Zinc transporter 1 functions in copper uptake and cuproptosis.

Copper (Cu) is a co-factor for several essential metabolic enzymes. Disruption of Cu homeostasis results in genetic diseases such as Wilson's disease. Here, we show that the zinc transporter 1 (ZnT1), known to export zinc (Zn) out of the cell, also mediates Cu entry into cells and is required for Cu-induced cell death, cuproptosis.

Specific binding of GPR174 by endogenous lysophosphatidylserine leads to high constitutive G signaling.

Many orphan G protein-coupled receptors (GPCRs) remain understudied because their endogenous ligands are unknown. Here, we show that a group of class A/rhodopsin-like orphan GPCRs including GPR61, GPR161 and GPR174 increase the cAMP level similarly to fully activated D1 dopamine receptor (D1R). We report cryo-electron microscopy structures of the GPR61‒G, GPR161‒G and GPR174‒G complexes without any exogenous ligands.

Structural basis for the ubiquitination of G protein βγ subunits by KCTD5/Cullin3 E3 ligase.

G protein-coupled receptor (GPCR) signaling is precisely controlled to avoid overstimulation that results in detrimental consequences. Gβγ signaling is negatively regulated by a Cullin3 (Cul3)-dependent E3 ligase, KCTD5, which triggers ubiquitination and degradation of free Gβγ. Here, we report the cryo-electron microscopy structures of the KCTD5-Gβγ fusion complex and the KCTD7-Cul3 complex.

In Silico Discovery of Small Molecule Modulators Targeting the Achilles' Heel of SARS-CoV-2 Spike Protein.

The spike protein of SARS-CoV-2 has been a promising target for developing vaccines and therapeutics due to its crucial role in the viral entry process. Previously reported cryogenic electron microscopy (cryo-EM) structures have revealed that free fatty acids (FFA) bind with SARS-CoV-2 spike protein, stabilizing its closed conformation and reducing its interaction with the host cell target in vitro. Inspired by these, we utilized a structure-based virtual screening approach against the conserved FFA-binding pocket to identify small molecule modulators of SARS-CoV-2 spike protein, which helped us identify six hits with micromolar binding affinities.

Chemical inhibition of mitochondrial fission via targeting the DRP1-receptor interaction.

Mitochondrial fission is critical for mitochondrial dynamics and homeostasis. The dynamin superfamily GTPase DRP1 is recruited by three functionally redundant receptors, MFF, MiD49, and MiD51, to mitochondria to drive fission. Here, we exploit high-content live-cell imaging to screen for mitochondrial fission inhibitors and have developed a covalent compound, mitochondrial division inhibitor (MIDI).

A pH-dependent anti-CD47 antibody that selectively targets solid tumors and improves therapeutic efficacy and safety.

Background: The antiphagocytic molecule CD47 is overexpressed in a wide variety of cancer cells, and antibodies targeting CD47 for cancer therapies are currently under intensive investigation. However, owing to the ubiquitous expression of CD47 on healthy cells, anti-CD47 therapies often achieve only weak therapeutic benefits and can induce severe side effects. Here, we report the generation of a pH-dependent anti-CD47 antibody (BC31M4) which selectively binds to tumors under the acidic solid tumor microenvironment.

Molecular basis for the selective G protein signaling of somatostatin receptors.

G protein-coupled receptors (GPCRs) modulate every aspect of physiological functions mainly through activating heterotrimeric G proteins. A majority of GPCRs promiscuously couple to multiple G protein subtypes. Here we validate that in addition to the well-known G pathway, somatostatin receptor 2 and 5 (SSTR2 and SSTR5) couple to the G pathway and show that smaller ligands preferentially activate the G pathway.

Structural insights into G protein activation by D1 dopamine receptor.

G protein-coupled receptors (GPCRs) comprise the largest family of membrane receptors and are the most important drug targets. An agonist-bound GPCR engages heterotrimeric G proteins and triggers the exchange of guanosine diphosphate (GDP) with guanosine triphosphate (GTP) to promote G protein activation. A complete understanding of molecular mechanisms of G protein activation has been hindered by a lack of structural information of GPCR-G protein complex in nucleotide-bound states.

Ligand recognition and biased agonism of the D1 dopamine receptor.

Dopamine receptors are widely distributed in the central nervous system and are important therapeutic targets for treatment of various psychiatric and neurological diseases. Here, we report three cryo-electron microscopy structures of the D1 dopamine receptor (D1R)-Gs complex bound to two agonists, fenoldopam and tavapadon, and a positive allosteric modulator LY3154207. The structure reveals unusual binding of two fenoldopam molecules, one to the orthosteric binding pocket (OBP) and the other to the extended binding pocket (EBP).

Structural insights into galanin receptor signaling.

Galanin is a biologically active neuropeptide, and functions through three distinct G protein–coupled receptors (GPCRs), namely GALR1, GALR2, and GALR3. GALR signaling plays important roles in regulating various physiological processes such as energy metabolism, neuropathic pain, epileptic activity, and sleep homeostasis. GALR1 and GALR3 signal through the Gi/o pathway, whereas GALR2 signals mainly through the Gq/11 pathway.

A highland-adaptation mutation of the Epas1 protein increases its stability and disrupts the circadian clock in the plateau pika.

The Qinghai-Tibet Plateau (QTP) harbors hundreds of species well adapted to its extreme conditions, including its low-oxygen (hypoxic) atmosphere. Here, we show that the plateau pika-a keystone mammal of the QTP-lacks robust circadian rhythms. The major form of the plateau pika Epas1 protein includes a 24-residue insert caused by a point mutation at the 5' juncture site of Intron14 and is more stable than other mammalian orthologs.

KCTD8 and KCTD12 Facilitate Axonal Expression of GABA Receptors in Habenula Cholinergic Neurons.

GABA receptors in habenula cholinergic neurons mediate strong presynaptic excitation and control aversive memory expression. K channel tetramerization domain (KCTD) proteins are key interacting partners of GABA receptors; it remains unclear whether and how KCTDs contribute to GABA excitatory signaling. Here, we show that KCTD8 and KCTD12 in these neurons facilitate the GABA receptors expression in axonal terminals and contribute to presynaptic excitation by GABA receptors.

High-Throughput Mutagenesis and Cross-Complementation Experiments Reveal Substrate Preference and Critical Residues of the Capsule Transporters in .

MOP (Multidrug/Oligosaccharidyl-lipid/Polysaccharide) family transporters are found in almost all life forms. They are responsible for transporting lipid-linked precursors across the cell membrane to support the synthesis of various glycoconjugates. While significant progress has been made in elucidating their transport mechanism, how these transporters select their substrates remains unclear.

Cryo-EM structure of S-Trimer, a subunit vaccine candidate for COVID-19.

Within a year after its emergence, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected over 100 million people worldwide with a death toll over 2 million. Vaccination remains the best hope to ultimately put this pandemic to an end. Here, using Trimer-Tag technology, we produced both wild-type (WT) and furin site mutant (MT) S-Trimers for COVID-19 vaccine studies.

Structural coordination of polymerization and crosslinking by a SEDS-bPBP peptidoglycan synthase complex.

The shape, elongation, division and sporulation (SEDS) proteins are a highly conserved family of transmembrane glycosyltransferases that work in concert with class B penicillin-binding proteins (bPBPs) to build the bacterial peptidoglycan cell wall. How these proteins coordinate polymerization of new glycan strands with their crosslinking to the existing peptidoglycan meshwork is unclear. Here, we report the crystal structure of the prototypical SEDS protein RodA from Thermus thermophilus in complex with its cognate bPBP at 3.

Novel Abs targeting the N-terminus of fibroblast growth factor 19 inhibit hepatocellular carcinoma growth without bile-acid-related side-effects.

Hepatocellular carcinoma (HCC) is a common and particularly fatal form of cancer for which very few drugs are effective. The fibroblast growth factor 19 (FGF19) has been viewed as a driver of HCC development and a potential Ab target for developing novel HCC therapy. However, a previously developed anti-FGF19 Ab disrupted FGF19's normal regulatory function and caused severe bile-acid-related side-effects despite of having potent antitumor effects in preclinical models.

Mapping and engineering the interaction between adiponectin and T-cadherin.

Adiponectin is a highly abundant protein hormone secreted by adipose tissue. It elicits diverse biological responses, including anti-diabetic, anti-inflammatory, anti-tumor, and anti-atherosclerotic effects. Adiponectin consists of a globular domain and a collagen-like domain, and it occurs in three major oligomeric forms that self-assemble: trimers, hexamers, and high-molecular-weight oligomers.

Structural basis for KCTD-mediated rapid desensitization of GABA signalling.

The GABA (γ-aminobutyric acid type B) receptor is one of the principal inhibitory neurotransmitter receptors in the brain, and it signals through heterotrimeric G proteins to activate a variety of effectors, including G-protein-coupled inwardly rectifying potassium channels (GIRKs). GABA-receptor signalling is tightly regulated by auxiliary subunits called KCTDs, which control the kinetics of GIRK activation and desensitization. However, the mechanistic basis for KCTD modulation of GABA signalling remains incompletely understood.

Solving a specificity mystery.

Differences in the kinetics of G protein activation can explain why only some receptors can activate potassium ion channels called GIRKs.

Structure and mutagenic analysis of the lipid II flippase MurJ from .

The peptidoglycan cell wall provides an essential protective barrier in almost all bacteria, defining cellular morphology and conferring resistance to osmotic stress and other environmental hazards. The precursor to peptidoglycan, lipid II, is assembled on the inner leaflet of the plasma membrane. However, peptidoglycan polymerization occurs on the outer face of the plasma membrane, and lipid II must be flipped across the membrane by the MurJ protein before its use in peptidoglycan synthesis.

Cryo-EM structure of an early precursor of large ribosomal subunit reveals a half-assembled intermediate.

Assembly of eukaryotic ribosome is a complicated and dynamic process that involves a series of intermediates. It is unknown how the highly intertwined structure of 60S large ribosomal subunits is established. Here, we report the structure of an early nucleolar pre-60S ribosome determined by cryo-electron microscopy at 3.