Modulation of Toll-like receptor 1 intracellular domain structure and activity by Zn2+ ions

AbstractToll-like receptors (TLRs) play an important role in the innate immune response. While a lot is known about the structures of their extracellular parts, many questions are still left unanswered, when the structural basis of TLR activation is analyzed for the TLR intracellular domains. Here we report the structure and dynamics of TLR1 toll-interleukin like (TIR) cytoplasmic domain in crystal and in solution. We found that the TLR1-TIR domain is capable of specific binding of Zn with nanomolar affinity. Interactions with Zn are mediated by cysteine residues 667 and 686 and C667 is essential for the Zn binding. Potential structures of the TLR1-TIR/Zn complex were predicted in silico. Using the functional assays for the heterodimeric TLR1/2 receptor, we found that both Zn addition and Zn depletion affect the activity of TLR1, and C667A mutation disrupts the receptor activity. Analysis of C667 position in the TLR1 structure and possible effects of C667A mutation, suggests that zinc-binding ability of TLR1-TIR domain is critical for the receptor activation.

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Faculty Opinions recommendation of Structural basis for specific binding of Polycomb chromodomain to histone H3 methylated at Lys 27.

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

10.3410/f.1014858.194909 ◽

2003 ◽

Author(s):

Robert Dutnall

Keyword(s):

Specific Binding ◽

Histone H3 ◽

Structural Basis

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Faculty Opinions recommendation of Structural basis for the activation of innate immune pattern-recognition receptor RIG-I by viral RNA.

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

10.3410/f.13357266.14730082 ◽

2011 ◽

Author(s):

Hao Wu ◽

Qian Yin

Keyword(s):

Pattern Recognition ◽

Pattern Recognition Receptor ◽

Innate Immune ◽

Viral Rna ◽

Structural Basis ◽

Recognition Receptor

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Preclinical Evaluation of [18F]FACH in Healthy Mice and Piglets: An 18F-Labeled Ligand for Imaging of Monocarboxylate Transporters with PET

International Journal of Molecular Sciences ◽

10.3390/ijms22041645 ◽

2021 ◽

Vol 22 (4) ◽

pp. 1645

Author(s):

Daniel Gündel ◽

Masoud Sadeghzadeh ◽

Winnie Deuther-Conrad ◽

Barbara Wenzel ◽

Paul Cumming ◽

...

Keyword(s):

Molecular Imaging ◽

Ex Vivo ◽

Specific Binding ◽

Monocarboxylate Transporters ◽

Binding Potential ◽

Kidney Cortex ◽

Binding Studies ◽

Imaging Tool ◽

Pre Treatment

The expression of monocarboxylate transporters (MCTs) is linked to pathophysiological changes in diseases, including cancer, such that MCTs could potentially serve as diagnostic markers or therapeutic targets. We recently developed [18F]FACH as a radiotracer for non-invasive molecular imaging of MCTs by positron emission tomography (PET). The aim of this study was to evaluate further the specificity, metabolic stability, and pharmacokinetics of [18F]FACH in healthy mice and piglets. We measured the [18F]FACH plasma protein binding fractions in mice and piglets and the specific binding in cryosections of murine kidney and lung. The biodistribution of [18F]FACH was evaluated by tissue sampling ex vivo and by dynamic PET/MRI in vivo, with and without pre-treatment by the MCT inhibitor α-CCA-Na or the reference compound, FACH-Na. Additionally, we performed compartmental modelling of the PET signal in kidney cortex and liver. Saturation binding studies in kidney cortex cryosections indicated a KD of 118 ± 12 nM and Bmax of 6.0 pmol/mg wet weight. The specificity of [18F]FACH uptake in the kidney cortex was confirmed in vivo by reductions in AUC0–60min after pre-treatment with α-CCA-Na in mice (−47%) and in piglets (−66%). [18F]FACH was metabolically stable in mouse, but polar radio-metabolites were present in plasma and tissues of piglets. The [18F]FACH binding potential (BPND) in the kidney cortex was approximately 1.3 in mice. The MCT1 specificity of [18F]FACH uptake was confirmed by displacement studies in 4T1 cells. [18F]FACH has suitable properties for the detection of the MCTs in kidney, and thus has potential as a molecular imaging tool for MCT-related pathologies, which should next be assessed in relevant disease models.

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Crystallization of and selenomethionine phasing strategy for a SETMAR–DNA complex

Acta Crystallographica Section F Structural Biology Communications ◽

10.1107/s2053230x16012723 ◽

2016 ◽

Vol 72 (9) ◽

pp. 713-719 ◽

Cited By ~ 2

Author(s):

Qiujia Chen ◽

Millie Georgiadis

Keyword(s):

Dna Binding ◽

Catalytic Domain ◽

Specific Binding ◽

Critical Role ◽

Binding Activity ◽

Structural Basis ◽

Unexpected Finding ◽

Terminal Inverted Repeat ◽

Dna Binding Activity ◽

New Genes

Transposable elements have played a critical role in the creation of new genes in all higher eukaryotes, including humans. Although the chimeric fusion protein SETMAR is no longer active as a transposase, it contains both the DNA-binding domain (DBD) and catalytic domain of theHsmar1transposase. The amino-acid sequence of the DBD has been virtually unchanged in 50 million years and, as a consequence, SETMAR retains its sequence-specific binding to the ancestralHsmar1terminal inverted repeat (TIR) sequence. Thus, the DNA-binding activity of SETMAR is likely to have an important biological function. To determine the structural basis for the recognition of TIR DNA by SETMAR, the design of TIR-containing oligonucleotides and SETMAR DBD variants, crystallization of DBD–DNA complexes, phasing strategies and initial phasing experiments are reported here. An unexpected finding was that oligonucleotides containing two BrdUs in place of thymidines produced better quality crystals in complex with SETMAR than their natural counterparts.

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The dysfunctional innate immune response triggered by Toll-like receptor activation is restored by TLR7/TLR8 and TLR9 ligands in cutaneous lichen planus

British Journal of Dermatology ◽

10.1111/bjd.13214 ◽

2014 ◽

Vol 172 (1) ◽

pp. 48-55 ◽

Cited By ~ 15

Author(s):

R. Domingues ◽

G. Costa de Carvalho ◽

L.M. da Silva Oliveira ◽

E. Futata Taniguchi ◽

J.M. Zimbres ◽

...

Keyword(s):

Immune Response ◽

Lichen Planus ◽

Innate Immune Response ◽

Receptor Activation ◽

Innate Immune ◽

Toll Like Receptor

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Quantification of Ligand PET Studies using a Reference Region with a Displaceable Fraction: Application to Occupancy Studies with [11C]-DASB as an Example

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.2011.108 ◽

2011 ◽

Vol 32 (1) ◽

pp. 70-80 ◽

Cited By ~ 21

Author(s):

Federico E Turkheimer ◽

Sudhakar Selvaraj ◽

Rainer Hinz ◽

Venkatesha Murthy ◽

Zubin Bhagwagar ◽

...

Keyword(s):

Specific Binding ◽

Normal Subjects ◽

Volume Of Distribution ◽

Binding Potential ◽

Accurate Estimation ◽

Data Sets ◽

Reference Region ◽

Reference Tissue ◽

Positron Emission ◽

Definition Of

This paper aims to build novel methodology for the use of a reference region with specific binding for the quantification of brain studies with radioligands and positron emission tomography (PET). In particular: (1) we introduce a definition of binding potential BPD = DVR–1 where DVR is the volume of distribution relative to a reference tissue that contains ligand in specifically bound form, (2) we validate a numerical methodology, rank-shaping regularization of exponential spectral analysis (RS-ESA), for the calculation of BPD that can cope with a reference region with specific bound ligand, (3) we demonstrate the use of RS-ESA for the accurate estimation of drug occupancies with the use of correction factors to account for the specific binding in the reference. [11C]-DASB with cerebellum as a reference was chosen as an example to validate the methodology. Two data sets were used; four normal subjects scanned after infusion of citalopram or placebo and further six test—retest data sets. In the drug occupancy study, the use of RS-ESA with cerebellar input plus corrections produced estimates of occupancy very close the ones obtained with plasma input. Test-retest results demonstrated a tight linear relationship between BPD calculated either with plasma or with a reference input and high reproducibility.

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Ribosome inhibition by C9ORF72-ALS/FTD-associated poly-PR and poly-GR proteins revealed by cryo-EM

10.1101/2020.08.30.274597 ◽

2020 ◽

Author(s):

Anna B. Loveland ◽

Egor Svidritskiy ◽

Denis Susorov ◽

Soojin Lee ◽

Alexander Park ◽

...

Keyword(s):

Amyotrophic Lateral Sclerosis ◽

Specific Binding ◽

Structural Basis ◽

Transferase Activity ◽

Peptidyl Transferase ◽

Peptidyl Transferase Center ◽

Ribosomal Tunnel ◽

Cellular Translation ◽

Lateral Sclerosis ◽

Dipeptide Repeat

AbstractToxic dipeptide repeat (DPR) proteins are produced from expanded G4C2 hexanucleotide repeats in the C9ORF72 gene, which cause amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Two DPR proteins, poly-PR and poly-GR, repress cellular translation but the molecular mechanism remains unknown. Here we show that poly-PR and poly-GR of ≥ 20 repeats inhibit the ribosome’s peptidyl-transferase activity at nanomolar concentrations, comparable to specific translation inhibitors. High-resolution cryo-EM structures reveal that poly-PR and poly-GR block the polypeptide tunnel of the ribosome, extending into the peptidyl-transferase center. Consistent with these findings, the macrolide erythromycin, which binds in the tunnel, competes with the DPR proteins and restores peptidyl-transferase activity. Our results demonstrate that strong and specific binding of poly-PR and poly-GR in the ribosomal tunnel blocks translation, revealing the structural basis of their toxicity in C9ORF72-ALS/FTD.

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