Global S&T Development Trend Analysis Platform of Resources and Environment
Advanced deep-sea imaging tools yield insights into the structure and function of mucus filtration houses built by midwater giant larvaceans.
Many animals build complex structures to aid in their survival, but very few are built exclusively from materials that animals create (1,2). In the midwaters of the ocean, mucoid structures are readily secreted by numerous animals, and serve many vital functions(3,4). However, little is known about these mucoid structures owing to the challenges of observing them in the deep sea. Among these mucoid forms, the '
A neuromodulator produced by commensalProvidenciabacteria that colonize the gut ofCaenorhabditis elegansmimics the functions of the cognate host molecule to manipulate a sensory decision of the host.
Animals coexist in commensal, pathogenic or mutualistic relationships with complex communities of diverse organisms, including microorganisms(1). Some bacteria produce bioactive neurotransmitters that have previously been proposed to modulate nervous system activity and behaviours of their hosts(2,3). However, the mechanistic basis of this microbiota-brain signalling and its physiological relevance are largely unknown. Here we show that inCaenorhabditis elegans, the neuromodulator tyramine produced by commensalProvidenciabacteria, which colonize the gut, bypasses the requirement for host tyramine biosynthesis and manipulates a host sensory decision. Bacterially produced tyramine is probably converted to octopamine by the host tyramine beta-hydroxylase enzyme. Octopamine, in turn, targets the OCTR-1 octopamine receptor on ASH nociceptive neurons to modulate an aversive olfactory response. We identify the genes that are required for tyramine biosynthesis inProvidencia, and show that these genes are necessary for the modulation of host behaviour. We further find thatC. eleganscolonized byProvidenciapreferentially select these bacteria in food choice assays, and that this selection bias requires bacterially produced tyramine and host octopamine signalling. Our results demonstrate that a neurotransmitter produced by gut bacteria mimics the functions of the cognate host molecule to override host control of a sensory decision, and thereby promotes fitness of both the host and the microorganism.
The cyclin-dependent kinase inhibitor CR8 acts as a molecular glue compound by inducing the formation of a complex between CDK12-cyclin K and DDB1, which results in the ubiquitination and degradation of cyclin K.
Molecular glue compounds induce protein-protein interactions that, in the context of a ubiquitin ligase, lead to protein degradation(1). Unlike traditional enzyme inhibitors, these molecular glue degraders act substoichiometrically to catalyse the rapid depletion of previously inaccessible targets(2). They are clinically effective and highly sought-after, but have thus far only been discovered serendipitously. Here, through systematically mining databases for correlations between the cytotoxicity of 4,518 clinical and preclinical small molecules and the expression levels of E3 ligase components across hundreds of human cancer cell lines(3-5), we identify CR8-a cyclin-dependent kinase (CDK) inhibitor(6)-as a compound that acts as a molecular glue degrader. The CDK-bound form of CR8 has a solvent-exposed pyridyl moiety that induces the formation of a complex between CDK12-cyclin K and the CUL4 adaptor protein DDB1, bypassing the requirement for a substrate receptor and presenting cyclin K for ubiquitination and degradation. Our studies demonstrate that chemical alteration of surface-exposed moieties can confer gain-of-function glue properties to an inhibitor, and we propose this as a broader strategy through which target-binding molecules could be converted into molecular glues.