Volume 16 Issue 3, March 2020

Characterization of biased receptor signaling has ushered in opportunities for unprecedented control of G-protein-coupled receptors. Elucidation of distinct M1 muscarinic acetylcholine receptor signaling pathways and development of biased ligands may offer novel and safer Alzheimer’s disease therapeutics.

The site-specific monoubiquitination of FANCD2 is crucial for the Fanconi anemia DNA repair pathway and tumor suppression. This modification is mediated by the E2 enzyme UBE2T and the E3 ligase FANCL through a novel allosteric mechanism.

Retro-2 is a drug that protects cells against bacterial and plant toxins by arresting their trafficking in endosomes. New data show that the target for Retro-2 is surprisingly not within the endosomal system, but on the endoplasmic reticulum.

Cryo-EM and Cryo-ET have emerged as useful tools to study the efficient and dynamic processes of the viral assembly.

Use of receptor variants in knock-in mice to dissect phosphorylation-dependent signaling from G protein-dependent signaling mediated by acetylcholine receptor M1 mAChR defines the ability of receptor ligands to modulate anxiety and locomotion behaviors.

In cotton, a specialized glyoxalase I variant, SPG, has lost its glutathione-binding sites and organelle-targeting signal during its evolution to catalyze the aromatization of cyclic sesquiterpenes as part of the gossypol biosynthetic pathway.

Single-particle tracking and mathematical modeling methods reveal the searching mechanism of CTCF for its cognate sites on DNA. An RNA-binding region in CTCF mediates its trapping in small zones and increases its target search efficiency.

X-ray crystallography, solution NMR and biochemical and cell-based analyses reveal a model where catalytically repressed receptor tyrosine kinases accomplish activation loop (A-loop) tyrosine transphosphorylation.

Susceptibility to ferroptosis can be modulated by nitric oxide (NO^•) and NO synthase iNOS and through enrichment of activated M1 macrophages. NO inhibits the lipoxygenase 15-LOX that drives production of pro-ferroptotic lipids in macrophages.

UBE2T adopts an allosteric activation mechanism to mediate site-specific ubiquitination of Fanconi anemia complex. Interaction with FANCL induces a cascade of conformational changes of UBE2T and leads to exposure of substrate-binding sites.

Using genome-wide CRISPR–Cas9-mediated suppressor screens, cytochrome P450 oxidoreductase was identified as a contributor to ferroptotic cell death by promoting phospholipid peroxidation in various cellular lineages.

Single-molecule FRET technologies reveal the mechanism of sequence-specific translational inhibition induced by two antibiotics, chloramphenicol and linezolid, where aminoacyl-tRNA was repeatedly rejected from the A-site and failed to form a peptide bond.

A covalent pan-inhibitor of bacterial bile salt hydrolases developed by adding a chenodeoxycholic acid moiety to the warhead is not bactericidal and is therefore useful for studying the effects of bile acids on host physiology.

The ER exit site component Sec16A was identified as the target of Retro-2, a small-molecule inhibitor of protein toxins and pathogens. Retro-2 treatment alters retrograde early/maturing endosomes-to-Golgi trafficking of Shiga toxin.

In the fungal pathogen Cryptococcus neoformans, Bim1 is a copper-binding lytic polysaccharide monooxygenase-like protein that participates in copper uptake in concert with the Ctr1 importer to drive virulence mechanisms during fungal meningitis.

The X325 protein family is highly similar to lytic polysaccharide monooxygenases (LPMOs) in regulation, structure and copper coordination by a histidine brace, yet lacks LPMO activity and suggests the evolution of an alternative function in fungi.

Polypeptide GalNAc-transferase T3 catalyzes the specific glycosylation of threonine-178 of fibroblast growth factor 23, and structural insights reveal a unique lectin-based mechanism of substrate recognition.