1
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Kefauver JM, Hakala M, Zou L, Alba J, Espadas J, Tettamanti MG, Gajić J, Gabus C, Campomanes P, Estrozi LF, Sen NE, Vanni S, Roux A, Desfosses A, Loewith R. Cryo-EM architecture of a near-native stretch-sensitive membrane microdomain. Nature 2024:10.1038/s41586-024-07720-6. [PMID: 39048819 DOI: 10.1038/s41586-024-07720-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 06/14/2024] [Indexed: 07/27/2024]
Abstract
Biological membranes are partitioned into functional zones termed membrane microdomains, which contain specific lipids and proteins1-3. The composition and organization of membrane microdomains remain controversial because few techniques are available that allow the visualization of lipids in situ without disrupting their native behaviour3,4. The yeast eisosome, composed of the BAR-domain proteins Pil1 and Lsp1 (hereafter, Pil1/Lsp1), scaffolds a membrane compartment that senses and responds to mechanical stress by flattening and releasing sequestered factors5-9. Here we isolated near-native eisosomes as helical tubules made up of a lattice of Pil1/Lsp1 bound to plasma membrane lipids, and solved their structures by helical reconstruction. Our structures reveal a striking organization of membrane lipids, and, using in vitro reconstitutions and molecular dynamics simulations, we confirmed the positioning of individual PI(4,5)P2, phosphatidylserine and sterol molecules sequestered beneath the Pil1/Lsp1 coat. Three-dimensional variability analysis of the native-source eisosomes revealed a dynamic stretching of the Pil1/Lsp1 lattice that affects the sequestration of these lipids. Collectively, our results support a mechanism in which stretching of the Pil1/Lsp1 lattice liberates lipids that would otherwise be anchored by the Pil1/Lsp1 coat, and thus provide mechanistic insight into how eisosome BAR-domain proteins create a mechanosensitive membrane microdomain.
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Affiliation(s)
- Jennifer M Kefauver
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
- Nanomaterials and Nanotechnology Research Center (CINN), Spanish National Research Council (CSIC), El Entrego, Spain
| | - Markku Hakala
- Department of Biochemistry, University of Geneva, Geneva, Switzerland
| | - Luoming Zou
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
| | - Josephine Alba
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Javier Espadas
- Department of Biochemistry, University of Geneva, Geneva, Switzerland
| | - Maria G Tettamanti
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
- Department of Biochemistry, University of Geneva, Geneva, Switzerland
| | - Jelena Gajić
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
- Department of Organic Chemistry, University of Geneva, Geneva, Switzerland
| | - Caroline Gabus
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
| | - Pablo Campomanes
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Leandro F Estrozi
- Institut de Biologie Structurale, Université Grenoble Alpes, CEA, CNRS, IBS, Grenoble, France
| | - Nesli E Sen
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
| | - Stefano Vanni
- Department of Biology, University of Fribourg, Fribourg, Switzerland
- Swiss National Center for Competence in Research (NCCR) Bio-inspired Materials, University of Fribourg, Fribourg, Switzerland
| | - Aurélien Roux
- Department of Biochemistry, University of Geneva, Geneva, Switzerland
| | - Ambroise Desfosses
- Institut de Biologie Structurale, Université Grenoble Alpes, CEA, CNRS, IBS, Grenoble, France
| | - Robbie Loewith
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland.
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2
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Nomura W, Inoue Y. Activation of the cell wall integrity pathway negatively regulates TORC2-Ypk1/2 signaling through blocking eisosome disassembly in Saccharomyces cerevisiae. Commun Biol 2024; 7:722. [PMID: 38862688 PMCID: PMC11166964 DOI: 10.1038/s42003-024-06411-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2023] [Accepted: 06/03/2024] [Indexed: 06/13/2024] Open
Abstract
The target of rapamycin complex 2 (TORC2) signaling is associated with plasma membrane (PM) integrity. In Saccharomyces cerevisiae, TORC2-Ypk1/2 signaling controls sphingolipid biosynthesis, and Ypk1/2 phosphorylation by TORC2 under PM stress conditions is increased in a Slm1/2-dependent manner, under which Slm1 is known to be released from an eisosome, a furrow-like invagination PM structure. However, it remains unsolved how the activation machinery of TORC2-Ypk1/2 signaling is regulated. Here we show that edelfosine, a synthetic lysophospholipid analog, inhibits the activation of TORC2-Ypk1/2 signaling, and the cell wall integrity (CWI) pathway is involved in this inhibitory effect. The activation of CWI pathway blocked the eisosome disassembly promoted by PM stress and the release of Slm1 from eisosomes. Constitutive activation of TORC2-Ypk1/2 signaling exhibited increased sensitivity to cell wall stress. We propose that the CWI pathway negatively regulates the TORC2-Ypk1/2 signaling, which is involved in the regulatory mechanism to ensure the proper stress response to cell wall damage.
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Affiliation(s)
- Wataru Nomura
- Laboratory of Molecular Microbiology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Uji, Kyoto, 611-0011, Japan.
- Research Unit for Physiological Chemistry, the Center for the Promotion of Interdisciplinary Education and Research, Kyoto University, Kyoto, 606-8501, Japan.
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Shinshu University, Nagano, 399-4598, Japan.
| | - Yoshiharu Inoue
- Laboratory of Molecular Microbiology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Uji, Kyoto, 611-0011, Japan.
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3
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Pinto CM, Schnepper AP, Trindade PHE, Cardoso LH, Fioretto MN, Justulin LA, Zanelli CF, Valente GT. The joint action of yeast eisosomes and membraneless organelles in response to ethanol stress. Heliyon 2024; 10:e31561. [PMID: 38818138 PMCID: PMC11137566 DOI: 10.1016/j.heliyon.2024.e31561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 05/13/2024] [Accepted: 05/17/2024] [Indexed: 06/01/2024] Open
Abstract
Elevated ethanol concentrations in yeast affect the plasma membrane. The plasma membrane in yeast has many lipid-protein complexes, such as Pma1 (MCP), Can1 (MCC), and the eisosome complex. We investigated the response of eisosomes, MCPs, and membraneless structures to ethanol stress. We found a correlation between ethanol stress and proton flux with quick acidification of the medium. Moreover, ethanol stress influences the symporter expression in stressed cells. We also suggest that acute stress from ethanol leads to increases in eisosome size and SG number: we hypothesized that eisosomes may protect APC symporters and accumulate an mRNA decay protein in ethanol-stressed cells. Our findings suggest that the joint action of these factors may provide a protective effect on cells under ethanol stress.
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Affiliation(s)
- Camila Moreira Pinto
- Laboratory of Applied Biotechnology. São Paulo State University (UNESP). Botucatu, Brazil
| | | | - Pedro Henrique Esteves Trindade
- Department of Population Health and Pathobiology College of Veterinary Medicine, North Carolina State University (NCSU) Raleigh, USA
| | - Luiz Henrique Cardoso
- Laboratory of Applied Biotechnology. São Paulo State University (UNESP). Botucatu, Brazil
| | - Matheus Naia Fioretto
- Department of Structural and Functional Biology, Institute of Biosciences. São Paulo State University (UNESP). Botucatu, Brazil
| | - Luís Antônio Justulin
- Department of Structural and Functional Biology, Institute of Biosciences. São Paulo State University (UNESP). Botucatu, Brazil
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4
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Jiang J, Keniya MV, Puri A, Zhan X, Cheng J, Wang H, Lin G, Lee YK, Jaber N, Hassoun Y, Shor E, Shi Z, Lee SH, Xu M, Perlin DS, Dai W. Structural and Biophysical Dynamics of Fungal Plasma Membrane Proteins and Implications for Echinocandin Action in Candida glabrata. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.29.596243. [PMID: 38854035 PMCID: PMC11160696 DOI: 10.1101/2024.05.29.596243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Fungal plasma membrane proteins represent key therapeutic targets for antifungal agents, yet their structure and spatial distribution in the native context remain poorly characterized. Herein, we employ an integrative multimodal approach to elucidate the structural and functional organization of plasma membrane protein complexes in Candida glabrata , focusing on prominent and essential membrane proteins, the polysaccharide synthase β-(1,3)-glucan synthase (GS) and the proton pump Pma1. Cryo-electron tomography (cryo-ET) and live cell imaging reveal that GS and Pma1 are heterogeneously distributed into distinct plasma membrane microdomains. Treatment with caspofungin, an echinocandin antifungal that targets GS, alters the plasma membrane and disrupts the native distribution of GS and Pma1. Based on these findings, we propose a model for echinocandin action that considers how drug interactions with the plasma membrane environment lead to inhibition of GS. Our work underscores the importance of interrogating the structural and dynamic characteristics of fungal plasma membrane proteins in situ to understand function and facilitate precisely targeted development of novel antifungal therapies.
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5
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Makasewicz K, Linse S, Sparr E. Interplay of α-synuclein with Lipid Membranes: Cooperative Adsorption, Membrane Remodeling and Coaggregation. JACS AU 2024; 4:1250-1262. [PMID: 38665673 PMCID: PMC11040681 DOI: 10.1021/jacsau.3c00579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 01/18/2024] [Accepted: 01/18/2024] [Indexed: 04/28/2024]
Abstract
α-Synuclein is a small neuronal protein enriched at presynaptic termini. It is hypothesized to play a role in neurotransmitter release and synaptic vesicle cycling, while the formation of α-synuclein amyloid fibrils is associated with several neurodegenerative diseases, most notably Parkinson's Disease. The molecular mechanisms of both the physiological and pathological functions of α-synuclein remain to be fully understood, but in both cases, interactions with membranes play an important role. In this Perspective, we discuss several aspects of α-synuclein interactions with lipid membranes including cooperative adsorption, membrane remodeling and α-synuclein amyloid fibril formation in the presence of lipid membranes. We highlight the coupling between the different phenomena and their interplay in the context of physiological and pathological functions of α-synuclein.
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Affiliation(s)
- Katarzyna Makasewicz
- Division
of Physical Chemistry, Center for Chemistry and Chemical Engineering, Lund University, P.O. Box 124, SE-22100 Lund, Sweden
| | - Sara Linse
- Biochemistry
and Structural Biology, Lund University, SE-22100 Lund, Sweden
| | - Emma Sparr
- Department
of Chemistry, Lund University, P.O. Box 124, SE-22100 Lund, Sweden
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6
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Haase D, Rasch C, Keller U, Tsytsyura Y, Glyvuk N, Elting A, Wittmar J, Janning A, Kahms M, Wedlich N, Schuberth C, Heuer A, Klingauf J, Wedlich-Söldner R. Tetraspanner-based nanodomains modulate BAR domain-induced membrane curvature. EMBO Rep 2023; 24:e57232. [PMID: 37902009 DOI: 10.15252/embr.202357232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 10/02/2023] [Accepted: 10/11/2023] [Indexed: 10/31/2023] Open
Abstract
The topography of biological membranes is critical for formation of protein and lipid microdomains. One prominent example in the yeast plasma membrane (PM) are BAR domain-induced PM furrows. Here we report a novel function for the Sur7 family of tetraspanner proteins in the regulation of local PM topography. Combining TIRF imaging, STED nanoscopy, freeze-fracture EM and membrane simulations we find that Sur7 tetraspanners form multimeric strands at the edges of PM furrows, where they modulate forces exerted by BAR domain proteins at the furrow base. Loss of Sur7 tetraspanners or Sur7 displacement due to altered PIP2 homeostasis leads to increased PM invagination and a distinct form of membrane tubulation. Physiological defects associated with PM tubulation are rescued by synthetic anchoring of Sur7 to furrows. Our findings suggest a key role for tetraspanner proteins in sculpting local membrane domains. The maintenance of stable PM furrows depends on a balance between negative curvature at the base which is generated by BAR domains and positive curvature at the furrows' edges which is stabilized by strands of Sur7 tetraspanners.
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Affiliation(s)
- Daniel Haase
- Institute of Cell Dynamics and Imaging, and Cells-in-Motion Interfaculty Center (CiMIC), University of Münster, Münster, Germany
| | - Christiane Rasch
- Institute for Medical Physics and Biophysics, and Cells-in-Motion Interfaculty Center (CiMIC), Münster, Germany
- Center for Soft Nanoscience, Münster, Germany
| | - Ulrike Keller
- Institute for Medical Physics and Biophysics, and Cells-in-Motion Interfaculty Center (CiMIC), Münster, Germany
- Center for Soft Nanoscience, Münster, Germany
| | - Yaroslav Tsytsyura
- Institute for Medical Physics and Biophysics, and Cells-in-Motion Interfaculty Center (CiMIC), Münster, Germany
| | - Nataliya Glyvuk
- Institute for Medical Physics and Biophysics, and Cells-in-Motion Interfaculty Center (CiMIC), Münster, Germany
| | - Annegret Elting
- Institute of Cell Dynamics and Imaging, and Cells-in-Motion Interfaculty Center (CiMIC), University of Münster, Münster, Germany
| | - Julia Wittmar
- Institute of Cell Dynamics and Imaging, and Cells-in-Motion Interfaculty Center (CiMIC), University of Münster, Münster, Germany
| | - Annette Janning
- Institute of Cell Dynamics and Imaging, and Cells-in-Motion Interfaculty Center (CiMIC), University of Münster, Münster, Germany
| | - Martin Kahms
- Institute for Medical Physics and Biophysics, and Cells-in-Motion Interfaculty Center (CiMIC), Münster, Germany
| | - Noah Wedlich
- Institute of Cell Dynamics and Imaging, and Cells-in-Motion Interfaculty Center (CiMIC), University of Münster, Münster, Germany
- Institute for Physical Chemistry, Münster, Germany
| | - Christian Schuberth
- Institute of Cell Dynamics and Imaging, and Cells-in-Motion Interfaculty Center (CiMIC), University of Münster, Münster, Germany
| | | | - Jürgen Klingauf
- Institute for Medical Physics and Biophysics, and Cells-in-Motion Interfaculty Center (CiMIC), Münster, Germany
- Center for Soft Nanoscience, Münster, Germany
| | - Roland Wedlich-Söldner
- Institute of Cell Dynamics and Imaging, and Cells-in-Motion Interfaculty Center (CiMIC), University of Münster, Münster, Germany
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7
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Vesela P, Zahumensky J, Malinsky J. Lsp1 partially substitutes for Pil1 function in eisosome assembly under stress conditions. J Cell Sci 2023; 136:286927. [PMID: 36601791 DOI: 10.1242/jcs.260554] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 12/22/2022] [Indexed: 01/06/2023] Open
Abstract
Eisosomes are large hemitubular structures that underlie the invaginated microdomains in the plasma membrane of various ascomycetous fungi, lichens and unicellular algae. In fungi, they are organized by BAR-domain containing proteins of the Pil1 family. Two such proteins, Pil1 and Lsp1, participate in eisosome formation in the yeast Saccharomyces cerevisiae. Under normal laboratory conditions, deletion of the PIL1 gene results in the inability of cells to assemble wild-type-like eisosomes. We found that under certain stress conditions, Lsp1 partially substitutes for the Pil1 function and mediates assembly of eisosomes, specifically following a decrease in the activity of serine palmitoyltransferase, for example, in response to hyperosmotic stress. Besides Lsp1, the assembly of eisosomes lacking Pil1 also requires Seg1 and Nce102 proteins. Using next-generation sequencing, we found that the seg1Δnce102Δpil1Δ strain, which is unable to form eisosomes, overexpresses genes coding for proteins of oxidative phosphorylation and tricarboxylic acid cycle. By contrast, genes involved in DNA repair, ribosome biogenesis and cell cycle are downregulated. Our results identify Lsp1 as a stress-responsive eisosome organizer and indicate several novel functional connections between the eisosome and essential cellular processes.
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Affiliation(s)
- Petra Vesela
- Department of Functional Organization of Biomembranes, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, 142 20 Prague, Czech Republic
| | - Jakub Zahumensky
- Department of Functional Organization of Biomembranes, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, 142 20 Prague, Czech Republic
| | - Jan Malinsky
- Department of Functional Organization of Biomembranes, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, 142 20 Prague, Czech Republic
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8
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Kollath-Leiß K, Yang Q, Winter H, Kempken F. Complementation of an Eisosomal Yeast pil1 Mutant and Characteristics of Eisosomal Distribution in Hyphae of Neurospora crassa Germinating from Two Different Spore Types. J Fungi (Basel) 2023; 9:jof9020147. [PMID: 36836262 PMCID: PMC9964885 DOI: 10.3390/jof9020147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 01/13/2023] [Accepted: 01/15/2023] [Indexed: 01/24/2023] Open
Abstract
Eisosomes are plasma-membrane-associated protein complexes of fungi and algae involved in various cellular processes. The eisosome composition of the budding yeast is well described, but there is a limited number of studies only about eisosomes in filamentous fungi. In our study, we examined the Neurospora crassa LSP-1 protein (NcLSP1). By complementing a Saccharomyces cerevisiae Δpil1 mutant strain with nclsp1, we show the functional homology of the NcLSP1 to yeast PIL1 rather than to yeast LSP1 and hereby confirm that the NcLSP1 is an eisosomal core protein and suitable eisosomal marker. The subsequent cloning and expression of the nclsp1::trfp reporter gene construct in N. crassa allowed for a systematical investigation of the characteristics of eisosome formation and distribution in different developmental stages. In N. crassa, the hyphae germinating from sexual and asexual spores are morphologically identical and have been historically recognized as the same type of cells. Here, we demonstrate the structural differences on the cellular level between the hyphae germinating from sexual and asexual spores.
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9
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Feng MW, Delneri D, Millar CB, O'Keefe RT. Eisosome disruption by noncoding RNA deletion increases protein secretion in yeast. PNAS NEXUS 2022; 1:pgac241. [PMID: 36712349 PMCID: PMC9802208 DOI: 10.1093/pnasnexus/pgac241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 10/24/2022] [Indexed: 11/07/2022]
Abstract
Noncoding RNAs (ncRNAs) regulate many aspects of gene expression. We investigated how ncRNAs affected protein secretion in yeast by large-scale screening for improved endogenous invertase secretion in ncRNA deletion strains with deletion of stable unannotated transcripts (SUTs), cryptic unstable transcripts (CUTs), tRNAs, or snRNAs. We identified three candidate ncRNAs, SUT418, SUT390, and SUT125, that improved endogenous invertase secretion when deleted. As SUTs can affect expression of nearby genes, we quantified adjacent gene transcription and found that the PIL1 gene was down-regulated in the SUT125 deletion strain. Pil1 is a core component of eisosomes, nonmobile invaginations found throughout the plasma membrane. PIL1 knockout alone, or in combination with eisosome components LSP1 or SUR7, resulted in further increased secretion of invertase. Secretion of heterologous GFP was also increased upon PIL1 deletion, but this increase was signal sequence dependent. To reveal the potential for increased biopharmaceutical production, secretion of monoclonal antibody Pexelizumab scFv peptide was increased by PIL1 deletion. Global analysis of secreted proteins revealed that approximately 20% of secreted proteins, especially serine-enriched secreted proteins, including invertase, were increased upon eisosome disruption. Eisosomes are enriched with APC transporters and sphingolipids, which are essential components for secretory vesicle formation and protein sorting. Sphingolipid and serine biosynthesis pathways were up-regulated upon PIL1 deletion. We propose that increased secretion of endogenous and heterologous proteins upon PIL1 deletion resulted from sphingolipid redistribution in the plasma membrane and up-regulated sphingolipid biosynthesis. Overall, a new pathway to improve protein secretion in yeast via eisosome disruption has been identified.
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Affiliation(s)
- Matthew Wenjie Feng
- Division of Evolution, Infection and Genomics, Faculty of Biology, Medicine and Health, The University of Manchester, Oxford Road, Manchester M13 9PT, UK
| | - Daniela Delneri
- Division of Evolution, Infection and Genomics, Faculty of Biology, Medicine and Health, The University of Manchester, Oxford Road, Manchester M13 9PT, UK,Manchester Institute of Biotechnology, Faculty of Biology Medicine and Health, The University of Manchester, 131 Princess street, Manchester, M1 7DN, UK
| | - Catherine B Millar
- Division of Evolution, Infection and Genomics, Faculty of Biology, Medicine and Health, The University of Manchester, Oxford Road, Manchester M13 9PT, UK
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10
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TOR complex 2 is a master regulator of plasma membrane homeostasis. Biochem J 2022; 479:1917-1940. [PMID: 36149412 PMCID: PMC9555796 DOI: 10.1042/bcj20220388] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 08/30/2022] [Accepted: 09/01/2022] [Indexed: 11/17/2022]
Abstract
As first demonstrated in budding yeast (Saccharomyces cerevisiae), all eukaryotic cells contain two, distinct multi-component protein kinase complexes that each harbor the TOR (Target Of Rapamycin) polypeptide as the catalytic subunit. These ensembles, dubbed TORC1 and TORC2, function as universal, centrally important sensors, integrators, and controllers of eukaryotic cell growth and homeostasis. TORC1, activated on the cytosolic surface of the lysosome (or, in yeast, on the cytosolic surface of the vacuole), has emerged as a primary nutrient sensor that promotes cellular biosynthesis and suppresses autophagy. TORC2, located primarily at the plasma membrane, plays a major role in maintaining the proper levels and bilayer distribution of all plasma membrane components (sphingolipids, glycerophospholipids, sterols, and integral membrane proteins). This article surveys what we have learned about signaling via the TORC2 complex, largely through studies conducted in S. cerevisiae. In this yeast, conditions that challenge plasma membrane integrity can, depending on the nature of the stress, stimulate or inhibit TORC2, resulting in, respectively, up-regulation or down-regulation of the phosphorylation and thus the activity of its essential downstream effector the AGC family protein kinase Ypk1. Through the ensuing effect on the efficiency with which Ypk1 phosphorylates multiple substrates that control diverse processes, membrane homeostasis is maintained. Thus, the major focus here is on TORC2, Ypk1, and the multifarious targets of Ypk1 and how the functions of these substrates are regulated by their Ypk1-mediated phosphorylation, with emphasis on recent advances in our understanding of these processes.
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11
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Pal A, Paripati A, Deolal P, Chatterjee A, Prasad PR, Adla P, Sepuri NBV. Eisosome protein Pil1 regulates mitochondrial morphology, mitophagy, and cell death in Saccharomyces cerevisiae. J Biol Chem 2022; 298:102533. [PMID: 36162502 PMCID: PMC9619184 DOI: 10.1016/j.jbc.2022.102533] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 09/18/2022] [Accepted: 09/19/2022] [Indexed: 12/06/2022] Open
Abstract
Mitochondrial morphology and dynamics maintain mitochondrial integrity by regulating its size, shape, distribution, and connectivity, thereby modulating various cellular processes. Several studies have established a functional link between mitochondrial dynamics, mitophagy, and cell death, but further investigation is needed to identify specific proteins involved in mitochondrial dynamics. Any alteration in the integrity of mitochondria has severe ramifications that include disorders like cancer and neurodegeneration. In this study, we used budding yeast as a model organism and found that Pil1, the major component of the eisosome complex, also localizes to the periphery of mitochondria. Interestingly, the absence of Pil1 causes the branched tubular morphology of mitochondria to be abnormally fused or aggregated, whereas its overexpression leads to mitochondrial fragmentation. Most importantly, pil1Δ cells are defective in mitophagy and bulk autophagy, resulting in elevated levels of reactive oxygen species and protein aggregates. In addition, we show that pil1Δ cells are more prone to cell death. Yeast two-hybrid analysis and co-immunoprecipitations show the interaction of Pil1 with two major proteins in mitochondrial fission, Fis1 and Dnm1. Additionally, our data suggest that the role of Pil1 in maintaining mitochondrial shape is dependent on Fis1 and Dnm1, but it functions independently in mitophagy and cell death pathways. Together, our data suggest that Pil1, an eisosome protein, is a novel regulator of mitochondrial morphology, mitophagy, and cell death.
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Affiliation(s)
- Amita Pal
- Department of Biochemistry, University of Hyderabad, Prof. C.R Rao Road, Gachibowli, Hyderabad, TS -500046
| | - Arunkumar Paripati
- Department of Biochemistry, University of Hyderabad, Prof. C.R Rao Road, Gachibowli, Hyderabad, TS -500046
| | - Pallavi Deolal
- Department of Biochemistry, University of Hyderabad, Prof. C.R Rao Road, Gachibowli, Hyderabad, TS -500046
| | - Arpan Chatterjee
- Department of Biochemistry, University of Hyderabad, Prof. C.R Rao Road, Gachibowli, Hyderabad, TS -500046
| | - Pushpa Rani Prasad
- Department of Biochemistry, University of Hyderabad, Prof. C.R Rao Road, Gachibowli, Hyderabad, TS -500046
| | - Priyanka Adla
- Department of Biochemistry, University of Hyderabad, Prof. C.R Rao Road, Gachibowli, Hyderabad, TS -500046
| | - Naresh Babu V Sepuri
- Department of Biochemistry, University of Hyderabad, Prof. C.R Rao Road, Gachibowli, Hyderabad, TS -500046.
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12
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Correa Tedesco FG, Aguilar PS, Estrada L. Correlation analyses reveal differential diffusion behavior of eisosomal proteins between mother and daughter cells. Methods Appl Fluoresc 2022; 10. [PMID: 36067776 DOI: 10.1088/2050-6120/ac8fe1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Accepted: 09/05/2022] [Indexed: 11/12/2022]
Abstract
Eisosomes are nanoscale plasma membrane domains shaped as furrow-like invaginations. In Saccharomyces cerevisiae these relatively immobile and uniform structures are mainly composed of two cytoplasmic proteins Pil1 and Lsp1. The present work uses fluctuation of fluorescence signals and analytical methods to determine Pil1 and Lsp1 dynamics at different subcellular locations. Using scanning techniques and autocorrelation analysis we determine that the cytoplasmic pools of Pil1 and Lsp1 behave mainly by passive diffusion. Single-point FCS experiments performed at several subcellular locations reveal that Pil1 mobility is faster in daughter cells. Furthermore, pair correlation function analysis indicates a rapid dynamic of Pil1 near the plasma membrane of growing yeast buds, where the membrane is expected to be actively assembling eisosomes.
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Affiliation(s)
- Francisco G Correa Tedesco
- Laboratorio de Biología Celular de Membranas, Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín, San Martín, Argentina, Campus Miguelete, Buenos Aires, 1650, ARGENTINA
| | - Pablo Sebastian Aguilar
- Laboratorio de Biología Celular de Membranas, Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín, San Martín, Argentina, Campus Miguelete, Buenos Aires, 1650, ARGENTINA
| | - Laura Estrada
- Departamento de Física, Facultad de Ciencias Exactas y Naturales, UBA,, Intendente Guiraldes 2160, Pabellon 1, CABA, Buenos Aires, 1428, ARGENTINA
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Zahumenský J, Mota Fernandes C, Veselá P, Del Poeta M, Konopka JB, Malínský J. Microdomain Protein Nce102 Is a Local Sensor of Plasma Membrane Sphingolipid Balance. Microbiol Spectr 2022; 10:e0196122. [PMID: 35758748 PMCID: PMC9431316 DOI: 10.1128/spectrum.01961-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 06/06/2022] [Indexed: 01/17/2023] Open
Abstract
Sphingolipids are essential building blocks of eukaryotic membranes and important signaling molecules that are regulated tightly in response to environmental and physiological inputs. While their biosynthetic pathway has been well-described, the mechanisms that facilitate the perception of sphingolipid levels at the plasma membrane remain to be uncovered. In Saccharomyces cerevisiae, the Nce102 protein has been proposed to function as a sphingolipid sensor as it changes its plasma membrane distribution in response to sphingolipid biosynthesis inhibition. We show that Nce102 redistributes specifically in regions of increased sphingolipid demand, e.g., membranes of nascent buds. Furthermore, we report that the production of Nce102 increases following sphingolipid biosynthesis inhibition and that Nce102 is internalized when excess sphingolipid precursors are supplied. This finding suggests that the total amount of Nce102 in the plasma membrane is a measure of the current need for sphingolipids, whereas its local distribution marks sites of high sphingolipid demand. The physiological role of Nce102 in the regulation of sphingolipid synthesis is demonstrated by mass spectrometry analysis showing reduced levels of hydroxylated complex sphingolipids in response to heat stress in the nce102Δ deletion mutant. We also demonstrate that Nce102 behaves analogously in the widespread human fungal pathogen Candida albicans, suggesting a conserved principle of local sphingolipid control across species. IMPORTANCE Microorganisms are challenged constantly by their rapidly changing environment. To survive, they have developed diverse mechanisms to quickly perceive stressful situations and adapt to them appropriately. The primary site of both stress sensing and adaptation is the plasma membrane. We identified the yeast protein Nce102 as a marker of local sphingolipid levels and fluidity in the plasma membrane. Nce102 is an important structural and functional component of the membrane compartment Can1 (MCC), a plasma membrane microdomain stabilized by a large cytosolic hemitubular protein scaffold, the eisosome. The MCC/eisosomes are widely conserved among fungi and unicellular algae. To determine if Nce102 carries out similar functions in other organisms, we analyzed the human fungal pathogen Candida albicans and found that Nce102 responds to sphingolipid levels also in this organism, which has potential applications for the development of novel therapeutic approaches. The presented study represents a valuable model for how organisms regulate plasma membrane sphingolipids.
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Affiliation(s)
- Jakub Zahumenský
- Department of Functional Organization of Biomembranes, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Caroline Mota Fernandes
- Department of Microbiology and Immunology, School of Medicine, Stony Brook University, Stony Brook, New York, USA
| | - Petra Veselá
- Department of Functional Organization of Biomembranes, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Maurizio Del Poeta
- Department of Microbiology and Immunology, School of Medicine, Stony Brook University, Stony Brook, New York, USA
- Division of Infectious Diseases, School of Medicine, Stony Brook University, Stony Brook, New York, USA
- Veterans Administration Medical Center, Northport, New York, USA
| | - James B. Konopka
- Department of Microbiology and Immunology, School of Medicine, Stony Brook University, Stony Brook, New York, USA
| | - Jan Malínský
- Department of Functional Organization of Biomembranes, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czech Republic
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14
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Sakata KT, Hashii K, Yoshizawa K, Tahara YO, Yae K, Tsuda R, Tanaka N, Maeda T, Miyata M, Tabuchi M. Coordinated regulation of TORC2 signaling by MCC/eisosome-associated proteins, Pil1 and tetraspan membrane proteins during the stress response. Mol Microbiol 2022; 117:1227-1244. [PMID: 35383382 DOI: 10.1111/mmi.14903] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 03/29/2022] [Accepted: 03/30/2022] [Indexed: 11/28/2022]
Abstract
MCCs are linear invaginations of the yeast plasma membrane that form stable membrane microdomains. Although over 20 proteins are localized in the MCCs, it is not well understood how these proteins coordinately maintain normal MCC function. Pil1 is a core eisosome protein and is responsible for MCC-invaginated structures. In addition, six-tetraspan membrane proteins (6-Tsp) are localized in the MCCs and classified into two families, the Sur7 family and Nce102 family. To understand the coordinated function of these MCC proteins, single and multiple deletion mutants of Pil1 and 6-Tsp were generated and their MCC structure and growth under various stresses were investigated. Genetic interaction analysis revealed that the Sur7 family and Nce102 function in stress tolerance and normal eisosome assembly, respectively, by cooperating with Pil1. To further understand the role of MCCs/eisosomes in stress tolerance, we screened for suppressor mutants using the SDS-sensitive phenotype of pil1Δ 6-tspΔ cells. This revealed that SDS sensitivity is caused by hyperactivation of Tor kinase complex 2 (TORC2)-Ypk1 signaling. Interestingly, inhibition of sphingolipid metabolism, a well-known downstream pathway of TORC2-Ypk1 signaling, did not rescue the SDS-sensitivity of pil1Δ 6-tspΔ cells. These results suggest that Pil1 and 6-Tsp cooperatively regulate TORC2 signaling during the stress response.
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Affiliation(s)
- Ken-Taro Sakata
- Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, Miki, Kagawa, Japan
| | - Keisuke Hashii
- Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, Miki, Kagawa, Japan
| | - Koushiro Yoshizawa
- Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, Miki, Kagawa, Japan
| | - Yuhei O Tahara
- Department of Biology, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka, Japan
| | - Kaori Yae
- Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, Miki, Kagawa, Japan
| | - Ryohei Tsuda
- Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, Miki, Kagawa, Japan
| | - Naotaka Tanaka
- Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, Miki, Kagawa, Japan
| | - Tatsuya Maeda
- Department of Biology, Hamamatsu University School of Medicine, Handayama, Higashi-ku, Hamamatsu, Shizuoka, Japan
| | - Makoto Miyata
- Department of Biology, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka, Japan.,The OCU Advanced Research Institute for Natural Science and Technology (OCARINA), Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka, Japan
| | - Mitsuaki Tabuchi
- Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, Miki, Kagawa, Japan
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15
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Lanze CE, Zhou S, Konopka JB. The Sur7 cytoplasmic C terminus regulates morphogenesis and stress responses in Candida albicans. Mol Microbiol 2021; 116:1201-1215. [PMID: 34465004 DOI: 10.1111/mmi.14806] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 08/12/2021] [Accepted: 08/28/2021] [Indexed: 11/27/2022]
Abstract
MCC/eisosome subdomains of the plasma membrane promote proper cell wall morphogenesis that is critical for the fungal pathogen Candida albicans to grow invasively and resist stressful environments in the host. Sur7 localizes to MCC/eisosomes and is needed for their function, so in this work, the role of this tetraspan membrane protein was studied by mutagenesis. Deletion mutant analysis showed that the N-terminal region containing the four transmembrane domains mediates Sur7 localization to MCC/eisosomes. Mutation of 32 conserved residues in the N-terminal region indicated that extracellular loop 1 is important, although these mutants generally displayed weak phenotypes. Surprisingly, two Cys residues in a conserved motif in extracellular loop 1 were not important. However, deletion of the entire 15 amino acid motif revealed that it was needed for proper membrane trafficking of Sur7. Deletion and substitution mutagenesis showed that the C terminus is important for resisting cell wall stress. This is significant as it indicates Sur7 carries out an important role in the cytoplasm. Altogether, these results indicate that the N-terminal region localizes Sur7 to MCC/eisosomes and that the C-terminal domain promotes responses in the cytoplasm needed for cell wall morphogenesis and stress resistance.
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Affiliation(s)
- Carla E Lanze
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
| | - Sai Zhou
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
| | - James B Konopka
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
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16
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The distribution of phosphatidylinositol 4,5-bisphosphate in the budding yeast plasma membrane. Histochem Cell Biol 2021; 156:109-121. [PMID: 34052862 DOI: 10.1007/s00418-021-01989-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/17/2021] [Indexed: 01/07/2023]
Abstract
Phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2) is generated through phosphorylation of phosphatidylinositol 4-phosphate (PtdIns(4)P) by Mss4p, the only PtdIns phosphate 5-kinase in yeast cells. PtdIns(4,5)P2 is involved in various kinds of yeast functions. PtdIns(4)P is not only the immediate precursor of PtdIns(4,5)P2, but also an essential signaling molecule in the plasma membrane, Golgi, and endosomal system. To analyze the distribution of PtdIns(4,5)P2 and PtdIns(4)P in the yeast plasma membrane at a nanoscale level, we employed a freeze-fracture electron microscopy (EM) method that physically immobilizes lipid molecules in situ. It has been reported that the plasma membrane of budding yeast can be divided into three distinct areas: furrowed, hexagonal, and undifferentiated flat. Previously, using the freeze-fracture EM method, we determined that PtdIns(4)P is localized in the undifferentiated flat area, avoiding the furrowed and hexagonal areas of the plasma membrane. In the present study, we found that PtdIns(4,5)P2 was localized in the cytoplasmic leaflet of the plasma membrane, and concentrated in the furrowed area. There are three types of PtdIns 4-kinases which are encoded by stt4, pik1, and lsb6. The labeling density of PtdIns(4)P in the plasma membrane significantly decreased in both pik1ts and stt4ts mutants. However, the labeling densities of PtdIns(4,5)P2 in the plasma membrane of both the pik1ts and stt4ts mutants were comparable to that of the wild type yeast. These results suggest that PtdIns(4)P produced by either Pik1p or Stt4p is immediately phosphorylated by Mss4p and converted to PtdIns(4,5)P2 at the plasma membrane.
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17
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Jhaveri A, Maisuria D, Varga M, Mohammadyani D, Johnson ME. Thermodynamics and Free Energy Landscape of BAR-Domain Dimerization from Molecular Simulations. J Phys Chem B 2021; 125:3739-3751. [PMID: 33826319 DOI: 10.1021/acs.jpcb.0c10992] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Proteins with BAR domains function to bind to and remodel biological membranes, where the dimerization of BAR domains is a key step in this function. These domains can dimerize in solution or after localizing to the membrane surface. Here, we characterize the binding thermodynamics of homodimerization between the LSP1 BAR domain proteins in solution, using molecular dynamics (MD) simulations. By combining the MARTINI coarse-grained protein models with enhanced sampling through metadynamics, we construct a two-dimensional free energy surface quantifying the bound versus unbound ensembles as a function of two distance variables. With this methodology, our simulations can simultaneously characterize the structures and relative stabilities of a range of sampled dimers, portraying a heterogeneous and extraordinarily stable bound ensemble, where the proper crystal structure dimer is the most stable in a 100 mM NaCl solution. Nonspecific dimers that are sampled involve contacts that are consistent with experimental structures of higher-order oligomers formed by the LSP1 BAR domain. Because the BAR dimers and oligomers can assemble on membranes, we characterize the relative alignment of the known membrane binding patches, finding that only the specific dimer is aligned to form strong interactions with the membrane. Hence, we would predict a strong selection of the specific dimer in binding to or assembling when on the membrane. Establishing the pairwise stabilities of homodimer contacts is difficult experimentally when the proteins form stable oligomers, but through the method used here, we can isolate these contacts, providing a foundation to study the same interactions on the membrane.
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Affiliation(s)
- Adip Jhaveri
- TC Jenkins Department of Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, Maryland 21218, United States
| | - Dhruw Maisuria
- TC Jenkins Department of Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, Maryland 21218, United States
| | - Matthew Varga
- TC Jenkins Department of Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, Maryland 21218, United States
| | - Dariush Mohammadyani
- TC Jenkins Department of Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, Maryland 21218, United States
| | - Margaret E Johnson
- TC Jenkins Department of Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, Maryland 21218, United States
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18
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Spangler EJ, Olinger AD, Kumar PBS, Laradji M. Binding, unbinding and aggregation of crescent-shaped nanoparticles on nanoscale tubular membranes. SOFT MATTER 2021; 17:1016-1027. [PMID: 33284936 DOI: 10.1039/d0sm01642j] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Using molecular dynamics simulations of a coarse-grained implicit solvent model, we investigate the binding of crescent-shaped nanoparticles (NPs) on tubular lipid membranes. The NPs adhere to the membrane through their concave side. We found that the binding/unbinding transition is first-order, with the threshold binding energy being higher than the unbinding threshold, and the energy barrier between the bound and unbound states at the transition that increases with increasing the NP's arclength Lnp or curvature mismatch μ = Rc/Rnp, where Rc and Rnp are the radii of curvature of the tubular membrane and the NP, respectively. Furthermore, we found that the threshold binding energy increases with increasing either Lnp or μ. NPs with curvature larger than that of the tubule (μ > 1) lie perpendicularly to the tubule's axis. However, for μ smaller than a specific arclength-dependent mismatch μ*, the NPs are tilted with respect to the tubule's axis, with the tilt angle that increases with decreasing μ. We also investigated the self-assembly of the NPs on the tubule at relatively weak adhesion strength and found that for μ > 1 and high values of Lnp, the NPs self-assemble into linear chains, and lie side-by-side. For μ < μ* and high Lnp, the NPs also self-assemble into chains, while being tilted with respect to the tubule's axis.
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Affiliation(s)
- Eric J Spangler
- Department of Biomedical Engineering and Department of Physics and Materials Science, The University of Memphis, Memphis, TN 38152, USA
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19
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Tulha J, Amorim-Rodrigues M, Esquembre LA, Rauch S, Tamás MJ, Lucas C. Physical, genetic and functional interactions between the eisosome protein Pil1 and the MBOAT O-acyltransferase Gup1. FEMS Yeast Res 2020; 21:6045508. [PMID: 33355361 DOI: 10.1093/femsyr/foaa070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 12/21/2020] [Indexed: 11/14/2022] Open
Abstract
The Saccharomyces cerevisiae MBOAT O-acyltransferase Gup1 is involved in many processes, including cell wall and membrane composition and integrity, and acetic acid-induced cell death. Gup1 was previously shown to interact physically with the mitochondrial membrane VDAC (Voltage-Dependent Anion Channel) protein Por1 and the ammonium transceptor Mep2. By co-immunoprecipitation, the eisosome core component Pil1 was identified as a novel physical interaction partner of Gup1. The expression of PIL1 and Pil1 protein levels were found to be unaffected by GUP1 deletion. In ∆gup1 cells, Pil1 was distributed in dots (likely representing eisosomes) in the membrane, identically to wt cells. However, ∆gup1 cells presented 50% less Pil1-GFP dots/eisosomes, suggesting that Gup1 is important for eisosome formation. The two proteins also interact genetically in the maintenance of cell wall integrity, and during arsenite and acetic acid exposure. We show that Δgup1 Δpil1 cells take up more arsenite than wt and are extremely sensitive to arsenite and to acetic acid treatments. The latter causes a severe apoptotic wt-like cell death phenotype, epistatically reverting the ∆gup1 necrotic type of death. Gup1 and Pil1 are thus physically, genetically and functionally connected.
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Affiliation(s)
- Joana Tulha
- Centre of Molecular and Environmental Biology, University of Minho, Campus de Gualtar 4710-057 Braga, Portugal
| | - Mariana Amorim-Rodrigues
- Centre of Molecular and Environmental Biology, University of Minho, Campus de Gualtar 4710-057 Braga, Portugal.,Institute of Science and Innovation for Bio-Sustainability (IB-S), University of Minho, Campus de Gualtar 4710-057 Braga, Portugal
| | - Lidia Alejo Esquembre
- Department of Chemistry and Molecular Biology, University of Gothenburg, Kemihuset 412 96 Gothenburg, Sweden
| | - Sebastien Rauch
- Water Environment Technology, Department of Architecture and Civil and Environmental Engineering, Chalmers University of Technology, S-412 96 Gothenburg, Sweden
| | - Markus J Tamás
- Department of Chemistry and Molecular Biology, University of Gothenburg, Kemihuset 412 96 Gothenburg, Sweden
| | - Cândida Lucas
- Centre of Molecular and Environmental Biology, University of Minho, Campus de Gualtar 4710-057 Braga, Portugal.,Institute of Science and Innovation for Bio-Sustainability (IB-S), University of Minho, Campus de Gualtar 4710-057 Braga, Portugal
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20
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Yang Q, Kempken F. The Composition and the Structure of MCC/Eisosomes in Neurospora crassa. Front Microbiol 2020; 11:2115. [PMID: 33071997 PMCID: PMC7533531 DOI: 10.3389/fmicb.2020.02115] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 08/11/2020] [Indexed: 12/15/2022] Open
Abstract
MCC/eisosomes are protein-organized domains in the plasma membrane of fungi and algae. However, the composition and function(s) of MCC/eisosomes in the filamentous fungus Neurospora crassa were previously unknown. To identify proteins that localize to MCC/eisosomes in N. crassa, we isolated proteins that co-purified with the core MCC/eisosome protein LSP-1, which was tagged with GFP. Proteins that co-fractionated with LSP-1:GFP were then identified by mass spectrometry. Eighteen proteins were GFP-tagged and used to identify six proteins that highly colocalized with the MCC/eisosome marker LSP-1:RFP, while five other proteins showed partial overlap with MCC/eisosomes. Seven of these proteins showed amino acid sequence homology with proteins known to localize to MCC/eisosomes in the yeast Saccharomyces cerevisiae. However, homologs of three proteins known to localize to MCC/eisosomes in S. cerevisiae (Can1, Pkh1/2, and Fhn1) were not found to colocalize with MCC/eisosome proteins in N. crassa by fluorescence microscopy. Interestingly, one new eisosome protein (glutamine-fructose-6-phosphate aminotransferase, gene ID: NCU07366) was detected in our studies. These findings demonstrate that there are interspecies differences of the protein composition of MCC/eisosomes. To gain further insight, molecular modeling and bioinformatics analysis of the identified proteins were used to propose the organization of MCC/eisosomes in N. crassa. A model will be discussed for how the broad range of functions predicted for the proteins localized to MCC/eisosomes, including cell wall synthesis, response and signaling, transmembrane transport, and actin organization, suggests that MCC/eisosomes act as organizing centers in the plasma membrane.
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Affiliation(s)
- Qin Yang
- Department of Genetics and Molecular Biology, Botanical Institute and Botanic Garden, Kiel University, Kiel, Germany
| | - Frank Kempken
- Department of Genetics and Molecular Biology, Botanical Institute and Botanic Garden, Kiel University, Kiel, Germany
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21
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Plasma Membrane MCC/Eisosome Domains Promote Stress Resistance in Fungi. Microbiol Mol Biol Rev 2020; 84:84/4/e00063-19. [PMID: 32938742 DOI: 10.1128/mmbr.00063-19] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
There is growing appreciation that the plasma membrane orchestrates a diverse array of functions by segregating different activities into specialized domains that vary in size, stability, and composition. Studies with the budding yeast Saccharomyces cerevisiae have identified a novel type of plasma membrane domain known as the MCC (membrane compartment of Can1)/eisosomes that correspond to stable furrows in the plasma membrane. MCC/eisosomes maintain proteins at the cell surface, such as nutrient transporters like the Can1 arginine symporter, by protecting them from endocytosis and degradation. Recent studies from several fungal species are now revealing new functional roles for MCC/eisosomes that enable cells to respond to a wide range of stressors, including changes in membrane tension, nutrition, cell wall integrity, oxidation, and copper toxicity. The different MCC/eisosome functions are often intertwined through the roles of these domains in lipid homeostasis, which is important for proper plasma membrane architecture and cell signaling. Therefore, this review will emphasize the emerging models that explain how MCC/eisosomes act as hubs to coordinate cellular responses to stress. The importance of MCC/eisosomes is underscored by their roles in virulence for fungal pathogens of plants, animals, and humans, which also highlights the potential of these domains to act as novel therapeutic targets.
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22
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Athanasopoulos A, André B, Sophianopoulou V, Gournas C. Fungal plasma membrane domains. FEMS Microbiol Rev 2020; 43:642-673. [PMID: 31504467 DOI: 10.1093/femsre/fuz022] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 08/25/2019] [Indexed: 12/11/2022] Open
Abstract
The plasma membrane (PM) performs a plethora of physiological processes, the coordination of which requires spatial and temporal organization into specialized domains of different sizes, stability, protein/lipid composition and overall architecture. Compartmentalization of the PM has been particularly well studied in the yeast Saccharomyces cerevisiae, where five non-overlapping domains have been described: The Membrane Compartments containing the arginine permease Can1 (MCC), the H+-ATPase Pma1 (MCP), the TORC2 kinase (MCT), the sterol transporters Ltc3/4 (MCL), and the cell wall stress mechanosensor Wsc1 (MCW). Additional cortical foci at the fungal PM are the sites where clathrin-dependent endocytosis occurs, the sites where the external pH sensing complex PAL/Rim localizes, and sterol-rich domains found in apically grown regions of fungal membranes. In this review, we summarize knowledge from several fungal species regarding the organization of the lateral PM segregation. We discuss the mechanisms of formation of these domains, and the mechanisms of partitioning of proteins there. Finally, we discuss the physiological roles of the best-known membrane compartments, including the regulation of membrane and cell wall homeostasis, apical growth of fungal cells and the newly emerging role of MCCs as starvation-protective membrane domains.
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Affiliation(s)
- Alexandros Athanasopoulos
- Microbial Molecular Genetics Laboratory, Institute of Biosciences and Applications, National Centre for Scientific Research 'Demokritos,' Patr. Grigoriou E & 27 Neapoleos St. 15341, Agia Paraskevi, Greece
| | - Bruno André
- Molecular Physiology of the Cell laboratory, Université Libre de Bruxelles (ULB), Institut de Biologie et de Médecine Moléculaires, rue des Pr Jeener et Brachet 12, 6041, Gosselies, Belgium
| | - Vicky Sophianopoulou
- Microbial Molecular Genetics Laboratory, Institute of Biosciences and Applications, National Centre for Scientific Research 'Demokritos,' Patr. Grigoriou E & 27 Neapoleos St. 15341, Agia Paraskevi, Greece
| | - Christos Gournas
- Microbial Molecular Genetics Laboratory, Institute of Biosciences and Applications, National Centre for Scientific Research 'Demokritos,' Patr. Grigoriou E & 27 Neapoleos St. 15341, Agia Paraskevi, Greece
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23
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Tumolo JM, Hepowit NL, Joshi SS, MacGurn JA. A Snf1-related nutrient-responsive kinase antagonizes endocytosis in yeast. PLoS Genet 2020; 16:e1008677. [PMID: 32191698 PMCID: PMC7176151 DOI: 10.1371/journal.pgen.1008677] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 04/22/2020] [Accepted: 02/17/2020] [Indexed: 12/18/2022] Open
Abstract
Endocytosis is regulated in response to changing environmental conditions to adjust plasma membrane (PM) protein composition for optimal cell growth. Protein networks involved in cargo capture and sorting, membrane sculpting and deformation, and vesicle scission have been well-characterized, but less is known about the networks that sense extracellular cues and relay signals to trigger endocytosis of specific cargo. Hal4 and Hal5 are yeast Snf1-related kinases that were previously reported to regulate nutrient transporter stability by an unknown mechanism. Here we demonstrate that loss of Hal4 and Hal5 activates endocytosis of many different kinds of PM proteins, including Art1-mediated and Art1-independent endocytic events. Acute inhibition of Hal5 in the absence of Hal4 triggers rapid endocytosis, suggesting that Hal kinases function in a nutrient-sensing relay upstream of the endocytic response. Interestingly, Hal5 localizes to the PM, but shifts away from the cell surface in response to stimulation with specific nutrients. We propose that Hal5 functions as a nutrient-responsive regulator of PM protein stability, antagonizing endocytosis and promoting stability of endocytic cargos at the PM in nutrient-limiting conditions. Cellular homeostasis, a fundamental requirement for all living organisms, is maintained in part through evolutionarily conserved mechanisms that regulate the abundance and activity of ion and nutrient transporters at the cell surface. These mechanisms often incorporate signaling networks that sense changes in the environment and relay signals to alter protein composition at the plasma membrane, often by inducing endocytosis of specific transporters in order to adjust and optimize transport activities at the cell surface. Here, we investigate two kinases in yeast–Hal4 and Hal5 –that are related to the yeast and human AMP sensing kinases. Loss of both Hal4 and Hal5 was previously reported to result in destabilization of ion and nutrient transporters by an unknown mechanism. Our data indicates that Hal kinases function broadly in the regulation of many different classes of endocytic cargo. Hal5 localizes to the plasma membrane in a manner that is responsive to nutrient availability and acute loss of Hal5 activity triggers rapid internalization of endocytic cargo. By uncovering a role for Hal5 as a nutrient-responsive regulator of endocytosis, this research sheds light on how signaling molecules regulate membrane trafficking events to coordinate adaptive growth responses.
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Affiliation(s)
- Jessica M. Tumolo
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Nathaniel L. Hepowit
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Samika S. Joshi
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Jason A. MacGurn
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee, United States of America
- * E-mail:
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24
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Amen T, Kaganovich D. Stress granules sense metabolic stress at the plasma membrane and potentiate recovery by storing active Pkc1. Sci Signal 2020; 13:13/623/eaaz6339. [DOI: 10.1126/scisignal.aaz6339] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
As the physical barrier between the cell and the outside environment, the plasma membrane is well-positioned to be the first responder to stress. The membrane is also highly vulnerable to many types of perturbation, including heat, force, osmotic pressure, lipid shortage, and starvation. To determine whether the structural changes in the plasma membrane of Saccharomyces cerevisiae brought about by nutrient stress can be communicated to regulatory networks within the cell, we identified proteins that interact with stress granules (SGs), subcellular structures composed of proteins, and nontranslated RNAs that form when cells are stressed. We found that SG proteins interacted with components of eisosomes, which are subcortical membrane structures with a distinct lipid and protein composition. In response to starvation-triggered phosphorylation of eisosome proteins, eisosomes clustered and recruited SG components, including active Pkc1. The absence of eisosomes impaired SG formation, resulting in delayed recovery from nutrient deprivation. Thus, eisosome clustering is an example of interdomain communication in response to stress and identifies a previously unknown mechanism of SG regulation.
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Affiliation(s)
- Triana Amen
- Department of Experimental Neurodegeneration, University Medical Center Göttingen, Göttingen, Germany
| | - Daniel Kaganovich
- Department of Experimental Neurodegeneration, University Medical Center Göttingen, Göttingen, Germany
- 1Base Pharmaceuticals, Boston, MA 02129, USA
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25
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Low ZJ, Xiong J, Xie Y, Ma GL, Saw H, Thi Tran H, Wong SL, Pang LM, Fong J, Lu P, Hu JF, Yang L, Miao Y, Liang ZX. Discovery, biosynthesis and antifungal mechanism of the polyene-polyol meijiemycin. Chem Commun (Camb) 2019; 56:822-825. [PMID: 31848534 DOI: 10.1039/c9cc08908j] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Produced by a newly isolated Streptomycetes strain, meijiemycin is a gigantic linear polyene-polyol that exhibits structural features not seen in other members of the polyene-polyol family. We propose a biosynthetic mechanism and demonstrate that meijiemycin inhibits hyphal growth by inducing the aggregation of ergosterol and restructuring of the fungal plasma membrane.
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Affiliation(s)
- Zhen Jie Low
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore.
| | - Juan Xiong
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore. and School of Pharmacy, Fudan University, Shanghai, China
| | - Ying Xie
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore.
| | - Guang-Lei Ma
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore.
| | - Howard Saw
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore.
| | - Hoa Thi Tran
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore.
| | - Soo Lin Wong
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore.
| | - Li Mei Pang
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore.
| | - July Fong
- The Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, 637551, Singapore
| | - Peng Lu
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore.
| | - Jin-Feng Hu
- School of Pharmacy, Fudan University, Shanghai, China
| | - Liang Yang
- School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Yansong Miao
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore.
| | - Zhao-Xun Liang
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore. and The Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, 637551, Singapore
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26
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Colou J, N'Guyen GQ, Dubreu O, Fontaine K, Kwasiborski A, Bastide F, Manero F, Hamon B, Aligon S, Simoneau P, Guillemette T. Role of membrane compartment occupied by Can1 (MCC) and eisosome subdomains in plant pathogenicity of the necrotrophic fungus Alternaria brassicicola. BMC Microbiol 2019; 19:295. [PMID: 31842747 PMCID: PMC6916069 DOI: 10.1186/s12866-019-1667-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 11/28/2019] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND MCC/eisosomes are membrane microdomains that have been proposed to participate in the plasma membrane function in particular by regulating the homeostasis of lipids, promoting the recruitment of specific proteins and acting as provider of membrane reservoirs. RESULTS Here we showed that several potential MCC/eisosomal protein encoding genes in the necrotrophic fungus A. brassicicola were overexpressed when germinated spores were exposed to antimicrobial defence compounds, osmotic and hydric stresses, which are major constraints encountered by the fungus during the plant colonization process. Mutants deficient for key MCC/eisosome components did not exhibit any enhanced susceptibility to phytoalexins and to applied stress conditions compared to the reference strain, except for a slight hypersensitivity of the ∆∆abpil1a-abpil1b strain to 2 M sorbitol. Depending on the considered mutants, we showed that the leaf and silique colonization processes were impaired by comparison to the wild-type, and assumed that these defects in aggressiveness were probably caused by a reduced appressorium formation rate. CONCLUSIONS This is the first study on the role of MCC/eisosomes in the pathogenic process of a plant pathogenic fungus. A link between these membrane domains and the fungus ability to form functional penetration structures was shown, providing new potential directions for plant disease control strategies.
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Affiliation(s)
- Justine Colou
- Institut de Recherche en Horticulture et Semences - UMR 1345, INRA, Université d'Angers, Agrocampus-Ouest, SFR 4207 QuaSaV, 42 rue Georges Morel, 49071 Beaucouzé Cedex, Angers, France
| | - Guillaume Quang N'Guyen
- Institut de Recherche en Horticulture et Semences - UMR 1345, INRA, Université d'Angers, Agrocampus-Ouest, SFR 4207 QuaSaV, 42 rue Georges Morel, 49071 Beaucouzé Cedex, Angers, France.,Institut de Biologie Intégrative et des Systèmes, Département de Biologie, PROTEO, Université Laval, Pavillon Charles-Eugène-Marchand, 1030 Avenue de la Médecine, QC, Québec, G1V 0A6, Canada
| | - Ophélie Dubreu
- Institut de Recherche en Horticulture et Semences - UMR 1345, INRA, Université d'Angers, Agrocampus-Ouest, SFR 4207 QuaSaV, 42 rue Georges Morel, 49071 Beaucouzé Cedex, Angers, France
| | - Kévin Fontaine
- Institut de Recherche en Horticulture et Semences - UMR 1345, INRA, Université d'Angers, Agrocampus-Ouest, SFR 4207 QuaSaV, 42 rue Georges Morel, 49071 Beaucouzé Cedex, Angers, France.,ANSES, Laboratoire de la Santé des Végétaux, Unité de Mycologie, Domaine de Pixérécourt, 54220, Malzéville, France
| | - Anthony Kwasiborski
- Institut de Recherche en Horticulture et Semences - UMR 1345, INRA, Université d'Angers, Agrocampus-Ouest, SFR 4207 QuaSaV, 42 rue Georges Morel, 49071 Beaucouzé Cedex, Angers, France
| | - Franck Bastide
- Institut de Recherche en Horticulture et Semences - UMR 1345, INRA, Université d'Angers, Agrocampus-Ouest, SFR 4207 QuaSaV, 42 rue Georges Morel, 49071 Beaucouzé Cedex, Angers, France
| | - Florence Manero
- Plateforme SCIAM, Institut de Biologie en Santé, CHU, Université d'Angers, 4, Rue Larrey, 49933, Angers Cedex, France
| | - Bruno Hamon
- Institut de Recherche en Horticulture et Semences - UMR 1345, INRA, Université d'Angers, Agrocampus-Ouest, SFR 4207 QuaSaV, 42 rue Georges Morel, 49071 Beaucouzé Cedex, Angers, France
| | - Sophie Aligon
- Institut de Recherche en Horticulture et Semences - UMR 1345, INRA, Université d'Angers, Agrocampus-Ouest, SFR 4207 QuaSaV, 42 rue Georges Morel, 49071 Beaucouzé Cedex, Angers, France
| | - Philippe Simoneau
- Institut de Recherche en Horticulture et Semences - UMR 1345, INRA, Université d'Angers, Agrocampus-Ouest, SFR 4207 QuaSaV, 42 rue Georges Morel, 49071 Beaucouzé Cedex, Angers, France
| | - Thomas Guillemette
- Institut de Recherche en Horticulture et Semences - UMR 1345, INRA, Université d'Angers, Agrocampus-Ouest, SFR 4207 QuaSaV, 42 rue Georges Morel, 49071 Beaucouzé Cedex, Angers, France.
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27
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Sterk C, Gräber L, Schmitz HP, Heinisch JJ. Analysis of Functional Domains in Rho5, the Yeast Homolog of Human Rac1 GTPase, in Oxidative Stress Response. Int J Mol Sci 2019; 20:ijms20225550. [PMID: 31703278 PMCID: PMC6888954 DOI: 10.3390/ijms20225550] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 11/03/2019] [Accepted: 11/05/2019] [Indexed: 12/23/2022] Open
Abstract
The small GTPase Rho5 of Saccharomyces cerevisiae is required for proper regulation of different signaling pathways, which includes the response to cell wall, osmotic, nutrient, and oxidative stress. We here show that proper in vivo function and intracellular distribution of Rho5 depends on its hypervariable region at the carboxyterminal end, which includes the CAAX box for lipid modification, a preceding polybasic region (PBR) carrying a serine residue, and a 98 amino acid–specific insertion only present in Rho5 of S. cerevisiae but not in its human homolog Rac1. Results from trapping GFP-Rho5 variants to the mitochondrial surface suggest that the GTPase needs to be activated at the plasma membrane prior to its translocation to mitochondria in order to fulfil its role in oxidative stress response. These findings are supported by heterologous expression of a codon-optimized human RAC1 gene, which can only complement a yeast rho5 deletion in a chimeric fusion with RHO5 sequences that restore the correct spatiotemporal distribution of the encoded protein.
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Abstract
Moseley discusses the molecular and mechanical functions of eisosomes - invaginations from the yeast plasma membrane.
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29
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Nishimura T, Gecht M, Covino R, Hummer G, Surma MA, Klose C, Arai H, Kono N, Stefan CJ. Osh Proteins Control Nanoscale Lipid Organization Necessary for PI(4,5)P 2 Synthesis. Mol Cell 2019; 75:1043-1057.e8. [PMID: 31402097 PMCID: PMC6739424 DOI: 10.1016/j.molcel.2019.06.037] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 05/13/2019] [Accepted: 06/25/2019] [Indexed: 11/28/2022]
Abstract
The plasma membrane (PM) is composed of a complex lipid mixture that forms heterogeneous membrane environments. Yet, how small-scale lipid organization controls physiological events at the PM remains largely unknown. Here, we show that ORP-related Osh lipid exchange proteins are critical for the synthesis of phosphatidylinositol (4,5)-bisphosphate [PI(4,5)P2], a key regulator of dynamic events at the PM. In real-time assays, we find that unsaturated phosphatidylserine (PS) and sterols, both Osh protein ligands, synergistically stimulate phosphatidylinositol 4-phosphate 5-kinase (PIP5K) activity. Biophysical FRET analyses suggest an unconventional co-distribution of unsaturated PS and phosphatidylinositol 4-phosphate (PI4P) species in sterol-containing membrane bilayers. Moreover, using in vivo imaging approaches and molecular dynamics simulations, we show that Osh protein-mediated unsaturated PI4P and PS membrane lipid organization is sensed by the PIP5K specificity loop. Thus, ORP family members create a nanoscale membrane lipid environment that drives PIP5K activity and PI(4,5)P2 synthesis that ultimately controls global PM organization and dynamics. The Osh lipid exchange proteins are required to maintain PI(4,5)P2 levels in the PM Unsaturated PS and sterols synergistically stimulate PIP5K activity The specificity loop conserved in PIP5Ks serves as a lipid sensor A simulation model of the PIP5K specificity loop embedded in a lipid bilayer
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Affiliation(s)
- Taki Nishimura
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK.
| | - Michael Gecht
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - Roberto Covino
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - Gerhard Hummer
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany; Institute for Biophysics, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
| | | | | | - Hiroyuki Arai
- Department of Health Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan; AMED-CREST, Japan Agency for Medical Research and Development, 1-7-1 Otemachi, Chiyodaku, Tokyo 100-0004, Japan
| | - Nozomu Kono
- Department of Health Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan; PRIME, Japan Agency for Medical Research and Development, 1-7-1 Otemachi, Chiyodaku, Tokyo 100-0004, Japan
| | - Christopher J Stefan
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK.
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30
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Zahumensky J, Malinsky J. Role of MCC/Eisosome in Fungal Lipid Homeostasis. Biomolecules 2019; 9:E305. [PMID: 31349700 PMCID: PMC6723945 DOI: 10.3390/biom9080305] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 07/19/2019] [Accepted: 07/22/2019] [Indexed: 12/11/2022] Open
Abstract
One of the best characterized fungal membrane microdomains is the MCC/eisosome. The MCC (membrane compartment of Can1) is an evolutionarily conserved ergosterol-rich plasma membrane domain. It is stabilized on its cytosolic face by the eisosome, a hemitubular protein complex composed of Bin/Amphiphysin/Rvs (BAR) domain-containing Pil1 and Lsp1. These two proteins bind directly to phosphatidylinositol 4,5-bisphosphate and promote the typical furrow-like shape of the microdomain, with highly curved edges and bottom. While some proteins display stable localization in the MCC/eisosome, others enter or leave it under particular conditions, such as misbalance in membrane lipid composition, changes in membrane tension, or availability of specific nutrients. These findings reveal that the MCC/eisosome, a plasma membrane microdomain with distinct morphology and lipid composition, acts as a multifaceted regulator of various cellular processes including metabolic pathways, cellular morphogenesis, signalling cascades, and mRNA decay. In this minireview, we focus on the MCC/eisosome's proposed role in the regulation of lipid metabolism. While the molecular mechanisms of the MCC/eisosome function are not completely understood, the idea of intracellular processes being regulated at the plasma membrane, the foremost barrier exposed to environmental challenges, is truly exciting.
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Affiliation(s)
- Jakub Zahumensky
- Department of Microscopy, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, 14220 Prague, Czech Republic
| | - Jan Malinsky
- Department of Microscopy, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, 14220 Prague, Czech Republic.
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31
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Chan C, Pang X, Zhang Y, Niu T, Yang S, Zhao D, Li J, Lu L, Hsu VW, Zhou J, Sun F, Fan J. ACAP1 assembles into an unusual protein lattice for membrane deformation through multiple stages. PLoS Comput Biol 2019; 15:e1007081. [PMID: 31291238 PMCID: PMC6663034 DOI: 10.1371/journal.pcbi.1007081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 07/29/2019] [Accepted: 05/06/2019] [Indexed: 11/19/2022] Open
Abstract
Studies on the Bin-Amphiphysin-Rvs (BAR) domain have advanced a fundamental understanding of how proteins deform membrane. We previously showed that a BAR domain in tandem with a Pleckstrin Homology (PH domain) underlies the assembly of ACAP1 (Arfgap with Coil-coil, Ankryin repeat, and PH domain I) into an unusual lattice structure that also uncovers a new paradigm for how a BAR protein deforms membrane. Here, we initially pursued computation-based refinement of the ACAP1 lattice to identify its critical protein contacts. Simulation studies then revealed how ACAP1, which dimerizes into a symmetrical structure in solution, is recruited asymmetrically to the membrane through dynamic behavior. We also pursued electron microscopy (EM)-based structural studies, which shed further insight into the dynamic nature of the ACAP1 lattice assembly. As ACAP1 is an unconventional BAR protein, our findings broaden the understanding of the mechanistic spectrum by which proteins assemble into higher-ordered structures to achieve membrane deformation.
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Affiliation(s)
- Chun Chan
- Department of Materials Science and Engineering, City University of Hong Kong, Hong Kong, China
| | - Xiaoyun Pang
- National Laboratory of Biomacromolecules, CAS Center for excellence in biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Yan Zhang
- National Laboratory of Biomacromolecules, CAS Center for excellence in biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Tongxin Niu
- National Laboratory of Biomacromolecules, CAS Center for excellence in biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Shengjiang Yang
- School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, Guangdong, China
| | - Daohui Zhao
- School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, Guangdong, China
| | - Jian Li
- Division of Rheumatology, Immunology and Allergy, Brigham and Women’s Hospital, and Department of Medicine, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Lanyuan Lu
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Victor W. Hsu
- Division of Rheumatology, Immunology and Allergy, Brigham and Women’s Hospital, and Department of Medicine, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Jian Zhou
- School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, Guangdong, China
- * E-mail: (JZ); (FS); (JF)
| | - Fei Sun
- National Laboratory of Biomacromolecules, CAS Center for excellence in biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- Center for Biological Imaging, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- * E-mail: (JZ); (FS); (JF)
| | - Jun Fan
- Department of Materials Science and Engineering, City University of Hong Kong, Hong Kong, China
- City University of Hong Kong Shenzhen Research Institute, Shenzhen, China
- Center for Advanced Nuclear Safety and Sustainable Development, City University of Hong Kong, Hong Kong, China
- * E-mail: (JZ); (FS); (JF)
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32
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VIPP1 rods engulf membranes containing phosphatidylinositol phosphates. Sci Rep 2019; 9:8725. [PMID: 31217458 PMCID: PMC6584618 DOI: 10.1038/s41598-019-44259-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2018] [Accepted: 05/14/2019] [Indexed: 12/15/2022] Open
Abstract
In cyanobacteria and plants, VIPP1 plays crucial roles in the biogenesis and repair of thylakoid membrane protein complexes and in coping with chloroplast membrane stress. In chloroplasts, VIPP1 localizes in distinct patterns at or close to envelope and thylakoid membranes. In vitro, VIPP1 forms higher-order oligomers of >1 MDa that organize into rings and rods. However, it remains unknown how VIPP1 oligomerization is related to function. Using time-resolved fluorescence anisotropy and sucrose density gradient centrifugation, we show here that Chlamydomonas reinhardtii VIPP1 binds strongly to liposomal membranes containing phosphatidylinositol-4-phosphate (PI4P). Cryo-electron tomography reveals that VIPP1 oligomerizes into rods that can engulf liposomal membranes containing PI4P. These findings place VIPP1 into a group of membrane-shaping proteins including epsin and BAR domain proteins. Moreover, they point to a potential role of phosphatidylinositols in directing the shaping of chloroplast membranes.
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33
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Martinez Marshall MN, Emmerstorfer-Augustin A, Leskoske KL, Zhang LH, Li B, Thorner J. Analysis of the roles of phosphatidylinositol-4,5- bisphosphate and individual subunits in assembly, localization, and function of Saccharomyces cerevisiae target of rapamycin complex 2. Mol Biol Cell 2019; 30:1555-1574. [PMID: 30969890 PMCID: PMC6724684 DOI: 10.1091/mbc.e18-10-0682] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Eukaryotic cell survival requires maintenance of plasma membrane (PM) homeostasis in response to environmental insults and changes in lipid metabolism. In yeast, a key regulator of PM homeostasis is target of rapamycin (TOR) complex 2 (TORC2), a multiprotein complex containing the evolutionarily conserved TOR protein kinase isoform Tor2. PM localization is essential for TORC2 function. One core TORC2 subunit (Avo1) and two TORC2-associated regulators (Slm1 and Slm2) contain pleckstrin homology (PH) domains that exhibit specificity for binding phosphatidylinositol-4,5-bisphosphate (PtdIns4,5P2). To investigate the roles of PtdIns4,5P2 and constituent subunits of TORC2, we used auxin-inducible degradation to systematically eliminate these factors and then examined localization, association, and function of the remaining TORC2 components. We found that PtdIns4,5P2 depletion significantly reduced TORC2 activity, yet did not prevent PM localization or disassembly of TORC2. Moreover, truncated Avo1 (lacking its C-terminal PH domain) was still recruited to the PM and supported growth. Even when all three PH-containing proteins were absent, the remaining TORC2 subunits were PM-bound. Revealingly, Avo3 localized to the PM independent of both Avo1 and Tor2, whereas both Tor2 and Avo1 required Avo3 for their PM anchoring. Our findings provide new mechanistic information about TORC2 and pinpoint Avo3 as pivotal for TORC2 PM localization and assembly in vivo.
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Affiliation(s)
- Maria Nieves Martinez Marshall
- Division of Biochemistry, Biophysics and Structural Biology, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720
| | - Anita Emmerstorfer-Augustin
- Division of Biochemistry, Biophysics and Structural Biology, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720
| | - Kristin L Leskoske
- Division of Biochemistry, Biophysics and Structural Biology, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720
| | - Lydia H Zhang
- Division of Biochemistry, Biophysics and Structural Biology, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720
| | - Biyun Li
- Division of Biochemistry, Biophysics and Structural Biology, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720
| | - Jeremy Thorner
- Division of Biochemistry, Biophysics and Structural Biology, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720
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Singh K, Lee ME, Entezari M, Jung CH, Kim Y, Park Y, Fioretti JD, Huh WK, Park HO, Kang PJ. Genome-Wide Studies of Rho5-Interacting Proteins That Are Involved in Oxidant-Induced Cell Death in Budding Yeast. G3 (BETHESDA, MD.) 2019; 9:921-931. [PMID: 30670610 PMCID: PMC6404601 DOI: 10.1534/g3.118.200887] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 01/18/2019] [Indexed: 12/28/2022]
Abstract
Rho GTPases play critical roles in cell proliferation and cell death in many species. As in animal cells, cells of the budding yeast Saccharomyces cerevisiae undergo regulated cell death under various physiological conditions and upon exposure to external stress. The Rho5 GTPase is necessary for oxidant-induced cell death, and cells expressing a constitutively active GTP-locked Rho5 are hypersensitive to oxidants. Yet how Rho5 regulates yeast cell death has been poorly understood. To identify genes that are involved in the Rho5-mediated cell death program, we performed two complementary genome-wide screens: one screen for oxidant-resistant deletion mutants and another screen for Rho5-associated proteins. Functional enrichment and interaction network analysis revealed enrichment for genes in pathways related to metabolism, transport, and plasma membrane organization. In particular, we find that ATG21, which is known to be involved in the CVT (Cytoplasm-to-Vacuole Targeting) pathway and mitophagy, is necessary for cell death induced by oxidants. Cells lacking Atg21 exhibit little cell death upon exposure to oxidants even when the GTP-locked Rho5 is expressed. Moreover, Atg21 interacts with Rho5 preferentially in its GTP-bound state, suggesting that Atg21 is a downstream target of Rho5 in oxidant-induced cell death. Given the high degree of conservation of Rho GTPases and autophagy from yeast to human, this study may provide insight into regulated cell death in eukaryotes in general.
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Affiliation(s)
- Komudi Singh
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210
| | - Mid Eum Lee
- Molecular Cellular Developmental Biology Program, The Ohio State University, Columbus, OH 43210
| | - Maryam Entezari
- Department of Biological Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Chan-Hun Jung
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210
| | - Yeonsoo Kim
- Department of Biological Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Youngmin Park
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210
| | - Jack D Fioretti
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210
| | - Won-Ki Huh
- Department of Biological Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Hay-Oak Park
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210
- Molecular Cellular Developmental Biology Program, The Ohio State University, Columbus, OH 43210
| | - Pil Jung Kang
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210
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35
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Douglas LM, Konopka JB. Plasma membrane architecture protects Candida albicans from killing by copper. PLoS Genet 2019; 15:e1007911. [PMID: 30633741 PMCID: PMC6345494 DOI: 10.1371/journal.pgen.1007911] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 01/24/2019] [Accepted: 12/20/2018] [Indexed: 12/21/2022] Open
Abstract
The ability to resist copper toxicity is important for microbial pathogens to survive attack by innate immune cells. A sur7Δ mutant of the fungal pathogen Candida albicans exhibits decreased virulence that correlates with increased sensitivity to copper, as well as defects in other stress responses and morphogenesis. Previous studies indicated that copper kills sur7Δ cells by a mechanism distinct from the known resistance pathways involving the Crp1 copper exporter or the Cup1 metallothionein. Since Sur7 resides in punctate plasma membrane domains known as MCC/eisosomes, we examined overexpression of SUR7 and found that it rescued the copper sensitivity of a mutant that fails to form MCC/eisosomes (pil1Δ lsp1Δ), indicating that these domains act to facilitate Sur7 function. Genetic screening identified new copper-sensitive mutants, the strongest of which were similar to sur7Δ in having altered plasma membranes due to defects in membrane trafficking, cortical actin, and morphogenesis (rvs161Δ, rvs167Δ, and arp2Δ arp3Δ). Consistent with the mutants having altered plasma membrane organization, they were all more readily permeabilized by copper, which is known to bind phosphatidylserine and phosphatidylethanolamine and cause membrane damage. Although these phospholipids are normally localized to the intracellular leaflet of the plasma membrane, their exposure on the surface of the copper-sensitive mutants was indicated by increased susceptibility to membrane damaging agents that bind to these phospholipids. Increased copper sensitivity was also detected for a drs2Δ mutant, which lacks a phospholipid flippase that is involved in maintaining phospholipid asymmetry. Copper binds phosphatidylserine with very high affinity, and deleting CHO1 to prevent phosphatidylserine synthesis rescued the copper sensitivity of sur7Δ cells, confirming a major role for phosphatidylserine in copper sensitivity. These results highlight how proper plasma membrane architecture protects fungal pathogens from copper and attack by the immune system, thereby opening up new avenues for therapeutic intervention. The transition metal copper is used by the innate immune system to attack microbial pathogens. To better understand how the human fungal pathogen Candida albicans resists this type of stress, we screened for mutants that were more susceptible to killing by copper. Interestingly, we identified a new class of copper-sensitive mutants whose plasma membranes are more readily permeabilized by copper. The common characteristic of these new copper-sensitive mutants is that they have an altered cell surface, which weakened their resistance to copper. These results help to explain the toxic effects of copper and suggest novel therapeutic strategies for fungal infections.
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Affiliation(s)
- Lois M. Douglas
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, United States of America
| | - James B. Konopka
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, United States of America
- * E-mail:
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36
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Leskoske KL, Roelants FM, Emmerstorfer-Augustin A, Augustin CM, Si EP, Hill JM, Thorner J. Phosphorylation by the stress-activated MAPK Slt2 down-regulates the yeast TOR complex 2. Genes Dev 2018; 32:1576-1590. [PMID: 30478248 PMCID: PMC6295167 DOI: 10.1101/gad.318709.118] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 10/10/2018] [Indexed: 12/13/2022]
Abstract
Here, Leskoske et al. studied how TORC2 activity is modulated in response to changes in the status of the cell envelope. They demonstrate that TORC2 subunit Avo2 is a direct target of Slt2, the MAPK of the cell wall integrity pathway, and their findings provide new insights into TORC2 function and regulation. Saccharomyces cerevisiae target of rapamycin (TOR) complex 2 (TORC2) is an essential regulator of plasma membrane lipid and protein homeostasis. How TORC2 activity is modulated in response to changes in the status of the cell envelope is unclear. Here we document that TORC2 subunit Avo2 is a direct target of Slt2, the mitogen-activated protein kinase (MAPK) of the cell wall integrity pathway. Activation of Slt2 by overexpression of a constitutively active allele of an upstream Slt2 activator (Pkc1) or by auxin-induced degradation of a negative Slt2 regulator (Sln1) caused hyperphosphorylation of Avo2 at its MAPK phosphoacceptor sites in a Slt2-dependent manner and diminished TORC2-mediated phosphorylation of its major downstream effector, protein kinase Ypk1. Deletion of Avo2 or expression of a phosphomimetic Avo2 allele rendered cells sensitive to two stresses (myriocin treatment and elevated exogenous acetic acid) that the cell requires Ypk1 activation by TORC2 to survive. Thus, Avo2 is necessary for optimal TORC2 activity, and Slt2-mediated phosphorylation of Avo2 down-regulates TORC2 signaling. Compared with wild-type Avo2, phosphomimetic Avo2 shows significant displacement from the plasma membrane, suggesting that Slt2 inhibits TORC2 by promoting Avo2 dissociation. Our findings are the first demonstration that TORC2 function is regulated by MAPK-mediated phosphorylation.
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Affiliation(s)
- Kristin L Leskoske
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720, USA
| | - Françoise M Roelants
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720, USA
| | - Anita Emmerstorfer-Augustin
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720, USA
| | - Christoph M Augustin
- Department of Mechanical Engineering, University of California at Berkeley, Berkeley, California 94720, USA
| | - Edward P Si
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720, USA
| | - Jennifer M Hill
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720, USA
| | - Jeremy Thorner
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720, USA
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37
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Alimohamadi H, Rangamani P. Modeling Membrane Curvature Generation due to Membrane⁻Protein Interactions. Biomolecules 2018; 8:E120. [PMID: 30360496 PMCID: PMC6316661 DOI: 10.3390/biom8040120] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 10/15/2018] [Accepted: 10/16/2018] [Indexed: 01/03/2023] Open
Abstract
To alter and adjust the shape of the plasma membrane, cells harness various mechanisms of curvature generation. Many of these curvature generation mechanisms rely on the interactions between peripheral membrane proteins, integral membrane proteins, and lipids in the bilayer membrane. Mathematical and computational modeling of membrane curvature generation has provided great insights into the physics underlying these processes. However, one of the challenges in modeling these processes is identifying the suitable constitutive relationships that describe the membrane free energy including protein distribution and curvature generation capability. Here, we review some of the commonly used continuum elastic membrane models that have been developed for this purpose and discuss their applications. Finally, we address some fundamental challenges that future theoretical methods need to overcome to push the boundaries of current model applications.
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Affiliation(s)
- Haleh Alimohamadi
- Department of Mechanical and Aerospace Engineering, University of California, San Diego, CA 92093, USA.
| | - Padmini Rangamani
- Department of Mechanical and Aerospace Engineering, University of California, San Diego, CA 92093, USA.
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38
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Alimohamadi H, Vasan R, Hassinger J, Stachowiak J, Rangamani P. The role of traction in membrane curvature generation. Mol Biol Cell 2018; 29:2024-2035. [PMID: 30044708 PMCID: PMC6232966 DOI: 10.1091/mbc.e18-02-0087] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 07/11/2018] [Accepted: 07/16/2018] [Indexed: 01/28/2023] Open
Abstract
Curvature of biological membranes can be generated by a variety of molecular mechanisms including protein scaffolding, compositional heterogeneity, and cytoskeletal forces. These mechanisms have the net effect of generating tractions (force per unit length) on the bilayer that are translated into distinct shapes of the membrane. Here, we demonstrate how the local shape of the membrane can be used to infer the traction acting locally on the membrane. We show that buds and tubes, two common membrane deformations studied in trafficking processes, have different traction distributions along the membrane and that these tractions are specific to the molecular mechanism used to generate these shapes. Furthermore, we show that the magnitude of an axial force applied to the membrane as well as that of an effective line tension can be calculated from these tractions. Finally, we consider the sensitivity of these quantities with respect to uncertainties in material properties and follow with a discussion on sources of uncertainty in membrane shape.
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Affiliation(s)
- H. Alimohamadi
- Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, CA 92093
| | - R. Vasan
- Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, CA 92093
| | - J.E. Hassinger
- Biophysics Graduate Program, University of California, Berkeley, Berkeley, CA 94720
| | - J.C. Stachowiak
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX 78712
| | - P. Rangamani
- Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, CA 92093
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39
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Bharat TAM, Hoffmann PC, Kukulski W. Correlative Microscopy of Vitreous Sections Provides Insights into BAR-Domain Organization In Situ. Structure 2018; 26:879-886.e3. [PMID: 29681471 PMCID: PMC5992340 DOI: 10.1016/j.str.2018.03.015] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 02/22/2018] [Accepted: 03/22/2018] [Indexed: 12/15/2022]
Abstract
Electron microscopy imaging of macromolecular complexes in their native cellular context is limited by the inherent difficulty to acquire high-resolution tomographic data from thick cells and to specifically identify elusive structures within crowded cellular environments. Here, we combined cryo-fluorescence microscopy with electron cryo-tomography of vitreous sections into a coherent correlative microscopy workflow, ideal for detection and structural analysis of elusive protein assemblies in situ. We used this workflow to address an open question on BAR-domain coating of yeast plasma membrane compartments known as eisosomes. BAR domains can sense or induce membrane curvature, and form scaffold-like membrane coats in vitro. Our results demonstrate that in cells, the BAR protein Pil1 localizes to eisosomes of varying membrane curvature. Sub-tomogram analysis revealed a dense protein coat on curved eisosomes, which was not present on shallow eisosomes, indicating that while BAR domains can assemble at shallow membranes in vivo, scaffold formation is tightly coupled to curvature generation. Cryo-fluorescence microscopy eases electron cryo-tomography of vitreous sections Elusive protein assemblies are localized in situ by correlative microscopy Yeast BAR-domain protein Pil1 binds to plasma membrane with varying curvature Scaffold-like coats are only seen when Pil1 is bound to high curvature membranes
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Affiliation(s)
- Tanmay A M Bharat
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK; Central Oxford Structural and Molecular Imaging Centre, South Parks Road, Oxford OX1 3RE, UK; Structural Studies Division, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Patrick C Hoffmann
- Cell Biology Division, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Wanda Kukulski
- Cell Biology Division, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK.
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40
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Bianchi F, Syga Ł, Moiset G, Spakman D, Schavemaker PE, Punter CM, Seinen AB, van Oijen AM, Robinson A, Poolman B. Steric exclusion and protein conformation determine the localization of plasma membrane transporters. Nat Commun 2018; 9:501. [PMID: 29402931 PMCID: PMC5799302 DOI: 10.1038/s41467-018-02864-2] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 01/04/2018] [Indexed: 11/09/2022] Open
Abstract
The plasma membrane (PM) of Saccharomyces cerevisiae contains membrane compartments, MCC/eisosomes and MCPs, named after the protein residents Can1 and Pma1, respectively. Using high-resolution fluorescence microscopy techniques we show that Can1 and the homologous transporter Lyp1 are able to diffuse into the MCC/eisosomes, where a limited number of proteins are conditionally trapped at the (outer) edge of the compartment. Upon addition of substrate, the immobilized proteins diffuse away from the MCC/eisosomes, presumably after taking a different conformation in the substrate-bound state. Our data indicate that the mobile fraction of all integral plasma membrane proteins tested shows extremely slow Brownian diffusion through most of the PM. We also show that proteins with large cytoplasmic domains, such as Pma1 and synthetic chimera of Can1 and Lyp1, are excluded from the MCC/eisosomes. We hypothesize that the distinct localization patterns found for these integral membrane proteins in S. cerevisiae arises from a combination of slow lateral diffusion, steric exclusion, and conditional trapping in membrane compartments.
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Affiliation(s)
- Frans Bianchi
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9700AB, Groningen, The Netherlands
| | - Łukasz Syga
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9700AB, Groningen, The Netherlands
| | - Gemma Moiset
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9700AB, Groningen, The Netherlands.,Zernike Institute for Advanced Materials, Nijenborgh 4, 9747AG, Groningen, The Netherlands
| | - Dian Spakman
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9700AB, Groningen, The Netherlands
| | - Paul E Schavemaker
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9700AB, Groningen, The Netherlands
| | - Christiaan M Punter
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9700AB, Groningen, The Netherlands.,Zernike Institute for Advanced Materials, Nijenborgh 4, 9747AG, Groningen, The Netherlands
| | - Anne-Bart Seinen
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9700AB, Groningen, The Netherlands.,Zernike Institute for Advanced Materials, Nijenborgh 4, 9747AG, Groningen, The Netherlands
| | - Antoine M van Oijen
- Zernike Institute for Advanced Materials, Nijenborgh 4, 9747AG, Groningen, The Netherlands
| | - Andrew Robinson
- Zernike Institute for Advanced Materials, Nijenborgh 4, 9747AG, Groningen, The Netherlands
| | - Bert Poolman
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9700AB, Groningen, The Netherlands. .,Zernike Institute for Advanced Materials, Nijenborgh 4, 9747AG, Groningen, The Netherlands.
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41
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Goudarzi M, Tarbashevich K, Mildner K, Begemann I, Garcia J, Paksa A, Reichman-Fried M, Mahabaleshwar H, Blaser H, Hartwig J, Zeuschner D, Galic M, Bagnat M, Betz T, Raz E. Bleb Expansion in Migrating Cells Depends on Supply of Membrane from Cell Surface Invaginations. Dev Cell 2017; 43:577-587.e5. [PMID: 29173819 PMCID: PMC5939956 DOI: 10.1016/j.devcel.2017.10.030] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2017] [Revised: 09/27/2017] [Accepted: 10/26/2017] [Indexed: 01/14/2023]
Abstract
Cell migration is essential for morphogenesis, organ formation, and homeostasis, with relevance for clinical conditions. The migration of primordial germ cells (PGCs) is a useful model for studying this process in the context of the developing embryo. Zebrafish PGC migration depends on the formation of cellular protrusions in form of blebs, a type of protrusion found in various cell types. Here we report on the mechanisms allowing the inflation of the membrane during bleb formation. We show that the rapid expansion of the protrusion depends on membrane invaginations that are localized preferentially at the cell front. The formation of these invaginations requires the function of Cdc42, and their unfolding allows bleb inflation and dynamic cell-shape changes performed by migrating cells. Inhibiting the formation and release of the invaginations strongly interfered with bleb formation, cell motility, and the ability of the cells to reach their target.
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Affiliation(s)
- Mohammad Goudarzi
- Institute for Cell Biology, ZMBE, Von-Esmarch-Strasse 56, 48149 Münster, Germany
| | | | - Karina Mildner
- Electron Microscopy Unit, Max Planck Institute for Molecular Biomedicine, Röntgenstrasse 20, 48149 Münster, Germany
| | - Isabell Begemann
- Workgroup Nanoforces in Cells, Institute of Medical Physics und Biophysics, DFG Cluster of Excellence 'Cells in Motion' (EXC 1003), Robert-Koch-Strasse 31, 48149 Münster, Germany
| | - Jamie Garcia
- Department of Cell Biology, Duke University, 333B Nanaline Duke Building, Box 3709, Durham, NC 27710, USA
| | - Azadeh Paksa
- Institute for Cell Biology, ZMBE, Von-Esmarch-Strasse 56, 48149 Münster, Germany
| | | | - Harsha Mahabaleshwar
- Institute for Cell Biology, ZMBE, Von-Esmarch-Strasse 56, 48149 Münster, Germany
| | - Heiko Blaser
- Germ Cell Development, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37070 Göttingen, Germany
| | - Johannes Hartwig
- Institute for Cell Biology, ZMBE, Von-Esmarch-Strasse 56, 48149 Münster, Germany
| | - Dagmar Zeuschner
- Electron Microscopy Unit, Max Planck Institute for Molecular Biomedicine, Röntgenstrasse 20, 48149 Münster, Germany
| | - Milos Galic
- Workgroup Nanoforces in Cells, Institute of Medical Physics und Biophysics, DFG Cluster of Excellence 'Cells in Motion' (EXC 1003), Robert-Koch-Strasse 31, 48149 Münster, Germany
| | - Michel Bagnat
- Department of Cell Biology, Duke University, 333B Nanaline Duke Building, Box 3709, Durham, NC 27710, USA
| | - Timo Betz
- Institute for Cell Biology, ZMBE, Von-Esmarch-Strasse 56, 48149 Münster, Germany
| | - Erez Raz
- Institute for Cell Biology, ZMBE, Von-Esmarch-Strasse 56, 48149 Münster, Germany.
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42
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MCC/Eisosomes Regulate Cell Wall Synthesis and Stress Responses in Fungi. J Fungi (Basel) 2017; 3:jof3040061. [PMID: 29371577 PMCID: PMC5753163 DOI: 10.3390/jof3040061] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 10/26/2017] [Accepted: 10/31/2017] [Indexed: 12/20/2022] Open
Abstract
The fungal plasma membrane is critical for cell wall synthesis and other important processes including nutrient uptake, secretion, endocytosis, morphogenesis, and response to stress. To coordinate these diverse functions, the plasma membrane is organized into specialized compartments that vary in size, stability, and composition. One recently identified domain known as the Membrane Compartment of Can1 (MCC)/eisosome is distinctive in that it corresponds to a furrow-like invagination in the plasma membrane. MCC/eisosomes have been shown to be formed by the Bin/Amphiphysin/Rvs (BAR) domain proteins Lsp1 and Pil1 in a range of fungi. MCC/eisosome domains influence multiple cellular functions; but a very pronounced defect in cell wall synthesis has been observed for mutants with defects in MCC/eisosomes in some yeast species. For example, Candida albicans MCC/eisosome mutants display abnormal spatial regulation of cell wall synthesis, including large invaginations and altered chemical composition of the walls. Recent studies indicate that MCC/eisosomes affect cell wall synthesis in part by regulating the levels of the key regulatory lipid phosphatidylinositol 4,5-bisphosphate (PI4,5P2) in the plasma membrane. One general way MCC/eisosomes function is by acting as protected islands in the plasma membrane, since these domains are very stable. They also act as scaffolds to recruit >20 proteins. Genetic studies aimed at defining the function of the MCC/eisosome proteins have identified important roles in resistance to stress, such as resistance to oxidative stress mediated by the flavodoxin-like proteins Pst1, Pst2, Pst3 and Ycp4. Thus, MCC/eisosomes play multiple roles in plasma membrane organization that protect fungal cells from the environment.
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43
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Sahu A, Sauer RA, Mandadapu KK. Irreversible thermodynamics of curved lipid membranes. Phys Rev E 2017; 96:042409. [PMID: 29347561 DOI: 10.1103/physreve.96.042409] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Indexed: 01/15/2023]
Abstract
The theory of irreversible thermodynamics for arbitrarily curved lipid membranes is presented here. The coupling between elastic bending and irreversible processes such as intramembrane lipid flow, intramembrane phase transitions, and protein binding and diffusion is studied. The forms of the entropy production for the irreversible processes are obtained, and the corresponding thermodynamic forces and fluxes are identified. Employing the linear irreversible thermodynamic framework, the governing equations of motion along with appropriate boundary conditions are provided.
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Affiliation(s)
- Amaresh Sahu
- Department of Chemical & Biomolecular Engineering, University of California at Berkeley, Berkeley, California 94720, USA
| | - Roger A Sauer
- Aachen Institute for Advanced Study in Computational Engineering Science (AICES), RWTH Aachen University, Templergraben 55, 52056 Aachen, Germany
| | - Kranthi K Mandadapu
- Department of Chemical & Biomolecular Engineering, University of California at Berkeley, Berkeley, California 94720, USA
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44
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The TORC2-Dependent Signaling Network in the Yeast Saccharomyces cerevisiae. Biomolecules 2017; 7:biom7030066. [PMID: 28872598 PMCID: PMC5618247 DOI: 10.3390/biom7030066] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 08/25/2017] [Accepted: 08/28/2017] [Indexed: 12/21/2022] Open
Abstract
To grow, eukaryotic cells must expand by inserting glycerolipids, sphingolipids, sterols, and proteins into their plasma membrane, and maintain the proper levels and bilayer distribution. A fungal cell must coordinate growth with enlargement of its cell wall. In Saccharomyces cerevisiae, a plasma membrane-localized protein kinase complex, Target of Rapamicin (TOR) complex-2 (TORC2) (mammalian ortholog is mTORC2), serves as a sensor and master regulator of these plasma membrane- and cell wall-associated events by directly phosphorylating and thereby stimulating the activity of two types of effector protein kinases: Ypk1 (mammalian ortholog is SGK1), along with a paralog (Ypk2); and, Pkc1 (mammalian ortholog is PKN2/PRK2). Ypk1 is a central regulator of pathways and processes required for plasma membrane lipid and protein homeostasis, and requires phosphorylation on its T-loop by eisosome-associated protein kinase Pkh1 (mammalian ortholog is PDK1) and a paralog (Pkh2). For cell survival under various stresses, Ypk1 function requires TORC2-mediated phosphorylation at multiple sites near its C terminus. Pkc1 controls diverse processes, especially cell wall synthesis and integrity. Pkc1 is also regulated by Pkh1- and TORC2-dependent phosphorylation, but, in addition, by interaction with Rho1-GTP and lipids phosphatidylserine (PtdSer) and diacylglycerol (DAG). We also describe here what is currently known about the downstream substrates modulated by Ypk1-mediated and Pkc1-mediated phosphorylation.
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45
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Vaškovičová K, Awadová T, Veselá P, Balážová M, Opekarová M, Malinsky J. mRNA decay is regulated via sequestration of the conserved 5′-3′ exoribonuclease Xrn1 at eisosome in yeast. Eur J Cell Biol 2017; 96:591-599. [DOI: 10.1016/j.ejcb.2017.05.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 04/07/2017] [Accepted: 05/02/2017] [Indexed: 01/08/2023] Open
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46
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Clathrin-Independent Endocytosis Suppresses Cancer Cell Blebbing and Invasion. Cell Rep 2017; 20:1893-1905. [DOI: 10.1016/j.celrep.2017.08.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 06/15/2017] [Accepted: 07/28/2017] [Indexed: 01/09/2023] Open
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47
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Lacy MM, Baddeley D, Berro J. Single-molecule imaging of the BAR-domain protein Pil1p reveals filament-end dynamics. Mol Biol Cell 2017; 28:2251-2259. [PMID: 28659415 PMCID: PMC5555653 DOI: 10.1091/mbc.e17-04-0238] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 06/22/2017] [Indexed: 12/21/2022] Open
Abstract
Molecular assemblies can have highly heterogeneous dynamics within the cell, but the limitations of conventional fluorescence microscopy can mask nanometer-scale features. Here we adapt a single-molecule strategy to perform single-molecule recovery after photobleaching (SRAP) within dense macromolecular assemblies to reveal and characterize binding and unbinding dynamics within such assemblies. We applied this method to study the eisosome, a stable assembly of BAR-domain proteins on the cytoplasmic face of the plasma membrane in fungi. By fluorescently labeling only a small fraction of cellular Pil1p, the main eisosome BAR-domain protein in fission yeast, we visualized whole eisosomes and, after photobleaching, localized recruitment of new Pil1p molecules with ∼30-nm precision. Comparing our data to computer simulations, we show that Pil1p exchange occurs specifically at eisosome ends and not along their core, supporting a new model of the eisosome as a dynamic filament. This result is the first direct observation of any BAR-domain protein dynamics in vivo under physiological conditions consistent with the oligomeric filaments reported from in vitro experiments.
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Affiliation(s)
- Michael M Lacy
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520.,Nanobiology Institute, Yale University, West Haven, CT 06516.,Integrated Graduate Program in Physical and Engineering Biology, Yale University, New Haven, CT 06520
| | - David Baddeley
- Nanobiology Institute, Yale University, West Haven, CT 06516.,Integrated Graduate Program in Physical and Engineering Biology, Yale University, New Haven, CT 06520.,Department of Cell Biology, Yale University, New Haven, CT 06520
| | - Julien Berro
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520 .,Nanobiology Institute, Yale University, West Haven, CT 06516.,Integrated Graduate Program in Physical and Engineering Biology, Yale University, New Haven, CT 06520.,Integrated Graduate Program in Physical and Engineering Biology, Yale University, New Haven, CT 06520
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48
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Zhang LB, Tang L, Ying SH, Feng MG. Two eisosome proteins play opposite roles in autophagic control and sustain cell integrity, function and pathogenicity in Beauveria bassiana. Environ Microbiol 2017; 19:2037-2052. [DOI: 10.1111/1462-2920.13727] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 03/02/2017] [Accepted: 03/03/2017] [Indexed: 01/06/2023]
Affiliation(s)
- Long-Bin Zhang
- Institute of Microbiology, College of Life Sciences; Zhejiang University; Hangzhou Zhejiang 310058 People's Republic of China
| | - Li Tang
- Institute of Microbiology, College of Life Sciences; Zhejiang University; Hangzhou Zhejiang 310058 People's Republic of China
| | - Sheng-Hua Ying
- Institute of Microbiology, College of Life Sciences; Zhejiang University; Hangzhou Zhejiang 310058 People's Republic of China
| | - Ming-Guang Feng
- Institute of Microbiology, College of Life Sciences; Zhejiang University; Hangzhou Zhejiang 310058 People's Republic of China
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49
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Theis J, Schroda M. Revisiting the photosystem II repair cycle. PLANT SIGNALING & BEHAVIOR 2016; 11:e1218587. [PMID: 27494214 PMCID: PMC5058467 DOI: 10.1080/15592324.2016.1218587] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 07/23/2016] [Accepted: 07/25/2016] [Indexed: 05/18/2023]
Abstract
The ability of photosystem (PS) II to catalyze the light-driven oxidation of water comes along with its vulnerability to oxidative damage, in particular of the D1 core subunit. Photodamaged PSII undergoes repair in a multi-step process involving (i) reversible phosphorylation of PSII core subunits; (ii) monomerization and lateral migration of the PSII core from grana to stroma thylakoids; (iii) partial disassembly of PSII; (iv) proteolytic degradation of damaged D1; (v) replacement of damaged D1 protein with a new copy; (vi) reassembly of PSII monomers and migration back to grana thylakoids for dimerization and supercomplex assembly. Here we review the current knowledge on the PSII repair cycle.
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Affiliation(s)
- Jasmine Theis
- Molekulare Biotechnologie & Systembiologie, TU Kaiserslautern, Kaiserslautern, Germany
| | - Michael Schroda
- Molekulare Biotechnologie & Systembiologie, TU Kaiserslautern, Kaiserslautern, Germany
- CONTACT Michael Schroda Molekulare Biotechnologie & Systembiologie, TU Kaiserslautern, Paul-Ehrlich-Str. 70, 67663 Kaiserslautern, Germany
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50
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Kock C, Arlt H, Ungermann C, Heinisch JJ. Yeast cell wall integrity sensors form specific plasma membrane microdomains important for signalling. Cell Microbiol 2016; 18:1251-67. [DOI: 10.1111/cmi.12635] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Revised: 06/14/2016] [Accepted: 06/17/2016] [Indexed: 02/06/2023]
Affiliation(s)
- Christian Kock
- Universität Osnabrück; Fachbereich Biologie/Chemie, AG Genetik; 49076 Osnabrück Germany
| | - Henning Arlt
- Universität Osnabrück; Fachbereich Biologie/Chemie, AG Biochemie; 49076 Osnabrück Germany
| | - Christian Ungermann
- Universität Osnabrück; Fachbereich Biologie/Chemie, AG Biochemie; 49076 Osnabrück Germany
| | - Jürgen J. Heinisch
- Universität Osnabrück; Fachbereich Biologie/Chemie, AG Genetik; 49076 Osnabrück Germany
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