Global S&T Development Trend Analysis Platform of Resources and Environment
TWIK-related acid-sensitive potassium (TASK) channels-members of the two pore domain potassium (K-2P) channel family-are found in neurons(1), cardiomyocytes(2-4) and vascular smooth muscle cells(5), where they are involved in the regulation of heart rate(6), pulmonary artery tone(5,7), sleep/wake cycles(8) and responses to volatile anaesthetics(8-11). K-2P channels regulate the resting membrane potential, providing background K+ currents controlled by numerous physiological stimuli(12-15). Unlike other K-2P channels, TASK channels are able to bind inhibitors with high affinity, exceptional selectivity and very slow compound washout rates. As such, these channels are attractive drug targets, and TASK-1 inhibitors are currently in clinical trials for obstructive sleep apnoea and atrial fibrillation(16). In general, potassium channels have an intramembrane vestibule with a selectivity filter situated above and a gate with four parallel helices located below
The X-ray crystal structure of the potassium channel TASK-1 reveals the presence of an X-gate, which traps small-molecule inhibitors in the intramembrane vestibule and explains their low washout rates from the channel.
Most proteins associate into multimeric complexes with specific architectures(1,2), which often have functional properties such as cooperative ligand binding or allosteric regulation(3). No detailed knowledge is available about how any multimer and its functions arose during evolution. Here we use ancestral protein reconstruction and biophysical assays to elucidate the origins of vertebrate haemoglobin, a heterotetramer of paralogous alpha- and beta-subunits that mediates respiratory oxygen transport and exchange by cooperatively binding oxygen with moderate affinity. We show that modern haemoglobin evolved from an ancient monomer and characterize the historical '
Experimental analysis of reconstructed ancestral globins reveals that haemoglobin'
Strongly correlated insulating Mott and generalized Wigner phases are detected in WSe2/WS2 moire superlattices, and their electrical properties and excited spin states are studied using an optical technique.
Moire superlattices can be used to engineer strongly correlated electronic states in two-dimensional van der Waals heterostructures, as recently demonstrated in the correlated insulating and superconducting states observed in magic-angle twisted-bilayer graphene and ABC trilayer graphene/boron nitride moire superlattices(1-4). Transition metal dichalcogenide moire heterostructures provide another model system for the study of correlated quantum phenomena(5) because of their strong light-matter interactions and large spin-orbit coupling. However, experimental observation of correlated insulating states in this system is challenging with traditional transport techniques. Here we report the optical detection of strongly correlated phases in semiconducting WSe2/WS2 moire superlattices. We use a sensitive optical detection technique and reveal a Mott insulator state at one hole per superlattice site and surprising insulating phases at 1/3 and 2/3 filling of the superlattice, which we assign to generalized Wigner crystallization on the underlying lattice(6-11). Furthermore, the spin-valley optical selection rules(12-14) of transition metal dichalcogenide heterostructures allow us to optically create and investigate low-energy excited spin states in the Mott insulator. We measure a very long spin relaxation lifetime of many microseconds in the Mott insulating state, orders of magnitude longer than that of charge excitations. Our studies highlight the value of using moire superlattices beyond graphene to explore correlated physics.
Neural control of the function of visceral organs is essential for homeostasis and health. Intestinal peristalsis is critical for digestive physiology and host defence, and is often dysregulated in gastrointestinal disorders(1). Luminal factors, such as diet and microbiota, regulate neurogenic programs of gut motility(2-5), but the underlying molecular mechanisms remain unclear. Here we show that the transcription factor aryl hydrocarbon receptor (AHR) functions as a biosensor in intestinal neural circuits, linking their functional output to the microbial environment of the gut lumen. Using nuclear RNA sequencing of mouse enteric neurons that represent distinct intestinal segments and microbiota states, we demonstrate that the intrinsic neural networks of the colon exhibit unique transcriptional profiles that are controlled by the combined effects of host genetic programs and microbial colonization. Microbiota-induced expression of AHR in neurons of the distal gastrointestinal tract enables these neurons to respond to the luminal environment and to induce expression of neuron-specific effector mechanisms. Neuron-specific deletion of Ahr, or constitutive overexpression of its negative feedback regulator CYP1A1, results in reduced peristaltic activity of the colon, similar to that observed in microbiota-depleted mice. Finally, expression of Ahr in the enteric neurons of mice treated with antibiotics partially restores intestinal motility. Together, our experiments identify AHR signalling in enteric neurons as a regulatory node that integrates the luminal environment with the physiological output of intestinal neural circuits to maintain gut homeostasis and health.
In a mouse model, aryl hydrocarbon receptor signalling in enteric neurons is revealed as a mechanism that helps to maintain gut homeostasis by integrating the luminal environment with the physiology of intestinal neural circuits.
The first 3D structure of a full-length G-protein-coupled receptor whose natural activator is unknown has been determined, providing insights into an unusual mode of activation and a basis for discovering therapeutics.
Inflammatory bowel disease (IBD) is a complex genetic disease that is instigated and amplified by the confluence of multiple genetic and environmental variables that perturb the immune-microbiome axis. The challenge of dissecting pathological mechanisms underlying IBD has led to the development of transformative approaches in human genetics and functional genomics. Here we describe IBD as a model disease in the context of leveraging human genetics to dissect interactions in cellular and molecular pathways that regulate homeostasis of the mucosal immune system. Finally, we synthesize emerging insights from multiple experimental approaches into pathway paradigms and discuss future prospects for disease-subtype classification and therapeutic intervention.
This Review examines inflammatory bowel disease in the context of human genetics studies that help to identify pathways that regulate homeostasis of the mucosal immune system and discusses future prospects for disease-subtype classification and therapeutic intervention.
A major United Nations summit could see China push for ambitious targets and spotlights the country'
Protein structure prediction can be used to determine the three-dimensional shape of a protein from its amino acid sequence(1). This problem is of fundamental importance as the structure of a protein largely determines its function(2)