Volume 15 Issue 5, May 2019

Chemical probes that irreversibly inhibit protein function may be used across species to discover proteins. Combining phenotypic screening and activity-based protein profiling, a new study uncovers a discrete lipid signaling pathway regulating lifespan in the worm Caenorhabditis elegans.

The molybdenum cofactor (Moco) is a fragile prosthetic group essential for most organisms. Nematodes are now capable of extracting Moco from their bacterial diet to mediate detoxification of sulfite.

Arginine protein kinases regulate bacterial signaling cascades through phosphorylation of key arginine residues. Crystal structures of the kinase McsB provide the first glimpse of how these unusual enzymes recognize their protein substrates and are allosterically regulated.

Orange CaMBI, a genetically encoded bioluminescent calcium indicator consisting of calcium-sensing domain CaM, luciferase, and fluorescent proteins, reports calcium dynamics in single cells and reveals calcium oscillations in whole mouse organs.

Combinatorial shuffling of peptide sequence modules, post-translational modification and screening with a high-throughput growth inhibition assay results in the identification of lanthipeptide variants with altered antibacterial activities.

The AAA protein spastin is needed for cell division and organelle transport. Testing spastin constructs with engineered mutations resulted in the identification of a chemical probe to analyze spastin-specific functions in cells.

Phenotypic screening identifies a small-molecule inhibitor of the C. elegans serine hydrolase FAAH-4 that promotes longevity and identifies the enzyme as the functional homolog of mammalian monoacylglycerol lipase (MAGL).

Genetic, structural and biochemical analysis identifies GacH as a glycerol phosphate transferase that modifies N-acetylglucosamine components of group A carbohydrates (GAC) in streptococcal cell walls.

Structural analysis of Mango-III in complex with fluorophores reveals a globular architecture and a planar conformation of fluorophores. Structure-guided mutation and functional reselection identified two mutants with improved fluorescence intensity.

The molybdenum cofactor (Moco) is required for survival to mitigate sulfite toxicity. Genetic studies in C. elegans reveal that Moco-biosynthetic mutants are able to survive if Moco is provided through the microbial diet.

A chemogenomic approach to explore activity of the free fatty acid receptor FFA2 independently of the related FFA3 shows that FFA2 in differentiated adipocytes and colonic crypt cells in mice is responsible for regulated lipolysis and GLP-1 release.

Single-molecule analysis by high-speed atomic force microscopy reveals that oxidized protein disulfide isomerase adopts a dynamic conformation in the absence of substrates and forms face-to-face dimers to accelerate oxidative folding in the presence of substrates.

Structural and biochemical characterization of arginine kinase McsB reveals how its phosphagen kinase–like catalytic domain is adapted to target protein substrates while its phosphoarginine-binding domain allosterically controls kinase activity.

A chromatin-focused chemical screen identified CBP/EP300 bromodomain inhibitors as enhancers of reprogramming. These inhibitors decrease histone H3 lysine 27 acetylation, chromatin accessibility and expression of somatic-specific genes.

A CRISPR–Cas9 screening-based structure–activity relationship profiling method reveals that LSD1 inhibitors suppress acute myeloid leukemia by disruption of the interaction between LSD1 and GFI1B instead of the enzyme activity of LSD1.

An engineered biosensor, which optimizes metal-sensing and couples it to transcriptional amplification cascades that produce a fluorescent protein, was applied to build a sensitive and easy-to-use sensor for the toxic metals As³⁺ and Hg²⁺.