Faculty Opinions recommendation of LRP5 and LRP6 are not required for protective antigen-mediated internalization or lethality of anthrax lethal toxin.

ABSTRACT Anthrax lethal factor (LF), secreted by Bacillus anthracis, interacts with protective antigen to form a bipartite toxin (lethal toxin [LT]) that exerts pleiotropic biological effects resulting in subversion of the innate immune response. Although the mitogen-activated protein kinase kinases (MKKs) are the major intracellular protein targets of LF, the pathology induced by LT is not well understood. The statin family of HMG-coenzyme A reductase inhibitors have potent anti-inflammatory effects independent of their cholesterol-lowering properties, which have been attributed to modulation of Rho family GTPase activity. The Rho GTPases regulate vesicular trafficking, cytoskeletal dynamics, and cell survival and proliferation. We hypothesized that disruption of Rho GTPase function by statins might alter LT action. We show here that statins delay LT-induced death and MKK cleavage in RAW macrophages and that statin-mediated effects on LT action are attributable to disruption of Rho GTPases. The Rho GTPase-inactivating toxin, toxin B, did not significantly affect LT binding or internalization, suggesting that the Rho GTPases regulate trafficking and/or localization of LT once internalized. The use of drugs capable of inhibiting Rho GTPase activity, such as statins, may provide a means to attenuate intoxication during B. anthracis infection.

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Faculty Opinions recommendation of Blocking anthrax lethal toxin at the protective antigen channel by using structure-inspired drug design.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1028790.342344 ◽

2005 ◽

Author(s):

Drusilla L Burns

Keyword(s):

Drug Design ◽

Protective Antigen ◽

Lethal Toxin ◽

Anthrax Lethal Toxin

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Trp 346 and Leu 352 Residues in Protective Antigen Are Required for the Expression of Anthrax Lethal Toxin Activity

Biochemical and Biophysical Research Communications ◽

10.1006/bbrc.2001.4320 ◽

2001 ◽

Vol 281 (1) ◽

pp. 186-192 ◽

Cited By ~ 10

Author(s):

Smriti Batra ◽

Pankaj Gupta ◽

Vibha Chauhan ◽

Aparna Singh ◽

Rakesh Bhatnagar

Keyword(s):

Protective Antigen ◽

Lethal Toxin ◽

Anthrax Lethal Toxin

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Participation of Residue F552 in Domain III of the Protective Antigen in the Biological Activity of Anthrax Lethal Toxin

Biological Chemistry ◽

10.1515/bc.2001.117 ◽

2001 ◽

Vol 382 (6) ◽

Cited By ~ 1

Author(s):

Hemant Khanna ◽

Pradeep K. Gupta ◽

Anubha Singh ◽

Ramesh Chandra ◽

Yogendra Singh

Keyword(s):

Biological Activity ◽

Protective Antigen ◽

Lethal Toxin ◽

Anthrax Lethal Toxin ◽

Domain Iii

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Search for Cyclodextrin-Based Inhibitors of Anthrax Toxins: Synthesis, Structural Features, and Relative Activities

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00693-06 ◽

2006 ◽

Vol 50 (11) ◽

pp. 3740-3753 ◽

Cited By ~ 48

Author(s):

Vladimir A. Karginov ◽

Ekaterina M. Nestorovich ◽

Adiamseged Yohannes ◽

Tanisha M. Robinson ◽

Nour Eddine Fahmi ◽

...

Keyword(s):

Lipid Membranes ◽

Protective Antigen ◽

Structural Features ◽

Lethal Toxin ◽

Anthrax Lethal Toxin ◽

Cell Protection ◽

Ion Conductance ◽

New Class ◽

Anthrax Toxins ◽

Derivatives Of

ABSTRACT Recently, using structure-inspired drug design, we demonstrated that aminoalkyl derivatives of β-cyclodextrin inhibited anthrax lethal toxin action by blocking the transmembrane pore formed by the protective antigen (PA) subunit of the toxin. In the present study, we evaluate a series of new β-cyclodextrin derivatives with the goal of identifying potent inhibitors of anthrax toxins. Newly synthesized hepta-6-thioaminoalkyl and hepta-6-thioguanidinoalkyl derivatives of β-cyclodextrin with alkyl spacers of various lengths were tested for the ability to inhibit cytotoxicity of lethal toxin in cells as well as to block ion conductance through PA channels reconstituted in planar bilayer lipid membranes. Most of the tested derivatives were protective against anthrax lethal toxin action at low or submicromolar concentrations. They also blocked ion conductance through PA channels at concentrations as low as 0.1 nM. The activities of the derivatives in both cell protection and channel blocking were found to depend on the length and chemical nature of the substituent groups. One of the compounds was also shown to block the edema toxin activity. It is hoped that these results will help to identify a new class of drugs for anthrax treatment, i.e., drugs that block the pathway for toxin translocation into the cytosol, the PA channel.

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Cryo-EM structure of the fully-loaded asymmetric anthrax lethal toxin in its heptameric pre-pore state

10.1101/2020.04.07.029140 ◽

2020 ◽

Cited By ~ 1

Author(s):

Claudia Antoni ◽

Dennis Quentin ◽

Alexander E. Lang ◽

Klaus Aktories ◽

Christos Gatsogiannis ◽

...

Keyword(s):

Protective Antigen ◽

Lethal Factor ◽

Lethal Toxin ◽

Anthrax Toxin ◽

Anthrax Lethal Toxin ◽

Terminal Domain ◽

Edema Factor ◽

Major Virulence Factor ◽

Cell Substrate ◽

Continuous Chain

AbstractAnthrax toxin is the major virulence factor secreted by Bacillus anthracis, causing high mortality in humans and other mammals. It consists of a membrane translocase, known as protective antigen (PA), that catalyzes the unfolding of its cytotoxic substrates lethal factor (LF) and edema factor (EF), followed by translocation into the host cell. Substrate recruitment to the heptameric PA pre-pore and subsequent translocation, however, are not well understood. Here, we report three high-resolution cryo-EM structures of the fully-loaded anthrax lethal toxin in its heptameric pre-pore state, which differ in the position and conformation of LFs. The structures reveal that three LFs interact with the heptameric PA and upon binding change their conformation to form a continuous chain of head-to-tail interactions. As a result of the underlying symmetry mismatch, one LF binding site in PA remains unoccupied. Whereas one LF directly interacts with a part of PA called α-clamp, the others do not interact with this region, indicating an intermediate state between toxin assembly and translocation. Interestingly, the interaction of the N-terminal domain with the α-clamp correlates with a higher flexibility in the C-terminal domain of the protein. Based on our data, we propose a model for toxin assembly, in which the order of LF binding determines which factor is translocated first.

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Identification of Amino Acid Residues of Anthrax Protective Antigen Involved in Binding with Lethal Factor

Infection and Immunity ◽

10.1128/iai.70.8.4477-4484.2002 ◽

2002 ◽

Vol 70 (8) ◽

pp. 4477-4484 ◽

Cited By ~ 18

Author(s):

Vibha Chauhan ◽

Rakesh Bhatnagar

Keyword(s):

Cell Surface ◽

Protective Antigen ◽

Lethal Factor ◽

Lethal Toxin ◽

Cell Surface Receptor ◽

Amino Acid Residues ◽

Anthrax Lethal Toxin ◽

Mutant Proteins ◽

Surface Receptors ◽

Surface Receptor

ABSTRACT Protective antigen (PA) and lethal factor (LF) are the two components of anthrax lethal toxin. PA is responsible for the translocation of LF to the cytosol. The binding of LF to cell surface receptor-bound PA is a prerequisite for the formation of lethal toxin. It has been hypothesized that hydrophobic residues P184, L187, F202, L203, P205, I207, I210, W226, and F236 of domain 1b of PA play an important role in the binding of PA to LF. These residues are normally buried in the 83-kDA version of PA, PA83, as determined by the crystal structure of PA. However, they become exposed due to the conformational change brought about by the cleavage of PA83 to PA63 by a cell surface protease. Mutation of the above-mentioned residues to alanine resulted in mutant proteins that were able to bind to the cell surface receptors and also to be specifically cleaved by the cellular proteases. All the mutant proteins except the F202A, L203A, P205A, and I207A mutants were able to bind to LF and were also toxic to macrophage cells in combination with LF. It was concluded that residues 202, 203, 205, and 207 of PA are essential for the binding of LF to PA.

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