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Lipsman V, Shlakhter O, Rocha J, Segev E. Bacteria contribute exopolysaccharides to an algal-bacterial joint extracellular matrix. NPJ Biofilms Microbiomes 2024; 10:36. [PMID: 38561371 PMCID: PMC10984933 DOI: 10.1038/s41522-024-00510-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 03/22/2024] [Indexed: 04/04/2024] Open
Abstract
Marine ecosystems are influenced by phytoplankton aggregation, which affects processes like marine snow formation and harmful events such as marine mucilage outbreaks. Phytoplankton secrete exopolymers, creating an extracellular matrix (ECM) that promotes particle aggregation. This ECM attracts heterotrophic bacteria, providing a nutrient-rich and protective environment. In terrestrial environments, bacterial colonization near primary producers relies on attachment and the formation of multidimensional structures like biofilms. Bacteria were observed attaching and aggregating within algal-derived exopolymers, but it is unclear if bacteria produce an ECM that contributes to this colonization. This study, using Emiliania huxleyi algae and Phaeobacter inhibens bacteria in an environmentally relevant model system, reveals a shared algal-bacterial ECM scaffold that promotes algal-bacterial aggregation. Algal exudates play a pivotal role in promoting bacterial colonization, stimulating bacterial exopolysaccharide (EPS) production, and facilitating a joint ECM formation. A bacterial biosynthetic pathway responsible for producing a specific EPS contributing to bacterial ECM formation is identified. Genes from this pathway show increased expression in algal-rich environments. These findings highlight the underestimated role of bacteria in aggregate-mediated processes in marine environments, offering insights into algal-bacterial interactions and ECM formation, with implications for understanding and managing natural and perturbed aggregation events.
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Affiliation(s)
- Valeria Lipsman
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Olesia Shlakhter
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Jorge Rocha
- Programa de Agricultura en Zonas Áridas, Centro de Investigaciones Biológicas del Noroeste, La Paz, Baja California Sur, 23096, México
| | - Einat Segev
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, 7610001, Israel.
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2
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Greiss F, Lardon N, Schütz L, Barak Y, Daube SS, Weinhold E, Noireaux V, Bar-Ziv R. A genetic circuit on a single DNA molecule as an autonomous dissipative nanodevice. Nat Commun 2024; 15:883. [PMID: 38287055 PMCID: PMC10825189 DOI: 10.1038/s41467-024-45186-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 01/16/2024] [Indexed: 01/31/2024] Open
Abstract
Realizing genetic circuits on single DNA molecules as self-encoded dissipative nanodevices is a major step toward miniaturization of autonomous biological systems. A circuit operating on a single DNA implies that genetically encoded proteins localize during coupled transcription-translation to DNA, but a single-molecule measurement demonstrating this has remained a challenge. Here, we use a genetically encoded fluorescent reporter system with improved temporal resolution and observe the synthesis of individual proteins tethered to a DNA molecule by transient complexes of RNA polymerase, messenger RNA, and ribosome. Against expectations in dilute cell-free conditions where equilibrium considerations favor dispersion, these nascent proteins linger long enough to regulate cascaded reactions on the same DNA. We rationally design a pulsatile genetic circuit by encoding an activator and repressor in feedback on the same DNA molecule. Driven by the local synthesis of only several proteins per hour and gene, the circuit dynamics exhibit enhanced variability between individual DNA molecules, and fluctuations with a broad power spectrum. Our results demonstrate that co-expressional localization, as a nonequilibrium process, facilitates single-DNA genetic circuits as dissipative nanodevices, with implications for nanobiotechnology applications and artificial cell design.
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Affiliation(s)
- Ferdinand Greiss
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel.
| | - Nicolas Lardon
- Department of Chemical Biology, Max Planck Institute for Medical Research, 69120, Heidelberg, Germany
| | - Leonie Schütz
- Institute of Organic Chemistry, RWTH Aachen University, 52056, Aachen, Germany
| | - Yoav Barak
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Shirley S Daube
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Elmar Weinhold
- Institute of Organic Chemistry, RWTH Aachen University, 52056, Aachen, Germany
| | - Vincent Noireaux
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Roy Bar-Ziv
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel.
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3
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Arbel-Goren R, Dassa B, Zhitnitsky A, Valladares A, Herrero A, Flores E, Stavans J. Spatio-temporal coherence of circadian clocks and temporal control of differentiation in Anabaena filaments. mSystems 2024; 9:e0070023. [PMID: 38079111 PMCID: PMC10805033 DOI: 10.1128/msystems.00700-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Accepted: 10/18/2023] [Indexed: 01/24/2024] Open
Abstract
Circadian clock arrays in multicellular filaments of the heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120 display remarkable spatio-temporal coherence under nitrogen-replete conditions. To shed light on the interplay between circadian clocks and the formation of developmental patterns, we followed the expression of a clock-controlled gene under nitrogen deprivation, at the level of individual cells. Our experiments showed that differentiation into heterocysts took place preferentially within a limited interval of the circadian clock cycle, that gene expression in different vegetative intervals along a developed filament was discoordinated, and that the circadian clock was active in individual heterocysts. Furthermore, Anabaena mutants lacking the kaiABC genes encoding the circadian clock core components produced heterocysts but failed in diazotrophy. Therefore, genes related to some aspect of nitrogen fixation, rather than early or mid-heterocyst differentiation genes, are likely affected by the absence of the clock. A bioinformatics analysis supports the notion that RpaA may play a role as master regulator of clock outputs in Anabaena, the temporal control of differentiation by the circadian clock and the involvement of the clock in proper diazotrophic growth. Together, these results suggest that under nitrogen-deficient conditions, the clock coherent unit in Anabaena is reduced from a full filament under nitrogen-rich conditions to the vegetative cell interval between heterocysts.IMPORTANCECircadian clocks, from unicellular organisms to animals, temporally align biological processes to day and night cycles. We study the dynamics of a circadian clock-controlled gene at the individual cell level in the multicellular filamentous cyanobacterium Anabaena, under nitrogen-stress conditions. Under these conditions, some cells along filaments differentiate to carry out atmospheric nitrogen fixation and lose their capability for oxygenic photosynthesis. We found that clock synchronization is limited to organismic units of contiguous photosynthetic cells, contrary to nitrogen-replete conditions in which clocks are synchronized over a whole filament. We provided evidence that the circadian clock regulates the process of differentiation, allowing it to occur preferentially within a limited time window during the circadian clock period. Lastly, we present evidence that the signal from the core clock to clock-regulated genes is conveyed in Anabaena as in unicellular cyanobacteria.
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Affiliation(s)
- Rinat Arbel-Goren
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot, Israel
| | - Bareket Dassa
- Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel
| | - Anna Zhitnitsky
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot, Israel
| | - Ana Valladares
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Seville, Spain
| | - Antonia Herrero
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Seville, Spain
| | - Enrique Flores
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Seville, Spain
| | - Joel Stavans
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot, Israel
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4
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Abayev-Avraham M, Salzberg Y, Gliksberg D, Oren-Suissa M, Rosenzweig R. DNAJB6 mutants display toxic gain of function through unregulated interaction with Hsp70 chaperones. Nat Commun 2023; 14:7066. [PMID: 37923706 PMCID: PMC10624832 DOI: 10.1038/s41467-023-42735-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 10/19/2023] [Indexed: 11/06/2023] Open
Abstract
Molecular chaperones are essential cellular components that aid in protein folding and preventing the abnormal aggregation of disease-associated proteins. Mutations in one such chaperone, DNAJB6, were identified in patients with LGMDD1, a dominant autosomal disorder characterized by myofibrillar degeneration and accumulations of aggregated protein within myocytes. The molecular mechanisms through which such mutations cause this dysfunction, however, are not well understood. Here we employ a combination of solution NMR and biochemical assays to investigate the structural and functional changes in LGMDD1 mutants of DNAJB6. Surprisingly, we find that DNAJB6 disease mutants show no reduction in their aggregation-prevention activity in vitro, and instead differ structurally from the WT protein, affecting their interaction with Hsp70 chaperones. While WT DNAJB6 contains a helical element regulating its ability to bind and activate Hsp70, in LGMDD1 disease mutants this regulation is disrupted. These variants can thus recruit and hyperactivate Hsp70 chaperones in an unregulated manner, depleting Hsp70 levels in myocytes, and resulting in the disruption of proteostasis. Interfering with DNAJB6-Hsp70 binding, however, reverses the disease phenotype, suggesting future therapeutic avenues for LGMDD1.
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Affiliation(s)
- Meital Abayev-Avraham
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, 761000, Israel
| | - Yehuda Salzberg
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, 761000, Israel
| | - Dar Gliksberg
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, 761000, Israel
| | - Meital Oren-Suissa
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, 761000, Israel
| | - Rina Rosenzweig
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, 761000, Israel.
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5
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Ullman S, Assif L, Strugatski A, Vatashsky BZ, Levi H, Netanyahu A, Yaari A. Human-like scene interpretation by a guided counterstream processing. Proc Natl Acad Sci U S A 2023; 120:e2211179120. [PMID: 37769256 PMCID: PMC10556630 DOI: 10.1073/pnas.2211179120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Accepted: 08/24/2023] [Indexed: 09/30/2023] Open
Abstract
In modeling vision, there has been a remarkable progress in recognizing a range of scene components, but the problem of analyzing full scenes, an ultimate goal of visual perception, is still largely open. To deal with complete scenes, recent work focused on the training of models for extracting the full graph-like structure of a scene. In contrast with scene graphs, humans' scene perception focuses on selected structures in the scene, starting with a limited interpretation and evolving sequentially in a goal-directed manner [G. L. Malcolm, I. I. A. Groen, C. I. Baker, Trends. Cogn. Sci. 20, 843-856 (2016)]. Guidance is crucial throughout scene interpretation since the extraction of full scene representation is often infeasible. Here, we present a model that performs human-like guided scene interpretation, using an iterative bottom-up, top-down processing, in a "counterstream" structure motivated by cortical circuitry. The process proceeds by the sequential application of top-down instructions that guide the interpretation process. The results show how scene structures of interest to the viewer are extracted by an automatically selected sequence of top-down instructions. The model shows two further benefits. One is an inherent capability to deal well with the problem of combinatorial generalization-generalizing broadly to unseen scene configurations, which is limited in current network models [B. Lake, M. Baroni, 35th International Conference on Machine Learning, ICML 2018 (2018)]. The second is the ability to combine visual with nonvisual information at each cycle of the interpretation process, which is a key aspect for modeling human perception as well as advancing AI vision systems.
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Affiliation(s)
- Shimon Ullman
- Department of Computer Science, the Weizmann Institute of Science, Rehovot76100, Israel
| | - Liav Assif
- Department of Computer Science, the Weizmann Institute of Science, Rehovot76100, Israel
| | - Alona Strugatski
- Department of Computer Science, the Weizmann Institute of Science, Rehovot76100, Israel
| | - Ben-Zion Vatashsky
- Department of Computer Science, the Weizmann Institute of Science, Rehovot76100, Israel
| | - Hila Levi
- Department of Computer Science, the Weizmann Institute of Science, Rehovot76100, Israel
| | - Aviv Netanyahu
- Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Adam Yaari
- Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, MA02139
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6
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Beiralas R, Ozer N, Segev E. Abundant Sulfitobacter marine bacteria protect Emiliania huxleyi algae from pathogenic bacteria. ISME Commun 2023; 3:100. [PMID: 37740057 PMCID: PMC10517135 DOI: 10.1038/s43705-023-00311-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 09/10/2023] [Accepted: 09/13/2023] [Indexed: 09/24/2023]
Abstract
Emiliania huxleyi is a unicellular micro-alga that forms massive oceanic blooms and plays key roles in global biogeochemical cycles. Mounting studies demonstrate various stimulatory and inhibitory influences that bacteria have on the E. huxleyi physiology. To investigate these algal-bacterial interactions, laboratory co-cultures have been established by us and by others. Owing to these co-cultures, various mechanisms of algal-bacterial interactions have been revealed, many involving bacterial pathogenicity towards algae. However, co-cultures represent a significantly simplified system, lacking the complexity of bacterial communities. In order to investigate bacterial pathogenicity within an ecologically relevant context, it becomes imperative to enhance the microbial complexity of co-culture setups. Phaeobacter inhibens bacteria are known pathogens that cause the death of E. huxleyi algae in laboratory co-culture systems. The bacteria depend on algal exudates for growth, but when algae senesce, bacteria switch to a pathogenic state and induce algal death. Here we investigate whether P. inhibens bacteria can induce algal death in the presence of a complex bacterial community. We show that an E. huxleyi-associated bacterial community protects the alga from the pathogen, although the pathogen occurs within the community. To study how the bacterial community regulates pathogenicity, we reduced the complex bacterial community to a five-member synthetic community (syncom). The syncom is comprised of a single algal host and five isolated bacterial species, which represent major bacterial groups that are naturally associated with E. huxleyi. We discovered that a single bacterial species in the reduced community, Sulfitobacter pontiacus, protects the alga from the pathogen. We further found that algal protection from P. inhibens pathogenicity is a shared trait among several Sulfitobacter species. Algal protection by bacteria might be a common phenomenon with ecological significance, which is overlooked in reduced co-culture systems.
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Affiliation(s)
- Roni Beiralas
- Department of Plant and Environmental Sciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Noy Ozer
- Department of Plant and Environmental Sciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Einat Segev
- Department of Plant and Environmental Sciences, The Weizmann Institute of Science, Rehovot, Israel.
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7
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Roy M, Fleisher RC, Alexandrov AI, Horovitz A. Reduced ADP off-rate by the yeast CCT2 double mutation T394P/R510H which causes Leber congenital amaurosis in humans. Commun Biol 2023; 6:888. [PMID: 37644231 PMCID: PMC10465592 DOI: 10.1038/s42003-023-05261-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Accepted: 08/20/2023] [Indexed: 08/31/2023] Open
Abstract
The CCT/TRiC chaperonin is found in the cytosol of all eukaryotic cells and assists protein folding in an ATP-dependent manner. The heterozygous double mutation T400P and R516H in subunit CCT2 is known to cause Leber congenital amaurosis (LCA), a hereditary congenital retinopathy. This double mutation also renders the function of subunit CCT2, when it is outside of the CCT/TRiC complex, to be defective in promoting autophagy. Here, we show using steady-state and transient kinetic analysis that the corresponding double mutation in subunit CCT2 from Saccharomyces cerevisiae reduces the off-rate of ADP during ATP hydrolysis by CCT/TRiC. We also report that the ATPase activity of CCT/TRiC is stimulated by a non-folded substrate. Our results suggest that the closed state of CCT/TRiC is stabilized by the double mutation owing to the slower off-rate of ADP, thereby impeding the exit of CCT2 from the complex that is required for its function in autophagy.
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Affiliation(s)
- Mousam Roy
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Rachel C Fleisher
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Alexander I Alexandrov
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Amnon Horovitz
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, 7610001, Israel.
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8
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Lemcoff T, Alus L, Haataja JS, Wagner A, Zhang G, Pavan MJ, Yallapragada VJ, Vignolini S, Oron D, Schertel L, Palmer BA. Brilliant whiteness in shrimp from ultra-thin layers of birefringent nanospheres. Nat Photonics 2023; 17:485-493. [PMID: 37287680 PMCID: PMC10241642 DOI: 10.1038/s41566-023-01182-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 02/24/2023] [Indexed: 06/09/2023]
Abstract
A fundamental question regarding light scattering is how whiteness, generated from multiple scattering, can be obtained from thin layers of materials. This challenge arises from the phenomenon of optical crowding, whereby, for scatterers packed with filling fractions higher than ~30%, reflectance is drastically reduced due to near-field coupling between the scatterers. Here we show that the extreme birefringence of isoxanthopterin nanospheres overcomes optical crowding effects, enabling multiple scattering and brilliant whiteness from ultra-thin chromatophore cells in shrimp. Strikingly, numerical simulations reveal that birefringence, originating from the spherulitic arrangement of isoxanthopterin molecules, enables intense broadband scattering almost up to the maximal packing for random spheres. This reduces the thickness of material required to produce brilliant whiteness, resulting in a photonic system that is more efficient than other biogenic or biomimetic white materials which operate in the lower refractive index medium of air. These results highlight the importance of birefringence as a structural variable to enhance the performance of such materials and could contribute to the design of biologically inspired replacements for artificial scatterers like titanium dioxide.
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Affiliation(s)
- Tali Lemcoff
- Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Lotem Alus
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot, Israel
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Johannes S. Haataja
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
- Department of Applied Physics, Aalto University School of Science, Espoo, Finland
| | - Avital Wagner
- Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Gan Zhang
- Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Present Address: College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, China
| | - Mariela J. Pavan
- Ilse Katz Institute for Nanoscale Science & Technology, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | | | - Silvia Vignolini
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Dan Oron
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot, Israel
| | - Lukas Schertel
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
- Department of Physics, University of Fribourg, Fribourg, Switzerland
| | - Benjamin A. Palmer
- Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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9
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Winter SL, Golani G, Lolicato F, Vallbracht M, Thiyagarajah K, Ahmed SS, Lüchtenborg C, Fackler OT, Brügger B, Hoenen T, Nickel W, Schwarz US, Chlanda P. The Ebola virus VP40 matrix layer undergoes endosomal disassembly essential for membrane fusion. EMBO J 2023:e113578. [PMID: 37082863 DOI: 10.15252/embj.2023113578] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 03/09/2023] [Accepted: 03/22/2023] [Indexed: 04/22/2023] Open
Abstract
Ebola viruses (EBOVs) assemble into filamentous virions, whose shape and stability are determined by the matrix viral protein 40 (VP40). Virus entry into host cells occurs via membrane fusion in late endosomes; however, the mechanism of how the remarkably long virions undergo uncoating, including virion disassembly and nucleocapsid release into the cytosol, remains unknown. Here, we investigate the structural architecture of EBOVs entering host cells and discover that the VP40 matrix disassembles prior to membrane fusion. We reveal that VP40 disassembly is caused by the weakening of VP40-lipid interactions driven by low endosomal pH that equilibrates passively across the viral envelope without a dedicated ion channel. We further show that viral membrane fusion depends on VP40 matrix integrity, and its disassembly reduces the energy barrier for fusion stalk formation. Thus, pH-driven structural remodeling of the VP40 matrix acts as a molecular switch coupling viral matrix uncoating to membrane fusion during EBOV entry.
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Affiliation(s)
- Sophie L Winter
- Schaller Research Groups, Department of Infectious Diseases, Virology, University Hospital Heidelberg, Heidelberg, Germany
- BioQuant-Center for Quantitative Biology, Heidelberg University, Heidelberg, Germany
| | - Gonen Golani
- BioQuant-Center for Quantitative Biology, Heidelberg University, Heidelberg, Germany
- Institute for Theoretical Physics, Heidelberg University, Heidelberg, Germany
| | - Fabio Lolicato
- Heidelberg University Biochemistry Center, Heidelberg, Germany
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - Melina Vallbracht
- Schaller Research Groups, Department of Infectious Diseases, Virology, University Hospital Heidelberg, Heidelberg, Germany
- BioQuant-Center for Quantitative Biology, Heidelberg University, Heidelberg, Germany
| | - Keerthihan Thiyagarajah
- Schaller Research Groups, Department of Infectious Diseases, Virology, University Hospital Heidelberg, Heidelberg, Germany
- BioQuant-Center for Quantitative Biology, Heidelberg University, Heidelberg, Germany
| | - Samy Sid Ahmed
- Department of Infectious Diseases, Integrative Virology, University Hospital Heidelberg, Heidelberg, Germany
| | | | - Oliver T Fackler
- Department of Infectious Diseases, Integrative Virology, University Hospital Heidelberg, Heidelberg, Germany
- German Centre for Infection Research (DZIF), Partner Site Heidelberg, Heidelberg, Germany
| | - Britta Brügger
- Heidelberg University Biochemistry Center, Heidelberg, Germany
| | - Thomas Hoenen
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Insitut, Greifswald-Insel Riems, Greifswald, Germany
| | - Walter Nickel
- Heidelberg University Biochemistry Center, Heidelberg, Germany
| | - Ulrich S Schwarz
- BioQuant-Center for Quantitative Biology, Heidelberg University, Heidelberg, Germany
- Institute for Theoretical Physics, Heidelberg University, Heidelberg, Germany
| | - Petr Chlanda
- Schaller Research Groups, Department of Infectious Diseases, Virology, University Hospital Heidelberg, Heidelberg, Germany
- BioQuant-Center for Quantitative Biology, Heidelberg University, Heidelberg, Germany
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10
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Choudhary K, Itzkovich Z, Alonso-Perez E, Bishara H, Dunn B, Sherlock G, Kupiec M. S. cerevisiae Cells Can Grow without the Pds5 Cohesin Subunit. mBio 2022; 13:e0142022. [PMID: 35708277 PMCID: PMC9426526 DOI: 10.1128/mbio.01420-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 05/31/2022] [Indexed: 12/11/2022] Open
Abstract
During DNA replication, the newly created sister chromatids are held together until their separation at anaphase. The cohesin complex is in charge of creating and maintaining sister chromatid cohesion (SCC) in all eukaryotes. In Saccharomyces cerevisiae cells, cohesin is composed of two elongated proteins, Smc1 and Smc3, bridged by the kleisin Mcd1/Scc1. The latter also acts as a scaffold for three additional proteins, Scc3/Irr1, Wpl1/Rad61, and Pds5. Although the HEAT-repeat protein Pds5 is essential for cohesion, its precise function is still debated. Deletion of the ELG1 gene, encoding a PCNA unloader, can partially suppress the temperature-sensitive pds5-1 allele, but not a complete deletion of PDS5. We carried out a genetic screen for high-copy-number suppressors and another for spontaneously arising mutants, allowing the survival of a pds5Δ elg1Δ strain. Our results show that cells remain viable in the absence of Pds5 provided that there is both an elevation in the level of Mcd1 (which can be due to mutations in the CLN2 gene, encoding a G1 cyclin), and an increase in the level of SUMO-modified PCNA on chromatin (caused by lack of PCNA unloading in elg1Δ mutants). The elevated SUMO-PCNA levels increase the recruitment of the Srs2 helicase, which evicts Rad51 molecules from the moving fork, creating single-stranded DNA (ssDNA) regions that serve as sites for increased cohesin loading and SCC establishment. Thus, our results delineate a double role for Pds5 in protecting the cohesin ring and interacting with the DNA replication machinery. IMPORTANCE Sister chromatid cohesion is vital for faithful chromosome segregation, chromosome folding into loops, and gene expression. A multisubunit protein complex known as cohesin holds the sister chromatids from S phase until the anaphase stage. In this study, we explore the function of the essential cohesin subunit Pds5 in the regulation of sister chromatid cohesion. We performed two independent genetic screens to bypass the function of the Pds5 protein. We observe that Pds5 protein is a cohesin stabilizer, and elevating the levels of Mcd1 protein along with SUMO-PCNA accumulation on chromatin can compensate for the loss of the PDS5 gene. In addition, Pds5 plays a role in coordinating the DNA replication and sister chromatid cohesion establishment. This work elucidates the function of cohesin subunit Pds5, the G1 cyclin Cln2, and replication factors PCNA, Elg1, and Srs2 in the proper regulation of sister chromatid cohesion.
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Affiliation(s)
- Karan Choudhary
- The Shmunis School of Biomedicine and Cancer Research, Tel Aviv University, Ramat Aviv, Israel
| | - Ziv Itzkovich
- The Shmunis School of Biomedicine and Cancer Research, Tel Aviv University, Ramat Aviv, Israel
| | - Elisa Alonso-Perez
- The Shmunis School of Biomedicine and Cancer Research, Tel Aviv University, Ramat Aviv, Israel
| | - Hend Bishara
- The Shmunis School of Biomedicine and Cancer Research, Tel Aviv University, Ramat Aviv, Israel
| | - Barbara Dunn
- Departments of Genetics, Stanford University, Stanford, California, USA
| | - Gavin Sherlock
- Departments of Genetics, Stanford University, Stanford, California, USA
| | - Martin Kupiec
- The Shmunis School of Biomedicine and Cancer Research, Tel Aviv University, Ramat Aviv, Israel
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Kastan N, Gnedeva K, Alisch T, Petelski AA, Huggins DJ, Chiaravalli J, Aharanov A, Shakked A, Tzahor E, Nagiel A, Segil N, Hudspeth AJ. Small-molecule inhibition of Lats kinases may promote Yap-dependent proliferation in postmitotic mammalian tissues. Nat Commun 2021; 12:3100. [PMID: 34035288 PMCID: PMC8149661 DOI: 10.1038/s41467-021-23395-3] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 04/20/2021] [Indexed: 02/04/2023] Open
Abstract
Hippo signaling is an evolutionarily conserved pathway that restricts growth and regeneration predominantly by suppressing the activity of the transcriptional coactivator Yap. Using a high-throughput phenotypic screen, we identified a potent and non-toxic activator of Yap. In vitro kinase assays show that the compound acts as an ATP-competitive inhibitor of Lats kinases-the core enzymes in Hippo signaling. The substance prevents Yap phosphorylation and induces proliferation of supporting cells in the murine inner ear, murine cardiomyocytes, and human Müller glia in retinal organoids. RNA sequencing indicates that the inhibitor reversibly activates the expression of transcriptional Yap targets: upon withdrawal, a subset of supporting-cell progeny exits the cell cycle and upregulates genes characteristic of sensory hair cells. Our results suggest that the pharmacological inhibition of Lats kinases may promote initial stages of the proliferative regeneration of hair cells, a process thought to be permanently suppressed in the adult mammalian inner ear.
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MESH Headings
- Adaptor Proteins, Signal Transducing/genetics
- Adaptor Proteins, Signal Transducing/metabolism
- Animals
- Cell Line
- Cell Line, Tumor
- Cell Proliferation/drug effects
- Cell Proliferation/genetics
- Ependymoglial Cells/cytology
- Ependymoglial Cells/drug effects
- Ependymoglial Cells/metabolism
- HEK293 Cells
- Hair Cells, Auditory, Inner/cytology
- Hair Cells, Auditory, Inner/drug effects
- Hair Cells, Auditory, Inner/metabolism
- Humans
- Mice, Knockout
- Mice, Transgenic
- Myocytes, Cardiac/cytology
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/metabolism
- Protein Serine-Threonine Kinases/antagonists & inhibitors
- Protein Serine-Threonine Kinases/metabolism
- Signal Transduction/drug effects
- Signal Transduction/genetics
- Small Molecule Libraries/pharmacology
- Tumor Suppressor Proteins/antagonists & inhibitors
- Tumor Suppressor Proteins/metabolism
- YAP-Signaling Proteins
- Mice
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Affiliation(s)
- Nathaniel Kastan
- Howard Hughes Medical Institute, The Rockefeller University, New York, NY, USA
- Laboratory of Sensory Neuroscience, The Rockefeller University, New York, NY, USA
| | - Ksenia Gnedeva
- Tina and Rick Caruso Department of Otolaryngology-Head and Neck Surgery, University of Southern California, Los Angles, CA, USA.
| | - Theresa Alisch
- Howard Hughes Medical Institute, The Rockefeller University, New York, NY, USA
- Laboratory of Sensory Neuroscience, The Rockefeller University, New York, NY, USA
| | - Aleksandra A Petelski
- Howard Hughes Medical Institute, The Rockefeller University, New York, NY, USA
- Laboratory of Sensory Neuroscience, The Rockefeller University, New York, NY, USA
- Department of Bioengineering and Barnett Institute, Northeastern University, Boston, MA, USA
| | - David J Huggins
- Tri-Institutional Therapeutics Discovery Institute, New York, NY, USA
- Department of Physiology and Biophysics, Weill Cornell Medical College of Cornell University, New York, NY, USA
| | - Jeanne Chiaravalli
- High-Throughput Screening Resource Center, The Rockefeller University, New York, NY, USA
- Institut Pasteur, Paris, France
| | - Alla Aharanov
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Avraham Shakked
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Eldad Tzahor
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Aaron Nagiel
- Department of Surgery Children's Hospital Los Angeles, Vision Center, Los Angeles, CA, USA
- Saban Research Institute, Children's Hospital Los Angeles, Los Angeles, CA, USA
- USC Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Neil Segil
- Tina and Rick Caruso Department of Otolaryngology-Head and Neck Surgery, University of Southern California, Los Angles, CA, USA
- Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research, University of Southern California, Los Angles, CA, USA
| | - A J Hudspeth
- Howard Hughes Medical Institute, The Rockefeller University, New York, NY, USA
- Laboratory of Sensory Neuroscience, The Rockefeller University, New York, NY, USA
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12
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Levi-Galibov O, Lavon H, Wassermann-Dozorets R, Pevsner-Fischer M, Mayer S, Wershof E, Stein Y, Brown LE, Zhang W, Friedman G, Nevo R, Golani O, Katz LH, Yaeger R, Laish I, Porco JA, Sahai E, Shouval DS, Kelsen D, Scherz-Shouval R. Heat Shock Factor 1-dependent extracellular matrix remodeling mediates the transition from chronic intestinal inflammation to colon cancer. Nat Commun 2020; 11:6245. [PMID: 33288768 PMCID: PMC7721883 DOI: 10.1038/s41467-020-20054-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 11/09/2020] [Indexed: 12/25/2022] Open
Abstract
In the colon, long-term exposure to chronic inflammation drives colitis-associated colon cancer (CAC) in patients with inflammatory bowel disease. While the causal and clinical links are well established, molecular understanding of how chronic inflammation leads to the development of colon cancer is lacking. Here we deconstruct the evolving microenvironment of CAC by measuring proteomic changes and extracellular matrix (ECM) organization over time in a mouse model of CAC. We detect early changes in ECM structure and composition, and report a crucial role for the transcriptional regulator heat shock factor 1 (HSF1) in orchestrating these events. Loss of HSF1 abrogates ECM assembly by colon fibroblasts in cell-culture, prevents inflammation-induced ECM remodeling in mice and inhibits progression to CAC. Establishing relevance to human disease, we find high activation of stromal HSF1 in CAC patients, and detect the HSF1-dependent proteomic ECM signature in human colorectal cancer. Thus, HSF1-dependent ECM remodeling plays a crucial role in mediating inflammation-driven colon cancer.
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Affiliation(s)
- Oshrat Levi-Galibov
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Hagar Lavon
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
| | | | | | - Shimrit Mayer
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
| | | | - Yaniv Stein
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Lauren E Brown
- Department of Chemistry and Center for Molecular Discovery (BU-CMD), Boston University, Boston, MA, USA
| | - Wenhan Zhang
- Department of Chemistry and Center for Molecular Discovery (BU-CMD), Boston University, Boston, MA, USA
| | - Gil Friedman
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Reinat Nevo
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Ofra Golani
- Department of Life Sciences Core Facilities, The Weizmann Institute of Science, Rehovot, Israel
| | - Lior H Katz
- Gastroenterology Institute, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
- Department of Gastroenterology and Hepatology, Hadassah Medical Center, Jerusalem, Israel
| | - Rona Yaeger
- Gastrointestinal Oncology Service, Memorial Sloan Kettering Cancer Center, and Weil Cornell Medical College, New York, NY, USA
| | - Ido Laish
- Gastroenterology Institute, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
- Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel
| | - John A Porco
- Department of Chemistry and Center for Molecular Discovery (BU-CMD), Boston University, Boston, MA, USA
| | | | - Dror S Shouval
- Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel
- Pediatric Gastroenterology Unit, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Ramat Gan, Israel
| | - David Kelsen
- Gastrointestinal Oncology Service, Memorial Sloan Kettering Cancer Center, and Weil Cornell Medical College, New York, NY, USA
| | - Ruth Scherz-Shouval
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel.
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