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Martín JF, Liras P. Targeting of Specialized Metabolites Biosynthetic Enzymes to Membranes and Vesicles by Posttranslational Palmitoylation: A Mechanism of Non-Conventional Traffic and Secretion of Fungal Metabolites. Int J Mol Sci 2024; 25:1224. [PMID: 38279221 PMCID: PMC10816013 DOI: 10.3390/ijms25021224] [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: 12/08/2023] [Revised: 12/30/2023] [Accepted: 01/09/2024] [Indexed: 01/28/2024] Open
Abstract
In nature, the formation of specialized (secondary) metabolites is associated with the late stages of fungal development. Enzymes involved in the biosynthesis of secondary metabolites in fungi are located in distinct subcellular compartments including the cytosol, peroxisomes, endosomes, endoplasmic reticulum, different types of vesicles, the plasma membrane and the cell wall space. The enzymes traffic between these subcellular compartments and the secretion through the plasma membrane are still unclear in the biosynthetic processes of most of these metabolites. Recent reports indicate that some of these enzymes initially located in the cytosol are later modified by posttranslational acylation and these modifications may target them to membrane vesicle systems. Many posttranslational modifications play key roles in the enzymatic function of different proteins in the cell. These modifications are very important in the modulation of regulatory proteins, in targeting of proteins, intracellular traffic and metabolites secretion. Particularly interesting are the protein modifications by palmitoylation, prenylation and miristoylation. Palmitoylation is a thiol group-acylation (S-acylation) of proteins by palmitic acid (C16) that is attached to the SH group of a conserved cysteine in proteins. Palmitoylation serves to target acylated proteins to the cytosolic surface of cell membranes, e.g., to the smooth endoplasmic reticulum, whereas the so-called toxisomes are formed in trichothecene biosynthesis. Palmitoylation of the initial enzymes involved in the biosynthesis of melanin serves to target them to endosomes and later to the conidia, whereas other non-palmitoylated laccases are secreted directly by the conventional secretory pathway to the cell wall space where they perform the last step(s) of melanin biosynthesis. Six other enzymes involved in the biosynthesis of endocrosin, gliotoxin and fumitremorgin believed to be cytosolic are also targeted to vesicles, although it is unclear if they are palmitoylated. Bioinformatic analysis suggests that palmitoylation may be frequent in the modification and targeting of polyketide synthetases and non-ribosomal peptide synthetases. The endosomes may integrate other small vesicles with different cargo proteins, forming multivesicular bodies that finally fuse with the plasma membrane during secretion. Another important effect of palmitoylation is that it regulates calcium metabolism by posttranslational modification of the phosphatase calcineurin. Mutants defective in the Akr1 palmitoyl transferase in several fungi are affected in calcium transport and homeostasis, thus impacting on the biosynthesis of calcium-regulated specialized metabolites. The palmitoylation of secondary metabolites biosynthetic enzymes and their temporal distribution respond to the conidiation signaling mechanism. In summary, this posttranslational modification drives the spatial traffic of the biosynthetic enzymes between the subcellular organelles and the plasma membrane. This article reviews the molecular mechanism of palmitoylation and the known fungal palmitoyl transferases. This novel information opens new ways to improve the biosynthesis of the bioactive metabolites and to increase its secretion in fungi.
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Affiliation(s)
- Juan F. Martín
- Departamento de Biología Molecular, Área de Microbiología, Universidad de León, 24071 León, Spain;
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2
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Atanasova L, Marchetti-Deschmann M, Nemes A, Bruckner B, Rehulka P, Stralis-Pavese N, Łabaj PP, Kreil DP, Zeilinger S. Mycoparasitism related targets of Tmk1 indicate stimulating regulatory functions of this MAP kinase in Trichoderma atroviride. Sci Rep 2023; 13:19976. [PMID: 37968441 PMCID: PMC10651915 DOI: 10.1038/s41598-023-47027-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 11/08/2023] [Indexed: 11/17/2023] Open
Abstract
Mycoparasitism is a key feature of Trichoderma (Hypocreales, Ascomycota) biocontrol agents. Recent studies of intracellular signal transduction pathways of the potent mycoparasite Trichoderma atroviride revealed the involvement of Tmk1, a mitogen-activated protein kinase (MAPK), in triggering the mycoparasitic response. We previously showed that mutants missing Tmk1 exhibit reduced mycoparasitic activity against several plant pathogenic fungi. In this study, we identified the most robustly regulated targets that were governed by Tmk1 during mycoparasitism using transcriptome and proteome profiling. Tmk1 mainly exerts a stimulating function for T. atroviride during its mycoparasitic interaction with the fungal plant pathogen Rhizoctonia solani, as reflected by 89% of strongly differently responding genes in the ∆tmk1 mutant compared to the wild type. Specifically, 54% of these genes showed strong downregulation in the response with a deletion of the tmk1 gene, whereas in the wild type the same genes were strongly upregulated during the interaction with the fungal host. These included the gene encoding the mycoparasitism-related proteinase Prb1; genes involved in signal transduction pathways such as a candidate coding for a conserved 14-3-3 protein, and a gene coding for Tmk2, the T. atroviride cell-wall integrity MAP kinase; genes encoding a specific siderophore synthetase, and multiple FAD-dependent oxidoreductases and aminotransferases. Due to the phosphorylating activity of Tmk1, different (phospho-)proteomics approaches were applied and identified proteins associated with cellular metabolism, energy production, protein synthesis and fate, and cell organization. Members of FAD- and NAD/NADP-binding-domain proteins, vesicular trafficking of molecules between cellular organelles, fungal translational, as well as protein folding apparatus were among others found to be phosphorylated by Tmk1 during mycoparasitism. Outstanding downregulation in the response of the ∆tmk1 mutant to the fungal host compared to the wild type at both the transcriptome and the proteome levels was observed for nitrilase, indicating that its defense and detoxification functions might be greatly dependent on Tmk1 during T. atroviride mycoparasitism. An intersection network analysis between the identified transcripts and proteins revealed a strong involvement of Tmk1 in molecular functions with GTPase and oxidoreductase activity. These data suggest that during T. atroviride mycoparasitism this MAPK mainly governs processes regulating cell responses to extracellular signals and those involved in reactive oxygen stress.
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Affiliation(s)
- Lea Atanasova
- Department of Food Science and Technology, University of Natural Resources and Life Sciences Vienna (BOKU), Vienna, Austria.
- Department of Microbiology, Universität Innsbruck, Innsbruck, Austria.
| | - Martina Marchetti-Deschmann
- Institute of Chemical Technologies and Analytics, TU Wien (Vienna University of Technology), Vienna, Austria
| | - Albert Nemes
- Institute of Chemical Technologies and Analytics, TU Wien (Vienna University of Technology), Vienna, Austria
| | - Bianca Bruckner
- Institute of Chemical Technologies and Analytics, TU Wien (Vienna University of Technology), Vienna, Austria
| | - Pavel Rehulka
- Institute of Chemical Technologies and Analytics, TU Wien (Vienna University of Technology), Vienna, Austria
- Department of Molecular Pathology, Faculty of Military Health Sciences, University of Defence, Hradec Králové, Czech Republic
| | - Nancy Stralis-Pavese
- IMBT Bioinformatics, Department of Biotechnology, University of Natural Resources and Life Sciences Vienna (BOKU), Vienna, Austria
| | - Paweł P Łabaj
- IMBT Bioinformatics, Department of Biotechnology, University of Natural Resources and Life Sciences Vienna (BOKU), Vienna, Austria
| | - David P Kreil
- IMBT Bioinformatics, Department of Biotechnology, University of Natural Resources and Life Sciences Vienna (BOKU), Vienna, Austria.
| | - Susanne Zeilinger
- Department of Microbiology, Universität Innsbruck, Innsbruck, Austria.
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3
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Rogers AM, Egan MJ. Septum-associated microtubule organizing centers within conidia support infectious development by the blast fungus Magnaporthe oryzae. Fungal Genet Biol 2023; 165:103768. [PMID: 36596442 DOI: 10.1016/j.fgb.2022.103768] [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: 09/19/2022] [Revised: 12/16/2022] [Accepted: 12/22/2022] [Indexed: 01/01/2023]
Abstract
Cytoplasmic microtubule arrays play important and diverse roles within fungal cells, including serving as molecular highways for motor-driven organelle motility. While the dynamic plus ends of cytoplasmic microtubules are free to explore the cytoplasm through their stochastic growth and shrinkage, their minus ends are nucleated at discrete organizing centers, composed of large multi-subunit protein complexes. The location and composition of these microtubule organizing centers varies depending on genus, cell type, and in some instances cell-cycle stage. Despite their obvious importance, our understanding of the nature, diversity, and regulation of microtubule organizing centers in fungi remains incomplete. Here, using three-color fluorescence microscopy based live-cell imaging, we investigate the organization and dynamic behavior of the microtubule cytoskeleton within infection-related cell types of the filamentous fungus,Magnaporthe oryzae, a highly destructive pathogen of rice and wheat. We provide data to support the idea that cytoplasmic microtubules are nucleated at septa, rather than at nuclear spindle pole bodies, within the three-celled blast conidium, and provide new insight into remodeling of the microtubule cytoskeleton during nuclear division and inheritance. Lastly, we provide a more complete picture of the architecture and subcellular organization of the prototypical blast appressorium, a specialized pressure-generating cell type used to invade host tissue. Taken together, our study provides new insight into microtubule nucleation, organization, and dynamics in specialized and differentiated fungal cell types.
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Affiliation(s)
- Audra Mae Rogers
- Department of Entomology and Plant Pathology, University of Arkansas, Fayetteville, AR 72701, USA
| | - Martin John Egan
- Department of Entomology and Plant Pathology, University of Arkansas, Fayetteville, AR 72701, USA.
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4
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Christensen JR, Reck-Peterson SL. Hitchhiking Across Kingdoms: Cotransport of Cargos in Fungal, Animal, and Plant Cells. Annu Rev Cell Dev Biol 2022; 38:155-178. [PMID: 35905769 PMCID: PMC10967659 DOI: 10.1146/annurev-cellbio-120420-104341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Eukaryotic cells across the tree of life organize their subcellular components via intracellular transport mechanisms. In canonical transport, myosin, kinesin, and dynein motor proteins interact with cargos via adaptor proteins and move along filamentous actin or microtubule tracks. In contrast to this canonical mode, hitchhiking is a newly discovered mode of intracellular transport in which a cargo attaches itself to an already-motile cargo rather than directly associating with a motor protein itself. Many cargos including messenger RNAs, protein complexes, and organelles hitchhike on membrane-bound cargos. Hitchhiking-like behaviors have been shown to impact cellular processes including local protein translation, long-distance signaling, and organelle network reorganization. Here, we review instances of cargo hitchhiking in fungal, animal, and plant cells and discuss the potential cellular and evolutionary importance of hitchhiking in these different contexts.
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Affiliation(s)
- Jenna R Christensen
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California, USA; ,
| | - Samara L Reck-Peterson
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California, USA; ,
- Department of Biological Sciences, Cell and Developmental Biology Section, University of California, San Diego, La Jolla, California, USA
- Howard Hughes Medical Institute, Chevy Chase, Maryland, USA
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5
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Shigeto S, Takeshita N. Raman Micro-spectroscopy and Imaging of Filamentous Fungi. Microbes Environ 2022; 37. [PMID: 35387945 PMCID: PMC10037093 DOI: 10.1264/jsme2.me22006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Filamentous fungi grow by the elongation of tubular cells called hyphae and form mycelia through repeated hyphal tip growth and branching. Since hyphal growth is closely related to the ability to secrete large amounts of enzymes or invade host cells, a more detailed understanding and the control of its growth are important in fungal biotechnology, ecology, and pathogenesis. Previous studies using fluorescence imaging revealed many of the molecular mechanisms involved in hyphal growth. Raman microspectroscopy and imaging methods are now attracting increasing attention as powerful alternatives due to their high chemical specificity and label-free, non-destructive properties. Spatially resolved information on the relative abundance, structure, and chemical state of multiple intracellular components may be simultaneously obtained. Although Raman studies on filamentous fungi are still limited, this review introduces recent findings from Raman studies on filamentous fungi and discusses their potential use in the future.
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Affiliation(s)
- Shinsuke Shigeto
- Department of Chemistry, School of Science, Kwansei Gakuin University
| | - Norio Takeshita
- Microbiology Research Center for Sustainability (MiCS), Faculty of Life and Environmental Sciences, University of Tsukuba
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6
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Mogre SS, Christensen JR, Reck-Peterson SL, Koslover EF. Optimizing microtubule arrangements for rapid cargo capture. Biophys J 2021; 120:4918-4931. [PMID: 34687720 DOI: 10.1016/j.bpj.2021.10.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 08/05/2021] [Accepted: 10/18/2021] [Indexed: 10/20/2022] Open
Abstract
Cellular functions such as autophagy, cell signaling, and vesicular trafficking involve the retrograde transport of motor-driven cargo along microtubules. Typically, newly formed cargo engages in slow undirected movement from its point of origin before attaching to a microtubule. In some cell types, cargo destined for delivery to the perinuclear region relies on capture at dynein-enriched loading zones located near microtubule plus ends. Such systems include extended cell regions of neurites and fungal hyphae, where the efficiency of the initial diffusive loading process depends on the axial distribution of microtubule plus ends relative to the initial cargo position. We use analytic mean first-passage time calculations and numerical simulations to model diffusive capture processes in tubular cells, exploring how the spatial arrangement of microtubule plus ends affects the efficiency of retrograde cargo transport. Our model delineates the key features of optimal microtubule arrangements that minimize mean cargo capture times. Namely, we show that configurations with a single microtubule plus end abutting the distal tip and broadly distributed other plus ends allow for efficient capture in a variety of different scenarios for retrograde transport. Live-cell imaging of microtubule plus ends in Aspergillus nidulans hyphae indicates that their distributions exhibit these optimal qualitative features. Our results highlight important coupling effects between the distribution of microtubule tips and retrograde cargo transport, providing guiding principles for the spatial arrangement of microtubules within tubular cell regions.
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Affiliation(s)
- Saurabh S Mogre
- Department of Physics, University of California San Diego, La Jolla, California
| | - Jenna R Christensen
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, California
| | - Samara L Reck-Peterson
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, California; Division of Biological Sciences, Cell and Developmental Biology Section, University of California San Diego, La Jolla, California; Howard Hughes Medical Institute, Chevy Chase, Maryland
| | - Elena F Koslover
- Department of Physics, University of California San Diego, La Jolla, California.
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7
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Higuchi Y. Membrane traffic related to endosome dynamics and protein secretion in filamentous fungi. Biosci Biotechnol Biochem 2021; 85:1038-1045. [PMID: 33686391 DOI: 10.1093/bbb/zbab004] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 12/29/2020] [Indexed: 12/27/2022]
Abstract
In eukaryotic cells, membrane-surrounded organelles are orchestrally organized spatiotemporally under environmental situations. Among such organelles, vesicular transports and membrane contacts occur to communicate each other, so-called membrane traffic. Filamentous fungal cells are highly polarized and thus membrane traffic is developed to have versatile functions. Early endosome (EE) is an endocytic organelle that dynamically exhibits constant long-range motility through the hyphal cell, which is proven to have physiological roles, such as other organelle distribution and signal transduction. Since filamentous fungal cells are also considered as cell factories, to produce valuable proteins extracellularly, molecular mechanisms of secretory pathway including protein glycosylation have been well investigated. In this review, molecular and physiological aspects of membrane traffic especially related to EE dynamics and protein secretion in filamentous fungi are summarized, and perspectives for application are also described.
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Affiliation(s)
- Yujiro Higuchi
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka, Japan
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8
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Li Y, Deng Z, Kamisugi Y, Chen Z, Wang J, Han X, Wei Y, He H, Terzaghi W, Cove DJ, Cuming AC, Chen H. A minus-end directed kinesin motor directs gravitropism in Physcomitrella patens. Nat Commun 2021; 12:4470. [PMID: 34294690 PMCID: PMC8298521 DOI: 10.1038/s41467-021-24546-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2020] [Accepted: 06/21/2021] [Indexed: 11/22/2022] Open
Abstract
Gravity is a critical environmental factor regulating directional growth and morphogenesis in plants, and gravitropism is the process by which plants perceive and respond to the gravity vector. The cytoskeleton is proposed to play important roles in gravitropism, but the underlying mechanisms are obscure. Here we use genetic screening in Physcomitrella patens, to identify a locus GTRC, that when mutated, reverses the direction of protonemal gravitropism. GTRC encodes a processive minus-end-directed KCHb kinesin, and its N-terminal, C-terminal and motor domains are all essential for transducing the gravity signal. Chimeric analysis between GTRC/KCHb and KCHa reveal a unique role for the N-terminus of GTRC in gravitropism. Further study shows that gravity-triggered normal asymmetric distribution of actin filaments in the tip of protonema is dependent on GTRC. Thus, our work identifies a microtubule-based cellular motor that determines the direction of plant gravitropism via mediating the asymmetric distribution of actin filaments. Gravitropism is the process by which plants perceive and respond to gravity. Here the authors identify a minus-end-directed kinesin required for gravity-triggered actin filament rearrangement and negative gravitropic response in the moss Physcomitrella patens, thus linking a microtubule-based cellular motor to gravitropism via actin.
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Affiliation(s)
- Yufan Li
- State Key Laboratory of Protein and Plant Gene Research, School of Advanced Agricultural Sciences and School of Life Sciences, Peking University, Beijing, China
| | - Zhaoguo Deng
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | | | - Zhiren Chen
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, China.,Tsinghua-Peking Center for Life Sciences, Beijing, China
| | - Jiajun Wang
- State Key Laboratory of Protein and Plant Gene Research, School of Advanced Agricultural Sciences and School of Life Sciences, Peking University, Beijing, China
| | - Xue Han
- State Key Laboratory of Protein and Plant Gene Research, School of Advanced Agricultural Sciences and School of Life Sciences, Peking University, Beijing, China
| | - Yuxiao Wei
- State Key Laboratory of Protein and Plant Gene Research, School of Advanced Agricultural Sciences and School of Life Sciences, Peking University, Beijing, China.,Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Hang He
- State Key Laboratory of Protein and Plant Gene Research, School of Advanced Agricultural Sciences and School of Life Sciences, Peking University, Beijing, China
| | | | - David J Cove
- Centre for Plant Sciences, University of Leeds, Leeds, UK
| | | | - Haodong Chen
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, China. .,Tsinghua-Peking Center for Life Sciences, Beijing, China.
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9
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Higuchi Y. Membrane Traffic in Aspergillus oryzae and Related Filamentous Fungi. J Fungi (Basel) 2021; 7:jof7070534. [PMID: 34356913 PMCID: PMC8303533 DOI: 10.3390/jof7070534] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 06/29/2021] [Accepted: 06/29/2021] [Indexed: 11/16/2022] Open
Abstract
The industrially important filamentous fungus Aspergillus oryzae, known as the yellow Koji mold and also designated the Japanese National fungus, has been investigated for understanding the intracellular membrane trafficking machinery due to the great ability of valuable enzyme production. The underlying molecular mechanisms of the secretory pathway delineate the main secretion route from the hyphal tip via the vesicle cluster Spitzenkörper, but also there is a growing body of evidence that septum-directed and unconventional secretion occurs in A. oryzae hyphal cells. Moreover, not only the secretory pathway but also the endocytic pathway is crucial for protein secretion, especially having a role in apical endocytic recycling. As a hallmark of multicellular filamentous fungal cells, endocytic organelles early endosome and vacuole are quite dynamic: the former exhibits constant long-range motility through the hyphal cells and the latter displays pleiomorphic structures in each hyphal region. These characteristics are thought to have physiological roles, such as supporting protein secretion and transporting nutrients. This review summarizes molecular and physiological mechanisms of membrane traffic, i.e., secretory and endocytic pathways, in A. oryzae and related filamentous fungi and describes the further potential for industrial applications.
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Affiliation(s)
- Yujiro Higuchi
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, 744 Motooka, Fukuoka 819-0395, Japan
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10
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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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11
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Abouward R, Schiavo G. Walking the line: mechanisms underlying directional mRNA transport and localisation in neurons and beyond. Cell Mol Life Sci 2021; 78:2665-2681. [PMID: 33341920 PMCID: PMC8004493 DOI: 10.1007/s00018-020-03724-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 11/02/2020] [Accepted: 11/25/2020] [Indexed: 12/21/2022]
Abstract
Messenger RNA (mRNA) localisation enables a high degree of spatiotemporal control on protein synthesis, which contributes to establishing the asymmetric protein distribution required to set up and maintain cellular polarity. As such, a tight control of mRNA localisation is essential for many biological processes during development and in adulthood, such as body axes determination in Drosophila melanogaster and synaptic plasticity in neurons. The mechanisms controlling how mRNAs are localised, including diffusion and entrapment, local degradation and directed active transport, are largely conserved across evolution and have been under investigation for decades in different biological models. In this review, we will discuss the standing of the field regarding directional mRNA transport in light of the recent discovery that RNA can hitchhike on cytoplasmic organelles, such as endolysosomes, and the impact of these transport modalities on our understanding of neuronal function during development, adulthood and in neurodegeneration.
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Affiliation(s)
- Reem Abouward
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK
- UK Dementia Research Institute, University College London, London, WC1E 6BT, UK
- The Francis Crick Institute, 1 Midland Rd, London, NW1 1AT, UK
| | - Giampietro Schiavo
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK.
- UK Dementia Research Institute, University College London, London, WC1E 6BT, UK.
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12
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Salogiannis J, Christensen JR, Songster LD, Aguilar-Maldonado A, Shukla N, Reck-Peterson SL. PxdA interacts with the DipA phosphatase to regulate peroxisome hitchhiking on early endosomes. Mol Biol Cell 2021; 32:492-503. [PMID: 33476181 PMCID: PMC8101442 DOI: 10.1091/mbc.e20-08-0559] [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] [Indexed: 01/04/2023] Open
Abstract
In canonical microtubule-based transport, adaptor proteins link cargoes to dynein and kinesin motors. Recently, an alternative mode of transport known as “hitchhiking” was discovered, where cargoes achieve motility by hitching a ride on already-motile cargoes, rather than attaching to a motor protein. Hitchhiking has been best studied in two filamentous fungi, Aspergillus nidulans and Ustilago maydis. In U. maydis, ribonucleoprotein complexes, peroxisomes, lipid droplets (LDs), and endoplasmic reticulum hitchhike on early endosomes (EEs). In A. nidulans, peroxisomes hitchhike using a putative molecular linker, peroxisome distribution mutant A (PxdA), which associates with EEs. However, whether other organelles use PxdA to hitchhike on EEs is unclear, as are the molecular mechanisms that regulate hitchhiking. Here we find that the proper distribution of LDs, mitochondria, and preautophagosomes do not require PxdA, suggesting that PxdA is a peroxisome-specific molecular linker. We identify two new pxdA alleles, including a point mutation (R2044P) that disrupts PxdA’s ability to associate with EEs and reduces peroxisome movement. We also identify a novel regulator of peroxisome hitchhiking, the phosphatase DipA. DipA colocalizes with EEs and its association with EEs relies on PxdA. Together, our data suggest that PxdA and the DipA phosphatase are specific regulators of peroxisome hitchhiking on EEs.
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Affiliation(s)
- John Salogiannis
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093.,Howard Hughes Medical Institute, Chevy Chase, MD 20815
| | - Jenna R Christensen
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093
| | - Livia D Songster
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093.,Division of Biological Sciences, Cell and Developmental Biology Section, University of California, San Diego, La Jolla, CA 92093
| | - Adriana Aguilar-Maldonado
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093
| | - Nandini Shukla
- The Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 043210.,Department of Molecular Genetics, The Ohio State University, Columbus, OH 043210
| | - Samara L Reck-Peterson
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093.,Division of Biological Sciences, Cell and Developmental Biology Section, University of California, San Diego, La Jolla, CA 92093.,Howard Hughes Medical Institute, Chevy Chase, MD 20815
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13
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Covill-Cooke C, Toncheva VS, Kittler JT. Regulation of peroxisomal trafficking and distribution. Cell Mol Life Sci 2020; 78:1929-1941. [PMID: 33141311 PMCID: PMC7966214 DOI: 10.1007/s00018-020-03687-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 09/02/2020] [Accepted: 10/19/2020] [Indexed: 12/18/2022]
Abstract
Peroxisomes are organelles that perform a wide range of essential metabolic processes. To ensure that peroxisomes are optimally positioned in the cell, they must be transported by both long- and short-range trafficking events in response to cellular needs. Here, we review our current understanding of the mechanisms by which the cytoskeleton and organelle contact sites alter peroxisomal distribution. Though the focus of the review is peroxisomal transport in mammalian cells, findings from flies and fungi are used for comparison and to inform the gaps in our understanding. Attention is given to the apparent overlap in regulatory mechanisms for mitochondrial and peroxisomal trafficking, along with the recently discovered role of the mitochondrial Rho-GTPases, Miro, in peroxisomal dynamics. Moreover, we outline and discuss the known pathological and pharmacological conditions that perturb peroxisomal positioning. We conclude by highlighting several gaps in our current knowledge and suggest future directions that require attention.
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Affiliation(s)
| | - Viktoriya S Toncheva
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, WC1E 6BT, UK
| | - Josef T Kittler
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, WC1E 6BT, UK.
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14
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Bieger BD, Rogers AM, Bates S, Egan MJ. Long-distance early endosome motility in Aspergillus fumigatus promotes normal hyphal growth behaviors in controlled microenvironments but is dispensable for virulence. Traffic 2020; 21:479-487. [PMID: 32378777 DOI: 10.1111/tra.12735] [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: 12/12/2019] [Revised: 05/01/2020] [Accepted: 05/04/2020] [Indexed: 12/13/2022]
Abstract
In filamentous fungi, early endosomes are continuously trafficked to, and from, the growing hyphal tip by microtubule-based motor proteins, serving as platforms for the long-distance transport of diverse cargos including mRNA, signaling molecules, and other organelles which hitchhike on them. While the cellular machinery for early endosome motility in filamentous fungi is fairly well characterized, the broader physiological significance of this process remains less well understood. We set out to determine the importance of long-distance early endosome trafficking in Aspergillus fumigatus, an opportunistic human pathogenic fungus that can cause devastating pulmonary infections in immunocompromised individuals. We first characterized normal early endosome motile behavior in A. fumigatus, then generated a mutant in which early endosome motility is severely perturbed through targeted deletion of the gene encoding for FtsA, one of a complex of proteins that links early endosomes to their motor proteins. Using a microfluidics-based approach we show that contact-induced hyphal branching behaviors are impaired in ΔftsA mutants, but that FtsA-mediated early endosome motility is dispensable for virulence in an invertebrate infection model. Overall, our study provides new insight into early endosome motility in an important human pathogenic fungus.
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Affiliation(s)
- Baronger Dowell Bieger
- Department of Entomology and Plant Pathology, University of Arkansas Systems Division of Agriculture, Fayetteville, Arkansas, USA.,Cell and Molecular Biology Program, University of Arkansas, Fayetteville, Arkansas, USA
| | - Audra Mae Rogers
- Department of Entomology and Plant Pathology, University of Arkansas Systems Division of Agriculture, Fayetteville, Arkansas, USA
| | - Steven Bates
- Medical Research Council Centre for Medical Mycology at the University of Exeter, Exeter, UK
| | - Martin John Egan
- Department of Entomology and Plant Pathology, University of Arkansas Systems Division of Agriculture, Fayetteville, Arkansas, USA.,Cell and Molecular Biology Program, University of Arkansas, Fayetteville, Arkansas, USA
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15
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Wang M, Dean RA. Movement of small RNAs in and between plants and fungi. MOLECULAR PLANT PATHOLOGY 2020; 21:589-601. [PMID: 32027079 PMCID: PMC7060135 DOI: 10.1111/mpp.12911] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 12/02/2019] [Accepted: 12/06/2019] [Indexed: 05/12/2023]
Abstract
RNA interference is a biological process whereby small RNAs inhibit gene expression through neutralizing targeted mRNA molecules. This process is conserved in eukaryotes. Here, recent work regarding the mechanisms of how small RNAs move within and between organisms is examined. Small RNAs can move locally and systemically in plants through plasmodesmata and phloem, respectively. In fungi, transportation of small RNAs may also be achieved by septal pores and vesicles. Recent evidence also supports bidirectional cross-kingdom communication of small RNAs between host plants and adapted fungal pathogens to affect the outcome of infection. We discuss several mechanisms for small RNA trafficking and describe evidence for transport through naked form, combined with RNA-binding proteins or enclosed by vesicles.
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Affiliation(s)
- Mengying Wang
- Fungal Genomics LaboratoryCenter for Integrated Fungal ResearchDepartment of Entomology and Plant PathologyNorth Carolina State UniversityRaleighNCUSA
| | - Ralph A. Dean
- Fungal Genomics LaboratoryCenter for Integrated Fungal ResearchDepartment of Entomology and Plant PathologyNorth Carolina State UniversityRaleighNCUSA
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16
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Hitching a Ride: Mechanics of Transport Initiation through Linker-Mediated Hitchhiking. Biophys J 2020; 118:1357-1369. [PMID: 32061275 DOI: 10.1016/j.bpj.2020.01.024] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 01/16/2020] [Accepted: 01/21/2020] [Indexed: 12/14/2022] Open
Abstract
In contrast to the canonical picture of transport by direct attachment to motor proteins, recent evidence shows that a number of intracellular "cargos" navigate the cytoplasm by hitchhiking on motor-driven "carrier" organelles. We describe a quantitative model of intracellular cargo transport via hitchhiking, examining the efficiency of hitchhiking initiation as a function of geometric and mechanical parameters. We focus specifically on the parameter regime relevant to the hitchhiking motion of peroxisome organelles in fungal hyphae. Our work predicts the dependence of transport initiation rates on the distribution of cytoskeletal tracks and carrier organelles, as well as the number, length, and flexibility of the linker proteins that mediate contact between the carrier and the hitchhiking cargo. Furthermore, we demonstrate that attaching organelles to microtubules can result in a substantial enhancement of the hitchhiking initiation rate in tubular geometries such as those found in fungal hyphae. This enhancement is expected to increase the overall transport rate of hitchhiking organelles and lead to greater efficiency in organelle dispersion. Our results leverage a quantitative physical model to highlight the importance of organelle encounter dynamics in noncanonical intracellular transport.
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17
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Kinnaer C, Dudin O, Martin SG. Yeast-to-hypha transition of Schizosaccharomyces japonicus in response to environmental stimuli. Mol Biol Cell 2019; 30:975-991. [PMID: 30726171 PMCID: PMC6589906 DOI: 10.1091/mbc.e18-12-0774] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 01/31/2019] [Accepted: 02/01/2019] [Indexed: 12/28/2022] Open
Abstract
Many fungal species are dimorphic, exhibiting both unicellular yeast-like and filamentous forms. Schizosaccharomyces japonicus, a member of the fission yeast clade, is one such dimorphic fungus. Here, we first identify fruit extracts as natural, stress-free, starvation-independent inducers of filamentation, which we use to describe the properties of the dimorphic switch. During the yeast-to-hypha transition, the cell evolves from a bipolar to a unipolar system with 10-fold accelerated polarized growth but constant width, vacuoles segregated to the nongrowing half of the cell, and hyper-lengthening of the cell. We demonstrate unusual features of S. japonicus hyphae: these cells lack a Spitzenkörper, a vesicle distribution center at the hyphal tip, but display more rapid cytoskeleton-based transport than the yeast form, with actin cables being essential for the transition. S. japonicus hyphae also remain mononuclear and undergo complete cell divisions, which are highly asymmetric: one daughter cell inherits the vacuole, the other the growing tip. We show that these elongated cells scale their nuclear size, spindle length, and elongation rates, but display altered division size controls. This establishes S. japonicus as a unique system that switches between symmetric and asymmetric modes of growth and division.
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Affiliation(s)
- Cassandre Kinnaer
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Omaya Dudin
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Sophie G. Martin
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland
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18
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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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19
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Olgeiser L, Haag C, Boerner S, Ule J, Busch A, Koepke J, König J, Feldbrügge M, Zarnack K. The key protein of endosomal mRNP transport Rrm4 binds translational landmark sites of cargo mRNAs. EMBO Rep 2018; 20:embr.201846588. [PMID: 30552148 DOI: 10.15252/embr.201846588] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 11/09/2018] [Accepted: 11/09/2018] [Indexed: 01/09/2023] Open
Abstract
RNA-binding proteins (RBPs) determine spatiotemporal gene expression by mediating active transport and local translation of cargo mRNAs. Here, we cast a transcriptome-wide view on the transported mRNAs and cognate RBP binding sites during endosomal messenger ribonucleoprotein (mRNP) transport in Ustilago maydis Using individual-nucleotide resolution UV crosslinking and immunoprecipitation (iCLIP), we compare the key transport RBP Rrm4 and the newly identified endosomal mRNP component Grp1 that is crucial to coordinate hyphal growth. Both RBPs bind predominantly in the 3' untranslated region of thousands of shared cargo mRNAs, often in close proximity. Intriguingly, Rrm4 precisely binds at stop codons, which constitute landmark sites of translation, suggesting an intimate connection of mRNA transport and translation. Towards uncovering the code of recognition, we identify UAUG as specific binding motif of Rrm4 that is bound by its third RRM domain. Altogether, we provide first insights into the positional organisation of co-localising RBPs on individual cargo mRNAs.
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Affiliation(s)
- Lilli Olgeiser
- Institute for Microbiology, Cluster of Excellence on Plant Sciences, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Carl Haag
- Institute for Microbiology, Cluster of Excellence on Plant Sciences, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Susan Boerner
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Jernej Ule
- The Francis Crick Institute, London, UK.,Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| | - Anke Busch
- Institute of Molecular Biology gGmbH, Mainz, Germany
| | - Janine Koepke
- Medical Clinic II (Molecular Pneumology), Excellence Cluster Cardio-Pulmonary System, Justus Liebig University of Gießen, Gießen, Germany
| | - Julian König
- Institute of Molecular Biology gGmbH, Mainz, Germany
| | - Michael Feldbrügge
- Institute for Microbiology, Cluster of Excellence on Plant Sciences, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Kathi Zarnack
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University Frankfurt, Frankfurt am Main, Germany
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20
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Mogre SS, Koslover EF. Multimodal transport and dispersion of organelles in narrow tubular cells. Phys Rev E 2018; 97:042402. [PMID: 29758750 DOI: 10.1103/physreve.97.042402] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Indexed: 11/07/2022]
Abstract
Intracellular components explore the cytoplasm via active motor-driven transport in conjunction with passive diffusion. We model the motion of organelles in narrow tubular cells using analytical techniques and numerical simulations to study the efficiency of different transport modes in achieving various cellular objectives. Our model describes length and time scales over which each transport mode dominates organelle motion, along with various metrics to quantify exploration of intracellular space. For organelles that search for a specific target, we obtain the average capture time for given transport parameters and show that diffusion and active motion contribute to target capture in the biologically relevant regime. Because many organelles have been found to tether to microtubules when not engaged in active motion, we study the interplay between immobilization due to tethering and increased probability of active transport. We derive parameter-dependent conditions under which tethering enhances long-range transport and improves the target capture time. These results shed light on the optimization of intracellular transport machinery and provide experimentally testable predictions for the effects of transport regulation mechanisms such as tethering.
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Affiliation(s)
- Saurabh S Mogre
- Department of Physics, University of California San Diego, La Jolla, California 92093, USA
| | - Elena F Koslover
- Department of Physics, University of California San Diego, La Jolla, California 92093, USA
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21
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Molecular basis of resistance to the microtubule-depolymerizing antitumor compound plocabulin. Sci Rep 2018; 8:8616. [PMID: 29872155 PMCID: PMC5988728 DOI: 10.1038/s41598-018-26736-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Accepted: 05/17/2018] [Indexed: 12/13/2022] Open
Abstract
Plocabulin (PM060184) is a microtubule depolymerizing agent with potent antiproliferative activity undergoing phase II clinical trials for the treatment of solid tumors. Plocabulin shows antifungal activity virtually abolishing growth of the filamentous fungus Aspergillus nidulans. A. nidulans hyphae depend both on mitotic and interphase microtubules, as human cells. Here, we exploited the A. nidulans genetic amenability to gain insight into the mechanism of action of plocabulin. By combining mutations in the two A. nidulans β-tubulin isotypes we obtained a plocabulin-insensitive strain, showing that β-tubulin is the only molecular target of plocabulin in fungal cells. From a genetic screen, we recovered five mutants that show plocabulin resistance but do not carry mutations in β-tubulin. Resistance mutations resulted in amino acid substitutions in (1) two subunits of the eukaryotic translation initiation factor eIF2B activating the General Amino Acid Control, (2) TIM44, an essential component of the inner mitochondrial membrane translocase, (3) two transcription factors of the binuclear zinc cluster family potentially interfering with the uptake or efflux of plocabulin. Given the conservation of some of the identified proteins and their respective cellular functions in the tumor environment, our results pinpoint candidates to be tested as potential biomarkers for determination of drug efficiency.
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22
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Zhao X, Chen Z, Yu L, Hu D, Song B. Investigating the antifungal activity and mechanism of a microbial pesticide Shenqinmycin against Phoma sp. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2018; 147:46-50. [PMID: 29933992 DOI: 10.1016/j.pestbp.2017.08.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 08/11/2017] [Accepted: 08/27/2017] [Indexed: 06/08/2023]
Abstract
Tea white scab (TWS) is a major disease affecting tea trees in mid-elevation regions and often occurs during rainy seasons with low temperatures. This disease is caused by the fungal pathogen Phoma sp. TWS can infect young stems, tender leaves, and tender shoots and lead to the production of low-quality tea. Owing to the absence of an effective control, TWS can result in substantial loss in tea production. In this study, we isolated and identified the pathogen from tea leaves infected by TWS and then evaluated in vitro the antifungal activity of Shenqinmycin, polyoxin, azoxystrobin, oligosaccharins, and tebuconazole against Phoma sp. Our results indicated that Shenqinmycin can inhibit the growth of Phoma sp. mycelia, with the EC50 value of 0.74μg/mL. After Phoma sp. being incubated in PDB liquid medium with Shenqinmycin, its mycelia were distorted and distended at 1.56μg/mL of minimum inhibitory concentration for 6h. Crucial genes associated with cell redox homeostasis, proteins synthesis, energy metabolism, and cytoskeleton were studied at mRNA and protein levels through RT-qPCR and Nano-LC-MS/MS. The results showed that the genes of 3-phosphate-glyceraldehyde dehydrogenase, citrate synthase, NADH-ubiquinone oxidoreductase subunit (NADH-subunit), ribosomal protein, eukaryotic initiation factor 4A-I, β-tubulin, and α-tubulin were up-regulated. Meanwhile, the genes of formate dehydrogenase (FDH), malate dehydrogenase, mitochondrial heat shock protein, and protein disulfide-isomerase (PDI) were up-regulated at mRNA level but down-regulated at protein level. These results indicated that Shenqinmycin contribute to cell redox homeostasis by up- or down-regulating NADH-subunit, FDH, and PDI.
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Affiliation(s)
- Xiaozhen Zhao
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Zhuo Chen
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China.
| | - Lu Yu
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Deyu Hu
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Baoan Song
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China.
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23
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Oscillatory fungal cell growth. Fungal Genet Biol 2017; 110:10-14. [PMID: 29229585 DOI: 10.1016/j.fgb.2017.12.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Revised: 11/26/2017] [Accepted: 12/06/2017] [Indexed: 12/20/2022]
Abstract
Cells are dynamic systems, the state of which undergoes constant alteration that results in morphological changes and movement. Many dynamic cellular processes that appear continuous are driven by underlying mechanisms that oscillate with distinct periods. For example eukaryotic cells do not grow continuously, but rather by pulsed extension of the periphery. Stepwise cell extension at the hyphal tips of several filamentous fungi was discovered 20 years ago, but only a few molecular details of the mechanism have been clarified since then. A recent study has provided evidence for correlations among intracellular Ca2+ levels, actin assembly, exocytosis and cell extension in growing hyphal tips. This suggests that pulsed Ca2+ influxes coordinate the temporal control of actin assembly and exocytosis, which results in stepwise cell extension. The coordinated oscillation of these machineries are likely to be ubiquitous among all eukaryotes. Indeed, intracellular Ca2+ levels and/or actin polymerization oscillate in mammalian and plant cells. This review summarizes the mechanisms of oscillation in several systems.
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24
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Etxebeste O, Espeso EA. Neurons show the path: tip-to-nucleus communication in filamentous fungal development and pathogenesis. FEMS Microbiol Rev 2017; 40:610-24. [PMID: 27587717 DOI: 10.1093/femsre/fuw021] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/17/2016] [Indexed: 01/11/2023] Open
Abstract
Multiple fungal species penetrate substrates and accomplish host invasion through the fast, permanent and unidirectional extension of filamentous cells known as hyphae. Polar growth of hyphae results, however, in a significant increase in the distance between the polarity site, which also receives the earliest information about ambient conditions, and nuclei, where adaptive responses are executed. Recent studies demonstrate that these long distances are overcome by signal transduction pathways which convey sensory information from the polarity site to nuclei, controlling development and pathogenesis. The present review compares the striking connections of the mechanisms for long-distance communication in hyphae with those from neurons, and discusses the importance of their study in order to understand invasion and dissemination processes of filamentous fungi, and design strategies for developmental control in the future.
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Affiliation(s)
- Oier Etxebeste
- Biochemistry II laboratory, Department of Applied Chemistry, Faculty of Chemistry, University of the Basque Country (UPV/EHU), 20018 San Sebastian, Spain
| | - Eduardo A Espeso
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas (CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain
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25
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Early endosome motility mediates α-amylase production and cell differentiation in Aspergillus oryzae. Sci Rep 2017; 7:15757. [PMID: 29150640 PMCID: PMC5693997 DOI: 10.1038/s41598-017-16163-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 11/08/2017] [Indexed: 01/09/2023] Open
Abstract
Recent research in filamentous fungi has revealed that the motility of an endocytic organelle early endosome (EE) has a versatile role in many physiological functions. Here, to further examine the motility of EEs in the industrially important fungus Aspergillus oryzae, we visualized these organelles via the Rab5 homolog AoRab5 and identified AoHok1, a putative linker protein between an EE and a motor protein. The Aohok1 disruptant showed retarded mycelial growth and no EE motility, in addition to an apical accumulation of EEs and peroxisomes. We further demonstrated that the Aohok1 disruptant exhibited less sensitivity to osmotic and cell wall stresses. Analyses on the protein secretory pathway in ΔAohok1 cells showed that, although distribution of the endoplasmic reticulum and Golgi was not affected, formation of the apical secretory vesicle cluster Spitzenkörper was impaired, probably resulting in the observed reduction of the A. oryzae major secretory protein α-amylase. Moreover, we revealed that the transcript level of α-amylase-encoding gene amyB was significantly reduced in the Aohok1 disruptant. Furthermore, we observed perturbed conidial and sclerotial formations, indicating a defect in cell differentiation, in the Aohok1 disruptant. Collectively, our results suggest that EE motility is crucial for α-amylase production and cell differentiation in A. oryzae.
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26
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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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27
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Pulses of Ca 2+ coordinate actin assembly and exocytosis for stepwise cell extension. Proc Natl Acad Sci U S A 2017; 114:5701-5706. [PMID: 28507141 DOI: 10.1073/pnas.1700204114] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Many eukaryotic cells grow by extending their cell periphery in pulses. The molecular mechanisms underlying this process are not yet fully understood. Here we present a comprehensive model of stepwise cell extension by using the unique tip growth system of filamentous fungi. Live-cell imaging analysis, including superresolution microscopy, revealed that the fungus Aspergillus nidulans extends the hyphal tip in an oscillatory manner. The amount of F-actin and secretory vesicles (SV) accumulating at the hyphal tip oscillated with a positive temporal correlation, whereas vesicle amounts were negatively correlated to the growth rate. The intracellular Ca2+ level also pulsed with a positive temporal correlation to the amount of F-actin and SV at the hyphal tip. Two Ca2+ channels, MidA and CchA, were needed for proper tip growth and the oscillations of actin polymerization, exocytosis, and the growth rate. The data indicate a model in which transient Ca2+ pluses cause depolymerization of F-actin at the cortex and promote SV fusion with the plasma membrane, thereby extending the cell tip. Over time, Ca2+ diffuses away and F-actin and SV accumulate again at the hyphal tip. Our data provide evidence that temporally controlled actin polymerization and exocytosis are coordinated by pulsed Ca2+ influx, resulting in stepwise cell extension.
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28
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Spatial organization of organelles in fungi: Insights from mathematical modelling. Fungal Genet Biol 2017; 103:55-59. [PMID: 28351675 PMCID: PMC5476193 DOI: 10.1016/j.fgb.2017.03.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 03/15/2017] [Accepted: 03/22/2017] [Indexed: 01/03/2023]
Abstract
Modelling of dynein motility reveals a stochastic role in dynein comet formation. Modelling helps to elucidate mechanisms in spatial organization of early endosomes. A combination of diffusion and directed motion distributes ribosomes and peroxisomes.
Mathematical modelling in cellular systems aims to describe biological processes in a quantitative manner. Most accurate modelling is based on robust experimental data. Here we review recent progress in the theoretical description of motor behaviour, early endosome motility, ribosome distribution and peroxisome transport in the fungal model system Ustilago maydis and illustrate the power of modelling in our quest to understand molecular details and cellular roles of membrane trafficking in filamentous fungi.
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Zhang J, Jin K, Xia Y. Contributions of β-tubulin to cellular morphology, sporulation and virulence in the insect-fungal pathogen, Metarhizium acridum. Fungal Genet Biol 2017; 103:16-24. [PMID: 28336393 DOI: 10.1016/j.fgb.2017.03.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 02/28/2017] [Accepted: 03/18/2017] [Indexed: 11/25/2022]
Abstract
β-tubulin is an elementary subunit of microtubules that form the cytoskeleton, participating in a wide range of cellular processes. The contributions of the single β-tubulin gene in affecting cell morphology, sporulation and virulence were examined in the entomopathogenic fungus Metarhizium acridum. Targeted gene knockout of β-tubulin resulted in resistance to benomyl but impaired proper nuclear segregation, lipid droplet transport, and deposition of chitin to the cell wall. M. acridum β-tubulin mutants displayed wavy hyphal growth and densely packed, wrinkled colonies. Decreases in the rate of phialides formation and conidial yield were observed for the β-tubulin mutant, which was also impaired in virulence towards locust hosts as compared to wild type and complemented strains. Morphological analyses of infection structures revealed development of bifurcated germ tubes, with reduced appressoria formation seen in the β-tubulin mutant. M. acridum β-tubulin mutant appressoria were aberrant in morphology and displayed decreased turgor pressure. The ability of the M. acridum β-tubulin mutant to proliferate in the insect hemolymph both in vitro and in vivo was also significantly reduced. Our results indicate that in M. acridum, β-tubulin is not essential for survival but that it contributes to cellular transport of organelles and cell wall materials, impacting growth, appressorial differentiation, virulence, and sporulation.
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Affiliation(s)
- Jie Zhang
- Genetic Engineering Research Center, School of Life Science, Chongqing University, Chongqing 400030, PR China; Chongqing Engineering Research Center for Fungal Insecticide, Chongqing 400030, PR China; Key Laboratory of Gene Function and Regulation Technologies under Chongqing Municipal Education Commission, Chongqing 400030, PR China.
| | - Kai Jin
- Genetic Engineering Research Center, School of Life Science, Chongqing University, Chongqing 400030, PR China; Chongqing Engineering Research Center for Fungal Insecticide, Chongqing 400030, PR China; Key Laboratory of Gene Function and Regulation Technologies under Chongqing Municipal Education Commission, Chongqing 400030, PR China.
| | - Yuxian Xia
- Genetic Engineering Research Center, School of Life Science, Chongqing University, Chongqing 400030, PR China; Chongqing Engineering Research Center for Fungal Insecticide, Chongqing 400030, PR China; Key Laboratory of Gene Function and Regulation Technologies under Chongqing Municipal Education Commission, Chongqing 400030, PR China.
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Leonhardt Y, Kakoschke SC, Wagener J, Ebel F. Lah is a transmembrane protein and requires Spa10 for stable positioning of Woronin bodies at the septal pore of Aspergillus fumigatus. Sci Rep 2017; 7:44179. [PMID: 28281662 PMCID: PMC5345055 DOI: 10.1038/srep44179] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 02/06/2017] [Indexed: 11/09/2022] Open
Abstract
Woronin bodies are specialized, fungal-specific organelles that enable an immediate closure of septal pores after injury to protect hyphae from excessive cytoplasmic bleeding. In most Ascomycetes, Woronin bodies are tethered at the septal pore by so-called Lah proteins. Using the pathogenic mold Aspergillus fumigatus as a model organism, we show that the C-terminal 288 amino acids of Lah (LahC288) bind to the rim of the septal pore. LahC288 essentially consists of a membrane spanning region and a putative extracellular domain, which are both required for the targeting to the septum. In an A. fumigatus rho4 deletion mutant that has a severe defect in septum formation, LahC288 is recruited to spot-like structures in or at the lateral membrane. This suggests that LahC is recruited before Rho4 starts to govern the septation process. Accordingly, we found that in wild type hyphae Lah is bound before a cross-wall emerges and thus enables a tethering of Woronin bodies at the site of the newly formed septum. Finally, we identified Spa10, a member of a recently described family of septal pore-associated proteins, as a first protein that directly or indirectly interacts with LahC to allow a stable positioning of Woronin bodies at the mature septum.
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Affiliation(s)
- Yannik Leonhardt
- Max-von-Pettenkofer-Institute, Ludwig-Maximilians-University, Munich, 80336, Germany
| | - Sara Carina Kakoschke
- Max-von-Pettenkofer-Institute, Ludwig-Maximilians-University, Munich, 80336, Germany
| | - Johannes Wagener
- Max-von-Pettenkofer-Institute, Ludwig-Maximilians-University, Munich, 80336, Germany
| | - Frank Ebel
- Max-von-Pettenkofer-Institute, Ludwig-Maximilians-University, Munich, 80336, Germany.,Institute for Infectious Diseases and Zoonoses, Ludwig-Maximilians-University, Munich, 80539, Germany
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31
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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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32
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Hernández-Ortiz P, Espeso EA. Spatiotemporal dynamics of the calcineurin target CrzA. Cell Signal 2016; 29:168-180. [PMID: 27832964 DOI: 10.1016/j.cellsig.2016.11.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 09/26/2016] [Accepted: 11/05/2016] [Indexed: 01/23/2023]
Abstract
The response of Aspergilli to elevated concentrations of extracellular calcium and manganese, or environmental alkalinization is mediated by CrzA, a calcineurin-responsive transcription factor (TF). CrzA is the effector of a signaling pathway which includes the apical protein's calmodulin and calcineurin, and the protein kinases GskA and CkiA. Preferentially located in the cytoplasm, CrzA is the only element of the pathway modifying its localization under those stress conditions, being imported into nuclei. Remarkably, there is a direct relationship between the nature/intensity of the stimulus and the pace of nuclear import and time of nuclear permanence of CrzA. Alkalinity caused a transient nuclear accumulation of CrzA while high Ca2+ and Mn2+ concentrations generated a long-lasting accumulation. Furthermore, Ca2+ concentrations (below 5mM) that are non-toxic for a crzAΔ mutant promoted full signaling of CrzA. However, micromolar concentrations or a mutation disrupting the interaction of CrzA with the phosphatase complex calcineurin, permitted the visualization of a transient and polarized nuclear accumulation of the TF in a tip-to-base gradient. Overall, these results support a model in which nucleo-cytoplasmic dynamics and transcriptional activity of CrzA are driven by apical signals transmitted by calmodulin and calcineurin. This communication is essential to understand Ca+2-induced stress response in fungi.
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Affiliation(s)
- Patricia Hernández-Ortiz
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
| | - Eduardo A Espeso
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain.
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33
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Increases in Retrograde Injury Signaling Complex-Related Transcripts in Central Axons following Injury. Neural Plast 2016; 2016:3572506. [PMID: 27847648 PMCID: PMC5099454 DOI: 10.1155/2016/3572506] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2016] [Revised: 09/01/2016] [Accepted: 09/20/2016] [Indexed: 12/11/2022] Open
Abstract
Axons in the peripheral nervous system respond to injury by activating retrograde injury signaling (RIS) pathways, which promote local axonal protein synthesis (LPS) and neuronal regeneration. RIS is also initiated following injury of neurons in the central nervous system (CNS). However, regulation of the localization of axonal mRNA required for LPS is not well understood. We used a hippocampal explant system to probe the regulation of axonal levels of RIS-associated transcripts following axonal injury. Axonal levels of importin β1 and RanBP1 were elevated biphasically at 1 and 24 hrs after axotomy. Transcript levels for β-actin, a prototypic axonally synthesized protein, were similarly elevated. Our data suggest differential regulation of axonal transcripts. At 1 hr after injury, deployment of actinomycin revealed that RanBP1, but not importin β1, requires de novo mRNA synthesis. At 24 hrs after injury, use of importazole revealed that the second wave of increased axonal mRNA levels required importin β-mediated nuclear import. We also observed increased importin β1 axonal protein levels at 1 and 6 hrs after injury. RanBP1 levels and vimentin levels fluctuated but were unchanged at 3 and 6 hrs after injury. This study revealed temporally complex regulation of axonal transcript levels, and it has implications for understanding neuronal response to injury in the CNS.
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Salogiannis J, Reck-Peterson SL. Hitchhiking: A Non-Canonical Mode of Microtubule-Based Transport. Trends Cell Biol 2016; 27:141-150. [PMID: 27665063 DOI: 10.1016/j.tcb.2016.09.005] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 08/29/2016] [Accepted: 09/02/2016] [Indexed: 01/01/2023]
Abstract
The long-range movement of organelles, vesicles, and macromolecular complexes by microtubule-based transport is crucial for cell growth and survival. The canonical view of intracellular transport is that each cargo directly recruits molecular motors via cargo-specific adaptor molecules. Recently, a new paradigm called 'hitchhiking' has emerged: some cargos can achieve motility by interacting with other cargos that have already recruited molecular motors. In this way, cargos are co-transported together and their movements are directly coupled. Cargo hitchhiking was discovered in fungi. However, the observation that organelle dynamics are coupled in mammalian cells suggests that this paradigm may be evolutionarily conserved. We review here the data for hitchhiking and discuss the biological significance of this non-canonical mode of microtubule-based transport.
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Affiliation(s)
- John Salogiannis
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA 92093, USA; Section of Cell and Developmental Biology, Division of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA; Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Samara L Reck-Peterson
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA 92093, USA; Section of Cell and Developmental Biology, Division of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA; Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
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Twelvetrees AE, Pernigo S, Sanger A, Guedes-Dias P, Schiavo G, Steiner RA, Dodding MP, Holzbaur ELF. The Dynamic Localization of Cytoplasmic Dynein in Neurons Is Driven by Kinesin-1. Neuron 2016; 90:1000-15. [PMID: 27210554 PMCID: PMC4893161 DOI: 10.1016/j.neuron.2016.04.046] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 03/11/2016] [Accepted: 04/18/2016] [Indexed: 12/01/2022]
Abstract
Cytoplasmic dynein, the major motor driving retrograde axonal transport, must be actively localized to axon terminals. This localization is critical as dynein powers essential retrograde trafficking events required for neuronal survival, such as neurotrophic signaling. Here, we demonstrate that the outward transport of dynein from soma to axon terminal is driven by direct interactions with the anterograde motor kinesin-1. In developing neurons, we find that dynein dynamically cycles between neurites, following kinesin-1 and accumulating in the nascent axon coincident with axon specification. In established axons, dynein is constantly transported down the axon at slow axonal transport speeds; inhibition of the kinesin-1-dynein interaction effectively blocks this process. In vitro and live-imaging assays to investigate the underlying mechanism lead us to propose a new model for the slow axonal transport of cytosolic cargos, based on short-lived direct interactions of cargo with a highly processive anterograde motor. VIDEO ABSTRACT.
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Affiliation(s)
- Alison E Twelvetrees
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6085, USA; Molecular NeuroPathobiology Laboratory, Sobell Department of Motor Neuroscience & Movement Disorders, UCL Institute of Neurology, University College London, London, WC1N 3BG, UK
| | - Stefano Pernigo
- Randall Division of Cell and Molecular Biophysics, King's College London, London, SE1 1UL, UK
| | - Anneri Sanger
- Randall Division of Cell and Molecular Biophysics, King's College London, London, SE1 1UL, UK
| | - Pedro Guedes-Dias
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6085, USA
| | - Giampietro Schiavo
- Molecular NeuroPathobiology Laboratory, Sobell Department of Motor Neuroscience & Movement Disorders, UCL Institute of Neurology, University College London, London, WC1N 3BG, UK
| | - Roberto A Steiner
- Randall Division of Cell and Molecular Biophysics, King's College London, London, SE1 1UL, UK
| | - Mark P Dodding
- Randall Division of Cell and Molecular Biophysics, King's College London, London, SE1 1UL, UK
| | - Erika L F Holzbaur
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6085, USA.
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36
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Bergs A, Ishitsuka Y, Evangelinos M, Nienhaus GU, Takeshita N. Dynamics of Actin Cables in Polarized Growth of the Filamentous Fungus Aspergillus nidulans. Front Microbiol 2016; 7:682. [PMID: 27242709 PMCID: PMC4860496 DOI: 10.3389/fmicb.2016.00682] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 04/26/2016] [Indexed: 12/20/2022] Open
Abstract
Highly polarized growth of filamentous fungi requires a continuous supply of proteins and lipids to the hyphal tip. This transport is managed by vesicle trafficking via the actin and microtubule cytoskeletons and their associated motor proteins. Particularly, actin cables originating from the hyphal tip are essential for hyphal growth. Although, specific marker proteins have been developed to visualize actin cables in filamentous fungi, the exact organization and dynamics of actin cables has remained elusive. Here, we observed actin cables using tropomyosin (TpmA) and Lifeact fused to fluorescent proteins in living Aspergillus nidulans hyphae and studied the dynamics and regulation. GFP tagged TpmA visualized dynamic actin cables formed from the hyphal tip with cycles of elongation and shrinkage. The elongation and shrinkage rates of actin cables were similar and approximately 0.6 μm/s. Comparison of actin markers revealed that high concentrations of Lifeact reduced actin dynamics. Simultaneous visualization of actin cables and microtubules suggests temporally and spatially coordinated polymerization and depolymerization between the two cytoskeletons. Our results provide new insights into the molecular mechanism of ordered polarized growth regulated by actin cables and microtubules.
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Affiliation(s)
- Anna Bergs
- Department of Microbiology, Institute for Applied Bioscience, Karlsruhe Institute of Technology Karlsruhe, Germany
| | - Yuji Ishitsuka
- Institute of Applied Physics, Karlsruhe Institute of Technology Karlsruhe, Germany
| | - Minoas Evangelinos
- Department of Microbiology, Institute for Applied Bioscience, Karlsruhe Institute of TechnologyKarlsruhe, Germany; Faculty of Biology, University of AthensAthens, Greece
| | - G U Nienhaus
- Institute of Applied Physics, Karlsruhe Institute of TechnologyKarlsruhe, Germany; Institute of Toxicology and Genetics, Karlsruhe Institute of TechnologyEggenstein-Leopoldshafen, Germany; Institute of Nanotechnology, Karlsruhe Institute of TechnologyEggenstein-Leopoldshafen, Germany; Department of Physics, University of Illinois at Urbana-ChampaignUrbana-Champaign, IL, USA
| | - Norio Takeshita
- Department of Microbiology, Institute for Applied Bioscience, Karlsruhe Institute of TechnologyKarlsruhe, Germany; Faculty of Life and Environmental Sciences, University of TsukubaTsukuba, Japan
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37
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Abstract
Filamentous fungi are extremely polarized organisms, exhibiting continuous growth at their hyphal tips. The hyphal form is related to their pathogenicity in animals and plants, and their high secretion ability for biotechnology. Polarized growth requires a sequential supply of proteins and lipids to the hyphal tip. This transport is managed by vesicle trafficking via the actin and microtubule cytoskeleton. Therefore, the arrangement of the cytoskeleton is a crucial step to establish and maintain the cell polarity. This review summarizes recent findings unraveling the mechanism of polarized growth with special emphasis on the role of actin and microtubule cytoskeleton and polarity marker proteins. Rapid insertions of membranes via highly active exocytosis at hyphal tips could quickly dilute the accumulated polarity marker proteins. Recent findings by a super-resolution microscopy indicate that filamentous fungal cells maintain their polarity at the tips by repeating transient assembly and disassembly of polarity sites.
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Affiliation(s)
- Norio Takeshita
- a Department of Microbiology , Institute for Applied Bioscience, Karlsruhe Institute of Technology (KIT) , Karlsruhe , Germany.,b Faculty of Life and Environmental Sciences , University of Tsukuba , Tsukuba , Japan
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38
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How peroxisomes partition between cells. A story of yeast, mammals and filamentous fungi. Curr Opin Cell Biol 2016; 41:73-80. [PMID: 27128775 DOI: 10.1016/j.ceb.2016.04.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 04/07/2016] [Accepted: 04/11/2016] [Indexed: 11/21/2022]
Abstract
Eukaryotic cells are subcompartmentalized into discrete, membrane-enclosed organelles. These organelles must be preserved in cells over many generations to maintain the selective advantages afforded by compartmentalization. Cells use complex molecular mechanisms of organelle inheritance to achieve high accuracy in the sharing of organelles between daughter cells. Here we focus on how a multi-copy organelle, the peroxisome, is partitioned in yeast, mammalian cells, and filamentous fungi, which differ in their mode of cell division. Cells achieve equidistribution of their peroxisomes through organelle transport and retention processes that act coordinately, although the strategies employed vary considerably by organism. Nevertheless, we propose that mechanisms common across species apply to the partitioning of all membrane-enclosed organelles.
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Schinke J, Kolog Gulko M, Christmann M, Valerius O, Stumpf SK, Stirz M, Braus GH. The DenA/DEN1 Interacting Phosphatase DipA Controls Septa Positioning and Phosphorylation-Dependent Stability of Cytoplasmatic DenA/DEN1 during Fungal Development. PLoS Genet 2016; 12:e1005949. [PMID: 27010942 PMCID: PMC4806917 DOI: 10.1371/journal.pgen.1005949] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 03/01/2016] [Indexed: 11/18/2022] Open
Abstract
DenA/DEN1 and the COP9 signalosome (CSN) represent two deneddylases which remove the ubiquitin-like Nedd8 from modified target proteins and are required for distinct fungal developmental programmes. The cellular DenA/DEN1 population is divided into a nuclear and a cytoplasmatic subpopulation which is especially enriched at septa. DenA/DEN1 stability control mechanisms are different for the two cellular subpopulations and depend on different physical interacting proteins and the C-terminal DenA/DEN1 phosphorylation pattern. Nuclear DenA/DEN1 is destabilized during fungal development by five of the eight CSN subunits which target nuclear DenA/DEN1 for degradation. DenA/DEN1 becomes stabilized as a phosphoprotein at S243/S245 during vegetative growth, which is necessary to support further asexual development. After the initial phase of development, the newly identified cytoplasmatic DenA/DEN1 interacting phosphatase DipA and an additional developmental specific C-terminal phosphorylation site at serine S253 destabilize DenA/DEN1. Outside of the nucleus, DipA is co-transported with DenA/DEN1 in the cytoplasm between septa and nuclei. Deletion of dipA resulted in increased DenA/DEN1 stability in a strain which is unresponsive to illumination. The mutant strain is dysregulated in cytokinesis and impaired in asexual development. Our results suggest a dual phosphorylation-dependent DenA/DEN1 stability control with stabilizing and destabilizing modifications and physical interaction partner proteins which function as control points in the nucleus and the cytoplasm.
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Affiliation(s)
- Josua Schinke
- Department of Molecular Microbiology and Genetics, Göttingen Center for Molecular Biosciences (GZMB), and Georg-August-University, Göttingen, Germany
| | - Miriam Kolog Gulko
- Department of Molecular Microbiology and Genetics, Göttingen Center for Molecular Biosciences (GZMB), and Georg-August-University, Göttingen, Germany
| | - Martin Christmann
- Department of Molecular Microbiology and Genetics, Göttingen Center for Molecular Biosciences (GZMB), and Georg-August-University, Göttingen, Germany
| | - Oliver Valerius
- Department of Molecular Microbiology and Genetics, Göttingen Center for Molecular Biosciences (GZMB), and Georg-August-University, Göttingen, Germany
| | - Sina Kristin Stumpf
- Department of Molecular Microbiology and Genetics, Göttingen Center for Molecular Biosciences (GZMB), and Georg-August-University, Göttingen, Germany
| | - Margarita Stirz
- Department of Molecular Microbiology and Genetics, Göttingen Center for Molecular Biosciences (GZMB), and Georg-August-University, Göttingen, Germany
| | - Gerhard H. Braus
- Department of Molecular Microbiology and Genetics, Göttingen Center for Molecular Biosciences (GZMB), and Georg-August-University, Göttingen, Germany
- * E-mail:
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40
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Mouriño-Pérez RR, Riquelme M, Callejas-Negrete OA, Galván-Mendoza JI. Microtubules and associated molecular motors in Neurospora crassa. Mycologia 2016; 108:515-27. [PMID: 26951369 DOI: 10.3852/15-323] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 03/02/2016] [Indexed: 11/10/2022]
Abstract
The cytoskeleton provides structure, shape and movement to various cells. Microtubules (MTs) are tubular structures made of α and β-tubulin heterodimers organized in 13 protofilaments, forming a hollow cylinder. A vast group of MT-associated proteins determines the function, behavior and interaction of the MTs with other cellular components. Among these proteins, molecular motors such as the dynein-dynactin complex and kinesin superfamily play roles in MT organization and organelle transport. This article focuses on the MT cytoskeleton and associated molecular motors in the filamentous fungus Neurospora crassa In addition to reviewing current available information for this fungus and contrasting it with knowledge of other fungal species, we present new experimental results that support the role of dynein, dynactin and conventional kinesin in MT organization, dynamics and transport of subcellular structures (nuclei and secretory vesicles). In wild type hyphae of N. crassa, cytoplasmic MTs are arranged longitudinally along hyphae and display a helical curvature. They interlace with one another to form a network throughout the cytoplasm. N. crassa dynein and dynactin mutants have a scant and disorganized MT cytoskeleton, an erratic and reduced Spitzenkörper (Spk) and distorted hyphal morphology. In contrast, hyphae of mutants with defective conventional kinesin exhibit only minor disruptions in MT and Spk organization. Although nuclear positioning is affected in all mutants, the MT-associated motor proteins are not major contributors to nuclear movement during hyphal growth. Cytoplasmic bulk flow is the vehicle for nuclear displacement in growing hyphal regions of N. crassa Motors are involved in nuclei saltatory movements in both retrograde or anterograde direction. In the dynein and kinesin mutants, micro and macrovesicles can reach the Spk, although growth is slightly impaired and the Spk displays an erratic path. Hyphal growth requires MTs, and their associated motors are required for their organization and dynamics and Spk integrity.
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Affiliation(s)
- Rosa Reyna Mouriño-Pérez
- Departamento de Microbiología. Centro de Investigación Científica y de Educación Superior de Ensenada, CICESE, Ensenada B.C. 22860 Mexico
| | - Meritxell Riquelme
- Departamento de Microbiología. Centro de Investigación Científica y de Educación Superior de Ensenada, CICESE, Ensenada B.C. 22860 Mexico
| | - Olga Alicia Callejas-Negrete
- Departamento de Microbiología. Centro de Investigación Científica y de Educación Superior de Ensenada, CICESE, Ensenada B.C. 22860 Mexico
| | - José Iván Galván-Mendoza
- Unidad de Microscopia Confocal y Multifotónica, CINVESTAV-Zacatenco. San Pedro Zacatenco, 07360 Ciudad de México DF, Mexico
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41
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Kilaru S, Schuster M, Latz M, Guo M, Steinberg G. Fluorescent markers of the endocytic pathway in Zymoseptoria tritici. Fungal Genet Biol 2016; 79:150-7. [PMID: 26092801 PMCID: PMC4502447 DOI: 10.1016/j.fgb.2015.03.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 03/12/2015] [Accepted: 03/17/2015] [Indexed: 12/28/2022]
Abstract
We establish Z. tritici fimbrin (ZtFim1) and small GTPases (ZtRab5, ZtRab7) as endocytic markers. All markers localize correctly, proven by live cell imaging and co-staining and pharmaceutical studies. We provide 3 carboxin-resistance conveying vectors for integration of all markers into the sdi1 locus. We provide 3 hygromycin B-resistance conveying vectors for random integration of all markers.
Hyphal growth in filamentous fungi is supported by the uptake (endocytosis) and recycling of membranes and associated proteins at the growing tip. An increasing body of published evidence in various fungi demonstrates that this process is of essential importance for fungal growth and pathogenicity. Here, we introduce fluorescent markers to visualize the endocytic pathway in the wheat pathogen Zymoseptoria tritici. We fused enhanced green-fluorescent protein (eGFP) to the actin-binding protein fimbrin (ZtFim1), which is located in actin patches that are formed at the plasma membrane and are participating in endocytic uptake at the cell surface. In addition, we tagged early endosomes by eGFP-labelling a Rab5-homologue (ZtRab5) and late endosomes and vacuoles by expressing eGFP-Rab7 homologue (ZtRab7). Using fluorescent dyes and live cell imaging we confirmed the dynamic behavior and localization of these markers. This set of molecular tools enables an in-depth phenotypic analysis of Z. tritici mutant strains thereby supporting new strategies towards the goal of controlling wheat against Z. tritici.
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Affiliation(s)
- S Kilaru
- Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - M Schuster
- Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - M Latz
- Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - M Guo
- Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - G Steinberg
- Biosciences, University of Exeter, Exeter EX4 4QD, UK.
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42
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Salogiannis J, Egan MJ, Reck-Peterson SL. Peroxisomes move by hitchhiking on early endosomes using the novel linker protein PxdA. J Cell Biol 2016; 212:289-96. [PMID: 26811422 PMCID: PMC4748578 DOI: 10.1083/jcb.201512020] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 01/05/2016] [Indexed: 11/22/2022] Open
Abstract
Eukaryotic cells use microtubule-based intracellular transport for the delivery of many subcellular cargos, including organelles. The canonical view of organelle transport is that organelles directly recruit molecular motors via cargo-specific adaptors. In contrast with this view, we show here that peroxisomes move by hitchhiking on early endosomes, an organelle that directly recruits the transport machinery. Using the filamentous fungus Aspergillus nidulans we found that hitchhiking is mediated by a novel endosome-associated linker protein, PxdA. PxdA is required for normal distribution and long-range movement of peroxisomes, but not early endosomes or nuclei. Using simultaneous time-lapse imaging, we find that early endosome-associated PxdA localizes to the leading edge of moving peroxisomes. We identify a coiled-coil region within PxdA that is necessary and sufficient for early endosome localization and peroxisome distribution and motility. These results present a new mechanism of microtubule-based organelle transport in which peroxisomes hitchhike on early endosomes and identify PxdA as the novel linker protein required for this coupling.
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Affiliation(s)
- John Salogiannis
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115
| | - Martin J Egan
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115
| | - Samara L Reck-Peterson
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115 Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093 Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093
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43
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Egan MJ, McClintock MA, Hollyer IHL, Elliott HL, Reck-Peterson SL. Cytoplasmic dynein is required for the spatial organization of protein aggregates in filamentous fungi. Cell Rep 2016; 11:201-9. [PMID: 25865884 DOI: 10.1016/j.celrep.2015.03.028] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Revised: 02/10/2015] [Accepted: 03/11/2015] [Indexed: 01/01/2023] Open
Abstract
Eukaryotes have evolved multiple strategies for maintaining cellular protein homeostasis. One such mechanism involves neutralization of deleterious protein aggregates via their defined spatial segregation. Here, using the molecular disaggregase Hsp104 as a marker for protein aggregation, we describe the spatial and temporal dynamics of protein aggregates in the filamentous fungus Aspergillus nidulans. Filamentous fungi, such as A. nidulans, are a diverse group of species of major health and economic importance and also serve as model systems for studying highly polarized eukaryotic cells. We find that microtubules promote the formation of Hsp104-positive aggregates, which coalesce into discrete subcellular structures in a process dependent on the microtubule-based motor cytoplasmic dynein. Finally, we find that impaired clearance of these inclusions negatively impacts retrograde trafficking of endosomes, a conventional dynein cargo, indicating that microtubule-based transport can be overwhelmed by chronic cellular stress.
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44
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Langner T, Göhre V. Fungal chitinases: function, regulation, and potential roles in plant/pathogen interactions. Curr Genet 2015; 62:243-54. [PMID: 26527115 DOI: 10.1007/s00294-015-0530-x] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 10/20/2015] [Accepted: 10/22/2015] [Indexed: 12/13/2022]
Abstract
In the past decades our knowledge about fungal cell wall architecture increased tremendously and led to the identification of many enzymes involved in polysaccharide synthesis and remodeling, which are also of biotechnological interest. Fungal cell walls play an important role in conferring mechanic stability during cell division and polar growth. Additionally, in phytopathogenic fungi the cell wall is the first structure that gets into intimate contact with the host plant. A major constituent of fungal cell walls is chitin, a homopolymer of N-acetylglucosamine units. To ensure plasticity, polymeric chitin needs continuous remodeling which is maintained by chitinolytic enzymes, including lytic polysaccharide monooxygenases N-acetylglucosaminidases, and chitinases. Depending on the species and lifestyle of fungi, there is great variation in the number of encoded chitinases and their function. Chitinases can have housekeeping function in plasticizing the cell wall or can act more specifically during cell separation, nutritional chitin acquisition, or competitive interaction with other fungi. Although chitinase research made huge progress in the last decades, our knowledge about their role in phytopathogenic fungi is still scarce. Recent findings in the dimorphic basidiomycete Ustilago maydis show that chitinases play different physiological functions throughout the life cycle and raise questions about their role during plant-fungus interactions. In this work we summarize these functions, mechanisms of chitinase regulation and their putative role during pathogen/host interactions.
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Affiliation(s)
- Thorsten Langner
- Institute for Microbiology, Heinrich-Heine University Düsseldorf, Universitätsstr. 1, 40225, Düsseldorf, Germany
| | - Vera Göhre
- Institute for Microbiology, Heinrich-Heine University Düsseldorf, Universitätsstr. 1, 40225, Düsseldorf, Germany.
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45
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Ishitsuka Y, Savage N, Li Y, Bergs A, Grün N, Kohler D, Donnelly R, Nienhaus GU, Fischer R, Takeshita N. Superresolution microscopy reveals a dynamic picture of cell polarity maintenance during directional growth. SCIENCE ADVANCES 2015; 1:e1500947. [PMID: 26665168 PMCID: PMC4673053 DOI: 10.1126/sciadv.1500947] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 09/14/2015] [Indexed: 05/02/2023]
Abstract
Polar (directional) cell growth, a key cellular mechanism shared among a wide range of species, relies on targeted insertion of new material at specific locations of the plasma membrane. How these cell polarity sites are stably maintained during massive membrane insertion has remained elusive. Conventional live-cell optical microscopy fails to visualize polarity site formation in the crowded cell membrane environment because of its limited resolution. We have used advanced live-cell imaging techniques to directly observe the localization, assembly, and disassembly processes of cell polarity sites with high spatiotemporal resolution in a rapidly growing filamentous fungus, Aspergillus nidulans. We show that the membrane-associated polarity site marker TeaR is transported on microtubules along with secretory vesicles and forms a protein cluster at that point of the apical membrane where the plus end of the microtubule touches. There, a small patch of membrane is added through exocytosis, and the TeaR cluster gets quickly dispersed over the membrane. There is an incessant disassembly and reassembly of polarity sites at the growth zone, and each new polarity site locus is slightly offset from preceding ones. On the basis of our imaging results and computational modeling, we propose a transient polarity model that explains how cell polarity is stably maintained during highly active directional growth.
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Affiliation(s)
- Yuji Ishitsuka
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany
| | - Natasha Savage
- Department of Functional and Comparative Genomics, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
| | - Yiming Li
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany
| | - Anna Bergs
- Department of Microbiology, Institute for Applied Biosciences, KIT, 76187 Karlsruhe, Germany
| | - Nathalie Grün
- Department of Microbiology, Institute for Applied Biosciences, KIT, 76187 Karlsruhe, Germany
| | - Daria Kohler
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany
| | - Rebecca Donnelly
- Department of Functional and Comparative Genomics, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
| | - G. Ulrich Nienhaus
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany
- Institute of Nanotechnology, KIT, 76344 Eggenstein-Leopoldshafen, Germany
- Institute of Toxicology and Genetics, KIT, 76344 Eggenstein-Leopoldshafen, Germany
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Corresponding author. E-mail: (G.U.N.); (R.F.); (N.T.)
| | - Reinhard Fischer
- Department of Microbiology, Institute for Applied Biosciences, KIT, 76187 Karlsruhe, Germany
- Corresponding author. E-mail: (G.U.N.); (R.F.); (N.T.)
| | - Norio Takeshita
- Department of Microbiology, Institute for Applied Biosciences, KIT, 76187 Karlsruhe, Germany
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
- Corresponding author. E-mail: (G.U.N.); (R.F.); (N.T.)
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46
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Abstract
Intracellular logistics are essential for delivery of newly synthesized material during polar growth of fungal hyphae. Proteins and lipids are actively transported throughout the cell by motor-dependent movement of small vesicles or larger units such as endosomes and the endoplasmic reticulum. A remarkably tight link is emerging between active membrane trafficking and mRNA transport, a process that determines the precise subcellular localization of translation products within the cell. Here, we report on recent insights into the mechanism and biological role of these intricate cotransport processes in fungal models such as Saccharomyces cerevisiae, Candida albicans, and Ustilago maydis. In the latter, we focus on the new finding of endosomal mRNA transport and its implications for protein targeting, complex assembly, and septin biology.
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Affiliation(s)
- Carl Haag
- Cluster of Excellence on Plant Sciences, Institute for Microbiology, Heinrich Heine University Düsseldorf, 40204 Düsseldorf, Germany; , ,
| | - Benedikt Steuten
- Cluster of Excellence on Plant Sciences, Institute for Microbiology, Heinrich Heine University Düsseldorf, 40204 Düsseldorf, Germany; , ,
| | - Michael Feldbrügge
- Cluster of Excellence on Plant Sciences, Institute for Microbiology, Heinrich Heine University Düsseldorf, 40204 Düsseldorf, Germany; , ,
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47
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Xiang X, Qiu R, Yao X, Arst HN, Peñalva MA, Zhang J. Cytoplasmic dynein and early endosome transport. Cell Mol Life Sci 2015; 72:3267-80. [PMID: 26001903 DOI: 10.1007/s00018-015-1926-y] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 05/04/2015] [Accepted: 05/05/2015] [Indexed: 11/25/2022]
Abstract
Microtubule-based distribution of organelles/vesicles is crucial for the function of many types of eukaryotic cells and the molecular motor cytoplasmic dynein is required for transporting a variety of cellular cargos toward the microtubule minus ends. Early endosomes represent a major cargo of dynein in filamentous fungi, and dynein regulators such as LIS1 and the dynactin complex are both required for early endosome movement. In fungal hyphae, kinesin-3 and dynein drive bi-directional movements of early endosomes. Dynein accumulates at microtubule plus ends; this accumulation depends on kinesin-1 and dynactin, and it is important for early endosome movements towards the microtubule minus ends. The physical interaction between dynein and early endosome requires the dynactin complex, and in particular, its p25 component. The FTS-Hook-FHIP (FHF) complex links dynein-dynactin to early endosomes, and within the FHF complex, Hook interacts with dynein-dynactin, and Hook-early endosome interaction depends on FHIP and FTS.
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Affiliation(s)
- Xin Xiang
- Department of Biochemistry and Molecular Biology, F. Edward Hébert School of Medicine, The Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, 20814, USA,
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48
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Higuchi Y, Steinberg G. Early endosomes motility in filamentous fungi: How and why they move. FUNGAL BIOL REV 2015. [DOI: 10.1016/j.fbr.2015.02.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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49
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Schuster M, Kilaru S, Latz M, Steinberg G. Fluorescent markers of the microtubule cytoskeleton in Zymoseptoria tritici. Fungal Genet Biol 2015; 79:141-9. [PMID: 25857261 PMCID: PMC4502552 DOI: 10.1016/j.fgb.2015.03.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 03/12/2015] [Accepted: 03/17/2015] [Indexed: 11/28/2022]
Abstract
The microtubule cytoskeleton supports vital processes in fungal cells, including hyphal growth and mitosis. Consequently, it is a target for fungicides, such as benomyl. The use of fluorescent fusion proteins to illuminate microtubules and microtubule-associated proteins has led to a break-through in our understanding of their dynamics and function in fungal cells. Here, we introduce fluorescent markers to visualize microtubules and accessory proteins in the wheat pathogen Zymoseptoria tritici. We fused enhanced green-fluorescent protein to α-tubulin (ZtTub2), to ZtPeb1, a homologue of the mammalian plus-end binding protein EB1, and to ZtGrc1, a component of the minus-end located γ-tubulin ring complex, involved in the nucleation of microtubules. In vivo observation confirms the localization and dynamic behaviour of all three markers. These marker proteins are useful tools for understanding the organization and importance of the microtubule cytoskeleton in Z. tritici.
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Affiliation(s)
- M Schuster
- Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - S Kilaru
- Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - M Latz
- Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - G Steinberg
- Biosciences, University of Exeter, Exeter EX4 4QD, UK.
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50
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Abstract
Endosomes are multipurpose membranous carriers important for endocytosis and secretion. During membrane trafficking, endosomes transport lipids, proteins, and even RNAs. In highly polarized cells such as fungal hyphae, they shuttle bidirectionally along microtubules mediated by molecular motors like kinesins and dynein. For in vivo studies of these highly dynamic protein/membrane complexes, advanced fluorescence microscopy is instrumental. In this chapter, we describe live cell imaging of endosomes in two distantly related fungal model systems, the basidiomycete Ustilago maydis and the ascomycete Aspergillus nidulans. We provide insights into live cell imaging of dynamic endosomal proteins and RNA, dual-color detection for colocalization studies, as well as fluorescence recovery after photobleaching (FRAP) for quantification and photo-activated localization microscopy (PALM) for super-resolution. These methods described in two well-studied fungal model systems are applicable to a broad range of other organisms.
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