Molecular mechanisms of stress-induced reactivation in mumps virus condensates.

Negative-stranded RNA viruses can establish long-term persistent infection in the form of large intracellular inclusions in the human host and cause chronic diseases. Here, we uncover how cellular stress disrupts the metastable host-virus equilibrium in persistent infection and induces viral replication in a culture model of mumps virus. Using a combination of cell biology, whole-cell proteomics, and cryo-electron tomography, we show that persistent viral replication factories are dynamic condensates and identify the largely disordered viral phosphoprotein as a driver of their assembly.

Defining basic rules for hardening influenza A virus liquid condensates.

In biological systems, liquid and solid-like biomolecular condensates may contain the same molecules but their behaviour, including movement, elasticity, and viscosity, is different on account of distinct physicochemical properties. As such, it is known that phase transitions affect the function of biological condensates and that material properties can be tuned by several factors including temperature, concentration, and valency. It is, however, unclear if some factors are more efficient than others at regulating their behaviour.

Thermal proteome profiling: Insights into protein modifications, associations, and functions.

Tracking proteins' biophysical characteristics on a proteome-wide scale can provide valuable information on their functions and interactions. Thermal proteome profiling (TPP) is a multiplexed quantitative proteomics approach that measures changes in protein thermal stability-a key biophysical property-across different cellular states. Developed in 2014, as a target-deconvolution assay for drugs and other small molecules, TPP has since evolved to a system-level biochemical omics technique providing insights into context-dependent changes in protein states.

A computational method for detection of ligand-binding proteins from dose range thermal proteome profiles.

Detecting ligand-protein interactions in living cells is a fundamental challenge in molecular biology and drug research. Proteome-wide profiling of thermal stability as a function of ligand concentration promises to tackle this challenge. However, current data analysis strategies use preset thresholds that can lead to suboptimal sensitivity/specificity tradeoffs and limited comparability across datasets.

Aggregation and disaggregation features of the human proteome.

Protein aggregates have negative implications in disease. While reductionist experiments have increased our understanding of aggregation processes, the systemic view in biological context is still limited. To extend this understanding, we used mass spectrometry-based proteomics to characterize aggregation and disaggregation in human cells after non-lethal heat shock.

Thermal proteome profiling for interrogating protein interactions.

Thermal proteome profiling (TPP) is based on the principle that, when subjected to heat, proteins denature and become insoluble. Proteins can change their thermal stability upon interactions with small molecules (such as drugs or metabolites), nucleic acids or other proteins, or upon post-translational modifications. TPP uses multiplexed quantitative mass spectrometry-based proteomics to monitor the melting profile of thousands of expressed proteins.

Venom natriuretic peptides guide the design of heart failure therapeutics.

Heart failure (HF) affects over 26 million people world-wide. It is a syndrome triggered by loss of normal cardiac function due to many acute (eg myocardial infarction) and/or chronic (eg hypertension) causes and characterized by mixed beneficial and deleterious activation of a complex of multifaceted neurohormonal systems the net effect of which frequently is further adverse disruption of pressure-volume homeostasis. Unlike the situation in chronic heart failure, current strategies for treatment of acute heart failure are empirical and lack a strong evidence base.

Proteome-wide solubility and thermal stability profiling reveals distinct regulatory roles for ATP.

Adenosine triphosphate (ATP) plays fundamental roles in cellular biochemistry and was recently discovered to function as a biological hydrotrope. Here, we use mass spectrometry to interrogate ATP-mediated regulation of protein thermal stability and protein solubility on a proteome-wide scale. Thermal proteome profiling reveals high affinity interactions of ATP as a substrate and as an allosteric modulator that has widespread influence on protein complexes and their stability.

Decoding the molecular switches of natriuretic peptides which differentiate its vascular and renal functions.

Heart failure (HF) is associated with high morbidity and mortality. Dysfunction of blood pressure and/or volume homeostatic processes result in lower perfusion and/or congestion. Treatment strategies exerting differential effects on pressure and volume mechanisms are critical in handling patients with HF.

Tail wags the dog: activity of krait natriuretic peptide is determined by its C-terminal tail in a natriuretic peptide receptor-independent manner.

Natriuretic peptides (NPs) are potent vasoactive hormones, which maintain pressure-volume homoeostasis. Snake venom NPs exhibit distinct biological activity compared with mammalian NPs due to subtle changes in their sequences. We recently identified a new NP from krait venom (KNP), with an unusual 38-residue long C-terminal tail, which has a propensity to form an α-helix.

A defined α-helix in the bifunctional O-glycosylated natriuretic peptide TcNPa from the venom of Tropidechis carinatus.

Natriuretic peptides (NP) play important roles in human cardiac physiology through their guanylyl cyclase receptors NPR-A and NPR-B. Described herein is a bifunctional O-glycosylated natriuretic peptide, TcNPa, from Tropidechis carinatus venom and it unusually targets both NPR-A and NPR-B. Characterization using specific glycosidases and ETD-MS identified the glycan as galactosyl-β(1-3)-N-acetylgalactosamine (Gal-GalNAc) and was α-linked to the C-terminal threonine residue.