1
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Kourkoulou A, Martzoukou O, Fischer R, Amillis S. A type II phosphatidylinositol-4-kinase coordinates sorting of cargo polarizing by endocytic recycling. Commun Biol 2024; 7:855. [PMID: 38997419 PMCID: PMC11245547 DOI: 10.1038/s42003-024-06553-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 07/04/2024] [Indexed: 07/14/2024] Open
Abstract
Depending on their phosphorylation status, derivatives of phosphatidylinositol play important roles in vesicle identity, recognition and intracellular trafficking processes. In eukaryotic cells, phosphatidylinositol-4 phosphate pools generated by specific kinases are key determinants of the conventional secretion pathways. Earlier work in yeast has classified phosphatidylinositol-4 kinases in two types, Stt4p and Pik1p belonging to type III and Lsb6p to type II, with distinct cellular localizations and functions. Eurotiomycetes appear to lack Pik1p homologues. In Aspergillus nidulans, unlike homologues in other fungi, AnLsb6 is associated to late Golgi membranes and when heterologously overexpressed, it compensates for the thermosensitive phenotype in a Saccharomyces cerevisiae pik1 mutant, whereas its depletion leads to disorganization of Golgi-associated PHOSBP-labelled membranes, that tend to aggregate dependent on functional Rab5 GTPases. Evidence provided herein, indicates that the single type II phosphatidylinositol-4 kinase AnLsb6 is the main contributor for decorating secretory vesicles with relevant phosphatidylinositol-phosphate species, which navigate essential cargoes following the route of apical polarization via endocytic recycling.
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Affiliation(s)
- Anezia Kourkoulou
- National and Kapodistrian University of Athens, Department of Biology, Athens, Hellas, Greece
| | - Olga Martzoukou
- National and Kapodistrian University of Athens, Department of Biology, Athens, Hellas, Greece
| | - Reinhard Fischer
- Karlsruhe Institute of Technology - South Campus, Institute for Applied Biosciences, Department of Microbiology, Karlsruhe, Germany
| | - Sotiris Amillis
- National and Kapodistrian University of Athens, Department of Biology, Athens, Hellas, Greece.
- Karlsruhe Institute of Technology - South Campus, Institute for Applied Biosciences, Department of Microbiology, Karlsruhe, Germany.
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2
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Azizullah, Noman M, Gao Y, Wang H, Xiong X, Wang J, Li D, Song F. The SUMOylation pathway regulates the pathogenicity of Fusarium oxysporum f. sp. niveum in watermelon through stabilizing the pH regulator FonPalC via SUMOylation. Microbiol Res 2024; 281:127632. [PMID: 38310728 DOI: 10.1016/j.micres.2024.127632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Revised: 01/12/2024] [Accepted: 01/28/2024] [Indexed: 02/06/2024]
Abstract
SUMOylation is a key post-translational modification, where small ubiquitin-related modifier (SUMO) proteins regulate crucial biological processes, including pathogenesis, in phytopathogenic fungi. Here, we investigated the function and mechanism of the SUMOylation pathway in the pathogenicity of Fusarium oxysporum f. sp. niveum (Fon), the fungal pathogen that causes watermelon Fusarium wilt. Disruption of key SUMOylation pathway genes, FonSMT3, FonAOS1, FonUBC9, and FonMMS21, significantly reduced pathogenicity, impaired penetration ability, and attenuated invasive growth capacity of Fon. Transcription and proteomic analyses identified a diverse set of SUMOylation-regulated differentially expressed genes and putative FonSMT3-targeted proteins, which are predicted to be involved in infection, DNA damage repair, programmed cell death, reproduction, growth, and development. Among 155 putative FonSMT3-targeted proteins, FonPalC, a Pal/Rim-pH signaling regulator, was confirmed to be SUMOylated. The FonPalC protein accumulation was significantly decreased in SUMOylation-deficient mutant ∆Fonsmt3. Deletion of FonPalC resulted in impaired mycelial growth, decreased pathogenicity, enhanced osmosensitivity, and increased intracellular vacuolation in Fon. Importantly, mutations in conserved SUMOylation sites of FonPalC failed to restore the defects in ∆Fonpalc mutant, indicating the critical function of the SUMOylation in FonPalC stability and Fon pathogenicity. Identifying key SUMOylation-regulated pathogenicity-related proteins provides novel insights into the molecular mechanisms underlying Fon pathogenesis regulated by SUMOylation.
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Affiliation(s)
- Azizullah
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insect Pests, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China; Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China; State Key Laboratory of Rice Biology and Breeding, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Muhammad Noman
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insect Pests, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China; Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China; State Key Laboratory of Rice Biology and Breeding, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China; State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-Products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Yizhou Gao
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insect Pests, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China; Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China; State Key Laboratory of Rice Biology and Breeding, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Hui Wang
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insect Pests, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China; Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China; State Key Laboratory of Rice Biology and Breeding, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Xiaohui Xiong
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insect Pests, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China; Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China; State Key Laboratory of Rice Biology and Breeding, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Jiajing Wang
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insect Pests, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China; Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China; State Key Laboratory of Rice Biology and Breeding, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Dayong Li
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insect Pests, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China; Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China; State Key Laboratory of Rice Biology and Breeding, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Fengming Song
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insect Pests, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China; Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China; State Key Laboratory of Rice Biology and Breeding, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058, China.
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3
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Chelius C, Huso W, Reese S, Doan A, Lincoln S, Lawson K, Tran B, Purohit R, Glaros T, Srivastava R, Harris SD, Marten MR. Dynamic Transcriptomic and Phosphoproteomic Analysis During Cell Wall Stress in Aspergillus nidulans. Mol Cell Proteomics 2020; 19:1310-1329. [PMID: 32430394 PMCID: PMC8014999 DOI: 10.1074/mcp.ra119.001769] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 03/30/2020] [Indexed: 12/15/2022] Open
Abstract
The fungal cell-wall integrity signaling (CWIS) pathway regulates cellular response to environmental stress to enable wall repair and resumption of normal growth. This complex, interconnected, pathway has been only partially characterized in filamentous fungi. To better understand the dynamic cellular response to wall perturbation, a β-glucan synthase inhibitor (micafungin) was added to a growing A. nidulans shake-flask culture. From this flask, transcriptomic and phosphoproteomic data were acquired over 10 and 120 min, respectively. To differentiate statistically-significant dynamic behavior from noise, a multivariate adaptive regression splines (MARS) model was applied to both data sets. Over 1800 genes were dynamically expressed and over 700 phosphorylation sites had changing phosphorylation levels upon micafungin exposure. Twelve kinases had altered phosphorylation and phenotypic profiling of all non-essential kinase deletion mutants revealed putative connections between PrkA, Hk-8-4, and Stk19 and the CWIS pathway. Our collective data implicate actin regulation, endocytosis, and septum formation as critical cellular processes responding to activation of the CWIS pathway, and connections between CWIS and calcium, HOG, and SIN signaling pathways.
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Affiliation(s)
- Cynthia Chelius
- Department of Chemical, Biochemical, and Environmental Engineering, University of Maryland Baltimore County, Baltimore, Maryland, USA
| | - Walker Huso
- Department of Chemical, Biochemical, and Environmental Engineering, University of Maryland Baltimore County, Baltimore, Maryland, USA
| | - Samantha Reese
- Center for Plant Science Innovation and Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Alexander Doan
- Department of Chemical, Biochemical, and Environmental Engineering, University of Maryland Baltimore County, Baltimore, Maryland, USA
| | - Stephen Lincoln
- Department of Chemical and Biomolecular Engineering, University of Connecticut, Storrs, Connecticut, USA
| | - Kelsi Lawson
- Department of Chemical, Biochemical, and Environmental Engineering, University of Maryland Baltimore County, Baltimore, Maryland, USA
| | - Bao Tran
- BioScience Mass Spectrometry Facility, The U.S. Army CCDC Chemical Biological Center, BioSciences Division, Aberdeen Proving Ground, Maryland, USA
| | - Raj Purohit
- Department of Chemical, Biochemical, and Environmental Engineering, University of Maryland Baltimore County, Baltimore, Maryland, USA
| | - Trevor Glaros
- BioSciences Division, B11 Bioenergy and Biome Sciences, Los Alamos National Laboratory, Los Alamos, New Mexico, USA
| | - Ranjan Srivastava
- Department of Chemical and Biomolecular Engineering, University of Connecticut, Storrs, Connecticut, USA
| | - Steven D Harris
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Mark R Marten
- Department of Chemical, Biochemical, and Environmental Engineering, University of Maryland Baltimore County, Baltimore, Maryland, USA.
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4
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COP9 Signalosome Interaction with UspA/Usp15 Deubiquitinase Controls VeA-Mediated Fungal Multicellular Development. Biomolecules 2019; 9:biom9060238. [PMID: 31216760 PMCID: PMC6627422 DOI: 10.3390/biom9060238] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 06/02/2019] [Accepted: 06/16/2019] [Indexed: 12/26/2022] Open
Abstract
COP9 signalosome (CSN) and Den1/A deneddylases physically interact and promote multicellular development in fungi. CSN recognizes Skp1/cullin-1/Fbx E3 cullin-RING ligases (CRLs) without substrate and removes their posttranslational Nedd8 modification from the cullin scaffold. This results in CRL complex disassembly and allows Skp1 adaptor/Fbx receptor exchange for altered substrate specificity. We characterized the novel ubiquitin-specific protease UspA of the mold Aspergillusnidulans, which corresponds to CSN-associated human Usp15 and interacts with six CSN subunits. UspA reduces amounts of ubiquitinated proteins during fungal development, and the uspA gene expression is repressed by an intact CSN. UspA is localized in proximity to nuclei and recruits proteins related to nuclear transport and transcriptional processing, suggesting functions in nuclear entry control. UspA accelerates the formation of asexual conidiospores, sexual development, and supports the repression of secondary metabolite clusters as the derivative of benzaldehyde (dba) genes. UspA reduces protein levels of the fungal NF-kappa B-like velvet domain protein VeA, which coordinates differentiation and secondary metabolism. VeA stability depends on the Fbx23 receptor, which is required for light controlled development. Our data suggest that the interplay between CSN deneddylase, UspA deubiquitinase, and SCF-Fbx23 ensures accurate levels of VeA to support fungal development and an appropriate secondary metabolism.
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5
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Hernández‐González M, Pantazopoulou A, Spanoudakis D, Seegers CL, Peñalva MA. Genetic dissection of the secretory route followed by a fungal extracellular glycosyl hydrolase. Mol Microbiol 2018; 109:781-800. [DOI: 10.1111/mmi.14073] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 06/15/2018] [Accepted: 07/02/2018] [Indexed: 01/16/2023]
Affiliation(s)
- Miguel Hernández‐González
- Department of Cellular and Molecular Biology and WhiteBiotech Interdepartmental Unit Centro de Investigaciones Biológicas CSIC Madrid Spain
| | - Areti Pantazopoulou
- Department of Cellular and Molecular Biology and WhiteBiotech Interdepartmental Unit Centro de Investigaciones Biológicas CSIC Madrid Spain
- Department of Molecular Genetics and Cell Biology The University of Chicago Chicago IL USA
| | - Dimitris Spanoudakis
- Department of Cellular and Molecular Biology and WhiteBiotech Interdepartmental Unit Centro de Investigaciones Biológicas CSIC Madrid Spain
| | - Christel L.C. Seegers
- Department of Cellular and Molecular Biology and WhiteBiotech Interdepartmental Unit Centro de Investigaciones Biológicas CSIC Madrid Spain
- Avebe UA Foxhol The Netherlands
| | - Miguel A. Peñalva
- Department of Cellular and Molecular Biology and WhiteBiotech Interdepartmental Unit Centro de Investigaciones Biológicas CSIC Madrid Spain
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6
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Boppidi KR, Ribeiro LFC, Iambamrung S, Nelson SM, Wang Y, Momany M, Richardson EA, Lincoln S, Srivastava R, Harris SD, Marten MR. Altered secretion patterns and cell wall organization caused by loss of PodB function in the filamentous fungus Aspergillus nidulans. Sci Rep 2018; 8:11433. [PMID: 30061727 PMCID: PMC6065416 DOI: 10.1038/s41598-018-29615-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 07/12/2018] [Indexed: 12/27/2022] Open
Abstract
Filamentous fungi are widely used in the production of a variety of industrially relevant enzymes and proteins as they have the unique ability to secrete tremendous amounts of proteins. However, the secretory pathways in filamentous fungi are not completely understood. Here, we investigated the role of a mutation in the POlarity Defective (podB) gene on growth, protein secretion, and cell wall organization in Aspergillus nidulans using a temperature sensitive (Ts) mutant. At restrictive temperature, the mutation resulted in lack of biomass accumulation, but led to a significant increase in specific protein productivity. Proteomic analysis of the secretome showed that the relative abundance of 584 (out of 747 identified) proteins was altered due to the mutation. Of these, 517 were secreted at higher levels. Other phenotypic differences observed in the mutant include up-regulation of unfolded protein response (UPR), deformation of Golgi apparatus and uneven cell wall thickness. Furthermore, proteomic analysis of cell wall components in the mutant revealed the presence of intracellular proteins in higher abundance accompanied by lower levels of most cell wall proteins. Taken together, results from this study suggest the importance of PodB as a target when engineering fungal strains for enhanced secretion of valuable biomolecules.
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Affiliation(s)
- Karthik R Boppidi
- University of Maryland - Baltimore County, Department of Chemical Biochemical and Environmental Engineering, Baltimore, MD, USA
| | - Liliane Fraga Costa Ribeiro
- University of Maryland - Baltimore County, Department of Chemical Biochemical and Environmental Engineering, Baltimore, MD, USA
| | - Sirasa Iambamrung
- University of Maryland - Baltimore County, Department of Chemical Biochemical and Environmental Engineering, Baltimore, MD, USA
| | - Sidney M Nelson
- University of Maryland - Baltimore County, Department of Chemical Biochemical and Environmental Engineering, Baltimore, MD, USA
| | - Yan Wang
- University of Maryland - College Park, Department of Cell Biology and Molecular Genetics, College Park, MD, USA
| | - Michelle Momany
- University of Georgia, Fungal Biology Group and Department of Plant Biology, Athens, GA, USA
| | | | - Stephen Lincoln
- University of Connecticut, Department of Chemical and Biomolecular Engineering, Storrs, CT, USA
| | - Ranjan Srivastava
- University of Connecticut, Department of Chemical and Biomolecular Engineering, Storrs, CT, USA
| | - Steven D Harris
- University of Manitoba, Department of Biological Sciences, Winnipeg, MB, Canada
| | - Mark R Marten
- University of Maryland - Baltimore County, Department of Chemical Biochemical and Environmental Engineering, Baltimore, MD, USA.
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7
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Pinar M, Peñalva MA. Aspergillus nidulansBapH is a RAB11 effector that connects membranes in the Spitzenkörper with basal autophagy. Mol Microbiol 2017; 106:452-468. [DOI: 10.1111/mmi.13777] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/22/2017] [Indexed: 12/13/2022]
Affiliation(s)
- Mario Pinar
- Departamento de Biología Celular y Molecular; Centro de Investigaciones Biológicas del CSIC, Ramiro de Maeztu 9; Madrid 28040 Spain
| | - Miguel A. Peñalva
- Departamento de Biología Celular y Molecular; Centro de Investigaciones Biológicas del CSIC, Ramiro de Maeztu 9; Madrid 28040 Spain
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8
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Abstract
Filamentous fungi are a large and ancient clade of microorganisms that occupy a broad range of ecological niches. The success of filamentous fungi is largely due to their elongate hypha, a chain of cells, separated from each other by septa. Hyphae grow by polarized exocytosis at the apex, which allows the fungus to overcome long distances and invade many substrates, including soils and host tissues. Hyphal tip growth is initiated by establishment of a growth site and the subsequent maintenance of the growth axis, with transport of growth supplies, including membranes and proteins, delivered by motors along the cytoskeleton to the hyphal apex. Among the enzymes delivered are cell wall synthases that are exocytosed for local synthesis of the extracellular cell wall. Exocytosis is opposed by endocytic uptake of soluble and membrane-bound material into the cell. The first intracellular compartment in the endocytic pathway is the early endosomes, which emerge to perform essential additional functions as spatial organizers of the hyphal cell. Individual compartments within septated hyphae can communicate with each other via septal pores, which allow passage of cytoplasm or organelles to help differentiation within the mycelium. This article introduces the reader to more detailed aspects of hyphal growth in fungi.
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9
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Labbaoui H, Bogliolo S, Ghugtyal V, Solis NV, Filler SG, Arkowitz RA, Bassilana M. Role of Arf GTPases in fungal morphogenesis and virulence. PLoS Pathog 2017; 13:e1006205. [PMID: 28192532 PMCID: PMC5325608 DOI: 10.1371/journal.ppat.1006205] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 02/24/2017] [Accepted: 01/29/2017] [Indexed: 12/30/2022] Open
Abstract
Virulence of the human fungal pathogen Candida albicans depends on the switch from budding to filamentous growth, which requires sustained membrane traffic and polarized growth. In many organisms, small GTPases of the Arf (ADP-ribosylation factor) family regulate membrane/protein trafficking, yet little is known about their role in fungal filamentous growth. To investigate these GTPases in C. albicans, we generated loss of function mutants in all 3 Arf proteins, Arf1-Arf3, and 2 Arf-like proteins, Arl1 and Arl3. Our results indicate that of these proteins, Arf2 is required for viability and sensitivity to antifungal drugs. Repressible ARF2 expression results in defects in filamentous growth, cell wall integrity and virulence, likely due to alteration of the Golgi. Arl1 is also required for invasive filamentous growth and, although arl1/arl1 cells can initiate hyphal growth, hyphae are substantially shorter than that of the wild-type, due to the inability of this mutant to maintain hyphal growth at a single site. We show that this defect does not result from an alteration of phospholipid distribution and is unlikely to result from the sole Golgin Imh1 mislocalization, as Imh1 is not required for invasive filamentous growth. Rather, our results suggest that the arl1/arl1 hyphal growth defect results from increased secretion in this mutant. Strikingly, the arl1/arl1 mutant is drastically reduced in virulence during oropharyngeal candidiasis. Together, our results highlight the importance of Arl1 and Arf2 as key regulators of hyphal growth and virulence in C. albicans and identify a unique function of Arl1 in secretion.
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Affiliation(s)
- Hayet Labbaoui
- Université Côte d’Azur, CNRS, INSERM, iBV, Parc Valrose, Nice, France
| | | | - Vikram Ghugtyal
- Université Côte d’Azur, CNRS, INSERM, iBV, Parc Valrose, Nice, France
| | - Norma V. Solis
- Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, United States of America
| | - Scott G. Filler
- Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, United States of America
| | | | - Martine Bassilana
- Université Côte d’Azur, CNRS, INSERM, iBV, Parc Valrose, Nice, France
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10
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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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11
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Arst HN, Hernandez-Gonzalez M, Peñalva MA, Pantazopoulou A. GBF/Gea mutant with a single substitution sustains fungal growth in the absence of BIG/Sec7. FEBS Lett 2014; 588:4799-806. [PMID: 25451223 PMCID: PMC4266534 DOI: 10.1016/j.febslet.2014.11.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 11/07/2014] [Accepted: 11/10/2014] [Indexed: 12/11/2022]
Abstract
A. nidulans has a GBF/Gea and a BIG/Sec7 subfamily Golgi Arf1-GEFs, both essential. The late Golgi Arf1-GEF mutant hypB5 conditionally blocks secretion. Residue substitution in the early Golgi Arf1-GEF GeaA suppresses hypB5 and hypBΔ. The mutation alters a GBF/Gea amino acid motif and shifts GeaA localization. GeaA1 alone satisfies the eukaryotic requirement for two Golgi Arf1 GEFs.
Golgi Arf1-guanine nucleotide exchange factors (GEFs) belong to two subfamilies: GBF/Gea and BIG/Sec7. Both are conserved across eukaryotes, but the physiological role of each is not well understood. Aspergillus nidulans has a single member of the early Golgi GBF/Gea-subfamily, geaA, and the late Golgi BIG/Sec7-subfamily, hypB. Both geaA and hypB are essential. hypB5 conditionally blocks secretion. We sought extragenic hypB5 suppressors and obtained geaA1. geaA1 results in Tyr1022Cys within a conserved GBF/Gea-specific S(Y/W/F)(L/I) motif in GeaA. This mutation alters GeaA localization. Remarkably, geaA1 suppresses hypBΔ, indicating that a single mutant Golgi Arf1-GEF suffices for growth.
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Affiliation(s)
- Herbert N Arst
- Section of Microbiology, Department of Medicine, Imperial College London, London SW7 2AZ, United Kingdom; Centro de Investigaciones Biológicas, CSIC, Madrid 28040, Spain
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12
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Characterization of the mutagenic spectrum of 4-nitroquinoline 1-oxide (4-NQO) in Aspergillus nidulans by whole genome sequencing. G3-GENES GENOMES GENETICS 2014; 4:2483-92. [PMID: 25352541 PMCID: PMC4267943 DOI: 10.1534/g3.114.014712] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
4-Nitroquinoline 1-oxide (4-NQO) is a highly carcinogenic chemical that induces mutations in bacteria, fungi, and animals through the formation of bulky purine adducts. 4-NQO has been used as a mutagen for genetic screens and in both the study of DNA damage and DNA repair. In the model eukaryote Aspergillus nidulans, 4-NQO-based genetic screens have been used to study diverse processes, including gene regulation, mitosis, metabolism, organelle transport, and septation. Early work during the 1970s using bacterial and yeast mutation tester strains concluded that 4-NQO was a guanine-specific mutagen. However, these strains were limited in their ability to determine full mutagenic potential, as they could not identify mutations at multiple sites, unlinked suppressor mutations, or G:C to C:G transversions. We have now used a whole genome resequencing approach with mutant strains generated from two independent genetic screens to determine the full mutagenic spectrum of 4-NQO in A. nidulans. Analysis of 3994 mutations from 38 mutant strains reveals that 4-NQO induces substitutions in both guanine and adenine residues, although with a 19-fold preference for guanine. We found no association between mutation load and mutagen dose and observed no sequence bias in the residues flanking the mutated purine base. The mutations were distributed randomly throughout most of the genome. Our data provide new evidence that 4-NQO can potentially target all base pairs. Furthermore, we predict that current practices for 4-NQO-induced mutagenesis are sufficient to reach gene saturation for genetic screens with feasible identification of causative mutations via whole genome resequencing.
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13
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Gremillion SK, Harris SD, Jackson-Hayes L, Kaminskyj SGW, Loprete DM, Gauthier AC, Mercer S, Ravita AJ, Hill TW. Mutations in proteins of the Conserved Oligomeric Golgi Complex affect polarity, cell wall structure, and glycosylation in the filamentous fungus Aspergillus nidulans. Fungal Genet Biol 2014; 73:69-82. [PMID: 25312861 DOI: 10.1016/j.fgb.2014.10.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 09/30/2014] [Accepted: 10/05/2014] [Indexed: 01/18/2023]
Abstract
We have described two Aspergillus nidulans gene mutations, designated podB1 (polarity defective) and swoP1 (swollen cell), which cause temperature-sensitive defects during polarization. Mutant strains also displayed unevenness and abnormal thickness of cell walls. Un-polarized or poorly-polarized mutant cells were capable of establishing normal polarity after a shift to a permissive temperature, and mutant hyphae shifted from permissive to restrictive temperature show wall and polarity abnormalities in subsequent growth. The mutated genes (podB=AN8226.3; swoP=AN7462.3) were identified as homologues of COG2 and COG4, respectively, each predicted to encode a subunit of the multi-protein COG (Conserved Oligomeric Golgi) Complex involved in retrograde vesicle trafficking in the Golgi apparatus. Down-regulation of COG2 or COG4 resulted in abnormal polarization and cell wall staining. The GFP-tagged COG2 and COG4 homologues displayed punctate, Golgi-like localization. Lectin-blotting indicated that protein glycosylation was altered in the mutant strains compared to the wild type. A multicopy expression experiment showed evidence for functional interactions between the homologues COG2 and COG4 as well as between COG2 and COG3. To date, this work is the first regarding a functional role of the COG proteins in the development of a filamentous fungus.
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Affiliation(s)
- S K Gremillion
- Department of Biology, Armstrong State University, 11935 Abercorn Street, Savannah, GA 31419, USA.
| | - S D Harris
- Center for Plant Science Innovation, University of Nebraska, Lincoln, NE 68588-0660, USA
| | - L Jackson-Hayes
- Department of Chemistry, Rhodes College, 2000 North Parkway, Memphis, TN 38112, USA
| | - S G W Kaminskyj
- Department of Biology, University of Saskatchewan, 112 Science Place Saskatoon, Saskatchewan S7N 5E2, Canada
| | - D M Loprete
- Department of Chemistry, Rhodes College, 2000 North Parkway, Memphis, TN 38112, USA
| | - A C Gauthier
- Department of Biology, Armstrong State University, 11935 Abercorn Street, Savannah, GA 31419, USA
| | - S Mercer
- Department of Biology, Rhodes College, 2000 North Parkway, Memphis, TN 38112, USA
| | - A J Ravita
- Department of Biology, Armstrong State University, 11935 Abercorn Street, Savannah, GA 31419, USA
| | - T W Hill
- Department of Biology, Rhodes College, 2000 North Parkway, Memphis, TN 38112, USA
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14
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Pantazopoulou A, Pinar M, Xiang X, Peñalva MA. Maturation of late Golgi cisternae into RabE(RAB11) exocytic post-Golgi carriers visualized in vivo. Mol Biol Cell 2014; 25:2428-43. [PMID: 24943841 PMCID: PMC4142615 DOI: 10.1091/mbc.e14-02-0710] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The mechanism(s) by which proteins traverse and exit the Golgi are incompletely understood. Using Aspergillus nidulans hyphae, we show that late Golgi cisternae undergo changes in composition to gradually lose Golgi identity while acquiring post-Golgi RabE(RAB11) identity. This behavior of late Golgi cisternae is consistent with the cisternal maturation model. Post-Golgi RabE(RAB11) carriers travel to, and accumulate at, the apex, indicating that fusion is rate limiting for exocytosis. These carriers, which are loaded with kinesin, dynein, and MyoE(MYO5), move on a microtubule-based bidirectional conveyor belt relaying them to actin, which ultimately focuses exocytosis at the apex. Dynein drags RabE(RAB11) carriers away if engagement of MyoE(MYO5) to actin cables fails. Microtubules seemingly cooperating with F-actin capture can sustain secretion if MyoE(MYO5) is absent. Thus, filamentous fungal secretion involving post-Golgi carriers is remarkably similar, mechanistically, to the transport of melanosomes in melanocyte dendrites, even though melanosome biogenesis involves lysosomes rather than Golgi.
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Affiliation(s)
- Areti Pantazopoulou
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Madrid 28040, Spain
| | - Mario Pinar
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Madrid 28040, Spain
| | - Xin Xiang
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814
| | - Miguel A Peñalva
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Madrid 28040, Spain
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15
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Alam MK, van Straaten KE, Sanders DAR, Kaminskyj SGW. Aspergillus nidulans cell wall composition and function change in response to hosting several Aspergillus fumigatus UDP-galactopyranose mutase activity mutants. PLoS One 2014; 9:e85735. [PMID: 24454924 PMCID: PMC3893270 DOI: 10.1371/journal.pone.0085735] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Accepted: 11/30/2013] [Indexed: 11/18/2022] Open
Abstract
Deletion or repression of Aspergillus nidulans ugmA (AnugmA), involved in galactofuranose biosynthesis, impairs growth and increases sensitivity to Caspofungin, a β-1,3-glucan synthesis antagonist. The A. fumigatus UgmA (AfUgmA) crystal structure has been determined. From that study, AfUgmA mutants with altered enzyme activity were transformed into AnugmA▵ to assess their effect on growth and wall composition in A. nidulans. The complemented (AnugmA::wild type AfugmA) strain had wild type phenotype, indicating these genes had functional homology. Consistent with in vitro studies, AfUgmA residues R182 and R327 were important for its function in vivo, with even conservative amino (RK) substitutions producing AnugmA? phenotype strains. Similarly, the conserved AfUgmA loop III histidine (H63) was important for Galf generation: the H63N strain had a partially rescued phenotype compared to AnugmA▵. Collectively, A. nidulans strains that hosted mutated AfUgmA constructs with low enzyme activity showed increased hyphal surface adhesion as assessed by binding fluorescent latex beads. Consistent with previous qPCR results, immunofluorescence and ELISA indicated that AnugmA▵ and AfugmA-mutated A. nidulans strains had increased α-glucan and decreased β-glucan in their cell walls compared to wild type and AfugmA-complemented strains. Like the AnugmA▵ strain, A. nidulans strains containing mutated AfugmA showed increased sensitivity to antifungal drugs, particularly Caspofungin. Reduced β-glucan content was correlated with increased Caspofungin sensitivity. Aspergillus nidulans wall Galf, α-glucan, and β-glucan content was correlated in A. nidulans hyphal walls, suggesting dynamic coordination between cell wall synthesis and cell wall integrity.
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Affiliation(s)
- Md Kausar Alam
- Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
- * E-mail:
| | - Karin E. van Straaten
- Department of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - David A. R. Sanders
- Department of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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16
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Harris SD. Golgi organization and the apical extension of fungal hyphae: an essential relationship. Mol Microbiol 2013; 89:212-5. [DOI: 10.1111/mmi.12291] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/06/2013] [Indexed: 11/30/2022]
Affiliation(s)
- Steven D. Harris
- Department of Plant Pathology and Center for Plant Science Innovation; University of Nebraska; Lincoln NE 68588-0660 USA
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17
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Pinar M, Pantazopoulou A, Arst HN, Peñalva MA. Acute inactivation of theAspergillus nidulans Golgi membrane fusion machinery: correlation of apical extension arrest and tip swelling with cisternal disorganization. Mol Microbiol 2013; 89:228-48. [DOI: 10.1111/mmi.12280] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/25/2013] [Indexed: 12/17/2022]
Affiliation(s)
- Mario Pinar
- Departamento de Biología Celular y Molecular; Centro de Investigaciones Biológicas CSIC; Ramiro de Maeztu 9 Madrid 28040 Spain
| | - Areti Pantazopoulou
- Departamento de Biología Celular y Molecular; Centro de Investigaciones Biológicas CSIC; Ramiro de Maeztu 9 Madrid 28040 Spain
| | - Herbert N. Arst
- Departamento de Biología Celular y Molecular; Centro de Investigaciones Biológicas CSIC; Ramiro de Maeztu 9 Madrid 28040 Spain
- Section of Microbiology; Department of Medicine; Imperial College; Armstrong Road London SW7 2AZ UK
| | - Miguel A. Peñalva
- Departamento de Biología Celular y Molecular; Centro de Investigaciones Biológicas CSIC; Ramiro de Maeztu 9 Madrid 28040 Spain
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18
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Pinar M, Pantazopoulou A, Peñalva MA. Live-cell imaging of Aspergillus nidulans autophagy: RAB1 dependence, Golgi independence and ER involvement. Autophagy 2013; 9:1024-43. [PMID: 23722157 DOI: 10.4161/auto.24483] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
We exploited the amenability of the fungus Aspergillus nidulans to genetics and live-cell microscopy to investigate autophagy. Upon nitrogen starvation, GFP-Atg8-containing pre-autophagosomal puncta give rise to cup-shaped phagophores and circular (0.9-μm diameter) autophagosomes that disappear in the vicinity of the vacuoles after their shape becomes irregular and their GFP-Atg8 fluorescence decays. This 'autophagosome cycle' gives rise to characteristic cone-shaped traces in kymographs. Autophagy does not require endosome maturation or ESCRTs, as autophagosomes fuse with vacuoles directly in a RabS (homolog of Saccharomyces cerevisiae Ypt7 and mammalian RAB7; written hereafter as RabS(RAB7))-HOPS-(homotypic fusion and vacuole protein sorting complex)-dependent manner. However, by removing RabS(RAB7) or Vps41 (a component of the HOPS complex), we show that autophagosomes may still fuse, albeit inefficiently, with the endovacuolar system in a process almost certainly mediated by RabA(RAB5)/RabB(RAB5) (yeast Vps21 homologs)-CORVET (class C core vacuole/endosome tethering complex), because acute inactivation of HbrA/Vps33, a key component of HOPS and CORVET, completely precludes access of GFP-Atg8 to vacuoles without affecting autophagosome biogenesis. Using a FYVE 2-GFP probe and endosomal PtdIns3P-depleted cells, we imaged PtdIns3P on autophagic membranes. PtdIns3P present on autophagosomes decays at late stages of the cycle, preceding fusion with the vacuole. Autophagy does not require Golgi traffic, but it is crucially dependent on RabO(RAB1). TRAPPIII-specific factor AN7311 (yeast Trs85) localizes to the phagophore assembly site (PAS) and RabO(RAB1) localizes to phagophores and autophagosomes. The Golgi and autophagy roles of RabO(RAB1) are dissociable by mutation: rabO(A136D) hyphae show relatively normal secretion at 28°C but are completely blocked in autophagy. This finding and the lack of Golgi traffic involvement pointed to the ER as one potential source of membranes for autophagy. In agreement, autophagosomes form in close association with ring-shaped omegasome-like ER structures resembling those described in mammalian cells.
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Affiliation(s)
- Mario Pinar
- Centro de Investigaciones Biológicas (CSIC); Madrid, Spain
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20
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Pantazopoulou A, Peñalva MA. Organization and dynamics of the Aspergillus nidulans Golgi during apical extension and mitosis. Mol Biol Cell 2009; 20:4335-47. [PMID: 19692566 DOI: 10.1091/mbc.e09-03-0254] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Aspergillus nidulans hyphae grow exclusively by apical extension. Golgi equivalents (GEs) labeled with mRFP-tagged PH(OSBP) domain form a markedly polarized, dynamic network of ring-shaped and fenestrated cisternae that remains intact during "closed" mitosis. mRFP-PH(OSBP) GEs advance associated with the growing apex where secretion predominates but do not undergo long-distance movement toward the tip that could account for their polarization. mRFP-PH(OSBP) GEs overlap with the trans-Golgi resident Sec7 but do not colocalize with also polarized accretions of the early Golgi marker GrhA(Grh1)-GFP, indicating that early and late Golgi membranes segregate spatially. AnSec23-GFP ER exit sites (ERES) are numerous, relatively static foci localizing across the entire cell. However, their density is greatest near the tip, correlating with predominance of early and trans-Golgi elements in this region. Whereas GrhA-GFP structures and ERES reach the apical dome, mRFP-PH(OSBP) GEs are excluded from this region, which contains the endosome dynein loading zone. After latrunculin-mediated F-actin disruption, mRFP-PH(OSBP) GEs fragment and, like AnSec23-GFP ERES, depolarize. Brefeldin A transiently collapses late and early GEs into distinct aggregates containing Sec7/mRFP-PH(OSBP) and GrhA-GFP, respectively, temporarily arresting apical extension. Rapid growth reinitiates after washout, correlating with reacquisition of the normal Golgi organization that, we conclude, is required for apical extension.
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Affiliation(s)
- Areti Pantazopoulou
- Departamento de Microbiología Molecular, Centro de Investigaciones Biológicas C.S.I.C., Madrid 28040, Spain
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21
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Aspergillus nidulans UDP-galactopyranose mutase, encoded by ugmA plays key roles in colony growth, hyphal morphogensis, and conidiation. Fungal Genet Biol 2008; 45:1533-42. [DOI: 10.1016/j.fgb.2008.09.008] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2008] [Revised: 09/15/2008] [Accepted: 09/17/2008] [Indexed: 11/18/2022]
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22
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Jackson-Hayes L, Hill TW, Loprete DM, Fay LM, Gordon BS, Nkashama SA, Patel RK, Sartain CV. Two GDP-mannose transporters contribute to hyphal form and cell wall integrity in Aspergillus nidulans. MICROBIOLOGY-SGM 2008; 154:2037-2047. [PMID: 18599832 DOI: 10.1099/mic.0.2008/017483-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In order to identify novel genes affecting cell wall integrity, we have generated mutant strains of the filamentous fungus Aspergillus nidulans that show hypersensitivity to the chitin-binding agent Calcofluor White (CFW). Affected loci are designated cal loci. The phenotype of one of these alleles, calI11, also includes shortened hyphal compartments and increased density of branching in the absence of CFW, as well as reduced staining of cell walls by the lectin FITC-Concanavalin A (ConA), which has strong binding affinity for mannosyl residues. We have identified two A. nidulans genes (AN8848.3 and AN9298.3, designated gmtA and gmtB, respectively) that complement all aspects of the phenotype. Both genes show strong sequence similarity to GDP-mannose transporters (GMTs) of Saccharomyces and other yeasts. Sequencing of gmtA from the calI11 mutant strain reveals a G to C mutation at position 943, resulting in a predicted alanine to proline substitution at amino acid position 315 within a region that is highly conserved among other fungi. No mutations were observed in the mutant strain's allele of gmtB. Meiotic mapping demonstrated a recombination frequency of under 1 % between the calI locus and the phenA locus (located approximately 9.5 kb from AN8848.3), confirming that gmtA and calI are identical. A GmtA-GFP chimera exhibits a punctate distribution pattern, consistent with that shown by putative Golgi markers in A. nidulans. However, this distribution did not overlap with that of the putative Golgi equivalent marker CopA-monomeric red fluorescent protein (mRFP), which may indicate that the physically separated Golgi-equivalent organelles of A. nidulans represent physiologically distinct counterparts of the stacked cisternae of plants and animals. These findings demonstrate that gmtA and gmtB play roles in cell wall metabolism in A. nidulans similar to those previously reported for GMTs in yeasts.
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Affiliation(s)
| | - Terry W Hill
- Departments of Chemistry and Biology, Rhodes College, Memphis, TN 38112, USA
| | - Darlene M Loprete
- Departments of Chemistry and Biology, Rhodes College, Memphis, TN 38112, USA
| | - Lauren M Fay
- Departments of Chemistry and Biology, Rhodes College, Memphis, TN 38112, USA
| | - Barbara S Gordon
- Departments of Chemistry and Biology, Rhodes College, Memphis, TN 38112, USA
| | - Sonia A Nkashama
- Departments of Chemistry and Biology, Rhodes College, Memphis, TN 38112, USA
| | - Ravi K Patel
- Departments of Chemistry and Biology, Rhodes College, Memphis, TN 38112, USA
| | - Caroline V Sartain
- Departments of Chemistry and Biology, Rhodes College, Memphis, TN 38112, USA
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