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Machtens DA, Willerding JM, Eschenburg S, Reubold TF. Crystal structure of the N-terminal domain of the effector protein SidI of Legionella pneumophila reveals a glucosyl transferase domain. Biochem Biophys Res Commun 2023; 661:50-55. [PMID: 37087798 DOI: 10.1016/j.bbrc.2023.04.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 04/13/2023] [Indexed: 04/25/2023]
Abstract
The Gram-negative bacterium Legionella pneumophila is an accidental human pathogen that can cause a life-threatening respiratory infection called Legionellosis. In the course of infection, L. pneumophila injects more than 300 effector proteins into the host cell. The effector proteins modify the intracellular environment in order to create a stable compartment for proliferation within the host cell. The effector protein SidI has been shown to potently inhibit host translation upon translocation. SidI is able to interact with the translation elongation factor eEF1A, which has been hypothesized to be a target of SidI. A postulated glycosyltransferase domain in the C-terminal half may be responsible for the toxic effect of SidI. Here, we present the crystal structure of an N-terminal fragment of SidI containing residues 37-573. The structure is divided into three subdomains, two of which display a novel fold. The third subdomain shows close structural homology to GT-B fold glycosyltransferases. Based on structural analysis we predict that the two previously identified residues R453 and E482 assume roles in the catalytic activity of SidI. Furthermore, we show that the N-terminal fragment of SidI is able to directly interact with a postulated target, the translation elongation factor eEF1A.
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Affiliation(s)
- Dominik A Machtens
- Institute for Biophysical Chemistry, Hannover Medical School, Carl-Neuberg-Straße 1, 30625, Hannover, Germany; Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Carl-Neuberg-Straße 1, 30625, Hannover, Germany
| | - Jonas M Willerding
- Institute for Biophysical Chemistry, Hannover Medical School, Carl-Neuberg-Straße 1, 30625, Hannover, Germany
| | - Susanne Eschenburg
- Institute for Biophysical Chemistry, Hannover Medical School, Carl-Neuberg-Straße 1, 30625, Hannover, Germany; Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Carl-Neuberg-Straße 1, 30625, Hannover, Germany
| | - Thomas F Reubold
- Institute for Biophysical Chemistry, Hannover Medical School, Carl-Neuberg-Straße 1, 30625, Hannover, Germany.
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2
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Lockwood DC, Amin H, Costa TRD, Schroeder GN. The Legionella pneumophila Dot/Icm type IV secretion system and its effectors. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 35639581 DOI: 10.1099/mic.0.001187] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
To prevail in the interaction with eukaryotic hosts, many bacterial pathogens use protein secretion systems to release virulence factors at the host–pathogen interface and/or deliver them directly into host cells. An outstanding example of the complexity and sophistication of secretion systems and the diversity of their protein substrates, effectors, is the Defective in organelle trafficking/Intracellular multiplication (Dot/Icm) Type IVB secretion system (T4BSS) of
Legionella pneumophila
and related species.
Legionella
species are facultative intracellular pathogens of environmental protozoa and opportunistic human respiratory pathogens. The Dot/Icm T4BSS translocates an exceptionally large number of effectors, more than 300 per
L. pneumophila
strain, and is essential for evasion of phagolysosomal degradation and exploitation of protozoa and human macrophages as replicative niches. Recent technological advancements in the imaging of large protein complexes have provided new insight into the architecture of the T4BSS and allowed us to propose models for the transport mechanism. At the same time, significant progress has been made in assigning functions to about a third of
L. pneumophila
effectors, discovering unprecedented new enzymatic activities and concepts of host subversion. In this review, we describe the current knowledge of the workings of the Dot/Icm T4BSS machinery and provide an overview of the activities and functions of the to-date characterized effectors in the interaction of
L. pneumophila
with host cells.
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Affiliation(s)
- Daniel C Lockwood
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, BT9 7BL, Northern Ireland, UK
| | - Himani Amin
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College, London, SW7 2AZ, UK
| | - Tiago R D Costa
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College, London, SW7 2AZ, UK
| | - Gunnar N Schroeder
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, BT9 7BL, Northern Ireland, UK
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3
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Grishin A, Voth K, Gagarinova A, Cygler M. Structural biology of the invasion arsenal of Gram-negative bacterial pathogens. FEBS J 2021; 289:1385-1427. [PMID: 33650300 DOI: 10.1111/febs.15794] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Revised: 02/11/2021] [Accepted: 02/26/2021] [Indexed: 12/20/2022]
Abstract
In the last several years, there has been a tremendous progress in the understanding of host-pathogen interactions and the mechanisms by which bacterial pathogens modulate behavior of the host cell. Pathogens use secretion systems to inject a set of proteins, called effectors, into the cytosol of the host cell. These effectors are secreted in a highly regulated, temporal manner and interact with host proteins to modify a multitude of cellular processes. The number of effectors varies between pathogens from ~ 30 to as many as ~ 350. The functional redundancy of effectors encoded by each pathogen makes it difficult to determine the cellular effects or function of individual effectors, since their individual knockouts frequently produce no easily detectable phenotypes. Structural biology of effector proteins and their interactions with host proteins, in conjunction with cell biology approaches, has provided invaluable information about the cellular function of effectors and underlying molecular mechanisms of their modes of action. Many bacterial effectors are functionally equivalent to host proteins while being structurally divergent from them. Other effector proteins display new, previously unobserved functionalities. Here, we summarize the contribution of the structural characterization of effectors and effector-host protein complexes to our understanding of host subversion mechanisms used by the most commonly investigated Gram-negative bacterial pathogens. We describe in some detail the enzymatic activities discovered among effector proteins and how they affect various cellular processes.
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Affiliation(s)
- Andrey Grishin
- Department of Biochemistry, Microbiology, & Immunology, University of Saskatchewan, Saskatoon, Canada
| | - Kevin Voth
- Department of Biochemistry, Microbiology, & Immunology, University of Saskatchewan, Saskatoon, Canada
| | - Alla Gagarinova
- Department of Biochemistry, Microbiology, & Immunology, University of Saskatchewan, Saskatoon, Canada
| | - Miroslaw Cygler
- Department of Biochemistry, Microbiology, & Immunology, University of Saskatchewan, Saskatoon, Canada
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4
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Abstract
Through coevolution with host cells, microorganisms have acquired mechanisms to avoid the detection by the host surveillance system and to use the cell's supplies to establish themselves. Indeed, certain pathogens have evolved proteins that imitate specific eukaryotic cell proteins, allowing them to manipulate host pathways, a phenomenon termed molecular mimicry. Bacterial "eukaryotic-like proteins" are a remarkable example of molecular mimicry. They are defined as proteins that strongly resemble eukaryotic proteins or that carry domains that are predominantly present in eukaryotes and that are generally absent from prokaryotes. The widest diversity of eukaryotic-like proteins known to date can be found in members of the bacterial genus Legionella, some of which cause a severe pneumonia in humans. The characterization of a number of these proteins shed light on their importance during infection. The subsequent identification of eukaryotic-like genes in the genomes of other amoeba-associated bacteria and bacterial symbionts suggested that eukaryotic-like proteins are a common means of bacterial evasion and communication, shaped by the continuous interactions between bacteria and their protozoan hosts. In this review, we discuss the concept of molecular mimicry using Legionella as an example and show that eukaryotic-like proteins effectively manipulate host cell pathways. The study of the function and evolution of such proteins is an exciting field of research that is leading us toward a better understanding of the complex world of bacterium-host interactions. Ultimately, this knowledge will teach us how host pathways are manipulated and how infections may possibly be tackled.
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5
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Forrest S, Welch M. Arming the troops: Post-translational modification of extracellular bacterial proteins. Sci Prog 2020; 103:36850420964317. [PMID: 33148128 PMCID: PMC10450907 DOI: 10.1177/0036850420964317] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Protein secretion is almost universally employed by bacteria. Some proteins are retained on the cell surface, whereas others are released into the extracellular milieu, often playing a key role in virulence. In this review, we discuss the diverse types and potential functions of post-translational modifications (PTMs) occurring to extracellular bacterial proteins.
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Affiliation(s)
- Suzanne Forrest
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Martin Welch
- Department of Biochemistry, University of Cambridge, Cambridge, UK
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6
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Belyi Y. Targeting Eukaryotic mRNA Translation by Legionella pneumophila. Front Mol Biosci 2020; 7:80. [PMID: 32411722 PMCID: PMC7201127 DOI: 10.3389/fmolb.2020.00080] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 04/07/2020] [Indexed: 02/01/2023] Open
Abstract
Legionella is a gram-negative microorganism and an infectious agent of pneumonia in humans. It is an intracellular pathogen and multiplies in different eukaryotic cells like amoebae, ciliated protozoa, macrophages, monocytes, and lung epithelial cells. Proliferation of L. pneumophila in eukaryotic cells depends on its type 4 secretion system, which delivers an arsenal of bacterial effector proteins to cytoplasm of its host. Once within the cytoplasm, effectors modify a broad range of host activities, including mRNA translation. Translation is inhibited by Legionella through the action of several effector proteins including Lgt1, Lgt2, Lgt3, SidI, LegK4, SidL, and RavX. Lgt1-3 and SidI target elongation factors: Lgt1-3 mono-glucosylate elongation factor eEF1A, while SidI binds eEF1A, and eEF1Bγ. Effector LegK4 inhibits protein synthesis by phosphorylating Hsp70 proteins, while SidL and RavX have no defined targets in protein synthesis machinery thus far. In addition to direct inhibition of protein synthesis, SidI also affects the stress response, whereas Lgt1-3 – unfolded protein response and cell-cycle progression of host cells. Whether manipulation of these processes is linked to canonical or non-canonical function(s) of targeted elongation factors remains unknown.
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Affiliation(s)
- Yury Belyi
- Gamaleya Research Centre for Epidemiology and Microbiology, Moscow, Russia
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7
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Alcântara A, Bosch J, Nazari F, Hoffmann G, Gallei M, Uhse S, Darino MA, Olukayode T, Reumann D, Baggaley L, Djamei A. Systematic Y2H Screening Reveals Extensive Effector-Complex Formation. FRONTIERS IN PLANT SCIENCE 2019; 10:1437. [PMID: 31803201 PMCID: PMC6872519 DOI: 10.3389/fpls.2019.01437] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 10/16/2019] [Indexed: 05/22/2023]
Abstract
During infection pathogens secrete small molecules, termed effectors, to manipulate and control the interaction with their specific hosts. Both the pathogen and the plant are under high selective pressure to rapidly adapt and co-evolve in what is usually referred to as molecular arms race. Components of the host's immune system form a network that processes information about molecules with a foreign origin and damage-associated signals, integrating them with developmental and abiotic cues to adapt the plant's responses. Both in the case of nucleotide-binding leucine-rich repeat receptors and leucine-rich repeat receptor kinases interaction networks have been extensively characterized. However, little is known on whether pathogenic effectors form complexes to overcome plant immunity and promote disease. Ustilago maydis, a biotrophic fungal pathogen that infects maize plants, produces effectors that target hubs in the immune network of the host cell. Here we assess the capability of U. maydis effector candidates to interact with each other, which may play a crucial role during the infection process. Using a systematic yeast-two-hybrid approach and based on a preliminary pooled screen, we selected 63 putative effectors for one-on-one matings with a library of nearly 300 effector candidates. We found that 126 of these effector candidates interacted either with themselves or other predicted effectors. Although the functional relevance of the observed interactions remains elusive, we propose that the observed abundance in complex formation between effectors adds an additional level of complexity to effector research and should be taken into consideration when studying effector evolution and function. Based on this fundamental finding, we suggest various scenarios which could evolutionarily drive the formation and stabilization of an effector interactome.
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Affiliation(s)
- André Alcântara
- Gregor Mendel Institute of Molecular Plant Biology, Vienna, Austria
| | - Jason Bosch
- Gregor Mendel Institute of Molecular Plant Biology, Vienna, Austria
| | - Fahimeh Nazari
- Gregor Mendel Institute of Molecular Plant Biology, Vienna, Austria
- Iranian Research Institute of Plant Protection, Tehran, Iran
| | - Gesa Hoffmann
- Gregor Mendel Institute of Molecular Plant Biology, Vienna, Austria
- Department of Plant Biology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Michelle Gallei
- Gregor Mendel Institute of Molecular Plant Biology, Vienna, Austria
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Simon Uhse
- Gregor Mendel Institute of Molecular Plant Biology, Vienna, Austria
| | - Martin A. Darino
- Gregor Mendel Institute of Molecular Plant Biology, Vienna, Austria
| | - Toluwase Olukayode
- Gregor Mendel Institute of Molecular Plant Biology, Vienna, Austria
- Global Institute for Food Security, University of Saskatchewan, Saskatoon, SK, Canada
| | - Daniel Reumann
- Gregor Mendel Institute of Molecular Plant Biology, Vienna, Austria
- Institute of Molecular Biotechnology, Vienna, Austria
| | - Laura Baggaley
- Gregor Mendel Institute of Molecular Plant Biology, Vienna, Austria
- Biotic Interactions and Crop Protection, Rothamsted Research, Harpenden, United Kingdom
| | - Armin Djamei
- Gregor Mendel Institute of Molecular Plant Biology, Vienna, Austria
- Department of Breeding Research, Leibniz-Institut für Pflanzengenetik und Kulturpflanzenforschung (IPK), Gatersleben, Germany
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8
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Velasco L, Dublang L, Moro F, Muga A. The Complex Phosphorylation Patterns that Regulate the Activity of Hsp70 and Its Cochaperones. Int J Mol Sci 2019; 20:ijms20174122. [PMID: 31450862 PMCID: PMC6747476 DOI: 10.3390/ijms20174122] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 08/21/2019] [Accepted: 08/22/2019] [Indexed: 12/26/2022] Open
Abstract
Proteins must fold into their native structure and maintain it during their lifespan to display the desired activity. To ensure proper folding and stability, and avoid generation of misfolded conformations that can be potentially cytotoxic, cells synthesize a wide variety of molecular chaperones that assist folding of other proteins and avoid their aggregation, which unfortunately is unavoidable under acute stress conditions. A protein machinery in metazoa, composed of representatives of the Hsp70, Hsp40, and Hsp110 chaperone families, can reactivate protein aggregates. We revised herein the phosphorylation sites found so far in members of these chaperone families and the functional consequences associated with some of them. We also discuss how phosphorylation might regulate the chaperone activity and the interaction of human Hsp70 with its accessory and client proteins. Finally, we present the information that would be necessary to decrypt the effect that post-translational modifications, and especially phosphorylation, could have on the biological activity of the Hsp70 system, known as the “chaperone code”.
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Affiliation(s)
- Lorea Velasco
- Biofisika Institute (UPV/EHU, CSIC) and Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940 Leioa, Spain
| | - Leire Dublang
- Biofisika Institute (UPV/EHU, CSIC) and Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940 Leioa, Spain
| | - Fernando Moro
- Biofisika Institute (UPV/EHU, CSIC) and Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940 Leioa, Spain.
| | - Arturo Muga
- Biofisika Institute (UPV/EHU, CSIC) and Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940 Leioa, Spain.
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9
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Maurice F, Pérébaskine N, Thore S, Fribourg S. In vitro dimerization of human RIO2 kinase. RNA Biol 2019; 16:1633-1642. [PMID: 31390939 DOI: 10.1080/15476286.2019.1653679] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
RIO proteins form a conserved family of atypical protein kinases. RIO2 is a serine/threonine protein kinase/ATPase involved in pre-40S ribosomal maturation. Current crystal structures of archaeal and fungal Rio2 proteins report a monomeric form of the protein. Here, we describe three atomic structures of the human RIO2 kinase showing that it forms a homodimer in vitro. Upon self-association, each protomer ATP-binding pocket is partially remodelled and found in an apostate. The homodimerization is mediated by key residues previously shown to be responsible for ATP binding and catalysis. This unusual in vitro protein kinase dimer reveals an intricate mechanism where identical residues are involved in substrate binding and oligomeric state formation. We speculate that such an oligomeric state might be formed also in vivo and might function in maintaining the protein in an inactive state and could be employed during import.
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Affiliation(s)
| | | | - Stéphane Thore
- INSERM U1212, UMR CNRS 5320, Université de Bordeaux , Bordeaux , France
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10
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Park BC, Reese M, Tagliabracci VS. Thinking outside of the cell: Secreted protein kinases in bacteria, parasites, and mammals. IUBMB Life 2019; 71:749-759. [PMID: 30941842 DOI: 10.1002/iub.2040] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Revised: 03/05/2019] [Accepted: 03/13/2019] [Indexed: 01/02/2023]
Abstract
Previous decades have seen an explosion in our understanding of protein kinase function in human health and disease. Hundreds of unique kinase structures have been solved, allowing us to create generalized rules for catalysis, assign roles of communities within the catalytic core, and develop specific drugs for targeting various pathways. Although our understanding of intracellular kinases has developed at a fast rate, our exploration into extracellular kinases has just begun. In this review, we will cover the secreted protein kinase families found in humans, bacteria, and parasites. © 2019 IUBMB Life, 71(6):749-759, 2019.
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Affiliation(s)
- Brenden C Park
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Michael Reese
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Vincent S Tagliabracci
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
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11
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Moss SM, Taylor IR, Ruggero D, Gestwicki JE, Shokat KM, Mukherjee S. A Legionella pneumophila Kinase Phosphorylates the Hsp70 Chaperone Family to Inhibit Eukaryotic Protein Synthesis. Cell Host Microbe 2019; 25:454-462.e6. [PMID: 30827827 DOI: 10.1016/j.chom.2019.01.006] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 11/10/2018] [Accepted: 12/27/2018] [Indexed: 11/25/2022]
Abstract
Legionella pneumophila (L.p.), the microbe responsible for Legionnaires' disease, secretes ∼300 bacterial proteins into the host cell cytosol. A subset of these proteins affects a wide range of post-translational modifications (PTMs) to disrupt host cellular pathways. L.p. has 5 conserved eukaryotic-like Ser/Thr effector kinases, LegK1-4 and LegK7, which are translocated during infection. Using a chemical genetic screen, we identified the Hsp70 chaperone family as a direct host target of LegK4. Phosphorylation of Hsp70s at T495 in the substrate-binding domain disrupted Hsp70's ATPase activity and greatly inhibited its protein folding capacity. Phosphorylation of cytosolic Hsp70 by LegK4 resulted in global translation inhibition and an increase in the amount of Hsp70 on highly translating polysomes. LegK4's ability to inhibit host translation via a single PTM uncovers a role for Hsp70 in protein synthesis and directly links it to the cellular translational machinery.
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Affiliation(s)
- Steven M Moss
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Isabelle R Taylor
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Davide Ruggero
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Hellen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Urology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Jason E Gestwicki
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Kevan M Shokat
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA.
| | - Shaeri Mukherjee
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA; George Williams Hooper Foundation, University of California, San Francisco, San Francisco, CA 94143, USA.
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