Trim-Away ubiquitinates and degrades lysine-less and N-terminally acetylated substrates.

TRIM proteins are the largest family of E3 ligases in mammals. They include the intracellular antibody receptor TRIM21, which is responsible for mediating targeted protein degradation during Trim-Away. Despite their importance, the ubiquitination mechanism of TRIM ligases has remained elusive.

Diet composition influences the metabolic benefits of short cycles of very low caloric intake.

Diet composition, calories, and fasting times contribute to the maintenance of health. However, the impact of very low-calorie intake (VLCI) achieved with either standard laboratory chow (SD) or a plant-based fasting mimicking diet (FMD) is not fully understood. Here, using middle-aged male mice we show that 5 months of short 4:10 VLCI cycles lead to decreases in both fat and lean mass, accompanied by improved physical performance and glucoregulation, and greater metabolic flexibility independent of diet composition.

A functional assay for serum detection of antibodies against SARS-CoV-2 nucleoprotein.

The humoral immune response to SARS-CoV-2 results in antibodies against spike (S) and nucleoprotein (N). However, whilst there are widely available neutralization assays for S antibodies, there is no assay for N-antibody activity. Here, we present a simple in vitro method called EDNA (electroporated-antibody-dependent neutralization assay) that provides a quantitative measure of N-antibody activity in unpurified serum from SARS-CoV-2 convalescents.

Rapid Non-Enzymatic Glycation of the Insulin Receptor under Hyperglycemic Conditions Inhibits Insulin Binding In Vitro: Implications for Insulin Resistance.

The causes of insulin resistance are not well-understood in either type 1 or type 2 diabetes. Insulin (INS) is known to undergo rapid non-enzymatic covalent conjugation to glucose or other sugars (glycation). Because the insulin receptor (IR) has INS-like regions associated with both glucose and INS binding, we hypothesize that hyperglycemic conditions may rapidly glycate the IR, chronically interfering with INS binding.

Multimer-PAGE: A Method for Capturing and Resolving Protein Complexes in Biological Samples.

There are many well-developed methods for purifying and studying single proteins and peptides. However, most cellular functions are carried out by networks of interacting protein complexes, which are often difficult to investigate because their binding is non-covalent and easily perturbed by purification techniques. This work describes a method of stabilizing and separating native protein complexes from unmodified tissue using two-dimensional polyacrylamide gel electrophoresis.

Enzymatic recycling of ascorbic acid from dehydroascorbic acid by glutathione-like peptides in the extracellular loops of aminergic G-protein coupled receptors.

The intracellular recycling of ascorbic acid from dehydroascorbic acid by the glutathione-glutathione reductase system has been well-characterized. We propose that extracellular recycling of ascorbic acid is performed in a similar manner by cysteine-rich, glutathione-like regions of the first and second extracellular loops of some aminergic receptors including adrenergic, histaminergic, and dopaminergic receptors. Previous research in our laboratory demonstrated that ascorbic acid binds to these receptors at a site on their first or second extracellular loops, significantly enhancing ligand activity, and apparently recycling hundreds of times their own concentration of ascorbate in an enzymatic fashion.