Biology subjects

Liu, B.

Publications and source records attributed to Liu, B..

At least 109 records · Page 6Linked to original sources

bioRxiv2025

Prime assembly with linear DNA donors enables large genomic insertions

Targeted insertion of large DNA fragments has promising applications for genome engineering and gene therapy1,2. Twin prime editing (PE) guide RNAs (pegRNAs) have enabled relatively large insertions, but the efficiency remains low for insertions greater than 400 base pairs3-6. Here we describe a Prime Assembly (PA) approach for the insertion of large DNA donor fragments, whose ends are designed to overlap with the flaps generated by twinPE. We used PA to insert one, two, or three overlapping DNA fragments, with total insertion sizes ranging from 0.1 to 11 kilobase pairs. An inhibitor of non-homologous end joining (NHEJ) enhanced both the efficiency and precision of insertions. PA relies on DNA templates that are easily produced and does not require co-delivery of exogenous DNA-dependent DNA polymerases. Our study demonstrates that PA can initiate "Gibson-like" assembly in cells to generate gene insertions without double-stranded DNA breaks or recombinases.

biochemistry↗

bioRxiv2025

Cell type specific CaMKII activation patterns revealed by CaMKAR, a bioactivity reporter deployable in living cells

An accurate and precise mechanism for measuring CaMKII activity in living cells is invaluable in the search for effective and targeted CaMKII-based therapeutics. Here, we employ our recently published CaMKII Activity Reporter (CaMKAR) biosensor in order to investigate the spatiotemporal dynamics of CaMKII activation in three different types of cells - cardiac myocytes, skeletal myocytes, and neurons. In doing so, we found a greater rate of CaMKII activation in skeletal muscle compared to cardiac muscle and also delineated CaMKARs ability to measure discrete CaMKII activation events in the presence of individual action potentials. By modifying the original CaMKAR sequence, we generated sensors that can be localized to subcellular compartments and thereby preferentially detect the activity of specific spatially-distributed CaMKII isoforms. Finally, we utilized the live-cell data to generate mathematical models of CaMKII activation kinetics, both as an integrated function across multiple calcium transients and as discrete on-off events following individual depolarizations. By furthering our understanding of CaMKII activity profiles across cell types and within subcellular compartments, we hope to support development of CaMKII inhibitors that are optimally precise and potent.

molecular biology↗

bioRxiv2025

Loss of Ythdf3 causes Danon disease-like features

YTH domain-containing family (YTHDF1/2/3) recognizes m6A modified mRNAs and regulates their stability, translation and function. We found loss of Ythdf3 in mice caused cardiac hypotrophy, myopathy, and intellectual abnormalities, resembling the clinical features of a rare inherited X-linked disorder Danon disease (DD). Mechanistically, this was attributable to the compromised mRNA decay of sex-determining region Y (SRY)-box 9 (Sox9), mediated by YTHDF3 m6A reader function. Targeted therapy with AAV-shRNA against Sox9 ameliorated fibrosis, increased neuron number, and significantly improved heart and brain function in Ythdf3-/- mice. Our data reveal that loss of murine Ythdf3 recapitulates systemic DD-like features, attributable to impaired Sox9 decay, and highlight a novel therapeutic target for DD.

molecular biology↗

bioRxiv2025

H3K4me1 directs H3K36me2 and H3K36me3 deposition in land plants

Monomethylation of histone H3 lysine 4 (H3K4me1) marks enhancers in mammals. However, the function of H3K4me1 in plants remains largely unclear. Here, we analyzed the genome-wide distribution of H3K4me1 in diverse species across evolution, revealing a distinctive H3K4me1 distribution pattern in land plants. To explore the function of H3K4me1 in plants, we identified an H3K4me1-specific reader protein, Early heading date 3 (Ehd3), and solved the structure of Ehd3 in complex with the H3K4me1 peptide, revealing a unique binding module differing from the previously reported PHD finger proteins. We further identified an Ehd3-binding protein, SET domain group 724 (SDG724), and the deletion of either Ehd3 or SDG724 caused similar defects in plant phenotype and changes in transcriptome and epigenome profiles. Both Ehd3 and SDG724 are enriched at chromatin regions marked by H3K4me1 but not H3K4me2 or H3K4me3. Ehd3 activates the H3K36 methyltransferase SDG724, and H3K36me2/me3 are colocalized with H3K4me1 in the genomes of land plants. Collectively, our results reveal that H3K4me1 directs the establishment of H3K36me2 and H3K36me3 in land plants.

molecular biology↗

bioRxiv2025

Skin microbiome composite features in Atopic Dermatitis via integration analysis across cohorts

Disruption of the skin microbiota is closely associated with the onset and progression of Atopic Dermatitis (AD). However, inconsistencies across studies have hindered a comprehensive understanding of their role in AD and their potential as reliable diagnostic biomarkers. To address this, we conducted a cross-cohort integrative analysis (CCIA) of raw 16S rRNA sequencing data and metadata from the largest available dataset to date, encompassing 1,522 samples across 10 independent studies. We identified consistent microbial signatures distinguishing AD patients from healthy controls. Significant alterations were observed in both -diversity and community composition between AD and control groups, while lesional and non-lesional sites within AD patients showed no significant differences. Given the impact of confounding factors on the skin microbiota, we applied MMUPHin framework to correct for batch effects and performed subgroup analyses based on different batches. Differential taxa were identified using Permutation testing, Wilcoxon rank-sum tests, and LEfSe analysis. These features were used to develop predictive models with four machine learning algorithms, achieving high diagnostic accuracy in an independent validation cohort (AUROC = 0.83). Our study provides a comprehensive reference of skin microbial alterations in AD, offering valuable insights into host-microbe interactions and highlighting their potential as diagnostic biomarkers for early detection and targeted therapeutic strategies.

bioinformatics↗

bioRxiv2025

F-53B damages cell viability leading to impaired root development in Arabidopsis

The emerging contaminant chlorinated polyfluoroalkyl ether sulfonate (Cl-PFAES/F-53B) has been detected in many plant species, however, the impact of F-53B on the development in plants and the underpinning mechanisms remain largely unelucidated. In this study, we demonstrate by molecular biology, cytogenetics, and fluorescence microscopy mythologies that F-53B impairs cell viability leading to disrupted root development in Arabidopsis (Arabidopsis thaliana). We show that F-53B suppresses root length and the inhibitory effect is pronunanced at increasing concentrations. F-53B disrupts cell wall and microtubule-mediated cell plate formation and configuration in meristem cells, revealing its toxicity to cell division and cytoskeleton organization. F-53B induces cell death predominantly at the meristematic zone, however, gene exression and genetic studies indicate that F-53B does not trigger DNA double-strand breaks, implying a divergent effect on DNA stability across species. Moreover, we show that F-53B damages nuclei stability and viability, and induces Autophagy-Related 8 protein foci formation implying that it triggers autophagy-mediated cell responses. Taken together, this study provides cellular and molecular insights into the toxicity of F-53B to plant cells, which highlights its damage to agriculture and ecology security that deserve imperative environmental management actions. Environmental ImplicationF-53B has been detected in many plant species, which raises increasing concerns on its toxicity to plants and thus agriculture and ecology safety. However, the toxicity of F-53B to development in plants and the underpinning mechanisms remain largely unelucidated. Here, we demonstrate that F-53B damages nuclei stability and viability leading to cell death and impaired root development in the model plant species Arabidopsis thaliana. Our study provides cytogenetic and molecular insights into the F-53B toxicity to plant cells, which highlights imperative environmental management actions and can be referenced for developing F-53B control and management policies. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=143 SRC="FIGDIR/small/653422v1_ufig1.gif" ALT="Figure 1"> View larger version (33K): org.highwire.dtl.DTLVardef@159b211org.highwire.dtl.DTLVardef@1b99a95org.highwire.dtl.DTLVardef@53b964org.highwire.dtl.DTLVardef@b089be_HPS_FORMAT_FIGEXP M_FIG C_FIG One-sentence summaryF-53B triggers DNA double-strand break-free cell unviability leading to impaired meristematic cell division and root development in plants. HIGHLIGHTSO_LIF-53B impairs root development in Arabidopsis. C_LIO_LIF-53B prohibits mitotic cell division at root tips. C_LIO_LIF-53B damages cell viability predominantly at the meristematic zone in seedlings. C_LIO_LIF-53B does not induce DNA double-strand breaks in Arabidopsis seedlings. C_LIO_LIF-53B damages nuclei viability and stability in seedlings. C_LI

developmental biology↗

bioRxiv2025

When is microbial cross-feeding evolutionarily stable?

Cross-feeding, a phenomenon in which organisms share metabolites, is frequently observed in microbial communities across the natural world. One of the most common forms is waste-product cross-feeding, a unidirectional interaction in which the waste products of one microbe support the growth of another. Despite its ubiquity, it is not well-understood why waste-product cross-feeding persists when a single organism could in principle perform both the producer and consumer role. To address this question, we first analyze cross-feeding evolution in a minimal model of microbial metabolism. The model describes multi-step extraction of energy from a substrate in a simple but thermodynamically correct formulation. Surprisingly, we find that cross-feeding is never evolutionarily stable in this model. By analyzing models with more complex growth functions, we identify a novel mechanism for the evolutionary stability of waste-product cross-feeding, namely, generalized intracellular metabolite toxicity. Such toxicity arises because, in excess, the same intracellular metabolites that cells require for metabolism can be detrimental to growth (e.g., due to osmotic stress). We show that some but not all forms of such toxicity can lead to evolutionarily stable consortia of microbes that cross-feed waste products. This stability results from the potential of such consortia to divide the burden of toxic metabolites among a larger population, allowing them to perform their collective metabolism more efficiently than non-cross-feeders. More generally, we predict that growth penalties that scale nonlinearly with intracellular metabolite levels promote cross-feeding. We find that this mechanism for cross-feeding evolutionary stability implies nontrivial population dynamics, such as a discontinuity in population biomass at the onset of cross-feeding. Significance statementThe chemical reactions performed by microbes have large impacts on our world: from nitrification within the nitrogen cycle to the breakdown of fiber in animal digestive tracts. A striking commonality in many of these processes is that the chemical reactions are a collective effort, with the complete reaction subdivided between many microbes. This phenomenon is known as cross-feeding, and its origins are poorly understood. Understanding the eco-evolutionary forces promoting cross-feeding have the potential to not only enhance our understanding of natural ecosystems, but also improve our ability to engineer such distributed reactions in biotechnology. Here, we develop mathematical theory for the evolution of a common type of cross-feeding and provide predictions for what metabolic and environmental conditions promote this behavior.

microbiology↗

bioRxiv2025

Structural insights into the remodeled RNA polymerase II complex on an RNA template

DNA-dependent RNA polymerases (DdRPs) recognize not only DNA but also RNA templates. This RNA-dependent RNA polymerase (RdRP) activity is exploited by viroids in plants and human hepatitis delta virus in animals. A major knowledge gap exists regarding the molecular basis conferring this RdRP activity. Here, we provide evidence supporting the reorganization of the 12-subunit Pol II to 7-subunit in vivo for PSTVd transcription. Rpb4, Rpb5, Rpb6, Rpb7, and Rpb9 are not involved in PSTVd transcription in planta. A splicing variant of transcription factor IIIA with seven zinc finger domains (TFIIIA-7ZF) aids the remodeled Pol II in transcribing PSTVd. Using AlphaFold3, the structure of the remodeled Pol II with PSTVd RNA and TFIIIA-7ZF was generated. The predicted structure and experimental data both show that the N-terminus of TFIIIA-7ZF binds to the left terminal domain of PSTVd, while the C-terminus interacts with Rpb2. Interestingly, AlphaFold3 also predicts the bending at PSTVd loop 8 in the TFIIIA-7ZF/PSTVd complex. Replacing this loop 8 with a rigid double-stranded conformation impairs the TFIIIA-7ZF/PSTVd interaction. Altogether, our demonstrate an active form of heterogenous organization of the essential Pol II enzyme in vivo and provide structural insights into the organization of Pol II transcription complex on RNA template.

molecular biology↗

bioRxiv2025

Biochemical characterization and mucosal immune function of IgT in grass carp (Ctenopharyngodon idella)

Immunoglobulin T (IgT) is a teleost-specific immunoglobulin discovered to be specialized in mucosal immunity. For fish that live in water throughout their lives, eliciting a local mucosal immune response through immersion immunization is an important and highly suitable way for preventing fish diseases. However, due to the lack of corresponding antibodies against IgT, studies on its immune responses to pathogens and vaccines in commercial fish have largely been limited to rainbow trout. Thus, a valuable tool for assessing mucosal immune response to immersion vaccination is still lacking in most commercial fish species. In this study, we expressed and purified recombinant protein of the heavy chain constant domains (CH) 1-2 of grass carp IgT and immunized mice to develop a mouse anti-grass carp IgT monoclonal antibody (mAb). Western blotting results showed that the mAb could specifically recognize grass carp IgT without cross-reacting with grass carp IgM, IgMT1 or IgMT2. We then measured IgM and IgT concentrations in the serum and gill mucus of grass carp and examined the responses of specific IgM and IgT to immersion immunization with grass carp reovirus genotype (GCRV-) and Flavobacterium columnare. We found that the concentration of IgT in gill mucus was higher than that in serum, and the IgT/IgM ratio in gill mucus was much higher than that in serum. Moreover, after immersion immunization, the specific IgT levels in gill mucus increased significantly, while no specific IgT was detected in serum. In contrast, the specific IgM levels in serum increased significantly, whereas there was little change in specific IgM levels in gill mucus. These results indicated that IgT is an important immunoglobulin in mucosal immune response, whereas IgM plays an important role in systemic immune response in grass carp. In summary, these findings not only further elucidate the biochemical and functional differences between IgM and IgT in grass carp, but also provide a valuable detection tool for accurately evaluating the immune efficacy of immersion vaccines in grass carp.

immunology↗

bioRxiv2025

A role of villin-dependent F-actin organization in peroxisome motility in Arabidopsis cells

Actin microfilaments (F-actin) serve as the track for directional movement of organelles in plants. To understand how the F-actin network is employed for the movement of peroxisomes, essential organelles in plant metabolism, we analyzed mutants of three villin (VLN) genes, which encode the primary actin-bundling factor and are most actively expressed in vegetative tissues in Arabidopsis thaliana. We found that the vln4 mutation greatly exacerbated the growth and subcellular defects in vln2 vln3. Compared to the wild-type cells, the double and triple vln mutants exhibit progressive reduction of stable F-actin bundles and rapid remodeling of the fine filaments. The defective F-actin network did not prevent peroxisomes from taking on both rapid and slow movements along the tracks but caused significantly reduced speed of movement and displacement distance of peroxisomes. Using a correlation analysis method, we classified the complex heterogeneous peroxisome movement patterns into clusters reflecting distinct movement directionalities. The vln triple mutant had significantly reduced number of peroxisomes with long-range and linear movement. Our results provide insights into how VLN-dependent F-actin organization is coupled with the complex pattern of peroxisome movement.

plant biology↗

bioRxiv2025

EasyMultiProfiler: An Efficient Multi-Omics Data Integration and Analysis Workflow for Microbiome Research

O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=141 SRC="FIGDIR/small/649266v1_ufig1.gif" ALT="Figure 1"> View larger version (60K): org.highwire.dtl.DTLVardef@14dd0b1org.highwire.dtl.DTLVardef@1c04a79org.highwire.dtl.DTLVardef@159894dorg.highwire.dtl.DTLVardef@1454a01_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical AbstractC_FLOATNO C_FIG HighlightsO_LIEasyMultiProfiler provides unified integration of microbial multi-omics data C_LIO_LIEasyMultiProfiler enables natural language-style analytical workflows C_LIO_LIEasyMultiProfiler solves key challenges in standardization and reproducibility C_LIO_LIEasyMultiProfiler extracts meaningful biological insights efficiently C_LI Host-microbiome interactions are crucial in maintaining physiological homeostasis and influencing disease progression. While traditional microbiome research, focused on microbial diversity and abundance, provided essential frameworks, the integration of multi-omics approaches established a far more comprehensive, systems-level understanding of microbiome functionality. However, significant methodological challenges in multi-omics data integration remain, including inconsistent sample coverage, heterogeneous data formats, and complex downstream analytical workflows. These challenges impact the reproducibility and reliability of results and underscore the critical requirement for developing standardized, systematic workflows. Thus, we developed the EasyMultiProfiler (EMP) workflow, a streamlined and efficient analytical framework for multi-omics data analysis. EMP provides a comprehensive infrastructure based on the SummarizedExperiment and MultiAssayExperiment classes, creating a unified framework for storing and analyzing omics data. The frameworks architecture comprises five interconnected functional modules: data extraction, preparation, support, analysis, and visualization. These modules are smoothly integrated into natural language-style analytical workflows, offering users an efficient and standardized solution for multi-omics analysis. EMP addresses critical challenges in multi-omics data analysis, including data integration, workflow standardization, and result reproducibility. The platforms modular architecture and intuitive interface provide researchers and clinicians with a robust, flexible workflow to systematically extract biologically relevant insights from complex multi-omics datasets.

bioinformatics↗

bioRxiv2025

Nuclear 2'-O-methylation regulates RNA splicing through its binding protein FUBP1

2'-O-methylation (Nm) is an abundant RNA modification exists on different mammalian RNA species. However, potential Nm recognition by proteins has not been extensively explored. Here, we employed RNA affinity purification followed by mass spectrometry to identify Nm-binding proteins. The candidates exhibit enriched binding at known Nm sites. Interestingly, some candidates display nuclear localization and functions. We focused on the splicing factor FUBP1. Electrophoretic mobility shift assay (EMSA) validated preference of FUBP1 to Nm-modified RNA. As FUBP1 predominantly binds intronic regions, we profiled Nm sites in chromatin-associated RNA (caRNA) and found Nm enrichment within introns. Depletion of Nm led to increased exon skipping, suggesting Nm-dependent splicing regulation. The caRNA Nm sites overlap with FUBP1 binding sites, and Nm depletion reduced FUBP1 occupancy on modified regions. Furthermore, FUBP1 depletion induced exon skipping in Nm-modified genes, supporting its role in mediating Nm-dependent splicing regulation. Overall, our findings identify FUBP1 as an Nm-binding protein and uncover previously unrecognized nuclear functions for RNA Nm modification.

molecular biology↗

bioRxiv2025

Shared genomic architecture of the brain white matter structural connectome and intelligence

White matter (WM) connections, which facilitate communication between brain regions, substantially impact intellectual performance. However, the shared genetic underpinnings of WM connections and intelligence remain unclear. In the present study, we first conducted genome-wide association studies on the global and regional topological properties of WM connectomes constructed from diffusion-weighted and T1-weighted magnetic resonance images of 26,655 participants from the UK Biobank. Forty-one independent significant single-nucleotide polymorphisms (SNPs) associated with global WM connectome efficiency and 45 SNPs linked to nodal efficiency for 246 brain regions were identified. Then, regional heterogeneity was demonstrated for the genetic correlations between WM connectome efficiency and intelligence. The nodal efficiency of 128 regions with nominally significant genetic correlations with intelligence was determined. Among these, 44 regions and 3 regions shared SNPs with intelligence within the chromosome 6q21 and 3p21.1 locus respectively, and significant causal effects on intelligence were found for 63 regions, mainly in the orbital gyrus and superior frontal gyrus. Finally, we found that the integration of polygenetic score and WM connectome efficiency data was more accurate for predicting individual intelligence than the use of a single data type. These findings improve our understanding of how genes shape the individual WM connectome and intelligence and the relationship between WM connectomes and intelligence.

genomics↗

bioRxiv2025

A differentiated and durable allogeneic strategy applicable to cell therapies

Autologous T cell therapies have shown profound clinical responses; however, their widespread use has been limited primarily due to their individualized manufacturing requirements. To develop a persistent "off-the-shelf" allogeneic (Allo) approach, a multiplex Nme2Cas9-based cytosine base editor was deployed to knockout select HLA Class I and II alleles (HLA-A, HLA-B, and the class II transactivator (CIITA)), while retaining HLA-C to protect from NK cell rejection. Matching the residual HLA-C allele from homozygous donors to the host prevented rejection of the donor T cells by allogeneic host T and NK cells. Site-specific integration of a tumor-specific CAR or TCR into the TRAC locus using SpyCas9 nuclease and an adeno-associated virus (AAV) template allowed for high localized insertion rate while simultaneously removing the endogenous TCR and preventing GvHD. Using a lipid nanoparticle (LNP)-based delivery system of the editing components enabled a robust cell engineering process, achieving high editing rates and cell expansion. These allogeneic T cells demonstrated comparable functional activity to their autologous counterparts in preclinical assays. Moreover, this gene editing approach generated cells with minimal chromosomal aberrations. The Allo strategy has also been applied to induced pluripotent stem cells (iPSCs), suggesting potential applications in regenerative medicine applications.

bioengineering↗

bioRxiv2025

Pangenome analyses of tea plant reveal structural variations driven gene expression alterations and agronomic trait diversification

Tea plants, one of the worlds most economically significant beverage crops, exhibit extensive genetic diversity and a rich array of secondary metabolites. While structural variations (SVs) are key drivers of phenotypic innovation, their regulatory roles in transcriptional networks and agronomic trait diversification remain underexplored in this perennial crop. We constructed a pangenome from 21 representative tea accessions and their wild relatives. Comparative analysis revealed that wild relatives harbor a greater abundance of gibberellin-related genes, whereas cultivated accessions exhibit an expansion of defense-related genes. We identified 522,428 non-redundant SVs, primarily insertions/deletions (73.56%), which were enriched in promoter regions. These SVs influenced the expression of genes governing flavor compounds, including those involved in flavonoid, amino acid, and terpenoid biosynthesis. Population SV analysis of 275 tea accessions uncovered three haplotypes in the ANS3 gene promoter region, with Hap1, containing a 192 bp insertion, predominantly found in wild relatives but largely lost in modern cultivars. This insertion enhanced CtANS3 expression, increasing anthocyanin accumulation. Additionally, a 159 bp insertion in the CtLRR1 promoter reduced resistance to Colletotrichum gloeosporioides in wild relatives. Our findings underscore SVs as pivotal regulators of genomic diversity, flavor differentiation, and adaptive evolution in tea plant domestication.

genomics↗

bioRxiv2025

MNetClass: A Control-Free Microbial Network Clustering Framework for Identifying Central Subcommunities Across Ecological Niches

Investigating microbiome subnetworks and identifying central microbes in specific ecological niches is a critical issue in human microbiome studies. Traditional methods typically require control samples, limiting the ability to study microbiomes at distinct body sites without matched controls. Moreover, some clustering methods are not well-suited for microbial data and fail to identify central subcommunities across ecological niches after clustering. In this study, we present MNetClass, a novel microbial network clustering analysis framework. It utilizes a random walk algorithm and a rank-sum ratio-entropy weight evaluation model to classify key subnetworks and identify central microbes at any body site without the need for control samples. By applying MNetClass to microbiome data from five distinct oral sites, we successfully uncovered site-specific microbial subgroups and their central microbes. Additionally, simulations and Autism Spectrum Disorder (ASD) cohort datasets demonstrated that MNetClass outperforms existing unsupervised microbial clustering methods in terms of both accuracy and predictive power. In case studies, MNetClass identified age-related microbial communities across different oral sites, highlighting its broad applicability in microbiome research. IMPORTANCEMNetClass provides a valuable tool for microbiome network analysis, enabling the identification of key microbial subcommunities across diverse ecological niches. Implemented as an R package (https://github.com/YihuaWWW/MNetClass), it offers broad accessibility for researchers. Here, we systematically benchmarked MNetClass against existing microbial clustering methods across multiple datasets using various performance metrics, demonstrating its superior efficacy. Notably, MNetClass operates without the need for control groups and effectively identifies central microbes, highlighting its potential as a robust framework for advancing microbiome research.

bioinformatics↗

bioRxiv2025

Anticlustering for Sample Allocation To Minimize Batch Effects

High throughput sequencing is a powerful tool for processing large amounts of DNA and RNA samples in batches. Proper experimental design and statistical methods are required to mitigate systematic technical factors due to differences in batches ("batch effects"), as data variation due to these non-biological factors can mask actual biological differences. We propose using anticlustering as an automated method to assign samples to balanced batches. Anticlustering effectively negates differences in (numeric and/or categorical) covariates among batches, and implements user-defined restrictions on the number of batches, the number of samples per batch, and whether to assign certain samples to the same batch ("must-link constraints"). A simulation study shows that anticlustering is better at achieving balance among batches than previous approaches. An application from the UCSF-Stanford Endometriosis Center for Discovery, Innovation, Training and Community Engagement ("ENACT", https://enactcenter.org/) is presented as a real-life example. In the application, multiple samples provided by an individual had to be processed on the same batch, so that comparisons among different samples of the same patient were not diluted by batch effects. The novel Two Phase Must Link (2PML) anticlustering algorithm realized the must-link restrictions while simultaneously obtaining balance among batches regarding disease stage, menstrual cycle phase, case versus control sample, and clinical site. All methods presented here are accessible via the free and open source R package anticlust (https://cran.r-project.org/package=anticlust). An interactive visualization and web-based batch assignment tool are made available in the Rshiny app "anticlust" (https://anticlust.org/).

bioinformatics↗

bioRxiv2025

Cryo-EM structures of the Plant Augmin reveal its intertwined coiled-coil assembly, antiparallel dimerization and NEDD1 binding mechanisms

Microtubule (MT) branch nucleation is fundamental for building parallel MT networks in eukaryotic cells. In plants and metazoans, MT branch nucleation requires Augmin and NEDD1 proteins which bind along MTs and then recruit and activate the gamma-tubulin ring complex ({gamma}-TuRC). Augmin is a fork-shaped assembly composed of eight coiled-coil subunits, while NEDD1 is a WD40 {beta}-propellor protein that bridges across MTs, Augmin, and {gamma}-TuRC during MT branch nucleation. Here, we reconstitute hetero-tetrameric and hetero-octameric Arabidopsis thaliana Augmin assemblies, resolve their subunit interactions using crosslinking mass spectrometry and determine 3.7 to 7.3-[A] cryo-EM structures for the V-junction and extended regions of Augmin. These structures allowed us to generate a complete de novo plant Augmin model that reveals the long-range multi coiled-coil interfaces that stabilize its 40-nm hetero-octameric fork-shaped organization. We discovered the dual calponin homology (CH) domain forming its MT binding site at the end of its V-junction undertake open and closed conformations. We determined a 12-[A] dimeric Augmin cryo-EM structure revealing Augmin undergoes anti-parallel dimerization through two conserved surfaces along Augmins extended region. We reconstituted the NEDD1 WD40 {beta}-propellor with Augmin revealing it directly binds on top its V-junction and enhances Augmin dimerization. Our studies suggest that cooperativity between the Augmin dual CH domains and NEDD1 WD40 binding site may regulate Augmin V-junction dual binding to MT lattices. This unique V-shaped dual binding and organization anchors Augmins along MTs generating a platform to recruit {gamma}-TuRC and activate branched MT nucleation.

biochemistry↗