1
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Doloman A, Sousa DZ. Mechanisms of microbial co-aggregation in mixed anaerobic cultures. Appl Microbiol Biotechnol 2024; 108:407. [PMID: 38963458 DOI: 10.1007/s00253-024-13246-8] [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: 05/02/2024] [Revised: 06/24/2024] [Accepted: 06/27/2024] [Indexed: 07/05/2024]
Abstract
Co-aggregation of anaerobic microorganisms into suspended microbial biofilms (aggregates) serves ecological and biotechnological functions. Tightly packed aggregates of metabolically interdependent bacteria and archaea play key roles in cycling of carbon and nitrogen. Additionally, in biotechnological applications, such as wastewater treatment, microbial aggregates provide a complete metabolic network to convert complex organic material. Currently, experimental data explaining the mechanisms behind microbial co-aggregation in anoxic environments is scarce and scattered across the literature. To what extent does this process resemble co-aggregation in aerobic environments? Does the limited availability of terminal electron acceptors drive mutualistic microbial relationships, contrary to the commensal relationships observed in oxygen-rich environments? And do co-aggregating bacteria and archaea, which depend on each other to harvest the bare minimum Gibbs energy from energy-poor substrates, use similar cellular mechanisms as those used by pathogenic bacteria that form biofilms? Here, we provide an overview of the current understanding of why and how mixed anaerobic microbial communities co-aggregate and discuss potential future scientific advancements that could improve the study of anaerobic suspended aggregates. KEY POINTS: • Metabolic dependency promotes aggregation of anaerobic bacteria and archaea • Flagella, pili, and adhesins play a role in the formation of anaerobic aggregates • Cyclic di-GMP/AMP signaling may trigger the polysaccharides production in anaerobes.
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Affiliation(s)
- Anna Doloman
- Laboratory of Microbiology, Wageningen University & Research, Stippeneng 4, 6708 WE, Wageningen, The Netherlands.
| | - Diana Z Sousa
- Laboratory of Microbiology, Wageningen University & Research, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
- Centre for Living Technologies, Eindhoven-Wageningen-Utrecht Alliance, Princetonlaan 6, 3584 CB, Utrecht, The Netherlands
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2
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Wang H, Zhang J, Toso D, Liao S, Sedighian F, Gunsalus R, Zhou ZH. Hierarchical organization and assembly of the archaeal cell sheath from an amyloid-like protein. Nat Commun 2023; 14:6720. [PMID: 37872154 PMCID: PMC10593813 DOI: 10.1038/s41467-023-42368-2] [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: 03/30/2023] [Accepted: 10/09/2023] [Indexed: 10/25/2023] Open
Abstract
Certain archaeal cells possess external proteinaceous sheath, whose structure and organization are both unknown. By cellular cryogenic electron tomography (cryoET), here we have determined sheath organization of the prototypical archaeon, Methanospirillum hungatei. Fitting of Alphafold-predicted model of the sheath protein (SH) monomer into the 7.9 Å-resolution structure reveals that the sheath cylinder consists of axially stacked β-hoops, each of which is comprised of two to six 400 nm-diameter rings of β-strand arches (β-rings). With both similarities to and differences from amyloid cross-β fibril architecture, each β-ring contains two giant β-sheets contributed by ~ 450 SH monomers that entirely encircle the outer circumference of the cell. Tomograms of immature cells suggest models of sheath biogenesis: oligomerization of SH monomers into β-ring precursors after their membrane-proximal cytoplasmic synthesis, followed by translocation through the unplugged end of a dividing cell, and insertion of nascent β-hoops into the immature sheath cylinder at the junction of two daughter cells.
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Affiliation(s)
- Hui Wang
- Department of Bioengineering, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA
- California NanoSystems Institute, UCLA, Los Angeles, CA, 90095, USA
- Department of Microbiology, Immunology, and Molecular Genetics, UCLA, Los Angeles, CA, 90095, USA
| | - Jiayan Zhang
- California NanoSystems Institute, UCLA, Los Angeles, CA, 90095, USA
- Department of Microbiology, Immunology, and Molecular Genetics, UCLA, Los Angeles, CA, 90095, USA
| | - Daniel Toso
- Department of Bioengineering, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA
- California NanoSystems Institute, UCLA, Los Angeles, CA, 90095, USA
- Department of Microbiology, Immunology, and Molecular Genetics, UCLA, Los Angeles, CA, 90095, USA
| | - Shiqing Liao
- California NanoSystems Institute, UCLA, Los Angeles, CA, 90095, USA
- Department of Microbiology, Immunology, and Molecular Genetics, UCLA, Los Angeles, CA, 90095, USA
| | - Farzaneh Sedighian
- Department of Microbiology, Immunology, and Molecular Genetics, UCLA, Los Angeles, CA, 90095, USA
| | - Robert Gunsalus
- Department of Microbiology, Immunology, and Molecular Genetics, UCLA, Los Angeles, CA, 90095, USA
- The UCLA-DOE Institute, UCLA, Los Angeles, CA, 90095, USA
| | - Z Hong Zhou
- Department of Bioengineering, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA.
- California NanoSystems Institute, UCLA, Los Angeles, CA, 90095, USA.
- Department of Microbiology, Immunology, and Molecular Genetics, UCLA, Los Angeles, CA, 90095, USA.
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3
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Zhou J, Smith JA, Li M, Holmes DE. Methane production by Methanothrix thermoacetophila via direct interspecies electron transfer with Geobacter metallireducens. mBio 2023; 14:e0036023. [PMID: 37306514 PMCID: PMC10470525 DOI: 10.1128/mbio.00360-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 04/13/2023] [Indexed: 06/13/2023] Open
Abstract
Methanothrix is widely distributed in natural and artificial anoxic environments and plays a major role in global methane emissions. It is one of only two genera that can form methane from acetate dismutation and through participation in direct interspecies electron transfer (DIET) with exoelectrogens. Although Methanothrix is a significant member of many methanogenic communities, little is known about its physiology. In this study, transcriptomics helped to identify potential routes of electron transfer during DIET between Geobacter metallireducens and Methanothrix thermoacetophila. Additions of magnetite to cultures significantly enhanced growth by acetoclastic methanogenesis and by DIET, while granular activated carbon (GAC) amendments impaired growth. Transcriptomics suggested that the OmaF-OmbF-OmcF porin complex and the octaheme outer membrane c-type cytochrome encoded by Gmet_0930, were important for electron transport across the outer membrane of G. metallireducens during DIET with Mx. thermoacetophila. Clear differences in the metabolism of Mx. thermoacetophila when grown via DIET or acetate dismutation were not apparent. However, genes coding for proteins involved in carbon fixation, the sheath fiber protein MspA, and a surface-associated quinoprotein, SqpA, were highly expressed in all conditions. Expression of gas vesicle genes was significantly lower in DIET- than acetate-grown cells, possibly to facilitate better contact between membrane-associated redox proteins during DIET. These studies reveal potential electron transfer mechanisms utilized by both Geobacter and Methanothrix during DIET and provide important insights into the physiology of Methanothrix in anoxic environments. IMPORTANCE Methanothrix is a significant methane producer in a variety of methanogenic environments including soils and sediments as well as anaerobic digesters. Its abundance in these anoxic environments has mostly been attributed to its high affinity for acetate and its ability to grow by acetoclastic methanogenesis. However, Methanothrix species can also generate methane by directly accepting electrons from exoelectrogenic bacteria through direct interspecies electron transfer (DIET). Methane production through DIET is likely to further increase their contribution to methane production in natural and artificial environments. Therefore, acquiring a better understanding of DIET with Methanothrix will help shed light on ways to (i) minimize microbial methane production in natural terrestrial environments and (ii) maximize biogas formation by anaerobic digesters treating waste.
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Affiliation(s)
- Jinjie Zhou
- Archaeal Biology Center, Institute for Advanced Study, Shenzhen University, Shenzhen, Guangdong, China
- Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, Guangdong, China
- Department of Microbiology, University of Massachusetts‐Amherst, Amherst, Massachusetts, USA
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, Guangdong, China
| | - Jessica A. Smith
- Department of Microbiology, University of Massachusetts‐Amherst, Amherst, Massachusetts, USA
- Department of Biomolecular Sciences, Central Connecticut State University, New Britain, Connecticut, USA
| | - Meng Li
- Archaeal Biology Center, Institute for Advanced Study, Shenzhen University, Shenzhen, Guangdong, China
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, Guangdong, China
| | - Dawn E. Holmes
- Department of Microbiology, University of Massachusetts‐Amherst, Amherst, Massachusetts, USA
- Department of Physical and Biological Science, Western New England University, Springfield, Massachusetts, USA
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4
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Abstract
Each prokaryotic domain, Bacteria and Archaea, contains a large and diverse group of organisms characterized by their ultrasmall cell size and symbiotic lifestyles (potentially commensal, mutualistic, and parasitic relationships), namely, Candidatus Patescibacteria (also known as the Candidate Phyla Radiation/CPR superphylum) and DPANN archaea, respectively. Cultivation-based approaches have revealed that Ca. Patescibacteria and DPANN symbiotically interact with bacterial and archaeal partners and hosts, respectively, but that cross-domain symbiosis and parasitism have never been observed. By amending wastewater treatment sludge samples with methanogenic archaea, we observed increased abundances of Ca. Patescibacteria (Ca. Yanofskybacteria/UBA5738) and, using fluorescence in situ hybridization (FISH), discovered that nearly all of the Ca. Yanofskybacteria/UBA5738 cells were attached to Methanothrix (95.7 ± 2.1%) and that none of the cells were attached to other lineages, implying high host dependency and specificity. Methanothrix filaments (multicellular) with Ca. Yanofskybacteria/UBA5738 attached had significantly more cells with no or low detectable ribosomal activity (based on FISH fluorescence) and often showed deformations at the sites of attachment (based on transmission electron microscopy), suggesting that the interaction is parasitic. Metagenome-assisted metabolic reconstruction showed that Ca. Yanofskybacteria/UBA5738 lacks most of the biosynthetic pathways necessary for cell growth and universally conserves three unique gene arrays that contain multiple genes with signal peptides in the metagenome-assembled genomes of the Ca. Yanofskybacteria/UBA5738 lineage. The results shed light on a novel cross-domain symbiosis and inspire potential strategies for culturing CPR and DPANN.
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5
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Christensen LFB, Alijanvand SH, Burdukiewicz M, Herbst FA, Kjeldal H, Dueholm MS, Otzen DE. Identification of amyloidogenic proteins in the microbiomes of a rat Parkinson's disease model and wild-type rats. Protein Sci 2021; 30:1854-1870. [PMID: 34075639 DOI: 10.1002/pro.4137] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 05/24/2021] [Accepted: 05/25/2021] [Indexed: 12/18/2022]
Abstract
Cross seeding between amyloidogenic proteins in the gut is receiving increasing attention as a possible mechanism for initiation or acceleration of amyloid formation by aggregation-prone proteins such as αSN, which is central in the development of Parkinson's disease (PD). This is particularly pertinent in view of the growing number of functional (i.e., benign and useful) amyloid proteins discovered in bacteria. Here we identify two amyloidogenic proteins, Pr12 and Pr17, in fecal matter from PD transgenic rats and their wild type counterparts, based on their stability against dissolution by formic acid (FA). Both proteins show robust aggregation into ThT-positive aggregates that contain higher-order β-sheets and have a fibrillar morphology, indicative of amyloid proteins. In addition, Pr17 aggregates formed in vitro showed significant resistance against FA, suggesting an ability to form highly stable amyloid. Treatment with proteinase K revealed a protected core of approx. 9 kDa. Neither Pr12 nor Pr17, however, affected αSN aggregation in vitro. Thus, amyloidogenicity does not per se lead to an ability to cross-seed fibrillation of αSN. Our results support the use of proteomics and FA to identify amyloidogenic protein in complex mixtures and suggests that there may be numerous functional amyloid proteins in microbiomes.
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Affiliation(s)
- Line Friis Bakmann Christensen
- Interdisciplinary Nanoscience Center (iNANO), Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Saeid Hadi Alijanvand
- Interdisciplinary Nanoscience Center (iNANO), Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark.,Institute of Biochemistry and Biophysics (IBB), Department of Biophysics, University of Tehran, Tehran, Iran
| | - Michał Burdukiewicz
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland.,Centre for Clinical Research, Medical University of Białystok, Białystok, Poland
| | - Florian-Alexander Herbst
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Henrik Kjeldal
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Morten Simonsen Dueholm
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Daniel E Otzen
- Interdisciplinary Nanoscience Center (iNANO), Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
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6
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Otzen DE, Dueholm MS, Najarzadeh Z, Knowles TPJ, Ruggeri FS. In situ Sub-Cellular Identification of Functional Amyloids in Bacteria and Archaea by Infrared Nanospectroscopy. SMALL METHODS 2021; 5:e2001002. [PMID: 34927901 DOI: 10.1002/smtd.202001002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 03/16/2021] [Indexed: 06/14/2023]
Abstract
Formation of amyloid structures is originally linked to human disease. However, amyloid materials are found extensively in the animal and bacterial world where they stabilize intra- and extra-cellular environments like biofilms or cell envelopes. To date, functional amyloids have largely been studied using optical microscopy techniques in vivo, or after removal from their biological context for higher-resolution studies in vitro. Furthermore, conventional microscopies only indirectly identify amyloids based on morphology or unspecific amyloid dyes. Here, the high chemical and spatial (≈20 nm) resolution of Infrared Nanospectroscopy (AFM-IR) to investigate functional amyloid from Escherichia coli (curli), Pseudomonas (Fap), and the Archaea Methanosaeta (MspA) in situ is exploited. It is demonstrated that AFM-IR identifies amyloid protein within single intact cells through their cross β-sheet secondary structure, which has a unique spectroscopic signature in the amide I band of protein. Using this approach, nanoscale-resolved chemical images and spectra of purified curli and Methanosaeta cell wall sheaths are provided. The results highlight significant differences in secondary structure between E. coli cells with and without curli. Taken together, these results suggest that AFM-IR is a new and powerful label-free tool for in situ investigations of the biophysical state of functional amyloid and biomolecules in general.
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Affiliation(s)
- Daniel E Otzen
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, Aarhus C, Aarhus, 8000, Denmark
| | - Morten S Dueholm
- Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, Aalborg, 9220, Denmark
| | - Zahra Najarzadeh
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, Aarhus C, Aarhus, 8000, Denmark
| | - Tuomas P J Knowles
- Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
- Cavendish Laboratory, University of Cambridge, Cambridge, CB30HE, UK
| | - Francesco Simone Ruggeri
- Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
- Laboratory of Organic Chemistry, Wageningen University, Wageningen, WE 6703, the Netherlands
- Laboratory of Physical Chemistry, Wageningen University, Wageningen, WE 6703, the Netherlands
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7
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Gao K, Lu Y. Putative Extracellular Electron Transfer in Methanogenic Archaea. Front Microbiol 2021; 12:611739. [PMID: 33828536 PMCID: PMC8019784 DOI: 10.3389/fmicb.2021.611739] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 03/03/2021] [Indexed: 11/14/2022] Open
Abstract
It has been suggested that a few methanogens are capable of extracellular electron transfers. For instance, Methanosarcina barkeri can directly capture electrons from the coexisting microbial cells of other species. Methanothrix harundinacea and Methanosarcina horonobensis retrieve electrons from Geobacter metallireducens via direct interspecies electron transfer (DIET). Recently, Methanobacterium, designated strain YSL, has been found to grow via DIET in the co-culture with Geobacter metallireducens. Methanosarcina acetivorans can perform anaerobic methane oxidation and respiratory growth relying on Fe(III) reduction through the extracellular electron transfer. Methanosarcina mazei is capable of electromethanogenesis under the conditions where electron-transfer mediators like H2 or formate are limited. The membrane-bound multiheme c-type cytochromes (MHC) and electrically-conductive cellular appendages have been assumed to mediate the extracellular electron transfer in bacteria like Geobacter and Shewanella species. These molecules or structures are rare but have been recently identified in a few methanogens. Here, we review the current state of knowledge for the putative extracellular electron transfers in methanogens and highlight the opportunities and challenges for future research.
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Affiliation(s)
- Kailin Gao
- College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Yahai Lu
- College of Urban and Environmental Sciences, Peking University, Beijing, China
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8
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Levkovich SA, Gazit E, Laor Bar-Yosef D. Two Decades of Studying Functional Amyloids in Microorganisms. Trends Microbiol 2020; 29:251-265. [PMID: 33041179 DOI: 10.1016/j.tim.2020.09.005] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 08/19/2020] [Accepted: 09/07/2020] [Indexed: 12/22/2022]
Abstract
In the past two decades, amyloids, typically associated with human diseases, have been described to play various functional roles in nearly all life forms. The structural and functional diversity of microbial 'functional amyloids' has dramatically increased in recent years, expanding the canonical definition of these assembled molecules. Here, we provide a broad review of the current understanding of microbial functional amyloids and their diverse roles, putting the spotlight on recent discoveries in the field. We discuss their functions as structural scaffolds, surface-tension modulators, adhesion molecules, cell-cycle and gametogenesis regulators, toxins, and mediators of host-pathogen interactions. We outline how noncanonical amyloid morphologies and sophisticated regulatory mechanisms underlie their functional diversity and emphasize their therapeutic and biotechnological implications and applications.
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Affiliation(s)
- Shon A Levkovich
- School of Molecular Cell Biology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Ehud Gazit
- School of Molecular Cell Biology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel; BLAVATNIK CENTER for Drug Discovery, Tel Aviv University, Tel Aviv 69978, Israel; Department of Materials Science and Engineering, Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, Tel Aviv 69978, Israel; Sagol Interdisciplinary School of Neurosciences, Tel Aviv University, Tel Aviv, Israel.
| | - Dana Laor Bar-Yosef
- School of Molecular Cell Biology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
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9
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Kosolapova AO, Antonets KS, Belousov MV, Nizhnikov AA. Biological Functions of Prokaryotic Amyloids in Interspecies Interactions: Facts and Assumptions. Int J Mol Sci 2020; 21:E7240. [PMID: 33008049 PMCID: PMC7582709 DOI: 10.3390/ijms21197240] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 09/25/2020] [Accepted: 09/28/2020] [Indexed: 02/07/2023] Open
Abstract
Amyloids are fibrillar protein aggregates with an ordered spatial structure called "cross-β". While some amyloids are associated with development of approximately 50 incurable diseases of humans and animals, the others perform various crucial physiological functions. The greatest diversity of amyloids functions is identified within prokaryotic species where they, being the components of the biofilm matrix, function as adhesins, regulate the activity of toxins and virulence factors, and compose extracellular protein layers. Amyloid state is widely used by different pathogenic bacterial species in their interactions with eukaryotic organisms. These amyloids, being functional for bacteria that produce them, are associated with various bacterial infections in humans and animals. Thus, the repertoire of the disease-associated amyloids includes not only dozens of pathological amyloids of mammalian origin but also numerous microbial amyloids. Although the ability of symbiotic microorganisms to produce amyloids has recently been demonstrated, functional roles of prokaryotic amyloids in host-symbiont interactions as well as in the interspecies interactions within the prokaryotic communities remain poorly studied. Here, we summarize the current findings in the field of prokaryotic amyloids, classify different interspecies interactions where these amyloids are involved, and hypothesize about their real occurrence in nature as well as their roles in pathogenesis and symbiosis.
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Affiliation(s)
- Anastasiia O. Kosolapova
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology (ARRIAM), 196608 St. Petersburg, Russia (K.S.A.); (M.V.B.)
- Faculty of Biology, St. Petersburg State University (SPbSU), 199034 St. Petersburg, Russia
| | - Kirill S. Antonets
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology (ARRIAM), 196608 St. Petersburg, Russia (K.S.A.); (M.V.B.)
- Faculty of Biology, St. Petersburg State University (SPbSU), 199034 St. Petersburg, Russia
| | - Mikhail V. Belousov
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology (ARRIAM), 196608 St. Petersburg, Russia (K.S.A.); (M.V.B.)
- Faculty of Biology, St. Petersburg State University (SPbSU), 199034 St. Petersburg, Russia
| | - Anton A. Nizhnikov
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology (ARRIAM), 196608 St. Petersburg, Russia (K.S.A.); (M.V.B.)
- Faculty of Biology, St. Petersburg State University (SPbSU), 199034 St. Petersburg, Russia
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10
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Yarawsky AE, Johns SL, Schuck P, Herr AB. The biofilm adhesion protein Aap from Staphylococcus epidermidis forms zinc-dependent amyloid fibers. J Biol Chem 2020; 295:4411-4427. [PMID: 32102851 DOI: 10.1074/jbc.ra119.010874] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 02/23/2020] [Indexed: 12/17/2022] Open
Abstract
The skin-colonizing commensal bacterium Staphylococcus epidermidis is a leading cause of hospital-acquired and device-related infections. Its pathogenicity in humans is largely due to its propensity to form biofilms, surface-adherent bacterial accumulations that are remarkably resistant to chemical and physical stresses. Accumulation-associated protein (Aap) from S. epidermidis has been shown to be necessary and sufficient for mature biofilm formation and catheter infection. Aap contains up to 17 tandem B-repeat domains, capable of zinc-dependent assembly into twisted, rope-like intercellular filaments in the biofilm. Using microscopic and biophysical techniques, we show here that Aap B-repeat constructs assemble further into zinc-dependent functional amyloid fibers. We observed such amyloid fibers by confocal microscopy during both early and late stages of S. epidermidis biofilm formation, and we confirmed that extracellular fibrils from these biofilms contain Aap. Unlike what has been observed for amyloidogenic biofilm proteins from other bacteria, which typically use chaperones or initiator proteins to initiate amyloid assembly, our findings indicate that Aap from S. epidermidis requires Zn2+ as a catalyst that drives amyloid fiber formation, similar to many mammalian amyloid-forming proteins that require metals for assembly. This work provides detailed insights into S. epidermidis biofilm formation and architecture that improve our understanding of persistent staphylococcal infections.
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Affiliation(s)
- Alexander E Yarawsky
- Graduate Program in Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267.,Division of Immunobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229
| | - Stefanie L Johns
- Graduate Program in Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267
| | - Peter Schuck
- Dynamics of Macromolecular Assembly Section, Laboratory of Cellular Imaging and Bioengineering, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland 20814
| | - Andrew B Herr
- Division of Immunobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229 .,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio 45229.,Division of Infectious Diseases, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229
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11
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Yee MO, Rotaru AE. Extracellular electron uptake in Methanosarcinales is independent of multiheme c-type cytochromes. Sci Rep 2020; 10:372. [PMID: 31941946 PMCID: PMC6962339 DOI: 10.1038/s41598-019-57206-z] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 12/23/2019] [Indexed: 11/14/2022] Open
Abstract
The co-occurrence of Geobacter and Methanosarcinales is often used as a proxy for the manifestation of direct interspecies electron transfer (DIET) in the environment. Here we tested eleven new co-culture combinations between methanogens and electrogens. Previously, only the most electrogenic Geobacter paired by DIET with Methanosarcinales methanogens, namely G. metallireducens and G. hydrogenophilus. Here we provide additional support, and show that five additional Methanosarcinales paired with G. metallireducens, while a strict hydrogenotroph could not. We also show that G. hydrogenophilus, which is incapable to grow with a strict hydrogenotrophic methanogen, could pair with a strict non-hydrogenotrophic Methanosarcinales. Likewise, an electrogen outside the Geobacter cluster (Rhodoferrax ferrireducens) paired with Methanosarcinales but not with strict hydrogenotrophic methanogens. The ability to interact with electrogens appears to be conserved among Methanosarcinales, the only methanogens with c-type cytochromes, including multihemes (MHC). Nonetheless, MHC, which are often linked to extracellular electron transfer, were neither unique nor universal to Methanosarcinales and only two of seven Methanosarcinales tested had MHC. Of these two, one strain had an MHC-deletion knockout available, which we hereby show is still capable to retrieve extracellular electrons from G. metallireducens or an electrode suggesting an MHC-independent strategy for extracellular electron uptake.
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Affiliation(s)
- Mon Oo Yee
- Nordcee, Department of Biology, University of Southern Denmark, Odense, Denmark
| | - Amelia-Elena Rotaru
- Nordcee, Department of Biology, University of Southern Denmark, Odense, Denmark.
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12
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Abstract
When protein/peptides aggregate, they usually form the amyloid state consisting of cross β-sheet structure built by repetitively stacked β-strands forming long fibrils. Amyloids are usually associated with disease including Alzheimer's. However, amyloid has many useful features. It efficiently transforms protein from the soluble to the insoluble state in an essentially two-state process, while its repetitive structure provides high stability and a robust prion-like replication mechanism. Accordingly, amyloid is used by nature in multifaceted and ingenious ways of life, ranging from bacteria and fungi to mammals. These include (1) Structure: Templating for small chemical molecules (Pmel17), biofilm formation in bacteria (curli), assisting aerial hyphae formation in streptomycetes (chaplins) or monolayer formation at a surface (hydrophobins). (2) Reservoirs: A storage state for peptide/proteins to protect them from their surroundings or vice versa (storage of peptide hormones in mammalian secretory granules or major basic protein in eosinophils). (3) Information carriers: The fungal immune system (HET-s prion in Podospora anserina, yeast prions) or long-term memory (e.g., mnemons in yeast, cytoplasmic polyadenylation element-binding protein in aplysia). Aggregation is also used to (4) "suppress" the function of the soluble protein (e.g., Cdc19 in yeast stress granules), or (5) "signaling" through formation of oligomers (e.g., HET-s prion, necroptosis-related proteins RIP1/RIP3). This review summarizes current knowledge on functional amyloids with a focus on the amyloid systems curli in bacteria, HET-s prion in P. anserina, and peptide hormone storage in mammals together with an attempt to highlight differences between functional and disease-associated amyloids.
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Affiliation(s)
- Daniel Otzen
- iNANO, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Roland Riek
- Laboratory of Physical Chemistry, Swiss Federal Institute of Technology, CH-8093 Zürich, Switzerland
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13
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Kosolapova AO, Belousov MV, Sulatskaya AI, Belousova ME, Sulatsky MI, Antonets KS, Volkov KV, Lykholay AN, Shtark OY, Vasileva EN, Zhukov VA, Ivanova AN, Zykin PA, Kuznetsova IM, Turoverov KK, Tikhonovich IA, Nizhnikov AA. Two Novel Amyloid Proteins, RopA and RopB, from the Root Nodule Bacterium Rhizobium leguminosarum. Biomolecules 2019; 9:biom9110694. [PMID: 31690032 PMCID: PMC6920782 DOI: 10.3390/biom9110694] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 10/29/2019] [Accepted: 10/31/2019] [Indexed: 12/14/2022] Open
Abstract
Amyloids represent protein fibrils with a highly ordered spatial structure, which not only cause dozens of incurable human and animal diseases but also play vital biological roles in Archaea, Bacteria, and Eukarya. Despite the fact that association of bacterial amyloids with microbial pathogenesis and infectious diseases is well known, there is a lack of information concerning the amyloids of symbiotic bacteria. In this study, using the previously developed proteomic method for screening and identification of amyloids (PSIA), we identified amyloidogenic proteins in the proteome of the root nodule bacterium Rhizobium leguminosarum. Among 54 proteins identified, we selected two proteins, RopA and RopB, which are predicted to have β-barrel structure and are likely to be involved in the control of plant-microbial symbiosis. We demonstrated that the full-length RopA and RopB form bona fide amyloid fibrils in vitro. In particular, these fibrils are β-sheet-rich, bind Thioflavin T (ThT), exhibit green birefringence upon staining with Congo Red (CR), and resist treatment with ionic detergents and proteases. The heterologously expressed RopA and RopB intracellularly aggregate in yeast and assemble into amyloid fibrils at the surface of Escherichia coli. The capsules of the R. leguminosarum cells bind CR, exhibit green birefringence, and contain fibrils of RopA and RopB in vivo.
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Affiliation(s)
- Anastasiia O Kosolapova
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology (ARRIAM), 196608 St. Petersburg, Russia.
- Faculty of Biology, St. Petersburg State University (SPbSU), 199034 St. Petersburg, Russia.
| | - Mikhail V Belousov
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology (ARRIAM), 196608 St. Petersburg, Russia.
- Faculty of Biology, St. Petersburg State University (SPbSU), 199034 St. Petersburg, Russia.
| | - Anna I Sulatskaya
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology of the Russian Academy of Sciences, 194064 St. Petersburg, Russia.
| | - Maria E Belousova
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology (ARRIAM), 196608 St. Petersburg, Russia.
| | - Maksim I Sulatsky
- Laboratory of Cell Morphology, Institute of Cytology of the Russian Academy of Sciences, 194064 St. Petersburg, Russia.
| | - Kirill S Antonets
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology (ARRIAM), 196608 St. Petersburg, Russia.
- Faculty of Biology, St. Petersburg State University (SPbSU), 199034 St. Petersburg, Russia.
| | - Kirill V Volkov
- Research Resource Center "Molecular and Cell Technologies", Research Park, St. Petersburg State University (SPbSU), 199034 St. Petersburg, Russia.
| | - Anna N Lykholay
- Research Resource Center "Molecular and Cell Technologies", Research Park, St. Petersburg State University (SPbSU), 199034 St. Petersburg, Russia.
| | - Oksana Y Shtark
- Department of Biotechnology, All-Russia Research Institute for Agricultural Microbiology (ARRIAM), St. Petersburg, 196608, Russia.
| | - Ekaterina N Vasileva
- Faculty of Biology, St. Petersburg State University (SPbSU), 199034 St. Petersburg, Russia.
- Department of Biotechnology, All-Russia Research Institute for Agricultural Microbiology (ARRIAM), St. Petersburg, 196608, Russia.
| | - Vladimir A Zhukov
- Department of Biotechnology, All-Russia Research Institute for Agricultural Microbiology (ARRIAM), St. Petersburg, 196608, Russia.
| | - Alexandra N Ivanova
- Research Resource Center "Molecular and Cell Technologies", Research Park, St. Petersburg State University (SPbSU), 199034 St. Petersburg, Russia.
- Komarov Botanical Institute RAS, 197376 Komarov Botanical Institute RAS, Russia.
| | - Pavel A Zykin
- Faculty of Biology, St. Petersburg State University (SPbSU), 199034 St. Petersburg, Russia.
| | - Irina M Kuznetsova
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology of the Russian Academy of Sciences, 194064 St. Petersburg, Russia.
| | - Konstantin K Turoverov
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology of the Russian Academy of Sciences, 194064 St. Petersburg, Russia.
- Peter the Great St. Petersburg Polytechnic University, 195251 St. Petersburg, Russia.
| | - Igor A Tikhonovich
- Faculty of Biology, St. Petersburg State University (SPbSU), 199034 St. Petersburg, Russia.
- Department of Biotechnology, All-Russia Research Institute for Agricultural Microbiology (ARRIAM), St. Petersburg, 196608, Russia.
| | - Anton A Nizhnikov
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology (ARRIAM), 196608 St. Petersburg, Russia.
- Faculty of Biology, St. Petersburg State University (SPbSU), 199034 St. Petersburg, Russia.
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14
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Liu C, Sun D, Zhao Z, Dang Y, Holmes DE. Methanothrix enhances biogas upgrading in microbial electrolysis cell via direct electron transfer. BIORESOURCE TECHNOLOGY 2019; 291:121877. [PMID: 31376672 DOI: 10.1016/j.biortech.2019.121877] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 07/20/2019] [Accepted: 07/22/2019] [Indexed: 06/10/2023]
Abstract
Bioelectrochemical conversion of CO2 to CH4 is a promising way to increase the calorific value of biogas produced during anaerobic digestion. There are two groups of methanogens enriched in these systems, hydrogenotrophs and acetoclastic methanogens that can also directly accept electrons from an electrode or another microorganism. In this study, a microbial electrolysis cell (MEC) poised at -500 mV (vs. SHE) was operated for biogas upgrading. Methane content in the biogas increased from 71% to >90%, and 8.2% of the CO2 was converted to methane. Methanothrix, an acetoclastic methanogen that can participate in direct electron transfer (DET), and Azonexus, an acetate-oxidizing electrogen, were enriched on the cathode. Transcriptomics revealed that Methanothrix on the cathode were using the CO2 reduction pathway, while Methanothrix in the bulk sludge were using the acetate decarboxylation pathway for production of methane. These results show that stimulation of DET in MEC enhances biogas-upgrading processes.
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Affiliation(s)
- Chuanqi Liu
- Beijing Key Laboratory for Source Control Technology of Water Pollution, Engineering Research Center for Water Pollution Source Control and Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Dezhi Sun
- Beijing Key Laboratory for Source Control Technology of Water Pollution, Engineering Research Center for Water Pollution Source Control and Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Zhiqiang Zhao
- Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Yan Dang
- Beijing Key Laboratory for Source Control Technology of Water Pollution, Engineering Research Center for Water Pollution Source Control and Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China.
| | - Dawn E Holmes
- Department of Physical and Biological Sciences, Western New England University, 1215 Wilbraham Rd, Springfield, MA 01119, United States
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15
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Shanmugam N, Baker MODG, Ball SR, Steain M, Pham CLL, Sunde M. Microbial functional amyloids serve diverse purposes for structure, adhesion and defence. Biophys Rev 2019; 11:287-302. [PMID: 31049855 PMCID: PMC6557962 DOI: 10.1007/s12551-019-00526-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 04/15/2019] [Indexed: 12/22/2022] Open
Abstract
The functional amyloid state of proteins has in recent years garnered much attention for its role in serving crucial and diverse biological roles. Amyloid is a protein fold characterised by fibrillar morphology, binding of the amyloid-specific dyes Thioflavin T and Congo Red, insolubility and underlying cross-β structure. Amyloids were initially characterised as an aberrant protein fold associated with mammalian disease. However, in the last two decades, functional amyloids have been described in almost all biological systems, from viruses, to bacteria and archaea, to humans. Understanding the structure and role of these amyloids elucidates novel and potentially ancient mechanisms of protein function throughout nature. Many of these microbial functional amyloids are utilised by pathogens for invasion and maintenance of infection. As such, they offer novel avenues for therapies. This review examines the structure and mechanism of known microbial functional amyloids, with a particular focus on the pathogenicity conferred by the production of these structures and the strategies utilised by microbes to interfere with host amyloid structures. The biological importance of microbial amyloid assemblies is highlighted by their ubiquity and diverse functionality.
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Affiliation(s)
- Nirukshan Shanmugam
- Discipline of Pharmacology, School of Medical Sciences, Faculty of Medicine and Health and Sydney Nano, University of Sydney, Sydney, NSW, 2006, Australia
| | - Max O D G Baker
- Discipline of Pharmacology, School of Medical Sciences, Faculty of Medicine and Health and Sydney Nano, University of Sydney, Sydney, NSW, 2006, Australia
| | - Sarah R Ball
- Discipline of Pharmacology, School of Medical Sciences, Faculty of Medicine and Health and Sydney Nano, University of Sydney, Sydney, NSW, 2006, Australia
| | - Megan Steain
- Infectious Diseases and Immunology, Central Clinical School, Sydney Medical School, University of Sydney, Sydney, NSW, 2006, Australia
| | - Chi L L Pham
- Discipline of Pharmacology, School of Medical Sciences, Faculty of Medicine and Health and Sydney Nano, University of Sydney, Sydney, NSW, 2006, Australia
| | - Margaret Sunde
- Discipline of Pharmacology, School of Medical Sciences, Faculty of Medicine and Health and Sydney Nano, University of Sydney, Sydney, NSW, 2006, Australia.
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16
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Christensen LF, Jensen KF, Nielsen J, Vad BS, Christiansen G, Otzen DE. Reducing the Amyloidogenicity of Functional Amyloid Protein FapC Increases Its Ability To Inhibit α-Synuclein Fibrillation. ACS OMEGA 2019; 4:4029-4039. [PMID: 31459612 PMCID: PMC6647998 DOI: 10.1021/acsomega.8b03590] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 02/11/2019] [Indexed: 05/15/2023]
Abstract
Functional amyloid (FA) proteins have evolved to assemble into fibrils with a characteristic cross-β structure, which stabilizes biofilms and contributes to bacterial virulence. Some of the most studied bacterial FAs are the curli protein CsgA, expressed in a wide range of bacteria, and FapC, produced mainly by members of the Pseudomonas genus. Though unrelated, both CsgA and FapC contain imperfect repeats believed to drive the formation of amyloid fibrils. While much is known about CsgA biogenesis and fibrillation, the mechanism of FapC fibrillation remains less explored. Here, we show that removing the three imperfect repeats of FapC (FapC ΔR1R2R3) slows down the fibrillation but does not prevent it. The increased lag phase seen for FapC ΔR1R2R3 allows for disulfide bond formation, which further delays fibrillation. Remarkably, these disulfide-bonded species of FapC ΔR1R2R3 also significantly delay the fibrillation of human α-synuclein, a key protein in Parkinson's disease pathology. This attenuation of α-synuclein fibrillation was not seen for the reduced form of FapC ΔR1R2R3. The results presented here shed light on the FapC fibrillation mechanism and emphasize how unrelated fibrillation systems may share such common fibril formation mechanisms, allowing inhibitors of one fibrillating protein to affect a completely different protein.
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Affiliation(s)
- Line Friis
Bakmann Christensen
- Interdisciplinary
Nanoscience Center (iNANO), Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 14, DK, 8000 Aarhus C, Denmark
| | - Kirstine Friis Jensen
- Interdisciplinary
Nanoscience Center (iNANO), Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 14, DK, 8000 Aarhus C, Denmark
| | - Janni Nielsen
- Interdisciplinary
Nanoscience Center (iNANO), Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 14, DK, 8000 Aarhus C, Denmark
| | - Brian Stougaard Vad
- Interdisciplinary
Nanoscience Center (iNANO), Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 14, DK, 8000 Aarhus C, Denmark
| | - Gunna Christiansen
- Section
for Medical Microbiology and Immunology, Department of Biomedicine, Aarhus University, Vennelyst Boulevard 4, 8000 Aarhus C, Denmark
| | - Daniel Erik Otzen
- Interdisciplinary
Nanoscience Center (iNANO), Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 14, DK, 8000 Aarhus C, Denmark
- E-mail:
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17
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Abstract
The cell wall of archaea, as of any other prokaryote, is surrounding the cell outside the cytoplasmic membrane and is mediating the interaction with the environment. In this regard, it can be involved in cell shape maintenance, protection against virus, heat, acidity or alkalinity. Throughout the formation of pore like structures, it can resemble a micro sieve and thereby enable or disable transport processes. In some cases, cell wall components can make up more than 10% of the whole cellular protein. So far, a great variety of different cell envelope structures and compounds have be found and described in detail. From all archaeal cell walls described so far, the most common structure is the S-layer. Other archaeal cell wall structures are pseudomurein, methanochondroitin, glutaminylglycan, sulfated heteropolysaccharides and protein sheaths and they are sometimes associated with additional proteins and protein complexes like the STABLE protease or the bindosome. Recent advances in electron microscopy also illustrated the presence of an outer(most) cellular membrane within several archaeal groups, comparable to the Gram-negative cell wall within bacteria. Each new cell wall structure that can be investigated in detail and that can be assigned with a specific function helps us to understand, how the earliest cells on earth might have looked like.
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Affiliation(s)
- Andreas Klingl
- Plant Development and Electron Microscopy, Department of Biology I, Biocenter LMU Munich, Großhaderner Str. 2-4, 82152, Planegg-Martinsried, Germany.
| | - Carolin Pickl
- Plant Development and Electron Microscopy, Department of Biology I, Biocenter LMU Munich, Großhaderner Str. 2-4, 82152, Planegg-Martinsried, Germany
| | - Jennifer Flechsler
- Plant Development and Electron Microscopy, Department of Biology I, Biocenter LMU Munich, Großhaderner Str. 2-4, 82152, Planegg-Martinsried, Germany
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18
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Bacterial Amyloids: Biogenesis and Biomaterials. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1174:113-159. [DOI: 10.1007/978-981-13-9791-2_4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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19
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Christensen LFB, Hansen LM, Finster K, Christiansen G, Nielsen PH, Otzen DE, Dueholm MS. The Sheaths of Methanospirillum Are Made of a New Type of Amyloid Protein. Front Microbiol 2018; 9:2729. [PMID: 30483237 PMCID: PMC6242892 DOI: 10.3389/fmicb.2018.02729] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 10/25/2018] [Indexed: 12/12/2022] Open
Abstract
The genera Methanospirillum and Methanosaeta contain species of anaerobic archaea that grow and divide within proteinaceous tubular sheaths that protect them from environmental stressors. The sheaths of Methanosaeta thermophila PT are composed of the 60.9 kDa major sheath protein MspA. In this study we show that sheaths purified from Methanospirillum hungatei JF-1 are regularly striated tubular structures with amyloid-like properties similar to those of M. thermophila PT. Depolymerizing the sheaths from M. hungatei JF-1 allowed us to identify a 40.6 kDa protein (WP_011449234.1) that shares 23% sequence similarity to MspA from M. thermophila PT (ABK14853.1), indicating that they might be distant homologs. The genome of M. hungatei JF-1 encodes six homologs of the identified MspA protein. Several homologs also exist in the related strains Methanospirillum stamsii Pt1 (7 homologs, 28–66% sequence identity), M. lacunae Ki8-1 C (15 homologs, 29–60% sequence identity) and Methanolinea tarda NOBI-1 (2 homologs, 31% sequence identity). The MspA protein discovered here could accordingly represent a more widely found sheath protein than the MspA from M. thermophila PT, which currently has no homologs in the NCBI Reference Sequence database (RefSeq).
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Affiliation(s)
- Line Friis Bakmann Christensen
- Interdisciplinary Nanoscience Center (iNANO), Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Lonnie Maria Hansen
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Kai Finster
- Section for Microbiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Gunna Christiansen
- Section for Medical Microbiology and Immunology, Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Per Halkjær Nielsen
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Daniel Erik Otzen
- Interdisciplinary Nanoscience Center (iNANO), Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Morten Simonsen Dueholm
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
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20
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Bondarev SA, Antonets KS, Kajava AV, Nizhnikov AA, Zhouravleva GA. Protein Co-Aggregation Related to Amyloids: Methods of Investigation, Diversity, and Classification. Int J Mol Sci 2018; 19:ijms19082292. [PMID: 30081572 PMCID: PMC6121665 DOI: 10.3390/ijms19082292] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 07/29/2018] [Accepted: 08/02/2018] [Indexed: 01/04/2023] Open
Abstract
Amyloids are unbranched protein fibrils with a characteristic spatial structure. Although the amyloids were first described as protein deposits that are associated with the diseases, today it is becoming clear that these protein fibrils play multiple biological roles that are essential for different organisms, from archaea and bacteria to humans. The appearance of amyloid, first of all, causes changes in the intracellular quantity of the corresponding soluble protein(s), and at the same time the aggregate can include other proteins due to different molecular mechanisms. The co-aggregation may have different consequences even though usually this process leads to the depletion of a functional protein that may be associated with different diseases. The protein co-aggregation that is related to functional amyloids may mediate important biological processes and change of protein functions. In this review, we survey the known examples of the amyloid-related co-aggregation of proteins, discuss their pathogenic and functional roles, and analyze methods of their studies from bacteria and yeast to mammals. Such analysis allow for us to propose the following co-aggregation classes: (i) titration: deposition of soluble proteins on the amyloids formed by their functional partners, with such interactions mediated by a specific binding site; (ii) sequestration: interaction of amyloids with certain proteins lacking a specific binding site; (iii) axial co-aggregation of different proteins within the same amyloid fibril; and, (iv) lateral co-aggregation of amyloid fibrils, each formed by different proteins.
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Affiliation(s)
- Stanislav A Bondarev
- Department of Genetics and Biotechnology, St. Petersburg State University, Universitetskaya nab., 7/9, St. Petersburg 199034, Russia.
- Laboratory of Amyloid Biology, St. Petersburg State University, Russia, Universitetskaya nab., 7/9, St. Petersburg 199034, Russia.
| | - Kirill S Antonets
- Department of Genetics and Biotechnology, St. Petersburg State University, Universitetskaya nab., 7/9, St. Petersburg 199034, Russia.
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology, Podbelskogo sh., 3, Pushkin, St. Petersburg 196608, Russia.
| | - Andrey V Kajava
- Centre de Recherche en Biologie cellulaire de Montpellier (CRBM), UMR 5237 CNRS, Université Montpellier 1919 Route de Mende, CEDEX 5, 34293 Montpellier, France.
- Institut de Biologie Computationnelle (IBC), 34095 Montpellier, France.
- University ITMO, Institute of Bioengineering, Kronverksky Pr. 49, St. Petersburg 197101, Russia.
| | - Anton A Nizhnikov
- Department of Genetics and Biotechnology, St. Petersburg State University, Universitetskaya nab., 7/9, St. Petersburg 199034, Russia.
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology, Podbelskogo sh., 3, Pushkin, St. Petersburg 196608, Russia.
| | - Galina A Zhouravleva
- Department of Genetics and Biotechnology, St. Petersburg State University, Universitetskaya nab., 7/9, St. Petersburg 199034, Russia.
- Laboratory of Amyloid Biology, St. Petersburg State University, Russia, Universitetskaya nab., 7/9, St. Petersburg 199034, Russia.
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21
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Antonets KS, Kliver SF, Nizhnikov AA. Exploring Proteins Containing Amyloidogenic Regions in the Proteomes of Bacteria of the Order Rhizobiales. Evol Bioinform Online 2018; 14:1176934318768781. [PMID: 29720870 PMCID: PMC5922492 DOI: 10.1177/1176934318768781] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 02/27/2018] [Indexed: 11/16/2022] Open
Abstract
Amyloids are protein fibrils with a highly ordered spatial structure called cross-β. To date, amyloids were shown to be implicated in a wide range of biological processes, both pathogenic and functional. In bacteria, functional amyloids are involved in forming biofilms, storing toxins, overcoming the surface tension, and other functions. Rhizobiales represent an economically important group of Alphaproteobacteria, various species of which are not only capable of fixing nitrogen in the symbiosis with leguminous plants but also act as the causative agents of infectious diseases in animals and plants. Here, we implemented bioinformatic screening for potentially amyloidogenic proteins in the proteomes of more than 80 species belonging to the order Rhizobiales. Using SARP (Sequence Analysis based on the Ranking of Probabilities) and Waltz bioinformatic algorithms, we identified the biological processes, where potentially amyloidogenic proteins are overrepresented. We detected protein domains and regions associated with amyloidogenic sequences in the proteomes of various Rhizobiales species. We demonstrated that amyloidogenic regions tend to occur in the membrane or extracellular proteins, many of which are involved in pathogenesis-related processes, including adhesion, assembly of flagellum, and transport of siderophores and lipopolysaccharides, and contain domains typical of the virulence factors (hemolysin, RTX, YadA, LptD); some of them (rhizobiocins, LptD) are also related to symbiosis.
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Affiliation(s)
- Kirill S Antonets
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology, St. Petersburg, Russian Federation.,Department of Genetics, St. Petersburg State University, St. Petersburg, Russian Federation
| | - Sergey F Kliver
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology, St. Petersburg, Russian Federation.,Department of Genetics, St. Petersburg State University, St. Petersburg, Russian Federation
| | - Anton A Nizhnikov
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology, St. Petersburg, Russian Federation.,Department of Genetics, St. Petersburg State University, St. Petersburg, Russian Federation
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22
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Belousov MV, Bondarev SA, Kosolapova AO, Antonets KS, Sulatskaya AI, Sulatsky MI, Zhouravleva GA, Kuznetsova IM, Turoverov KK, Nizhnikov AA. M60-like metalloprotease domain of the Escherichia coli YghJ protein forms amyloid fibrils. PLoS One 2018; 13:e0191317. [PMID: 29381728 PMCID: PMC5790219 DOI: 10.1371/journal.pone.0191317] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 01/03/2018] [Indexed: 12/31/2022] Open
Abstract
Amyloids are protein fibrils with a characteristic spatial structure. Amyloids were long perceived as the pathogens involved in a set of lethal diseases in humans and animals. In recent decades, it has become clear that amyloids represent a quaternary protein structure that is not only pathological but also functionally important and is widely used by different organisms, ranging from archaea to animals, to implement diverse biological functions. The greatest biological variety of amyloids is found in prokaryotes, where they control the formation of biofilms and cell wall sheaths, facilitate the overcoming of surface tension, and regulate the metabolism of toxins. Several amyloid proteins were identified in the important model, biotechnological and pathogenic bacterium Escherichia coli. In previous studies, using a method for the proteomic screening and identification of amyloids, we identified 61 potentially amyloidogenic proteins in the proteome of E. coli. Among these proteins, YghJ was the most enriched with bioinformatically predicted amyloidogenic regions. YghJ is a lipoprotein with a zinc metalloprotease M60-like domain that is involved in mucin degradation in the intestine as well as in proinflammatory responses. In this study, we analyzed the amyloid properties of the YghJ M60-like domain and demonstrated that it forms amyloid-like fibrils in vitro and in vivo.
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Affiliation(s)
- Mikhail V. Belousov
- Department of Genetics and Biotechnology, St. Petersburg State University, Universitetskaya nab., St. Petersburg, Russian Federation
| | - Stanislav A. Bondarev
- Department of Genetics and Biotechnology, St. Petersburg State University, Universitetskaya nab., St. Petersburg, Russian Federation
- Laboratory of Amyloid Biology, St. Petersburg State University, Universitetskaya nab., St. Petersburg, Russian Federation
| | - Anastasiia O. Kosolapova
- Department of Genetics and Biotechnology, St. Petersburg State University, Universitetskaya nab., St. Petersburg, Russian Federation
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology (ARRIAM), Podbelskogo sh., Pushkin, St. Petersburg, Russian Federation
| | - Kirill S. Antonets
- Department of Genetics and Biotechnology, St. Petersburg State University, Universitetskaya nab., St. Petersburg, Russian Federation
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology (ARRIAM), Podbelskogo sh., Pushkin, St. Petersburg, Russian Federation
| | - Anna I. Sulatskaya
- Institute of Cytology, Russian Academy of Science, St. Petersburg, Russian Federation
| | - Maksim I. Sulatsky
- Institute of Cytology, Russian Academy of Science, St. Petersburg, Russian Federation
| | - Galina A. Zhouravleva
- Department of Genetics and Biotechnology, St. Petersburg State University, Universitetskaya nab., St. Petersburg, Russian Federation
- Laboratory of Amyloid Biology, St. Petersburg State University, Universitetskaya nab., St. Petersburg, Russian Federation
| | - Irina M. Kuznetsova
- Institute of Cytology, Russian Academy of Science, St. Petersburg, Russian Federation
| | - Konstantin K. Turoverov
- Institute of Cytology, Russian Academy of Science, St. Petersburg, Russian Federation
- Peter the Great St. Petersburg Polytechnic University, Polytechnicheskaya, St. Petersburg, Russian Federation
| | - Anton A. Nizhnikov
- Department of Genetics and Biotechnology, St. Petersburg State University, Universitetskaya nab., St. Petersburg, Russian Federation
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology (ARRIAM), Podbelskogo sh., Pushkin, St. Petersburg, Russian Federation
- Vavilov Institute of General Genetics, Russian Academy of Sciences, St Petersburg Branch, Universitetskaya nab., St. Petersburg, Russian Federation
- * E-mail:
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Amyloid-Like β-Aggregates as Force-Sensitive Switches in Fungal Biofilms and Infections. Microbiol Mol Biol Rev 2017; 82:82/1/e00035-17. [PMID: 29187516 DOI: 10.1128/mmbr.00035-17] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Cellular aggregation is an essential step in the formation of biofilms, which promote fungal survival and persistence in hosts. In many of the known yeast cell adhesion proteins, there are amino acid sequences predicted to form amyloid-like β-aggregates. These sequences mediate amyloid formation in vitro. In vivo, these sequences mediate a phase transition from a disordered state to a partially ordered state to create patches of adhesins on the cell surface. These β-aggregated protein patches are called adhesin nanodomains, and their presence greatly increases and strengthens cell-cell interactions in fungal cell aggregation. Nanodomain formation is slow (with molecular response in minutes and the consequences being evident for hours), and strong interactions lead to enhanced biofilm formation. Unique among functional amyloids, fungal adhesin β-aggregation can be triggered by the application of physical shear force, leading to cellular responses to flow-induced stress and the formation of robust biofilms that persist under flow. Bioinformatics analysis suggests that this phenomenon may be widespread. Analysis of fungal abscesses shows the presence of surface amyloids in situ, a finding which supports the idea that phase changes to an amyloid-like state occur in vivo. The amyloid-coated fungi bind the damage-associated molecular pattern receptor serum amyloid P component, and there may be a consequential modulation of innate immune responses to the fungi. Structural data now suggest mechanisms for the force-mediated induction of the phase change. We summarize and discuss evidence that the sequences function as triggers for protein aggregation and subsequent cellular aggregation, both in vitro and in vivo.
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Antonets KS, Nizhnikov AA. Predicting Amyloidogenic Proteins in the Proteomes of Plants. Int J Mol Sci 2017; 18:ijms18102155. [PMID: 29035294 PMCID: PMC5666836 DOI: 10.3390/ijms18102155] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 10/12/2017] [Accepted: 10/13/2017] [Indexed: 12/21/2022] Open
Abstract
Amyloids are protein fibrils with characteristic spatial structure. Though amyloids were long perceived to be pathogens that cause dozens of incurable pathologies in humans and mammals, it is currently clear that amyloids also represent a functionally important form of protein structure implicated in a variety of biological processes in organisms ranging from archaea and bacteria to fungi and animals. Despite their social significance, plants remain the most poorly studied group of organisms in the field of amyloid biology. To date, amyloid properties have only been demonstrated in vitro or in heterologous systems for a small number of plant proteins. Here, for the first time, we performed a comprehensive analysis of the distribution of potentially amyloidogenic proteins in the proteomes of approximately 70 species of land plants using the Waltz and SARP (Sequence Analysis based on the Ranking of Probabilities) bioinformatic algorithms. We analyzed more than 2.9 million protein sequences and found that potentially amyloidogenic proteins are abundant in plant proteomes. We found that such proteins are overrepresented among membrane as well as DNA- and RNA-binding proteins of plants. Moreover, seed storage and defense proteins of most plant species are rich in amyloidogenic regions. Taken together, our data demonstrate the diversity of potentially amyloidogenic proteins in plant proteomes and suggest biological processes where formation of amyloids might be functionally important.
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Affiliation(s)
- Kirill S Antonets
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology, 196608 Podbelskogo sh., 3, Pushkin, St. Petersburg 196608, Russia.
- Department of Genetics and Biotechnology, St. Petersburg State University, 199034 Universitetskaya nab., 7/9, St. Petersburg 199034, Russia.
| | - Anton A Nizhnikov
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology, 196608 Podbelskogo sh., 3, Pushkin, St. Petersburg 196608, Russia.
- Department of Genetics and Biotechnology, St. Petersburg State University, 199034 Universitetskaya nab., 7/9, St. Petersburg 199034, Russia.
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25
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Dragoš A, Kovács ÁT, Claessen D. The Role of Functional Amyloids in Multicellular Growth and Development of Gram-Positive Bacteria. Biomolecules 2017; 7:biom7030060. [PMID: 28783117 PMCID: PMC5618241 DOI: 10.3390/biom7030060] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 08/01/2017] [Accepted: 08/03/2017] [Indexed: 01/15/2023] Open
Abstract
Amyloid fibrils play pivotal roles in all domains of life. In bacteria, these fibrillar structures are often part of an extracellular matrix that surrounds the producing organism and thereby provides protection to harsh environmental conditions. Here, we discuss the role of amyloid fibrils in the two distant Gram-positive bacteria, Streptomyces coelicolor and Bacillus subtilis. We describe how amyloid fibrils contribute to a multitude of developmental processes in each of these systems, including multicellular growth and community development. Despite this variety of tasks, we know surprisingly little about how their assembly is organized to fulfill all these roles.
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Affiliation(s)
- Anna Dragoš
- Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University Jena, 07743 Jena, Germany.
| | - Ákos T Kovács
- Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800 Lyngby, Denmark.
| | - Dennis Claessen
- Institute of Biology, Leiden University, 2333BE Leiden, The Netherlands.
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26
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Bleem A, Daggett V. Structural and functional diversity among amyloid proteins: Agents of disease, building blocks of biology, and implications for molecular engineering. Biotechnol Bioeng 2016; 114:7-20. [PMID: 27474784 DOI: 10.1002/bit.26059] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2016] [Revised: 07/25/2016] [Accepted: 07/28/2016] [Indexed: 12/23/2022]
Abstract
Amyloids have long been associated with protein dysfunction and neurodegenerative diseases, but recent research has demonstrated that some organisms utilize the unique properties of the amyloid fold to create functional structures with important roles in biological processes. Additionally, new engineering approaches have taken advantage of amyloid structures for implementation in a wide variety of materials and devices. In this review, the role of amyloid in human disease is discussed and compared to the functional amyloids, which serve a largely structural purpose. We then consider the use of amyloid constructs in engineering applications, including their utility as building blocks for synthetic biology and molecular engineering. Biotechnol. Bioeng. 2017;114: 7-20. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Alissa Bleem
- Department of Bioengineering, University of Washington, Box 355013, Seattle, Washington, 98195-5013
| | - Valerie Daggett
- Department of Bioengineering, University of Washington, Box 355013, Seattle, Washington, 98195-5013
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27
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The Human Disease-Associated Aβ Amyloid Core Sequence Forms Functional Amyloids in a Fungal Adhesin. mBio 2016; 7:e01815-15. [PMID: 26758179 PMCID: PMC4725003 DOI: 10.1128/mbio.01815-15] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
UNLABELLED There is increasing evidence that many amyloids in living cells have physiological functions. On the surfaces of fungal cells, amyloid core sequences in adhesins can aggregate into 100- to 1,000-nm-wide patches to form high-avidity adhesion nanodomains on the cell surface. The nanodomains form through interactions that have amyloid-like properties: binding of amyloid dyes, perturbation by antiamyloid agents, and interaction with homologous sequences. To test whether these functional interactions are mediated by typical amyloid interactions, we substituted an amyloid core sequence, LVFFA, from human Aβ protein for the native sequence IVIVA in the 1,419-residue Candida albicans adhesin Als5p. The chimeric protein formed cell surface nanodomains and mediated cellular aggregation. The native sequence and chimeric adhesins responded similarly to the amyloid dye thioflavin T and to amyloid perturbants. However, unlike the native protein, the nanodomains formed by the chimeric protein were not force activated and formed less-robust aggregates under flow. These results showed the similarity of amyloid interactions in the amyloid core sequences of native Als5p and Aβ, but they also highlighted emergent properties of the native sequence. Also, a peptide composed of the Aβ amyloid sequence flanked by amino acids from the adhesin formed two-dimensional sheets with sizes similar to the cell surface patches of the adhesins. These results inform an initial model for the structure of fungal cell surface amyloid nanodomains. IMPORTANCE Protein amyloid aggregates are markers of neurodegenerative diseases such as Alzheimer's and Parkinsonism. Nevertheless, there are also functional amyloids, including biofilm-associated amyloids in bacteria and fungi. In fungi, glycoprotein adhesins aggregate into cell surface patches through amyloid-like interactions, and the adhesin clustering strengthens cell-cell binding. These fungal surface amyloid nanodomains mediate biofilm persistence under flow, and they also moderate host inflammatory responses in fungal infections. To determine whether the amyloid-like properties of fungal surface nanodomains are sequence specific, we ask whether a disease-associated amyloid core sequence has properties equivalent to those of the native sequence in a fungal adhesin. A chimeric adhesin with an amyloid sequence from the Alzheimer's disease protein Aβ instead of its native sequence effectively clustered the adhesins on the cell surface, but it showed a different response to hydrodynamic shear. These results begin an analysis of the sequence dependence for newly discovered activities for fungal surface amyloid nanodomains.
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28
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Tian P, Lindorff-Larsen K, Boomsma W, Jensen MH, Otzen DE. A Monte Carlo Study of the Early Steps of Functional Amyloid Formation. PLoS One 2016; 11:e0146096. [PMID: 26745180 PMCID: PMC4706413 DOI: 10.1371/journal.pone.0146096] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 12/14/2015] [Indexed: 11/18/2022] Open
Abstract
In addition to their well-known roles in neurodegenerative diseases and amyloidoses, amyloid structures also assume important functional roles in the cell. Although functional amyloid shares many physiochemical properties with its pathogenic counterpart, it is evolutionarily optimized to avoid cytotoxicity. This makes it an interesting study case for aggregation phenomenon in general. One of the most well-known examples of a functional amyloid, E. coli curli, is an essential component in the formation of bacterial biofilm, and is primarily formed by aggregates of the protein CsgA. Previous studies have shown that the minor sequence variations observed in the five different subrepeats (R1-R5), which comprise the CsgA primary sequence, have a substantial influence on their individual aggregation propensities. Using a recently described diffusion-optimized enhanced sampling approach for Monte Carlo simulations, we here investigate the equilibrium properties of the monomeric and dimeric states of these subrepeats, to probe whether structural properties observed in these early stage oligomers are decisive for the characteristics of the resulting aggregate. We show that the dimerization propensities of these peptides have strong correlations with their propensity for amyloid formation, and provide structural insights into the inter- and intramolecular contacts that appear to be essential in this process.
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Affiliation(s)
- Pengfei Tian
- Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, 2100, Copenhagen, Denmark.,Linderstrøm-Lang Centre for Protein Science and Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200, Copenhagen N, Denmark
| | - Kresten Lindorff-Larsen
- Linderstrøm-Lang Centre for Protein Science and Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200, Copenhagen N, Denmark
| | - Wouter Boomsma
- Linderstrøm-Lang Centre for Protein Science and Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200, Copenhagen N, Denmark
| | - Mogens Høgh Jensen
- Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, 2100, Copenhagen, Denmark
| | - Daniel Erik Otzen
- Interdisciplinary Nanoscience Center (iNANO), Centre for Insoluble Protein Structures (inSPIN), Department of Molecular Biology, Aarhus University, Gustav Wieds Vej 10, 8000, Aarhus C, Denmark
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29
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Zeng G, Vad BS, Dueholm MS, Christiansen G, Nilsson M, Tolker-Nielsen T, Nielsen PH, Meyer RL, Otzen DE. Functional bacterial amyloid increases Pseudomonas biofilm hydrophobicity and stiffness. Front Microbiol 2015; 6:1099. [PMID: 26500638 PMCID: PMC4595789 DOI: 10.3389/fmicb.2015.01099] [Citation(s) in RCA: 110] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 09/22/2015] [Indexed: 12/20/2022] Open
Abstract
The success of Pseudomonas species as opportunistic pathogens derives in great part from their ability to form stable biofilms that offer protection against chemical and mechanical attack. The extracellular matrix of biofilms contains numerous biomolecules, and it has recently been discovered that in Pseudomonas one of the components includes β-sheet rich amyloid fibrils (functional amyloid) produced by the fap operon. However, the role of the functional amyloid within the biofilm has not yet been investigated in detail. Here we investigate how the fap-based amyloid produced by Pseudomonas affects biofilm hydrophobicity and mechanical properties. Using atomic force microscopy imaging and force spectroscopy, we show that the amyloid renders individual cells more resistant to drying and alters their interactions with hydrophobic probes. Importantly, amyloid makes Pseudomonas more hydrophobic and increases biofilm stiffness 20-fold. Deletion of any one of the individual members of in the fap operon (except the putative chaperone FapA) abolishes this ability to increase biofilm stiffness and correlates with the loss of amyloid. We conclude that amyloid makes major contributions to biofilm mechanical robustness.
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Affiliation(s)
- Guanghong Zeng
- Interdisciplinary Nanoscience Centre, Aarhus UniversityAarhus, Denmark
| | - Brian S. Vad
- Interdisciplinary Nanoscience Centre, Aarhus UniversityAarhus, Denmark
| | - Morten S. Dueholm
- Center for Microbial Communities, Aalborg UniversityAalborg, Denmark
| | - Gunna Christiansen
- Department of Biomedicine-Medical Microbiology and Immunology, Aarhus UniversityAarhus, Denmark
| | - Martin Nilsson
- Department of Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of CopenhagenCopenhagen, Denmark
| | - Tim Tolker-Nielsen
- Department of Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of CopenhagenCopenhagen, Denmark
| | - Per H. Nielsen
- Center for Microbial Communities, Aalborg UniversityAalborg, Denmark
| | - Rikke L. Meyer
- Interdisciplinary Nanoscience Centre, Aarhus UniversityAarhus, Denmark
| | - Daniel E. Otzen
- Interdisciplinary Nanoscience Centre, Aarhus UniversityAarhus, Denmark
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