1
|
Kang-Pettinger T, Walker K, Brown R, Cowan R, Wright H, Baravalle R, Waters LC, Muskett FW, Bowler MW, Sawmynaden K, Coombs PJ, Carr MD, Hall G. Identification, binding, and structural characterization of single domain anti-PD-L1 antibodies inhibitory of immune regulatory proteins PD-1 and CD80. J Biol Chem 2022; 299:102769. [PMID: 36470427 PMCID: PMC9811221 DOI: 10.1016/j.jbc.2022.102769] [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] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 11/23/2022] [Accepted: 11/30/2022] [Indexed: 12/12/2022] Open
Abstract
Programmed death-ligand 1 (PD-L1) is a key immune regulatory protein that interacts with programmed cell death protein 1 (PD-1), leading to T-cell suppression. Whilst this interaction is key in self-tolerance, cancer cells evade the immune system by overexpressing PD-L1. Inhibition of the PD-1/PD-L1 pathway with standard monoclonal antibodies has proven a highly effective cancer treatment; however, single domain antibodies (VHH) may offer numerous potential benefits. Here, we report the identification and characterization of a diverse panel of 16 novel VHHs specific to PD-L1. The panel of VHHs demonstrate affinities of 0.7 nM to 5.1 μM and were able to completely inhibit PD-1 binding to PD-L1. The binding site for each VHH on PD-L1 was determined using NMR chemical shift perturbation mapping and revealed a common binding surface encompassing the PD-1-binding site. Additionally, we solved crystal structures of two representative VHHs in complex with PD-L1, which revealed unique binding modes. Similar NMR experiments were used to identify the binding site of CD80 on PD-L1, which is another immune response regulatory element and interacts with PD-L1 localized on the same cell surface. CD80 and PD-1 were revealed to share a highly overlapping binding site on PD-L1, with the panel of VHHs identified expected to inhibit CD80 binding. Comparison of the CD80 and PD-1 binding sites on PD-L1 enabled the identification of a potential antibody binding region able to confer specificity for the inhibition of PD-1 binding only, which may offer therapeutic benefits to counteract cancer cell evasion of the immune system.
Collapse
Affiliation(s)
- Tara Kang-Pettinger
- Leicester Institute of Structural and Chemical Biology and Department of Molecular and Cell Biology, Henry Wellcome Building, University of Leicester, Leicester, UK
| | - Kayleigh Walker
- Leicester Institute of Structural and Chemical Biology and Department of Molecular and Cell Biology, Henry Wellcome Building, University of Leicester, Leicester, UK
| | - Richard Brown
- LifeArc, Centre for Therapeutics Discovery, Open Innovation Campus, Stevenage, UK
| | - Richard Cowan
- Leicester Institute of Structural and Chemical Biology and Department of Molecular and Cell Biology, Henry Wellcome Building, University of Leicester, Leicester, UK
| | - Helena Wright
- Leicester Institute of Structural and Chemical Biology and Department of Molecular and Cell Biology, Henry Wellcome Building, University of Leicester, Leicester, UK
| | - Roberta Baravalle
- Leicester Institute of Structural and Chemical Biology and Department of Molecular and Cell Biology, Henry Wellcome Building, University of Leicester, Leicester, UK
| | - Lorna C. Waters
- Leicester Institute of Structural and Chemical Biology and Department of Molecular and Cell Biology, Henry Wellcome Building, University of Leicester, Leicester, UK
| | - Frederick W. Muskett
- Leicester Institute of Structural and Chemical Biology and Department of Molecular and Cell Biology, Henry Wellcome Building, University of Leicester, Leicester, UK
| | | | - Kovilen Sawmynaden
- LifeArc, Centre for Therapeutics Discovery, Open Innovation Campus, Stevenage, UK
| | - Peter J. Coombs
- LifeArc, Centre for Therapeutics Discovery, Open Innovation Campus, Stevenage, UK
| | - Mark D. Carr
- Leicester Institute of Structural and Chemical Biology and Department of Molecular and Cell Biology, Henry Wellcome Building, University of Leicester, Leicester, UK,For correspondence: Gareth Hall; Mark D. Carr
| | - Gareth Hall
- Leicester Institute of Structural and Chemical Biology and Department of Molecular and Cell Biology, Henry Wellcome Building, University of Leicester, Leicester, UK,For correspondence: Gareth Hall; Mark D. Carr
| |
Collapse
|
2
|
Deng M, Chen H, Liu X, Huang R, He Y, Yoo B, Xie J, John S, Zhang N, An Z, Zhang CC. Leukocyte immunoglobulin-like receptor subfamily B: therapeutic targets in cancer. Antib Ther 2021; 4:16-33. [PMID: 33928233 PMCID: PMC7944505 DOI: 10.1093/abt/tbab002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 01/12/2021] [Accepted: 01/13/2021] [Indexed: 02/06/2023] Open
Abstract
Inhibitory leukocyte immunoglobulin-like receptors (LILRBs 1–5) transduce signals via intracellular immunoreceptor tyrosine-based inhibitory motifs that recruit phosphatases to negatively regulate immune activation. The activation of LILRB signaling in immune cells may contribute to immune evasion. In addition, the expression and signaling of LILRBs in cancer cells especially in certain hematologic malignant cells directly support cancer development. Certain LILRBs thus have dual roles in cancer biology—as immune checkpoint molecules and tumor-supporting factors. Here, we review the expression, ligands, signaling, and functions of LILRBs, as well as therapeutic development targeting them. LILRBs may represent attractive targets for cancer treatment, and antagonizing LILRB signaling may prove to be effective anti-cancer strategies.
Collapse
Affiliation(s)
- Mi Deng
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Heyu Chen
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Xiaoye Liu
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Ryan Huang
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Yubo He
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Byounggyu Yoo
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jingjing Xie
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Samuel John
- Department of Pediatrics, Pediatric Hematology-Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Ningyan Zhang
- Texas Therapeutics Institute, Brown Foundation Institute of Molecular Medicine, University of Texas Houston Health Science Center, Houston, TX 77030, USA
| | - Zhiqiang An
- Texas Therapeutics Institute, Brown Foundation Institute of Molecular Medicine, University of Texas Houston Health Science Center, Houston, TX 77030, USA
| | - Cheng Cheng Zhang
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| |
Collapse
|
3
|
Abstract
The virulence mechanisms required for infection and evasion of immunity by pathogenic Leptospira species remain poorly understood. A number of L. interrogans surface proteins have been discovered, lying at the interface between the pathogen and host. Among these proteins, the functional properties of the Lig (leptospiral immunoglobulin-like domain) proteins have been examined most thoroughly. LigA, LigB, and LigC contain a series of, 13, 12, and 12 closely related domains, respectively, each containing a bacterial immunoglobulin (Big) -like fold. The multidomain region forms a mostly elongated structure that exposes a large surface area. Leptospires wield the Lig proteins to promote interactions with a range of specific host proteins, including those that aid evasion of innate immune mechanisms. These diverse binding events mediate adhesion of L. interrogans to the extracellular matrix, inhibit hemostasis, and inactivate key complement proteins. These interactions may help L. interrogans overcome the physical, hematological, and immunological barriers that would otherwise prevent the spirochete from establishing a systemic infection. Despite significant differences in the affinities of the LigA and LigB proteins for host targets, their functions overlap during lethal infection of hamsters; virulence is lost only when both ligA and ligB transcription is knocked down simultaneously. Lig proteins have been shown to be promising vaccine antigens through evaluation of a variety of different adjuvant strategies. This review serves to summarize current knowledge of Lig protein roles in virulence and immunity and to identify directions needed to better understand the precise functions of the Lig proteins during infection.
Collapse
Affiliation(s)
- David A. Haake
- Division of Infectious Diseases, VA Greater Los Angeles Healthcare System, Los Angeles, CA, United States
- Departments of Medicine, and Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA, United States
| | - James Matsunaga
- Research Service, VA Greater Los Angeles Healthcare System, Los Angeles, CA, United States
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA, United States
| |
Collapse
|
4
|
Amraei R, Alwani T, Ho RXY, Aryan Z, Wang S, Rahimi N. Cell adhesion molecule IGPR-1 activates AMPK connecting cell adhesion to autophagy. J Biol Chem 2020; 295:16691-16699. [PMID: 32978258 PMCID: PMC7864065 DOI: 10.1074/jbc.ra120.014790] [Citation(s) in RCA: 6] [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: 06/11/2020] [Revised: 09/22/2020] [Indexed: 01/17/2023] Open
Abstract
Autophagy plays critical roles in the maintenance of endothelial cells in response to cellular stress caused by blood flow. There is growing evidence that both cell adhesion and cell detachment can modulate autophagy, but the mechanisms responsible for this regulation remain unclear. Immunoglobulin and proline-rich receptor-1 (IGPR-1) is a cell adhesion molecule that regulates angiogenesis and endothelial barrier function. In this study, using various biochemical and cellular assays, we demonstrate that IGPR-1 is activated by autophagy-inducing stimuli, such as amino acid starvation, nutrient deprivation, rapamycin, and lipopolysaccharide. Manipulating the IκB kinase β activity coupled with in vivo and in vitro kinase assays demonstrated that IκB kinase β is a key serine/threonine kinase activated by autophagy stimuli and that it catalyzes phosphorylation of IGPR-1 at Ser220 The subsequent activation of IGPR-1, in turn, stimulates phosphorylation of AMP-activated protein kinase, which leads to phosphorylation of the major pro-autophagy proteins ULK1 and Beclin-1 (BECN1), increased LC3-II levels, and accumulation of LC3 punctum. Thus, our data demonstrate that IGPR-1 is activated by autophagy-inducing stimuli and in response regulates autophagy, connecting cell adhesion to autophagy. These findings may have important significance for autophagy-driven pathologies such cardiovascular diseases and cancer and suggest that IGPR-1 may serve as a promising therapeutic target.
Collapse
Affiliation(s)
- Razie Amraei
- Department of Pathology, School of Medicine, Boston University Medical Campus, Boston, Massachusetts, USA
| | - Tooba Alwani
- Department of Pathology, School of Medicine, Boston University Medical Campus, Boston, Massachusetts, USA
| | - Rachel Xi-Yeen Ho
- Department of Pathology, School of Medicine, Boston University Medical Campus, Boston, Massachusetts, USA
| | - Zahra Aryan
- Department of Pathology, School of Medicine, Boston University Medical Campus, Boston, Massachusetts, USA
| | - Shawn Wang
- Department of Pathology, School of Medicine, Boston University Medical Campus, Boston, Massachusetts, USA
| | - Nader Rahimi
- Department of Pathology, School of Medicine, Boston University Medical Campus, Boston, Massachusetts, USA.
| |
Collapse
|
5
|
Zyla D, Echeverria B, Glockshuber R. Donor strand sequence, rather than donor strand orientation, determines the stability and non-equilibrium folding of the type 1 pilus subunit FimA. J Biol Chem 2020; 295:12437-12448. [PMID: 32651228 DOI: 10.1074/jbc.ra120.014324] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 07/07/2020] [Indexed: 11/06/2022] Open
Abstract
FimA is the main structural subunit of adhesive type 1 pili from uropathogenic Escherichia coli strains. Up to 3000 copies of FimA assemble to the helical pilus rod through a mechanism termed donor strand complementation, in which the incomplete immunoglobulin-like fold of each FimA subunit is complemented by the N-terminal extension (Nte) of the next subunit. The Nte of FimA, which exhibits a pseudo-palindromic sequence, is inserted in an antiparallel orientation relative to the last β-strand of the preceding subunit in the pilus. The resulting subunit-subunit interactions are extraordinarily stable against dissociation and unfolding. Alternatively, FimA can fold to a self-complemented monomer with anti-apoptotic activity, in which the Nte inserts intramolecularly into the FimA core in the opposite, parallel orientation. The FimA monomers, however, show dramatically lower thermodynamic stability compared with FimA subunits in the assembled pilus. Using self-complemented FimA variants with reversed, pseudo-palindromic extensions, we demonstrate that the high stability of FimA polymers is primarily caused by the specific interactions between the side chains of the Nte residues and the FimA core and not by the antiparallel orientation of the donor strand alone. In addition, we demonstrate that nonequilibrium two-state folding, a hallmark of FimA with the Nte inserted in the pilus rod-like, antiparallel orientation, only depends on the identity of the inserted Nte side chains and not on Nte orientation.
Collapse
Affiliation(s)
- Dawid Zyla
- Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland
| | - Blanca Echeverria
- Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland
| | - Rudi Glockshuber
- Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland
| |
Collapse
|
6
|
Iwagishi R, Tanaka R, Seto M, Takagi T, Norioka N, Ueyama T, Kawamura T, Takagi J, Ogawa Y, Shirakabe K. Negatively charged amino acids in the stalk region of membrane proteins reduce ectodomain shedding. J Biol Chem 2020; 295:12343-12352. [PMID: 32580944 DOI: 10.1074/jbc.ra120.013758] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 06/11/2020] [Indexed: 01/12/2023] Open
Abstract
Ectodomain shedding is a post-translational modification mechanism by which the entire extracellular domain of membrane proteins is liberated through juxtamembrane processing. Because shedding rapidly and irreversibly alters the characteristics of cells, this process is properly regulated. However, the molecular mechanisms governing the propensity of membrane proteins to shedding are largely unknown. Here, we present evidence that negatively charged amino acids within the stalk region, an unstructured juxtamembrane region at which shedding occurs, contribute to shedding susceptibility. We show that two activated leukocyte cell adhesion molecule (ALCAM) protein variants produced by alternative splicing have different susceptibilities to ADAM metallopeptidase domain 17 (ADAM17)-mediated shedding. Of note, the inclusion of a stalk region encoded by a 39-bp-long alternative exon conferred shedding resistance. We found that this alternative exon encodes a large proportion of negatively charged amino acids, which we demonstrate are indispensable for conferring the shedding resistance. We also show that the introduction of negatively charged amino acids into the stalk region of shedding-susceptible ALCAM variant protein attenuates its shedding. Furthermore, we observed that negatively charged amino acids residing in the stalk region of Erb-B2 receptor tyrosine kinase 4 (ERBB4) are indispensable for its shedding resistance. Collectively, our results indicate that negatively charged amino acids within the stalk region interfere with the shedding of multiple membrane proteins. We conclude that the composition of the stalk region determines the shedding susceptibility of membrane proteins.
Collapse
Affiliation(s)
- Ryo Iwagishi
- Department of Biomedical Sciences, College of Life Sciences, Ritsumeikan University, Kusatsu, Japan
| | - Rika Tanaka
- Department of Biomedical Sciences, College of Life Sciences, Ritsumeikan University, Kusatsu, Japan
| | - Munenosuke Seto
- Department of Biomedical Sciences, College of Life Sciences, Ritsumeikan University, Kusatsu, Japan
| | - Tomoyo Takagi
- Department of Biomedical Sciences, College of Life Sciences, Ritsumeikan University, Kusatsu, Japan
| | - Naoko Norioka
- Laboratory of Protein Synthesis and Expression, Institute for Protein Research, Osaka University, Osaka, Japan
| | - Tomoe Ueyama
- Department of Biomedical Sciences, College of Life Sciences, Ritsumeikan University, Kusatsu, Japan.,Ritsumeikan Global Innovation Research Organization, Ritsumeikan University, Kusatsu, Japan
| | - Teruhisa Kawamura
- Department of Biomedical Sciences, College of Life Sciences, Ritsumeikan University, Kusatsu, Japan.,Ritsumeikan Global Innovation Research Organization, Ritsumeikan University, Kusatsu, Japan
| | - Junichi Takagi
- Laboratory of Protein Synthesis and Expression, Institute for Protein Research, Osaka University, Osaka, Japan
| | - Yoshihiro Ogawa
- Department of Molecular and Cellular Metabolism, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.,Department of Medical and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.,Japan Agency for Medical Research and Development (AMED), Core Research for Evolutional Science and Technology (CREST), Tokyo, Japan
| | - Kyoko Shirakabe
- Department of Biomedical Sciences, College of Life Sciences, Ritsumeikan University, Kusatsu, Japan .,Ritsumeikan Global Innovation Research Organization, Ritsumeikan University, Kusatsu, Japan.,Department of Molecular and Cellular Metabolism, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| |
Collapse
|
7
|
Vlieg HC, Huizinga EG, Janssen BJC. Structure and flexibility of the extracellular region of the PirB receptor. J Biol Chem 2019; 294:4634-4643. [PMID: 30674550 DOI: 10.1074/jbc.ra118.004396] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 01/14/2019] [Indexed: 11/06/2022] Open
Abstract
Murine paired immunoglobulin receptor B (PirB) and its human ortholog leukocyte immunoglobulin-like receptor B2 (LILRB2) are widely expressed inhibitory receptors that interact with a diverse set of extracellular ligands and exert functions ranging from down-regulation of immune responses to inhibition of neuronal growth. However, structural information that could shed light on how PirB interacts with its ligands is lacking. Here, we report crystal structures of the PirB ectodomain; the first full ectodomain structure for a LILR family member, at 3.3-4.5 Å resolution. The structures reveal that PirB's six Ig-like domains are arranged at acute angles, similar to the structures of leukocyte immunoglobulin-like receptor (LILR) and killer-cell immunoglobulin-like receptor (KIR). We observe that this regular arrangement is followed throughout the ectodomain, resulting in an extended zigzag conformation. In two out of the five structures reported here, the repeating zigzag is broken by the first domain that can adopt two alternative orientations. Quantitative binding experiments revealed a 9 μm dissociation constant for PirB-myelin-associated glycoprotein (MAG) ectodomain interactions. Taken together, these structural findings and the observed PirB-MAG interactions are compatible with a model for intercellular signaling in which the PirB extracellular domains, which point away from the cell surface, enable interaction with ligands in trans.
Collapse
Affiliation(s)
- Hedwich C Vlieg
- From Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Eric G Huizinga
- From Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Bert J C Janssen
- From Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands
| |
Collapse
|
8
|
Ströh LJ, Nagarathinam K, Krey T. Conformational Flexibility in the CD81-Binding Site of the Hepatitis C Virus Glycoprotein E2. Front Immunol 2018; 9:1396. [PMID: 29967619 PMCID: PMC6015841 DOI: 10.3389/fimmu.2018.01396] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 06/05/2018] [Indexed: 01/15/2023] Open
Abstract
Numerous antibodies have been described that potently neutralize a broad range of hepatitis C virus (HCV) isolates and the majority of these antibodies target the binding site for the cellular receptor CD81 within the major HCV glycoprotein E2. A detailed understanding of the major antigenic determinants is crucial for the design of an efficient vaccine that elicits high levels of such antibodies. In the past 6 years, structural studies have shed additional light on the way the host’s humoral immune system recognizes neutralization epitopes within the HCV glycoproteins. One of the most striking findings from these studies is that the same segments of the E2 polypeptide chain induce antibodies targeting distinct antigen conformations. This was demonstrated by several crystal structures of identical polypeptide segments bound to different antibodies, highlighting an unanticipated intrinsic structural flexibility that allows binding of antibodies with distinct paratope shapes following an “induced-fit” mechanism. This unprecedented flexibility extends to the entire binding site for the cellular receptor CD81, underlining the importance of dynamic analyses to understand (1) the interplay between HCV and the humoral immune system and (2) the relevance of this structural flexibility for virus entry. This review summarizes the current understanding how neutralizing antibodies target structurally flexible epitopes. We focus on differences and common features of the reported structures and discuss the implications of the observed structural flexibility for the viral replication cycle, the full scope of the interplay between the virus and the host immune system and—most importantly—informed vaccine design.
Collapse
Affiliation(s)
- Luisa J Ströh
- Institute of Virology, Hannover Medical School, Hannover, Germany
| | | | - Thomas Krey
- Institute of Virology, Hannover Medical School, Hannover, Germany
| |
Collapse
|
9
|
de Brevern AG. Analysing the Structural Effect of Point Mutations of Cytotoxic Necrotizing Factor 1 (CNF1) on Lu/BCAM Adhesion Glycoprotein Association. Toxins (Basel) 2018; 10:E122. [PMID: 29533999 DOI: 10.3390/toxins10030122] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Cytotoxic Necrotizing Factor 1 (CNF1) was identified in 1983 as a protein toxin produced by certain pathogenic strains of Escherichia coli. Since then, numerous studies have investigated its particularities. For instance, it is associated with the single chain AB-toxin family, and can be divided into different functional and structural domains, e.g., catalytic and transmembrane domain and interaction sites. A few years ago, the identification of the Lutheran (Lu) adhesion glycoprotein/basal cell adhesion molecule (BCAM) as a cellular receptor for CNF1 provided new insights into the adhesion process of CNF1. Very recently, the Ig-like domain 2 of Lu/BCAM was confirmed as the main interaction site using protein-protein interaction and competition studies with various different mutants. Here, I present in silico approaches that precisely explain the impact of these mutations, leading to a better explanation of these experimental studies. These results can be used in the development of future antitoxin strategies.
Collapse
|
10
|
Furlong EJ, Choudhury HG, Kurth F, Duff AP, Whitten AE, Martin JL. Disulfide isomerase activity of the dynamic, trimeric Proteus mirabilis ScsC protein is primed by the tandem immunoglobulin-fold domain of ScsB. J Biol Chem 2018; 293:5793-5805. [PMID: 29491145 DOI: 10.1074/jbc.ra118.001860] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 02/15/2018] [Indexed: 11/06/2022] Open
Abstract
Correct disulfide bond formation is essential for proper folding of many proteins, including bacterial virulence factors. The suppressor of copper sensitivity (Scs) proteins have roles in dithiol/disulfide interchange and the bacterial response to copper stress. Encoded in a four-gene cassette (ScsABCD) present in many Gram-negative bacteria, the Scs proteins are enigmatic and poorly characterized. Here, we show that the periplasmic α-domain of the membrane protein ScsB in the Gram-negative bacterium Proteus mirabilis forms a redox relay with the soluble periplasmic protein PmScsC. We also found that the periplasmic α-domain is sufficient to activate the disulfide isomerase activity of PmScsC. The crystal structure of PmScsBα at a resolution of 1.54 Å revealed that it comprises two structurally similar immunoglobulin-like folds, one of which includes a putative redox-active site with the sequence CXXXC. We confirmed the importance of these cysteine residues for PmScsBα function, and in addition, we engineered cysteine variants that produced a stable complex between PmScsC and PmScsBα. Using small-angle X-ray and neutron scattering analyses with contrast variation, we determined a low-resolution structure of the PmScsC-PmScsBα complex. The structural model of this complex suggested that PmScsBα uses both of its immunoglobulin-like folds to interact with PmScsC and revealed that the highly dynamic PmScsC becomes ordered upon PmScsBα binding. These findings add to our understanding of the poorly characterized Scs proteins.
Collapse
Affiliation(s)
- Emily J Furlong
- From the Institute for Molecular Bioscience, University of Queensland, St, Lucia, Queensland 4072, Australia.,Griffith Institute for Drug Discovery, Griffith University, Nathan, Queensland 4111 Australia, and
| | - Hassanul G Choudhury
- From the Institute for Molecular Bioscience, University of Queensland, St, Lucia, Queensland 4072, Australia
| | - Fabian Kurth
- From the Institute for Molecular Bioscience, University of Queensland, St, Lucia, Queensland 4072, Australia
| | - Anthony P Duff
- Australian Nuclear Science and Technology Organisation, Lucas Heights, New South Wales 2234, Australia
| | - Andrew E Whitten
- Australian Nuclear Science and Technology Organisation, Lucas Heights, New South Wales 2234, Australia
| | - Jennifer L Martin
- From the Institute for Molecular Bioscience, University of Queensland, St, Lucia, Queensland 4072, Australia, .,Griffith Institute for Drug Discovery, Griffith University, Nathan, Queensland 4111 Australia, and
| |
Collapse
|
11
|
Reppin F, Cochet S, El Nemer W, Fritz G, Schmidt G. High Affinity Binding of Escherichia coli Cytotoxic Necrotizing Factor 1 (CNF1) to Lu/BCAM Adhesion Glycoprotein. Toxins (Basel) 2017; 10:toxins10010003. [PMID: 29267242 PMCID: PMC5793090 DOI: 10.3390/toxins10010003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Revised: 12/19/2017] [Accepted: 12/19/2017] [Indexed: 01/07/2023] Open
Abstract
The protein toxin Cytotoxic Necrotizing Factor 1 (CNF1) is a major virulence factor of pathogenic Escherichia coli strains. It belongs to a family of single chain AB-toxins, which enter mammalian cells by receptor-mediated endocytosis. Recently, we identified the Lutheran (Lu) adhesion glycoprotein/basal cell adhesion molecule (BCAM) as a cellular receptor for CNF1. Here, we identified the Ig-like domain 2 of Lu/BCAM as main interaction site of the toxin by direct protein-protein interaction and competition studies. Using surface plasmon resonance, we showed a high affinity CNF-Lu/BCAM interaction with a KD of 2.8 nM. Furthermore, we performed small-angle X-ray scattering to define the molecular envelope of the Lu/BCAM-CNF1 complex, suggesting a 6:1 ratio of Lu/BCAM to CNF1 in the receptor-toxin complex. This study leads to a deeper understanding of the interaction between CNF1 and Lu/BCAM, and presents novel opportunities for the development of future anti-toxin strategies.
Collapse
Affiliation(s)
- Franziska Reppin
- Institute for Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, Albert-Ludwigs-University of Freiburg, Albert-Street 25, 79104 Freiburg, Germany.
- Biological Faculty, Albert-Ludwigs-University of Freiburg, Albert-Street 25, 79104 Freiburg, Germany.
| | - Sylvie Cochet
- Universite Sorbonne Paris Cite, Universite Paris Diderot, Inserm, INTS, Unite Biologie Integree du Globule Rouge, Laboratoire d'Excellence GR-Ex, 75013 Paris, France.
| | - Wassim El Nemer
- Universite Sorbonne Paris Cite, Universite Paris Diderot, Inserm, INTS, Unite Biologie Integree du Globule Rouge, Laboratoire d'Excellence GR-Ex, 75013 Paris, France.
| | - Günter Fritz
- Department of Neuropathology, Albert-Ludwigs-University of Freiburg, Breisacher Strasse 64, 79106 Freiburg, Germany.
| | - Gudula Schmidt
- Institute for Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, Albert-Ludwigs-University of Freiburg, Albert-Street 25, 79104 Freiburg, Germany.
| |
Collapse
|
12
|
Pilipczuk J, Zalewska-Piątek B, Bruździak P, Czub J, Wieczór M, Olszewski M, Wanarska M, Nowicki B, Augustin-Nowacka D, Piątek R. Role of the disulfide bond in stabilizing and folding of the fimbrial protein DraE from uropathogenic Escherichia coli. J Biol Chem 2017; 292:16136-16149. [PMID: 28739804 PMCID: PMC5625045 DOI: 10.1074/jbc.m117.785477] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 07/21/2017] [Indexed: 11/22/2022] Open
Abstract
Dr fimbriae are homopolymeric adhesive organelles of uropathogenic Escherichia coli composed of DraE subunits, responsible for the attachment to host cells. These structures are characterized by enormously high stability resulting from the structural properties of an Ig-like fold of DraE. One feature of DraE and other fimbrial subunits that makes them peculiar among Ig-like domain-containing proteins is a conserved disulfide bond that joins their A and B strands. Here, we investigated how this disulfide bond affects the stability and folding/unfolding pathway of DraE. We found that the disulfide bond stabilizes self-complemented DraE (DraE-sc) by ∼50 kJ mol−1 in an exclusively thermodynamic manner, i.e. by lowering the free energy of the native state and with almost no effect on the free energy of the transition state. This finding was confirmed by experimentally determined folding and unfolding rate constants of DraE-sc and a disulfide bond-lacking DraE-sc variant. Although the folding of both proteins exhibited similar kinetics, the unfolding rate constant changed upon deletion of the disulfide bond by 10 orders of magnitude, from ∼10−17 s−1 to 10−7 s−1. Molecular simulations revealed that unfolding of the disulfide bond-lacking variant is initiated by strands A or G and that disulfide bond-mediated joining of strand A to the core strand B cooperatively stabilizes the whole protein. We also show that the disulfide bond in DraE is recognized by the DraB chaperone, indicating a mechanism that precludes the incorporation of less stable, non-oxidized DraE forms into the fimbriae.
Collapse
Affiliation(s)
- Justyna Pilipczuk
- From the Departments of Molecular Biotechnology and Microbiology and
| | | | - Piotr Bruździak
- Physical Chemistry, Gdańsk University of Technology, 80-233 Gdańsk, Poland
| | - Jacek Czub
- Physical Chemistry, Gdańsk University of Technology, 80-233 Gdańsk, Poland
| | - Miłosz Wieczór
- Physical Chemistry, Gdańsk University of Technology, 80-233 Gdańsk, Poland
| | - Marcin Olszewski
- From the Departments of Molecular Biotechnology and Microbiology and
| | - Marta Wanarska
- From the Departments of Molecular Biotechnology and Microbiology and
| | - Bogdan Nowicki
- the Nowicki Institute for Women's Health Research, Brentwood, Tennessee 37027, and
| | | | - Rafał Piątek
- From the Departments of Molecular Biotechnology and Microbiology and
| |
Collapse
|
13
|
Shimizu H, Tosaki A, Ohsawa N, Ishizuka-Katsura Y, Shoji S, Miyazaki H, Oyama F, Terada T, Shirouzu M, Sekine SI, Nukina N, Yokoyama S. Parallel homodimer structures of the extracellular domains of the voltage-gated sodium channel β4 subunit explain its role in cell-cell adhesion. J Biol Chem 2017; 292:13428-13440. [PMID: 28655765 PMCID: PMC5555201 DOI: 10.1074/jbc.m117.786509] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 06/26/2017] [Indexed: 11/06/2022] Open
Abstract
Voltage-gated sodium channels (VGSCs) are transmembrane proteins required for the generation of action potentials in excitable cells and essential for propagating electrical impulses along nerve cells. VGSCs are complexes of a pore-forming α subunit and auxiliary β subunits, designated as β1/β1B-β4 (encoded by SCN1B-4B, respectively), which also function in cell-cell adhesion. We previously reported the structural basis for the trans homophilic interaction of the β4 subunit, which contributes to its adhesive function. Here, using crystallographic and biochemical analyses, we show that the β4 extracellular domains directly interact with each other in a parallel manner that involves an intermolecular disulfide bond between the unpaired Cys residues (Cys58) in the loop connecting strands B and C and intermolecular hydrophobic and hydrogen-bonding interactions of the N-terminal segments (Ser30-Val35). Under reducing conditions, an N-terminally deleted β4 mutant exhibited decreased cell adhesion compared with the wild type, indicating that the β4 cis dimer contributes to the trans homophilic interaction of β4 in cell-cell adhesion. Furthermore, this mutant exhibited increased association with the α subunit, indicating that the cis dimerization of β4 affects α-β4 complex formation. These observations provide the structural basis for the parallel dimer formation of β4 in VGSCs and reveal its mechanism in cell-cell adhesion.
Collapse
Affiliation(s)
- Hideaki Shimizu
- From the RIKEN Systems and Structural Biology Center, Tsurumi, Yokohama 230-0045, Japan.,the RIKEN Center for Life Science Technologies, Tsurumi, Yokohama 230-0045, Japan.,the Laboratory for Structural Neuropathology, RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan
| | - Asako Tosaki
- the Laboratory for Structural Neuropathology, RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan
| | - Noboru Ohsawa
- From the RIKEN Systems and Structural Biology Center, Tsurumi, Yokohama 230-0045, Japan.,the RIKEN Center for Life Science Technologies, Tsurumi, Yokohama 230-0045, Japan
| | - Yoshiko Ishizuka-Katsura
- From the RIKEN Systems and Structural Biology Center, Tsurumi, Yokohama 230-0045, Japan.,the RIKEN Center for Life Science Technologies, Tsurumi, Yokohama 230-0045, Japan
| | - Shisako Shoji
- From the RIKEN Systems and Structural Biology Center, Tsurumi, Yokohama 230-0045, Japan.,the RIKEN Center for Life Science Technologies, Tsurumi, Yokohama 230-0045, Japan
| | - Haruko Miyazaki
- the Laboratory for Structural Neuropathology, RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan.,the Department of Neuroscience for Neurodegenerative Disorders, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan.,the Laboratory of Structural Neuropathology, Doshisha University Graduate School of Brain Science, 1-3 Tatara Miyakodani, Kyotanabe-shi, Kyoto 610-0394, Japan
| | - Fumitaka Oyama
- the Laboratory for Structural Neuropathology, RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan.,the Department of Chemistry and Life Science, Kogakuin University, Hachioji, Tokyo 192-0015, Japan, and
| | - Takaho Terada
- From the RIKEN Systems and Structural Biology Center, Tsurumi, Yokohama 230-0045, Japan.,the RIKEN Structural Biology Laboratory, Tsurumi, Yokohama 230-0045, Japan
| | - Mikako Shirouzu
- From the RIKEN Systems and Structural Biology Center, Tsurumi, Yokohama 230-0045, Japan.,the RIKEN Center for Life Science Technologies, Tsurumi, Yokohama 230-0045, Japan
| | - Shun-Ichi Sekine
- From the RIKEN Systems and Structural Biology Center, Tsurumi, Yokohama 230-0045, Japan.,the RIKEN Center for Life Science Technologies, Tsurumi, Yokohama 230-0045, Japan
| | - Nobuyuki Nukina
- the Laboratory for Structural Neuropathology, RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan.,the Department of Neuroscience for Neurodegenerative Disorders, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan.,the Laboratory of Structural Neuropathology, Doshisha University Graduate School of Brain Science, 1-3 Tatara Miyakodani, Kyotanabe-shi, Kyoto 610-0394, Japan
| | - Shigeyuki Yokoyama
- From the RIKEN Systems and Structural Biology Center, Tsurumi, Yokohama 230-0045, Japan, .,the RIKEN Structural Biology Laboratory, Tsurumi, Yokohama 230-0045, Japan
| |
Collapse
|
14
|
Leo JC, Oberhettinger P, Yoshimoto S, Udatha DBRKG, Morth JP, Schütz M, Hori K, Linke D. Secretion of the Intimin Passenger Domain Is Driven by Protein Folding. J Biol Chem 2016; 291:20096-112. [PMID: 27466361 DOI: 10.1074/jbc.m116.731497] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Indexed: 11/06/2022] Open
Abstract
Intimin is an essential adhesin of attaching and effacing organisms such as entropathogenic Escherichia coli It is also the prototype of type Ve secretion or inverse autotransport, where the extracellular C-terminal region or passenger is exported with the help of an N-terminal transmembrane β-barrel domain. We recently reported a stalled secretion intermediate of intimin, where the passenger is located in the periplasm but the β-barrel is already inserted into the membrane. Stalling of this mutant is due to the insertion of an epitope tag at the very N terminus of the passenger. Here, we examined how this insertion disrupts autotransport and found that it causes misfolding of the N-terminal immunoglobulin (Ig)-like domain D00. We could also stall the secretion by making an internal deletion in D00, and introducing the epitope tag into the second Ig-like domain, D0, also resulted in reduced passenger secretion. In contrast to many classical autotransporters, where a proximal folding core in the passenger is required for secretion, the D00 domain is dispensable, as the passenger of an intimin mutant lacking D00 entirely is efficiently exported. Furthermore, the D00 domain is slightly less stable than the D0 and D1 domains, unfolding at ∼200 piconewtons (pN) compared with ∼250 pN for D0 and D1 domains as measured by atomic force microscopy. Our results support a model where the secretion of the passenger is driven by sequential folding of the extracellular Ig-like domains, leading to vectorial transport of the passenger domain across the outer membrane in an N to C direction.
Collapse
Affiliation(s)
- Jack C Leo
- From the Evolution and Genetics, Department of Biosciences, University of Oslo, 0316 Oslo, Norway
| | - Philipp Oberhettinger
- Interfaculty Institute for Microbiology and Infection Medicine, University Clinics Tübingen, 72076 Tübingen, Germany
| | - Shogo Yoshimoto
- Department of Biotechnology, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan, and
| | - D B R K Gupta Udatha
- From the Evolution and Genetics, Department of Biosciences, University of Oslo, 0316 Oslo, Norway
| | | | - Monika Schütz
- Interfaculty Institute for Microbiology and Infection Medicine, University Clinics Tübingen, 72076 Tübingen, Germany
| | - Katsutoshi Hori
- Department of Biotechnology, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan, and
| | - Dirk Linke
- From the Evolution and Genetics, Department of Biosciences, University of Oslo, 0316 Oslo, Norway,
| |
Collapse
|
15
|
Nishimura H, L'Hernault SW. Gamete interactions require transmembranous immunoglobulin-like proteins with conserved roles during evolution. Worm 2016; 5:e1197485. [PMID: 27695654 DOI: 10.1080/21624054.2016.1197485] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 05/20/2016] [Accepted: 05/27/2016] [Indexed: 10/21/2022]
Abstract
C. elegans spe-9 class genes are male germline-enriched in their expression and indispensable during sperm-oocyte fusion. Identification of mammalian orthologs that exhibit similar functions to these C. elegans genes has been a challenge. The mouse Izumo1 gene encodes a sperm-specific, immunoglobulin (Ig)-like transmembrane (TM) protein that is required for gamete fusion. We recently identified the C. elegans spe-45 gene, which shows male germline-enriched expression and encodes an Ig-like TM protein. spe-45 mutant worms produced otherwise normal spermatozoa that cannot fuse with oocytes, causing essentially the same phenotype as that seen in the Izumo1-knockout mice. By counting the number of self-sperm in the spermatheca of spe-45 hermaphrodites, it was found that this gene might be involved in sperm guidance from the uterus into the spermatheca, as well as gamete fusion. Moreover, we discovered that SPE-45 and IZUMO1 share certain functions for gamete fusion, which are presumably related to binding with cis- and/or trans-partners. Intriguingly, various organisms have Ig-like TM proteins that act during gamete interactions, indicating the wide-spread utility of Ig-like domains during fertilization.
Collapse
Affiliation(s)
- Hitoshi Nishimura
- Department of Life Science, Setsunan University , Neyagawa, Osaka, Japan
| | | |
Collapse
|
16
|
Yoon BR, Chung YH, Yoo SJ, Kawara K, Kim J, Yoo IS, Park CG, Kang SW, Lee WW. Preferential Induction of the T Cell Auxiliary Signaling Molecule B7-H3 on Synovial Monocytes in Rheumatoid Arthritis. J Biol Chem 2016; 291:4048-57. [PMID: 26702052 PMCID: PMC4759181 DOI: 10.1074/jbc.m115.680298] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 11/24/2015] [Indexed: 12/29/2022] Open
Abstract
B7-H3, a newly identified B7 family member, has functional duality as a co-stimulator and co-inhibitor that fine-tunes T cell-mediated immune responses. Given that B7-H3 expression on human monocytes and dendritic cells is enhanced by inflammatory cytokines, its potential inmmunoregulatory role at sites of inflammation has been suggested. Further, monocytes play crucial roles in the pathophysiology of various inflammatory disorders including autoimmune diseases; however, the immunological role of B7-H3 in rheumatoid arthritis (RA) has not been defined. Thus, we aimed to investigate the possible roles of monocyte B7-H3 in the pathogenesis of RA. Synovial monocytes, but not peripheral monocytes, in RA patients predominantly express surface B7-H3. The 4Ig isoform of B7-H3 is exclusively induced on the cell surface, whereas the 2Ig B7-H3 isoform is constitutively expressed in the intracytoplasmic region of both peripheral and synovial monocytes. B7-H3 knockdown experiments reveal that surface B7-H3 has an inhibitory effect on IFN-γ production in CD4 memory cells. Moreover, surface B7-H3 expression on synovial monocytes inversely correlates with RA clinical parameters. Our findings demonstrate that activation-induced B7-H3 expression on synovial monocytes has the potential to inhibit Th1-mediated immune responses and immunomodulatory roles affecting RA pathogenesis.
Collapse
Affiliation(s)
- Bo Ruem Yoon
- From the Departments of Microbiology and Immunology and
| | - Yeon-Ho Chung
- From the Departments of Microbiology and Immunology and the BK21Plus Biomedical Science Project, and the Seoul National University College of Medicine, Seoul 110-799, South Korea
| | - Su-Jin Yoo
- the Department of Internal Medicine, Chungnam National University School of Medicine, Daejeon 301-721, South Korea
| | - Kenji Kawara
- From the Departments of Microbiology and Immunology and the Tokyo Medical and Dental University School of Medicine, Tokyo 113-8510, Japan, and
| | - Jinhyun Kim
- the Department of Internal Medicine, Chungnam National University School of Medicine, Daejeon 301-721, South Korea
| | - In Seol Yoo
- the Department of Internal Medicine, Chungnam National University School of Medicine, Daejeon 301-721, South Korea
| | - Chung-Gyu Park
- From the Departments of Microbiology and Immunology and Biomedical Sciences and
| | - Seong Wook Kang
- the Department of Internal Medicine, Chungnam National University School of Medicine, Daejeon 301-721, South Korea,
| | - Won-Woo Lee
- From the Departments of Microbiology and Immunology and the BK21Plus Biomedical Science Project, and the Seoul National University College of Medicine, Seoul 110-799, South Korea, Biomedical Sciences and the Cancer Research Institute, Ischemic/Hypoxic Disease Institute, and Institute of Infectious Diseases, Seoul National University College of Medicine, Seoul National University Hospital Biomedical Research Institute, Seoul 110-799, South Korea
| |
Collapse
|
17
|
Bensing BA, Loukachevitch LV, McCulloch KM, Yu H, Vann KR, Wawrzak Z, Anderson S, Chen X, Sullam PM, Iverson TM. Structural Basis for Sialoglycan Binding by the Streptococcus sanguinis SrpA Adhesin. J Biol Chem 2016; 291:7230-40. [PMID: 26833566 DOI: 10.1074/jbc.m115.701425] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Indexed: 11/06/2022] Open
Abstract
Streptococcus sanguinisis a leading cause of infective endocarditis, a life-threatening infection of the cardiovascular system. An important interaction in the pathogenesis of infective endocarditis is attachment of the organisms to host platelets.S. sanguinisexpresses a serine-rich repeat adhesin, SrpA, similar in sequence to platelet-binding adhesins associated with increased virulence in this disease. In this study, we determined the first crystal structure of the putative binding region of SrpA (SrpABR) both unliganded and in complex with a synthetic disaccharide ligand at 1.8 and 2.0 Å resolution, respectively. We identified a conserved Thr-Arg motif that orients the sialic acid moiety and is required for binding to platelet monolayers. Furthermore, we propose that sequence insertions in closely related family members contribute to the modulation of structural and functional properties, including the quaternary structure, the tertiary structure, and the ligand-binding site.
Collapse
Affiliation(s)
- Barbara A Bensing
- From the Division of Infectious Diseases, Veterans Affairs Medical Center, Department of Medicine, University of California, San Francisco and the Northern California Institute for Research and Education, San Francisco, California 94121
| | | | | | - Hai Yu
- the Department of Chemistry, University of California, Davis, California 95616, and
| | | | - Zdzislaw Wawrzak
- Life Sciences Collaborative Access Team, Synchrotron Research Center, Northwestern University, Argonne, Illinois 60439
| | - Spencer Anderson
- Life Sciences Collaborative Access Team, Synchrotron Research Center, Northwestern University, Argonne, Illinois 60439
| | - Xi Chen
- the Department of Chemistry, University of California, Davis, California 95616, and
| | - Paul M Sullam
- From the Division of Infectious Diseases, Veterans Affairs Medical Center, Department of Medicine, University of California, San Francisco and the Northern California Institute for Research and Education, San Francisco, California 94121
| | - T M Iverson
- the Departments of Pharmacology and Biochemistry, Center for Structural Biology, and Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37232,
| |
Collapse
|
18
|
Davidov G, Müller FD, Baumgartner J, Bitton R, Faivre D, Schüler D, Zarivach R. Crystal structure of the magnetobacterial protein MtxA C-terminal domain reveals a new sequence-structure relationship. Front Mol Biosci 2015; 2:25. [PMID: 26052516 PMCID: PMC4439547 DOI: 10.3389/fmolb.2015.00025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 05/04/2015] [Indexed: 01/07/2023] Open
Abstract
Magnetotactic bacteria (MTB) are a diverse group of aquatic bacteria that have the magnetotaxis ability to align themselves along the geomagnetic field lines and to navigate to a microoxic zone at the bottom of chemically stratified natural water. This special navigation is the result of a unique linear assembly of a specialized organelle, the magnetosome, which contains a biomineralized magnetic nanocrystal enveloped by a cytoplasmic membrane. The Magnetospirillum gryphiswaldense MtxA protein (MGR_0208) was suggested to play a role in bacterial magnetotaxis due to its gene location in an operon together with putative signal transduction genes. Since no homology is found for MtxA, and to better understand the role and function of MtxA in MTBés magnetotaxis, we initiated structural and functional studies of MtxA via X-ray crystallography and deletion mutagenesis. Here, we present the crystal structure of the MtxA C-terminal domain and provide new insights into its sequence-structure relationship.
Collapse
Affiliation(s)
- Geula Davidov
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the NegevBeer Sheva, Israel
| | - Frank D. Müller
- Department of Microbiology, University of BayreuthBayreuth, Germany
| | - Jens Baumgartner
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces (MPI)Potsdam, Germany
| | - Ronit Bitton
- Department of Chemical Engineering, Ilse Katz Institute for Nanoscale Science and Technology, Ben Gurion University of the NegevBeer-Sheva, Israel
| | - Damien Faivre
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces (MPI)Potsdam, Germany
| | - Dirk Schüler
- Department of Microbiology, University of BayreuthBayreuth, Germany
| | - Raz Zarivach
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the NegevBeer Sheva, Israel,*Correspondence: Raz Zarivach, Department of Life Sciences, Ben Gurion University of the Negev, PO Box. 653, Beer-Sheva 84105, Israel
| |
Collapse
|
19
|
Hemmasi S, Czulkies BA, Schorch B, Veit A, Aktories K, Papatheodorou P. Interaction of the Clostridium difficile Binary Toxin CDT and Its Host Cell Receptor, Lipolysis-stimulated Lipoprotein Receptor (LSR). J Biol Chem 2015; 290:14031-44. [PMID: 25882847 DOI: 10.1074/jbc.m115.650523] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2015] [Indexed: 12/17/2022] Open
Abstract
CDT (Clostridium difficile transferase) is a binary, actin ADP-ribosylating toxin frequently associated with hypervirulent strains of the human enteric pathogen C. difficile, the most serious cause of antibiotic-associated diarrhea and pseudomembranous colitis. CDT leads to the collapse of the actin cytoskeleton and, eventually, to cell death. Low doses of CDT result in the formation of microtubule-based protrusions on the cell surface that increase the adherence and colonization of C. difficile. The lipolysis-stimulated lipoprotein receptor (LSR) is the host cell receptor for CDT, and our aim was to gain a deeper insight into the interplay between both proteins. We show that CDT interacts with the extracellular, Ig-like domain of LSR with an affinity in the nanomolar range. We identified LSR splice variants in the colon carcinoma cell line HCT116 and disrupted the LSR gene in these cells by applying the CRISPR-Cas9 technology. LSR truncations ectopically expressed in LSR knock-out cells indicated that intracellular parts of LSR are not essential for plasma membrane targeting of the receptor and cellular uptake of CDT. By generating a series of N- and C-terminal truncations of the binding component of CDT (CDTb), we found that amino acids 757-866 of CDTb are sufficient for binding to LSR. With a transposon-based, random mutagenesis approach, we identified potential LSR-interacting epitopes in CDTb. This study increases our understanding about the interaction between CDT and its receptor LSR, which is key to the development of anti-toxin strategies for preventing cell entry of the toxin.
Collapse
Affiliation(s)
- Sarah Hemmasi
- From the Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, the Fakultät für Biologie
| | - Bernd A Czulkies
- From the Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, the Hermann Staudinger Graduate School
| | - Björn Schorch
- From the Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, the Fakultät für Biologie, the Spemann Graduate School of Biology and Medicine, and
| | - Antonia Veit
- From the Institut für Experimentelle und Klinische Pharmakologie und Toxikologie
| | - Klaus Aktories
- From the Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, the Centre for Biological Signalling Studies (BIOSS), Albert-Ludwigs-Universität Freiburg, D-79104 Freiburg, Germany
| | | |
Collapse
|
20
|
Nagata A, Ohnishi H, Yoshimura M, Ogawa A, Ujita S, Adachi H, Okada M, Matozaki T, Nakagawa A. Crystallization and preliminary X-ray analysis of rat SHPS-1. Acta Crystallogr Sect F Struct Biol Cryst Commun 2006; 62:189-91. [PMID: 16511298 PMCID: PMC2197194 DOI: 10.1107/s1744309106001941] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2005] [Accepted: 01/17/2006] [Indexed: 11/10/2022]
Abstract
SHPS-1, a receptor-type transmembrane protein, is abundantly expressed in neural and myeloid tissues. The most amino-terminal immunoglobulin-like domain of SHPS-1 plays an important role in a variety of cell functions by binding its ligand CD47. Interaction between SHPS-1 and CD47 is thought to be involved in negative regulation of phagocytosis. The ligand-binding domain of rat SHPS-1 was purified and crystallized using the vapour-diffusion method with the solution-stirring technique. Preliminary X-ray diffraction data were collected from SHPS-1 crystals to 2.8 A resolution and reduced to primitive hexagonal space group P622. Unit-cell parameters are a = b = 100.5, c = 101.3 A.
Collapse
Affiliation(s)
- Aki Nagata
- Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan
| | - Hiroshi Ohnishi
- Laboratory of Biosignal Sciences, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Gunma 371-8512, Japan
| | - Masato Yoshimura
- Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan
| | - Akira Ogawa
- Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan
| | - Sayuri Ujita
- Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan
| | - Hiroaki Adachi
- Department of Electrical Engineering, Osaka University, Suita, Osaka 565-0871, Japan
- SOSHO Inc., 7-7-15-208 Saito-Asagi, Ibaraki, Osaka 567-0085, Japan
| | - Masato Okada
- Department of Electrical Engineering, Osaka University, Suita, Osaka 565-0871, Japan
| | - Takashi Matozaki
- Laboratory of Biosignal Sciences, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Gunma 371-8512, Japan
| | - Atsushi Nakagawa
- Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan
| |
Collapse
|
21
|
Sasaki T, Knyazev PG, Clout NJ, Cheburkin Y, Göhring W, Ullrich A, Timpl R, Hohenester E. Structural basis for Gas6-Axl signalling. EMBO J 2006; 25:80-7. [PMID: 16362042 PMCID: PMC1356355 DOI: 10.1038/sj.emboj.7600912] [Citation(s) in RCA: 198] [Impact Index Per Article: 11.0] [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: 09/02/2005] [Accepted: 11/21/2005] [Indexed: 12/14/2022] Open
Abstract
Receptor tyrosine kinases of the Axl family are activated by the vitamin K-dependent protein Gas6. Axl signalling plays important roles in cancer, spermatogenesis, immunity, and platelet function. The crystal structure at 3.3 A resolution of a minimal human Gas6/Axl complex reveals an assembly of 2:2 stoichiometry, in which the two immunoglobulin-like domains of the Axl ectodomain are crosslinked by the first laminin G-like domain of Gas6, with no direct Axl/Axl or Gas6/Gas6 contacts. There are two distinct Gas6/Axl contacts of very different size, both featuring interactions between edge beta-strands. Structure-based mutagenesis, protein binding assays and receptor activation experiments demonstrate that both the major and minor Gas6 binding sites are required for productive transmembrane signalling. Gas6-mediated Axl dimerisation is likely to occur in two steps, with a high-affinity 1:1 Gas6/Axl complex forming first. Only the minor Gas6 binding site is highly conserved in the other Axl family receptors, Sky/Tyro3 and Mer. Specificity at the major contact is suggested to result from the segregation of charged and apolar residues to opposite faces of the newly formed beta-sheet.
Collapse
Affiliation(s)
- Takako Sasaki
- Max-Planck-Institut für Biochemie, Martinsried, Germany
| | | | - Naomi J Clout
- Division of Cell and Molecular Biology, Imperial College London, London, UK
| | | | | | - Axel Ullrich
- Max-Planck-Institut für Biochemie, Martinsried, Germany
| | - Rupert Timpl
- Max-Planck-Institut für Biochemie, Martinsried, Germany
| | - Erhard Hohenester
- Division of Cell and Molecular Biology, Imperial College London, London, UK
- Biophysics Section, Blackett Laboratory, Imperial College London, London SW7 2AZ, UK. Tel.:+44 20 7594 7701; Fax +44 20 7589 0191; E-mail:
| |
Collapse
|