sónia Castanheira
- Instituto de Biología Funcional y GenómicaCSIC, Universidad de Salamanca, 37007 Salamanca, Spain
| | - Mennat El Ghalid
- Department of Genetics, Edificio Gregor Mendel, Planta 1. Campus de Rabanales, University of Cordoba, 14071 Cordoba, Spain
| | - Elisabeth Grund
- Functional Genomics of Plant Pathogenic Fungi, UMR 5240 CNRS-UCB-INSA-Bayer SAS, Bayer CropScience, 69263 Lyon, France
| | - Klaus Lengeler
- Carlsberg Laboratory, Department of Yeast Genetics, Gamle Carlsberg Vej 10, DK-1799, Copenhagen V, Denmark
| | - Elisabetta Marchegiani
- Evolution and Genomics of Plant Pathogen Interactions, UR 1290 INRA, BIOGER-CPP, Campus AgroParisTech, 78850 Thiverval-Grignon, France
| | - Pankaj Vinod Mehrotra
- Aberdeen Fungal Group, School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK
| | - Marino Moretti
- Max-Planck-Institute for Terrestrial Microbiology, Department of Organismic Interactions, Karl-von-Frisch-Strasse 10, D-35043 Marburg, Germany
| | - Vikram Naik
- Max-Planck-Institute for Terrestrial Microbiology, Department of Organismic Interactions, Karl-von-Frisch-Strasse 10, D-35043 Marburg, Germany
| | - Miriam Oses-Ruiz
- School of Biosciences, Geoffrey Pope Building, University of Exeter, Exeter EX4 4QD, UK
| | - Therese Oskarsson
- Carlsberg Laboratory, Department of Yeast Genetics, Gamle Carlsberg Vej 10, DK-1799, Copenhagen V, Denmark
| | - Katja Schäfer
- Department of Genetics, Edificio Gregor Mendel, Planta 1. Campus de Rabanales, University of Cordoba, 14071 Cordoba, Spain
| | - Lisa Wasserstrom
- Carlsberg Laboratory, Department of Yeast Genetics, Gamle Carlsberg Vej 10, DK-1799, Copenhagen V, Denmark
| | - Axel A Brakhage
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (HKI), Beutembergstr. 11a, 07745 Jena, Germany; Department of Microbiology and Molecular Biology, Institute of Microbiology, Friedrich Schiller University Jena, Beutenbergstr. 11a, 07745 Jena, Germany
| | - Neil A R Gow
- Aberdeen Fungal Group, School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK
| | - Regine Kahmann
- Max-Planck-Institute for Terrestrial Microbiology, Department of Organismic Interactions, Karl-von-Frisch-Strasse 10, D-35043 Marburg, Germany
| | - Marc-Henri Lebrun
- Evolution and Genomics of Plant Pathogen Interactions, UR 1290 INRA, BIOGER-CPP, Campus AgroParisTech, 78850 Thiverval-Grignon, France
| | - José Perez-Martin
- Instituto de Biología Funcional y GenómicaCSIC, Universidad de Salamanca, 37007 Salamanca, Spain
| | - Antonio Di Pietro
- Department of Genetics, Edificio Gregor Mendel, Planta 1. Campus de Rabanales, University of Cordoba, 14071 Cordoba, Spain
| | - Nicholas J Talbot
- School of Biosciences, Geoffrey Pope Building, University of Exeter, Exeter EX4 4QD, UK
| | - Valerie Toquin
- Biochemistry Department, Bayer SAS, Bayer CropScience, CRLD, 69263 Lyon, France
| | - Andrea Walther
- Carlsberg Laboratory, Department of Yeast Genetics, Gamle Carlsberg Vej 10, DK-1799, Copenhagen V, Denmark
| | - Jürgen Wendland
- Carlsberg Laboratory, Department of Yeast Genetics, Gamle Carlsberg Vej 10, DK-1799, Copenhagen V, Denmark
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Nordmann D, Lickfeld M, Warnsmann V, Wiechert J, Jendretzki A, Schmitz HP. The small GTP-binding proteins AgRho2 and AgRho5 regulate tip-branching, maintenance of the growth axis and actin-ring-integrity in the filamentous fungus Ashbya gossypii. PLoS One 2014; 9:e106236. [PMID: 25171205 PMCID: PMC4149541 DOI: 10.1371/journal.pone.0106236] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Accepted: 08/04/2014] [Indexed: 12/02/2022] Open
Abstract
GTPases of the Rho family are important molecular switches that regulate many basic cellular processes. The function of the Rho2 and Rho5 proteins from Saccharomyces cerevisiae and of their homologs in other species is poorly understood. Here, we report on the analysis of the AgRho2 and AgRho5 proteins of the filamentous fungus Ashbya gossypii. In contrast to S. cerevisiae mutants of both encoding genes displayed a strong morphological phenotype. The Agrho2 mutants showed defects in tip-branching, while Agrho5 mutants had a significantly decreased growth rate and failed to maintain their growth axis. In addition, the Agrho5 mutants had highly defective actin rings at septation sites. We also found that a deletion mutant of a putative GDP-GTP-exchange factor (GEF) that was homologous to a Rac-GEF from other species phenocopied the Agrho5 mutant, suggesting that both proteins act in the same pathway, but the AgRho5 protein has acquired functions that are fulfilled by Rac-proteins in other species.
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Affiliation(s)
- Doris Nordmann
- Department of Genetics, University of Osnabrück, Osnabrück, Germany
| | - Manuela Lickfeld
- Department of Genetics, University of Osnabrück, Osnabrück, Germany
| | - Verena Warnsmann
- Department of Genetics, University of Osnabrück, Osnabrück, Germany
| | - Johanna Wiechert
- Department of Genetics, University of Osnabrück, Osnabrück, Germany
| | - Arne Jendretzki
- Department of Genetics, University of Osnabrück, Osnabrück, Germany
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47
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Riquelme M, Sánchez-León E. The Spitzenkörper: a choreographer of fungal growth and morphogenesis. Curr Opin Microbiol 2014; 20:27-33. [DOI: 10.1016/j.mib.2014.04.003] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Revised: 04/24/2014] [Accepted: 04/25/2014] [Indexed: 01/07/2023]
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48
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Takeshita N, Manck R, Grün N, de Vega SH, Fischer R. Interdependence of the actin and the microtubule cytoskeleton during fungal growth. Curr Opin Microbiol 2014; 20:34-41. [PMID: 24879477 DOI: 10.1016/j.mib.2014.04.005] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Revised: 04/28/2014] [Accepted: 04/29/2014] [Indexed: 02/04/2023]
Abstract
Cell polarization is a theme in biology conserved from bacteria to man. One of the most extremely polarized cells in nature is the hyphae of filamentous fungi. A continuous flow of secretion vesicles from the hyphal cell body to the tip is essential for cell wall and membrane extension. Microtubules (MTs) and actin, along with their corresponding motor proteins, are involved in the secretion process. Therefore, the arrangement of the cytoskeleton is a crucial step to establish and maintain polarity. Here we review recent findings unraveling the mechanism of polarized growth with special emphasis on the role of the actin and MT cytoskeletons and cell end markers linking the two cytoskeletons. We will mainly focus on Neurospora crassa and Aspergillus nidulans as model organisms.
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Affiliation(s)
- Norio Takeshita
- Karlsruhe Institute of Technology (KIT) - South Campus, Institute for Applied Biosciences, Department of Microbiology, Hertzstrasse 16, D-76187 Karlsruhe, Germany; University of Tsukuba, Faculty of Life and Environmental Sciences, Tsukuba, Ibaraki 305-8572, Japan.
| | - Raphael Manck
- Karlsruhe Institute of Technology (KIT) - South Campus, Institute for Applied Biosciences, Department of Microbiology, Hertzstrasse 16, D-76187 Karlsruhe, Germany
| | - Nathalie Grün
- Karlsruhe Institute of Technology (KIT) - South Campus, Institute for Applied Biosciences, Department of Microbiology, Hertzstrasse 16, D-76187 Karlsruhe, Germany
| | - Satur Herrero de Vega
- Karlsruhe Institute of Technology (KIT) - South Campus, Institute for Applied Biosciences, Department of Microbiology, Hertzstrasse 16, D-76187 Karlsruhe, Germany
| | - Reinhard Fischer
- Karlsruhe Institute of Technology (KIT) - South Campus, Institute for Applied Biosciences, Department of Microbiology, Hertzstrasse 16, D-76187 Karlsruhe, Germany.
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49
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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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50
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Riquelme M, Bredeweg EL, Callejas-Negrete O, Roberson RW, Ludwig S, Beltrán-Aguilar A, Seiler S, Novick P, Freitag M. The Neurospora crassa exocyst complex tethers Spitzenkörper vesicles to the apical plasma membrane during polarized growth. Mol Biol Cell 2014; 25:1312-26. [PMID: 24523289 PMCID: PMC3982996 DOI: 10.1091/mbc.e13-06-0299] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Fungal hyphae are among the most highly polarized cells. Hyphal polarized growth is supported by tip-directed transport of secretory vesicles, which accumulate temporarily in a stratified manner in an apical vesicle cluster, the Spitzenkörper. The exocyst complex is required for tethering of secretory vesicles to the apical plasma membrane. We determined that the presence of an octameric exocyst complex is required for the formation of a functional Spitzenkörper and maintenance of regular hyphal growth in Neurospora crassa. Two distinct localization patterns of exocyst subunits at the hyphal tip suggest the dynamic formation of two assemblies. The EXO-70/EXO-84 subunits are found at the peripheral part of the Spitzenkörper, which partially coincides with the outer macrovesicular layer, whereas exocyst components SEC-5, -6, -8, and -15 form a delimited crescent at the apical plasma membrane. Localization of SEC-6 and EXO-70 to the plasma membrane and the Spitzenkörper, respectively, depends on actin and microtubule cytoskeletons. The apical region of exocyst-mediated vesicle fusion, elucidated by the plasma membrane-associated exocyst subunits, indicates the presence of an exocytotic gradient with a tip-high maximum that dissipates gradually toward the subapex, confirming the earlier predictions of the vesicle supply center model for hyphal morphogenesis.
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Affiliation(s)
- Meritxell Riquelme
- Department of Microbiology, Center for Scientific Research and Higher Education of Ensenada, Ensenada, BC 22860, Mexico Department of Biochemistry and Biophysics, Center for Genome Research and Biocomputing, Oregon State University, Corvallis, OR 97331 School of Life Sciences, Arizona State University, Tempe, AZ 85287 Department of Molecular Plant Physiology, Institute for Biologie II, Albert-Ludwigs University Freiburg, 79104 Freiburg, Germany Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093
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