Biology subjects

Wong, J. P. H.

Publications and source records attributed to Wong, J. P. H..

3 recordsLinked to original sources

bioRxiv2026

Quantitative interactome mapping of skeletal muscle insulin resistance

Protein-protein interactions (PPIs) are dynamic and critical to adaptive homeostasis. While there have been massive efforts to catalogue proteome-wide PPIs, global quantification of changes remains a challenge. Here, we integrate dynamic protein correlation profiling - mass spectrometry (PCP-MS) and quantitative cross linking-mass spectrometry (qXL-MS) using multiplexed stable isotope labelling to characterise global PPI remodelling following the development of chronic skeletal muscle insulin resistance (IR) with or without acute insulin stimulation. We quantify >7,000 unique PPIs amongst 5,346 proteins and show changes in the interactome network dominate the proteome response. Our data show the dysregulation of protein processing in the endoplasmic/sarcoplasmic reticulum involving changes in PPIs with protein chaperones and disulfide isomerases is a major hallmark of skeletal muscle IR. Mechanistically, we show the dysregulation of PPIs with Protein-Disulfide Isomerase 6 (PDIA6) regulates cysteine oxidation and insulin sensitivity. Taken together, we show in vivo quantitative interactome mapping is a powerful approach to understand disease mechanisms and provide new insights into protein network re-organisations with IR.

biochemistry↗

bioRxiv2022

Fluid flow structures gut microbiota biofilm communities by distributing public goods

Bacterial gut commensals experience a biologically and physically complex mucosal environment. While many chemical factors mediate the composition and structure of these microbial communities, less is known about the role of mechanics. Here, we demonstrate that fluid flow impacts the spatial organization and composition of gut biofilm communities by shaping how different species interact metabolically. We first demonstrate that a model community composed of Bacteroides thetaiotaomicron (Bt) and Bacteroides fragilis (Bf), two representative human commensals, can form robust biofilms in flow. We identified dextran as a polysaccharide readily metabolized by Bt but not Bf, but whose fermentation generates a public good enabling Bf growth. We demonstrate that in flow, Bt biofilms share dextran metabolic by-products, promoting Bf biofilm formation. By transporting this public good, flow structures the spatial organization of the community, positioning the Bf population downstream from Bt. We show that sufficiently strong flows abolish Bf biofilm formation by limiting the effective public good concentration at the surface. Physical factors such as flow may therefore contribute to the composition of intestinal microbial communities, potentially impacting host health.

microbiology↗

bioRxiv2020

The membrane microenvironment regulates the sequential attachment of bacteria to host cells.

Pathogen attachment to host tissue is critical in the progress of many infections. Bacteria use adhesion in vivo to promote colonization and regulate the deployment of contact-dependent virulence traits. To specifically target host cells, they decorate themselves with adhesins, proteins that bind to mammalian cell surface receptors. One common assumption is that adhesin-receptor interactions entirely govern bacterial attachment. However, how adhesins engage with their receptors in an in vivo-like context remains unclear, in particular under the influence of a heterogeneous mechanical microenvironment. We here investigate the biophysical processes governing bacterial adhesion to host cells using a tunable adhesin-receptor system. By dynamically visualizing attachment, we found that bacterial adhesion to host cell surface, unlike adhesion to inert surfaces, involves two consecutive steps. Bacteria initially attach to their host without engaging adhesins. This step lasts about one minute during which bacteria can easily detach. We found that at this stage, the glycocalyx, a layer of glycosylated proteins and lipids, shields the host cell by keeping adhesin away from their receptor ligand. In a second step, adhesins engage with their target receptors to strengthen attachment for minutes to hours. The active properties of the membrane, endowed by the actin cytoskeleton, strengthen specific adhesion. Altogether, our results demonstrate that adhesin-ligand binding is not the sole regulator of bacterial adhesion. In fact, the host cells mechanical microenvironment relatively strongly mediated host-bacteria physical interactions, thereby playing an essential role in the onset of infection.

microbiology↗