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Henry, S. M.

Publications and source records attributed to Henry, S. M..

3 recordsLinked to original sources

Immune Antibodies Recognizing the Stem Region of SARS-CoV-2 Spike Protein: Molecular Modelling and In Vitro Study of Synthetic Peptides Presentation to the Antibodies

Antibodies to peptide 1147 (amino acids 1147-61) of the SARS-CoV-2 protein S are highly diagnostic. Peptide 1147, although located in a region that is partly spatially hidden in the intact protein, is not subject to mutations, suggesting therapeutic potential. The aim of this study was to elucidate the architecture of this region and the way in which it is presented to antibodies. As a model system, this peptide carrying a single lipophilic tail and the same peptide carrying a lipophilic tail at both ends (pseudocyclic) were incorporated into lipid membrane. Isolated anti-1147 antibodies interacted with it regardless of how the peptide was presented, be that freely exposed via the N-terminus, organized as a pseudocycle, or adsorbed on the surface. MDS showed that peptide 1147 is capable of closely approaching the membrane. Analysis of the surface properties of peptide 1147 in membrane-bound states and in available conformations in the full-sized S protein reveals interface for interaction with antibodies. Interestingly, the latter bears similarities to one published peptide-antibody complex. However, these antibodies, in spite of their high diagnostic significance, show no virus-neutralizing activity, indicating that peptide 1147 has no therapeutic value as a synthetic vaccine.

immunology↗

Tight control of the APP-Mint1 interaction in regulating amyloid production

Generation of amyloid-beta (A{beta}) peptides through the proteolytic processing of the amyloid precursor protein (APP) is one pathogenic event in Alzheimers disease (AD). APP is a type I transmembrane protein and endocytosis of APP mediated by the endocytic YENPTY sequence is a key step in A{beta} generation. We and others have found that Mints, a family of cytosolic adaptor proteins, directly binds to the YENPTY motif of APP via phosphotyrosine binding (PTB) domain of Mints, facilitates APP trafficking and processing. We also show mutation of Tyr633 of Mint1 (Mint1Y633A) enhances APP binding and processing. Now, we created a low-affinity Mint1 mutant that targets two conserved residues, Tyr549 and Phe610 (Mint1Y549A/F610A), that reduced APP binding. Here, we investigate how perturbing the APP-Mint1 interaction alters APP and Mint1 cellular dynamics as well as Mint1s interaction with its other binding partners. We show that Mint1Y633A increased binding affinity specifically for APP and presenilin1, enhanced APP endocytosis, and A{beta} secretion in primary neurons. Conversely, Mint1Y549A/F610A exhibited reduced APP affinity and A{beta} secretion. In fact, the effect of Mint1Y549A/F610A on A{beta} release was greater compared to knocking down all three Mint proteins, supporting targeting APP-Mint1 interaction as a potential AD therapeutic.

neuroscience↗

Bisphenol A promotes stress granule assembly and modulates the integrated stress response

Bisphenol-A (BPA) is a ubiquitous precursor of polycarbonate plastics that is found in the blood and serum of >92% of Americans. While BPA has been well documented to act as a weak estrogen receptor (ER) agonist, its effects on cellular stress are unclear. Here, we demonstrate that high-dose BPA causes stress granules (SGs) in human cells. A common estrogen derivative, {beta}-estradiol, does not trigger SGs, indicating the mechanism of SG induction is not via the ER pathway. We also tested other structurally related environmental contaminants including the common BPA substitutes BPS and BPF, the industrial chemical 4-nonylphenol (4-NP) and structurally related compounds 4-EP and 4-VP, and the pesticide 2,4-dichlorophenoxyacetic acid (2,4-D). The variable results from these related compounds suggest that structural homology is not a reliable predictor of the capacity of a compound to cause SGs. Also, we demonstrate that BPA acts primarily through the PERK pathway to generate canonical SGs. Finally, we show that chronic exposure to a low physiologically relevant dose of BPA disrupts SG assembly by inhibiting SGs upon additional acute stress. Our work identifies additional effects of BPA beyond endocrine disruption that may have consequences for human health.

cell biology↗