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Yang, Y.-Y.

Publications and source records attributed to Yang, Y.-Y..

12 recordsLinked to original sources

Architecture of the type II secretion system

The virulence of emerging Gram-negative pathogens frequently arises from toxins delivered by the type II secretion system1. Cryo-EM single particle analysis and cryo-electron tomography and have defined the outer membrane secretin pore in detail, but the organisation of proteins within the periplasm and inner membrane that form the pilus assembly platform is not well resolved2,3. Here we combine AlphaFold4 models with single particle cryo-EM to define the organisation of the pilus assembly platform. We show that CLM heterotrimers form a continuous link from the cytoplasmic ATPase, across the inner membrane and periplasm, to the base of the secretin channel. AlphaFold models of the inner membrane spanning rotor and cytoplasmic ATPase fit readily within the cryo-EM density. The resolved secretion system exhibits an offset between the inner membrane assembly platform and the outer membrane secretin pore, together with profound asymmetry and an unexpectedly open periplasmic architecture. This architecture provides a route by which large, folded proteins access the secretion channel from the periplasm and suggests that substrate engagement may trigger the final steps in secretion system assembly leading to secretion.

microbiology↗

Learning fragment-based segmentation of binding sites from molecular dynamics: a proof-of-concept on cardiac myosin.

The geometric and chemical features of protein binding sites tend to change as a consequence of conformational dynamics. In the ligand-unbound (apo) state, a binding site might be only transiently organised in a way that can accommodate a given ligand, with the relevant regions of the protein coming together in a suitable arrangement only in a subset of conformations. Ligand binding itself can also induce further changes in the binding site. Because most ligands can be decomposed into smaller fragments, we hypothesised that mapping onto the binding site surface the propensity of binding specific fragments could be used to monitor changes in the overall ability of the site to bind a ligand. This task can be formulated as semantic segmentation, which can now be performed successfully using deep learning methods. Here we introduce the Fragment-Based protein Ensemble semantic Segmentation Tool for Myosin (FragBEST-Myo), a deep learning method based on a 3D U-Net architecture, trained to partition the omecamtiv mecarbil (OM) binding site of cardiac myosin into fragment-specific regions using only local shape and physico-chemical features. The model was trained on labelled Molecular Dynamics (MD) trajectories of OM-bound myosin in both post-rigor (PR) and pre-power-stroke (PPS) states, achieving an accuracy of ~95% and a mean Intersection over Union (mIoU) > 0.75 on unseen trajectories from both states. When applied to apo trajectories, FragBEST-Myo-derived descriptors produced rankings consistent with similarity to holo conformations. Moreover, selecting apo frames based on FragBEST-Myo ranking increased the chance of recovering holo-like OM docking poses relative to randomly chosen control frames, supporting its use as a screening tool for ensemble docking. Beyond frame selection, fragment maps provide a compact representation to assess docking poses and to guide fragment-based design. Our proof-of-concept provides a basis for developing future general models applicable to a broader range of proteins and ligands, with the fragment-based formulation offering a natural route to generalisation. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=103 SRC="FIGDIR/small/703009v1_ufig1.gif" ALT="Figure 1"> View larger version (32K): org.highwire.dtl.DTLVardef@1551255org.highwire.dtl.DTLVardef@26bf73org.highwire.dtl.DTLVardef@1e3181forg.highwire.dtl.DTLVardef@44baf7_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioinformatics↗

Ultra-High-Throughput LC-MS Method for Targeted Protein Degradation Compound Screening Using the Orbitrap Astral Mass Spectrometer

High-throughput proteomics analysis is crucial for targeted protein degradation (TPD) compound screening. Here, we developed a 300 sample per day (SPD) LC-MS method using the Orbitrap Astral mass spectrometer for ultra-high-throughput TPD compound screening. We identified close to 8,000 protein groups from a single cell line with a coefficient of variance (CV) of less than 10%, highlighting the deep proteome coverage and method reproducibility even at 300 SPD. This high degree of precision provides the statistical confidence to detect subtle, yet significant, changes in protein abundance that were previously challenging to quantify in high-throughput workflows. To evaluate the quantitation accuracy of this method, we further mixed the digests from two or three species at different ratios. Our three-proteome mixture results demonstrated highly accurate quantitation for proteins with both small and large fold changes. Moreover, our two-proteome mixture experiment, where 20 to 160 ng of yeast digest was spiked into 200 ng of HeLa digest, showed an R2 of 0.999 for the yeast proteome, underscoring the quantitation accuracy of the method. Utilizing this workflow, we studied dose-dependent protein degradation patterns induced by pomalidomide, iberdomide, and mezigdomide. Our results indicate that mezigdomide may possess enhanced efficacy in T cells by degrading additional proteins such as IKZF2, thereby boosting anti-cancer immunity. Together, we developed an ultra-high-throughput LC-MS method with excellent proteome coverage and quantitation accuracy that is highly suitable for chemoproteomics screening of drug libraries.

biochemistry↗

Bivalent ligands as a new universal chemotype of BCL6 degrader by inducing aggregation

BCL6 naturally exists as a homodimer to exert its transcriptional repressive function. Previous studies shown that molecular glue BI3802 can induce BCL6 dimer polymerization and thus degradation by ubiquitin-proteasome system. In this study we proposed a new strategy to degrade BCL6 by its homo-bivalent ligands, which can be rationally designed by assemble two BCL6 BTB ligands via linker. These homo-bivalent degraders (HBiDs) can induce polymerization of BCL6 dimer through chain assembly and ultimately lead to its ubiquitination and degradation. Since HBiD does not require a fragment to interact with components of protein degradation system, it could exhibit better target selectivity than traditional protein degraders while avoid drug resistance caused by mutations in protein degradation components. Here we will provide the proof-of-concept evidences for HBiD as BCL6 degrader. Most HBiDs synthesized in this study could degrade BCL6 regardless of the chemotype of BCL6 ligands, with extraordinary target selectivity. The degradation of BCL6 depends on the aggregation of BCL6 dimer induced by HBiD and the recruitment of SIAH1, the natural E3 ligase of BCL6. As protein dimerization is a common phenomenon in cells, HBiD may provide us with a powerful strategy for designing protein degraders as drug candidates or molecular probes.

biochemistry↗

irCLIP-RNP and Re-CLIP reveal patterns of dynamic protein associations on RNA

RNA binding proteins (RBPs) control varied processes, including RNA splicing, stability, transport, and translation1-3. Dysfunctional RNA-RBP interactions contribute to the pathogenesis of human disease1,4,5, however, characterizing the nature and dynamics of multiprotein assemblies on RNA has been challenging. To address this, non-isotopic ligation-based ultraviolet crosslinking immunoprecipitation6 was combined with mass spectrometry (irCLIP-RNP) to identify RNA-dependent associated proteins (RDAPs) co-bound to RNA with any RBP of interest. irCLIP-RNP defined landscapes of multimeric protein assemblies on RNA, uncovering previously unknown patterns of RBP-RNA associations, including cell-type-selective combinatorial relationships between RDAPs and primary RBPs. irCLIP-RNP also defined dynamic RDAP remodeling in response to epidermal growth factor (EGF), uncovering EGF-induced recruitment of UPF1 adjacent to HNRNPC to effect splicing surveillance of cell proliferation mRNAs. To identify the RNAs simultaneously co-bound by multiple studied RBPs, a sequential immunoprecipitation irCLIP (Re-CLIP) method was also developed. Re-CLIP confirmed binding relationships seen in irCLIP-RNP and detected simultaneous HNRNPC and UPF1 co-binding on RND3 and DDX3X mRNAs. irCLIP-RNP and Re-CLIP provide a framework to identify and characterize dynamic RNA-protein assemblies in living cells.

molecular biology↗

Telomere-to-telomere, gap-free genome of mung beans (Vigna radiata) provides insights into domestication under structural variation

Mung bean (Vigna radiata), an essential annual legume, holds substantial value in global agriculture due to its short growth cycle, low input requirements, and nutritional benefits. Despite extensive domestication, the genetic mechanisms underlying its morphological and physiological evolution remain incompletely understood. In this study, we present a gap-free, telomere-to-telomere genome assembly of the mung bean cultivar Weilv-9, achieved through the integration of PacBio HiFi, Oxford Nanopore, and Hi-C sequencing technologies. The 500 Mb assembly, encompassing 11 chromosomes and containing 28,740 protein-coding genes, reveals that 49.17% of the genome comprises repetitive sequences. Within the genome, we found the recent amplification of transposable elements significantly impacts the expression of nearby genes. Furthermore, integrating structural variation and SNP data from resequencing, we identified that the fatty acid synthesis, suberin biosynthetic, and phenylpropanoid metabolic processes have undergone strong selection during domestication. These findings provide valuable insights into the genetic mechanisms driving domestication and offer a foundation for future genetic enhancement and breeding programs in mung beans and related species.

genomics↗

Genome duplications, genomic conflict, and rapid phenotypic evolution characterize the Cretaceous radiation of Fagales

O_LIFlowering plant lineages display remarkable diversity in life history and morphological form. However our understanding of how this phenotypic diversity or disparity, arises and what, if any, relation there is to processes such as gene and genome duplication remains unlcear. C_LIO_LIHere we investigate the relationship between phenotypic and genomic evolution in the angiosperm order Fagales, a lineage of woody plants that has been a dominant component of temperate and subtropical forests since the Late Cretaceous. To this end, we examine newly generated trait and transcriptomic datasets spanning the phylogenetic breadth of the order, including most extant genera as well as a rich diversity of Cretaceous fossil representatives. C_LIO_LIOur phylogenomic analyses resolved the location of an ancient polyploidization event in Juglandaceae and identified hotspots of gene-duplication and genomic conflict across the order. Examinations of phenotypic evolution (including morphospace occupancy and rate shifts) show that the morphospace occupied by Fagales was filled by the early Cenozoic and rates of evolution were highest during the early radiation of the Fagales crown and its major families. Many instances of phenotypic rates also correspond to hotspots of gene duplication. C_LIO_LIOur results show that Fagales conform to an "early burst" model of phenotypic diversification, with morphospace being filled early in the groups evolutionary history. Our study is consistent with others showing a decoupling of species diversification with other biological processes (e.g., phenotypic and genomic evolution), underscoring the complexity of understanding the major drivers of plant evolution over broad timescales. C_LI

evolutionary biology↗

Cancer mutations rewire the RNA methylation specificity of METTL3-METTL14

Chemical modification of RNAs is important for post-transcriptional gene regulation. The METTL3-METTL14 complex generates most N6-methyladenosine (m6A) modifications in mRNAs, and dysregulated methyltransferase expression has been linked to numerous cancers. Here we show that changes in m6A modification location can impact oncogenesis. A gain-of-function missense mutation found in cancer patients, METTL14R298P, promotes malignant cell growth in culture and in transgenic mice. The mutant methyltransferase preferentially modifies noncanonical sites containing a GGAU motif and transforms gene expression without increasing global m6A levels in mRNAs. The altered substrate specificity is intrinsic to METTL3-METTL14, helping us to propose a structural model for how the METTL3-METTL14 complex selects the cognate RNA sequences for modification. Together, our work highlights that sequence-specific m6A deposition is important for proper function of the modification and that noncanonical methylation events can impact aberrant gene expression and oncogenesis.

biochemistry↗

Geraniol Enhances Inhibitory Inputs to Paraventricular Thalamic Nucleus and Induces Sedation in Mice

Geraniol (GE), a plant-derived acyclic monoterpene, shows a wide variety of beneficial effects. Notably, recent studies have reported the potential sedative effects of GE in fish and rats. However, the mechanisms of GE in sedation remain elusive. Here, we found that GE reduced locomotion, relieved pentylenetetrazol (PTZ)-induced seizures, altered the electroencephalogram (EEG), and facilitated general anesthesia in mice. Meanwhile, GE decreased c-Fos expression and suppressed the calcium activity in the paraventricular thalamic nucleus (PVT). Microinjection of GE into the PVT reduced locomotion and facilitated propofol-induced anesthesia. Furthermore, the electrophysiology results showed that GE-induced dramatic membrane hyperpolarization and suppressed the neuronal activity of PVT neurons, mainly by prolonging spontaneous inhibitory postsynaptic currents and inducing tonic inhibitory currents via GABAA receptors. Our study revealed that GE enhances inhibitory inputs to PVT neurons and induces sedation in mice. These findings provide a potential candidate for further development of sedatives and anesthetics. Graphic Summary O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=156 SRC="FIGDIR/small/441289v1_ufig1.gif" ALT="Figure 1"> View larger version (37K): org.highwire.dtl.DTLVardef@fd8424org.highwire.dtl.DTLVardef@1ee77caorg.highwire.dtl.DTLVardef@faab42org.highwire.dtl.DTLVardef@101b921_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

Gene duplications and genomic conflict underlie major pulses of phenotypic evolution in gymnosperms

Inferring the intrinsic and extrinsic drivers of species diversification and phenotypic disparity across the Tree of Life is a major challenge in evolutionary biology. In green plants, polyploidy (or whole-genome duplication, WGD) is known to play a major role in microevolution and speciation1, but the extent to which WGD has shaped macroevolutionary patterns of diversification and phenotypic innovation across plant phylogeny remains an open question. Here we examine the relationship of various facets of genomic evolution--including gene and genome duplication, genome size, and chromosome number--with macroevolutionary patterns of phenotypic innovation, species diversification, and climatic occupancy in gymnosperms. We show that genomic changes, such as WGD and genome-size shifts, underlie the origins of most major extant gymnosperm clades, and notably our results support an ancestral WGD in the gymnosperm lineage. Spikes of gene duplication typically coincide with major spikes of phenotypic innovation, while increased rates of phenotypic evolution are typically found at nodes with high gene-tree conflict, representing historic population-level dynamics during speciation. Most shifts in gymnosperm diversification since the rise of angiosperms are decoupled from putative WGDs and instead are associated with increased rates of climatic occupancy evolution, particularly in cooler and/or more arid climatic conditions, suggesting that ecological opportunity, especially in the later Cenozoic, and environmental heterogeneity have driven a resurgence of gymnosperm diversification. Our study provides critical insight on the processes underlying diversification and phenotypic evolution in gymnosperms, with important broader implications for the major drivers of both micro- and macroevolution in plants.

evolutionary biology↗

The proximal proteome of 17 SARS-CoV-2 proteins links to disrupted antiviral signaling and host translation

Viral proteins localize within subcellular compartments to subvert host machinery and promote pathogenesis. To study SARS-CoV-2 biology, we generated an atlas of 2422 human proteins vicinal to 17 SARS-CoV-2 viral proteins using proximity proteomics. This identified viral proteins at specific intracellular locations, such as association of accessary proteins with intracellular membranes, and projected SARS-CoV-2 impacts on innate immune signaling, ER-Golgi transport, and protein translation. It identified viral protein adjacency to specific host proteins whose regulatory variants are linked to COVID-19 severity, including the TRIM4 interferon signaling regulator which was found proximal to the SARS-CoV-2 M protein. Viral NSP1 protein adjacency to the EIF3 complex was associated with inhibited host protein translation whereas ORF6 localization with MAVS was associated with inhibited RIG-I 2CARD-mediated IFNB1 promoter activation. Quantitative proteomics identified candidate host targets for the NSP5 protease, with specific functional cleavage sequences in host proteins CWC22 and FANCD2. This data resource identifies host factors proximal to viral proteins in living human cells and nominates pathogenic mechanisms employed by SARS-CoV-2. Author SummarySARS-CoV-2 is the latest pathogenic coronavirus to emerge as a public health threat. We create a database of proximal host proteins to 17 SARS-CoV-2 viral proteins. We validate that NSP1 is proximal to the EIF3 translation initiation complex and is a potent inhibitor of translation. We also identify ORF6 antagonism of RNA-mediate innate immune signaling. We produce a database of potential host targets of the viral protease NSP5, and create a fluorescence-based assay to screen cleavage of peptide sequences. We believe that this data will be useful for identifying roles for many of the uncharacterized SARS-CoV-2 proteins and provide insights into the pathogenicity of new or emerging coronaviruses.

microbiology↗

Base-rate neglect and neural computations for subjective weight in probabilistic inference

AO_SCPLOWBSTRACTC_SCPLOWHumans show systematic biases when estimating probability of uncertain events. Base-rate neglect is a well-known bias that describes the tendency to underweight information from the past relative to the present. In this study, we characterized base-rate neglect at the computational and neural implementation levels. At the computational level, we established that base-rate neglect arises from insufficient adjustment to weighting prior information in response to changes in prior variability. At the neural implementation level, we found that orbitofrontal cortex (OFC) and medial prefrontal cortex (mPFC) represent subjective weighting of information that reflects base-rate neglect. Critically, both subjective-weight and subjective-value signals that guide choice were found in mPFC. However, subjective-weight signals preceded subjective-value signals. These results indicate that when facing multiple sources of information, estimation bias such as base-rate neglect arises from information weighting computed in OFC and mPFC, which directly contributes to subjective-value computations that guide decisions under uncertainty.\n\nSO_SCPLOWIGNIFICANCEC_SCPLOW SO_SCPLOWTATEMENTC_SCPLOWFacing uncertainty, estimating the probability of different potential outcomes carries significant weight in affecting how we act and decide. Decades of research show that humans are prone to giving biased estimation but it remains elusive how these biases arise in the brain. We focus on base-rate neglect, a well-known bias in probability estimation and find that it is tightly associated with activity in the medial prefrontal cortex and orbitofrontal cortex. These regions represent the degree to which human participants weigh different sources of information, suggesting that base-rate neglect arises from information-weighting computations in the brain. As technology provides us the opportunity to seek and gather information at an ever-increasing pace, understanding information-weighting and its biases also carry important policy implications.

neuroscience↗