Biology subjects

Liu, Y.

Publications and source records attributed to Liu, Y..

At least 901 records · Page 50Linked to original sources

bioRxiv2025

Curvature generation and engineering principles from Shewanella oneidensis multi-flagellin flagellum

Motility driven by nanoscale flagella is vital to microbial survival and spread in fluid and structured environments. Absence of native flagellum structures, however, has limited our understanding of the mechanisms of microbial motility, hindering efforts to engineer microbe-based microbots for applications. Here, by cryogenic electron tomography (cryoET) and microscopy (cryoEM), we determined the structural basis of motility driven by the single flagellum anchored to one pole of Shewanella oneidensis MR-1 (S. oneidensis), an electrogenic bacterium commonly used in biotechnology. The structures of the curved flagellum, representing the conformation during motion, are captured, allowing delineation of molecular interactions among the subunits of its three components--filament, hook, and hook-filament junction. The structures of the filament, i.e., the propeller, reveal a varying composition of the flagellin isoforms FlaA and FlaB throughout the filament. Distinct inter-subunit interactions are identified at residues 129 and 134, which are the major determinants of functional differences in motility for the two isoforms. The hook--the universal joint--has a significantly larger curvature than that of the filament, despite both containing 11 curvature-defining conformers of their subunits. Transition between the propeller and universal joint is mediated by hook-filament junction, composed of 11 subunits of FlgK and FlgL, reconciling incompatibility between the filament and hook. Correlating these compositional and structural transitions with varying levels of curvature in flagellar segments reveals molecular mechanism enabling propulsive motility. Mechanistic understandings from S. oneidensis suggest engineering principles for nanoscale biomimetic systems. Graphic abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=133 SRC="FIGDIR/small/637127v1_ufig1.gif" ALT="Figure 1"> View larger version (43K): org.highwire.dtl.DTLVardef@17933forg.highwire.dtl.DTLVardef@1c44ab1org.highwire.dtl.DTLVardef@3d56dorg.highwire.dtl.DTLVardef@1b126b6_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

bioRxiv2025

DAZAP2 functions as a pan-coronavirus restriction factor by inhibiting viral entry and genomic replication

The SARS-CoV-2 pandemic and the emergence of novel variants underscore the need to understand host-virus interactions and identify host factors that restrict viral infection. Here, we perform a genome-wide CRISPR knockout screen to identify host restriction factors for SARS-CoV-2, revealing DAZAP2 as a potent antiviral gene. DAZAP2, previously implicated in SARS-CoV-2 restriction, is found to inhibit viral entry by blocking virion fusion with both endolysosomal and plasma membranes. Additionally, DAZAP2 suppresses genomic RNA replication without affecting the primary translation of viral replicases. We demonstrate that DAZAP2 functions as a pan-coronavirus restriction factor across four genera of coronaviruses. Importantly, knockout of DAZAP2 enhances SARS-CoV-2 infection in mouse models and in human primary airway epithelial cells, confirming its physiological relevance. Mechanistically, antiviral activity of DAZAP2 appears to be indirect, potentially through the regulation of host gene expression, as it primarily localizes to the nucleus. Our findings provide new insights into the host defense system against coronaviruses and highlight DAZAP2 as a potential target for host-directed antiviral therapies. IMPORTANCEDuring viral infection, the host defense response is mediated by a variety of host factors through distinct mechanisms that have yet to be fully elucidated. Although DAZAP2 was previously implicated in SARS-CoV-2 restriction, its mechanisms of action and in vivo relevance remain unclear. In this study, we identify the DAZAP2 as a potent pan-coronavirus restriction factor that inhibits viral infection through dual mechanisms: blocking virion fusion with both endolysosomal and plasma membranes, and suppressing genomic RNA replication. We confirm its physiological relevance in host defense using mouse models and primary cell cultures. This study advances our understanding of host-pathogen interactions. Targeting DAZAP2 or its regulatory pathways could provide a new approach to enhance host defense against current and future coronavirus threats.

microbiology↗

bioRxiv2025

In Silico Discovery of Small Molecule Modulators Targeting Ebola Virus VP 35 and VP 40 protein

Ebola virus (EBoV) proteins VP35 and VP40 are acknowledged as significant pharmacological targets for disrupting viral replication, virion assembly, and the budding process from host cells. We employed molecular docking based throughput virtual screening (HTVS), standard precision (SP), and extra precision (XP) docking to discover candidate compounds. Subsequently, molecular dynamics simulations, and ADMET analyses to identify potential small molecular compounds that could inhibit the Ebola virus. Among 210,590 compounds from the SPECS database, we found the compounds AO-022/43452438, AN-465/43369333, and AN-465/43369198 were optimal candidates for the EBOV-VP35 protein, while AN-465/43369160, AN-465/4341136, and AN-465/43369952 also emerged as optimal compounds for the EBOV-VP40 protein. Furthermore, we employed the energy decomposition technique, MM-GB/SA, to identify the top ten amino acids that significantly contribute to the binding interactions. ADMET result implicated that the six compounds have potential druggability, but special attention should be given to AN-465/43369333 due to potential cardiac toxicity. In conclusions, the six compounds and their key interacting amino acid sites identified in this study may serve as a valuable platform for the future development of novel therapeutics targeting the Ebola virus.

bioinformatics↗

bioRxiv2025

Leopard Cats Occupied Human Settlements in China for 3,500 years before the Arrival of Domestic cats in 600-900 CE around the Tang Dynasty

The earliest cats in human settlements in China were not domestic cats (Felis catus), but native leopard cats (Prionailurus bengalensis). To trace when and how domestic cats arrived in East Asia, we analyzed 22 feline bones from 14 sites across China spanning 5,000 years. Nuclear and mitochondrial genomes revealed that leopard cats began occupying anthropogenic scenes around 5,400 years ago and last appeared in 150 CE. Following several centuries gap of archeological feline remains, the first known domestic cat (706-883 CE) in China was identified in Shaanxi during the Tang Dynasty. Genomic analysis suggested a white or partially white coat and a link to a contemporaneous domestic cat from Kazakhstan, indicating a likely dispersal route via the Silk Road. The two felids once independently occupied ancient anthropogenic environments in China but followed divergent paths and reached different destinations in human-animal interactions.

evolutionary biology↗

bioRxiv2025

Mycobacterium intracellulare ABSURDO is a novel clinical isolate with three colony morphotypes that vary in pathogenicity and sequence at the PKS and MtrA loci

Mycobacterium intracellulare is a nontuberculous mycobacteria (NTM) species which can cause serious and sometimes fatal disease in immunocompromised individuals. Other NTM species, including M. avium and M. abscessus, commonly exhibit two colony morphotypes (smooth and rough) which vary in appearance and liquid growth properties. Here we characterize a novel clinical isolate of M. intracellulare which exhibits three (not two) colony morphotypes which differ in appearance, liquid growth properties, acid-fastness and in vivo survival following infection of mice via an inhalational exposure model. The genome of this isolate, which we have termed ABSURDO, as well as the genome of each morphotype components, aligns with that of M. intracellulare yet contains [~]16% more protein coding sequences than the M. intracellulare type strain ATCC 13590T. Variation analysis of each morphotype genome revealed that across the three morphotypes there were only two mutations which had a high likelihood of causing a phenotype due to a genetic change: one in the gene encoding modular polyketide synthase (PKS), and another in the two component system response regulator MtrA. Neither of these genes have been previously implicated in the morphotype shifting of an NTM. In summary, M. intracellulare ABSURDO is a novel pathogenic isolate with a genome that aligns with (but is nevertheless larger than) the M. intracellulare type strain and comprises three morphotype components which differ in two genes that have not been implicated in NTM appearance, acid-fastness, in vitro and in vivo growth.

microbiology↗

bioRxiv2025

SVCFit: Inferring structural variant cellular fraction in tumors

Therapeutic pressure shapes tumor evolution by selecting for subclones with distinct genomic architectures. In metastatic castration-resistant prostate cancer (mCRPC), structural variants (SVs) are central to this process but rarely incorporated into clonal reconstruction from bulk DNA sequencing. We describe SVCFit, a computational framework that estimates the cellular fraction of diverse SV classes from whole-genome sequencing and uses these estimates to reconstruct clonal evolutionary relationships. SVCFit explicitly models SV-type-specific breakpoint and breakend patterns and accounts for local copy-number context, enabling accurate SV cellular-fraction estimation across heterogeneous tumor genomes. On simulated datasets and in silico mixtures of metastatic prostate cancer samples, SVCFit achieves lower estimation error than SVclone, the current state-of-the-art for bulk-sequencing SV cellular-fraction estimation. Applied to longitudinal whole-genome sequencing from patients with mCRPC treated with bipolar androgen therapy, SVCFit reveals marked treatment-associated clonal reconfiguration, including contraction of highly rearranged subclones and expansion of resistant populations defined by distinct structural alterations. By enabling reconstruction of SV-defined clonal architecture from routine whole-genome sequencing, SVCFit expands the toolkit for studying tumor evolution under therapy in precision oncology. The COMBAT trial that provided these samples is registered on ClinicalTrials.gov (NCT03554317; first posted 13 June 2018).

bioinformatics↗

bioRxiv2025

Uridine Metabolism as a Targetable Metabolic Achilles' Heel for chemo-resistant B-ALL

Relapse continues to limit survival for patients with B-cell acute lymphoblastic leukemia (B-ALL). Previous studies have independently implicated activation of B-cell developmental signaling pathways and increased glucose consumption with chemo-resistance and relapse risk. Here, we connect these observations, demonstrating that B-ALL cells with active signaling, defined by high expression of phosphorylated ribosomal protein S6 ("pS6+ cells"), are metabolically unique and glucose dependent. Isotope tracing and metabolic flux analysis confirm that pS6+ cells are highly glycolytic and notably sensitive to glucose deprivation, relying on glucose for de novo nucleotide synthesis. Uridine, but not purine or pyrimidine, rescues pS6+ cells from glucose deprivation, highlighting uridine is essential for their survival. Active signaling in pS6+ cells drives uridine production through activating phosphorylation of carbamoyl phosphate synthetase (CAD), the enzyme catalyzing the initial steps of uridine synthesis. Inhibition of signaling abolishes glucose dependency and CAD phosphorylation in pS6+ cells. Primary pS6+ cells demonstrate high expression of uridine synthesis proteins, including dihydroorotate dehydrogenase (DHODH), the rate-limiting catalyst of de novo uridine synthesis. Gene expression demonstrates that increased expression of DHODH is associated with relapse and inferior event-free survival after chemotherapy. Further, the majority of B-ALL genomic subtypes demonstrate activity of DHODH. Inhibiting DHODH using BAY2402232 effectively kills pS6+ cells in vitro, with its IC50 correlated with the strength of pS6 signaling across 14 B-ALL cell lines and patient-derived xenografts (PDX). In vivo DHODH inhibition prolongs survival and decreases leukemia burden in pS6+ B-ALL cell line and PDX models. These findings link active signaling to uridine dependency in B-ALL cells and an associated risk of relapse. Targeting uridine synthesis through DHODH inhibition offers a promising therapeutic strategy for chemo-resistant B-ALL as a novel therapeutic approach for resistant disease.

cancer biology↗

bioRxiv2025

Rhamnose-mediated modulation of hair follicle growth: insights from chemical genomics

Pursuing compounds capable of stimulating hair follicle growth or regeneration presents a significant challenge in dermatological research. Dermal papilla (DP) cells, which serve as a dynamic niche for hair follicle stem cells, are often used to identify hair growth-promoting agents as a screening model. Here, we integrated human scalp single-cell RNA sequencing data with human DP cells (hDPCs) gene expression profiles to develop a gene panel for assessing hair follicle inductive potential, then applied a high-throughput sequencing-based high-throughput screening (HTS2) method to quantify the gene expressions of hDPCs perturbed by over 2000 small molecules. Notably, rhamnose was identified as a compound that restored the expression of hair-inducing genes in hDPCs. More importantly, the topical application of rhamnose accelerated hair follicle regeneration by promoting hair cycle into the anagen phase. Transcriptome and central carbon metabolism analyses revealed that rhamnose induced glucose metabolism remodeling favoring glycolysis in mice. A similar phenotype was also observed in rhamnose-treated hDPCs, as demonstrated by glycolysis and mitochondrial stress tests. The present study introduces a novel methodology for evaluating hair-inducing agents and provides valuable insights into the cellular and molecular mechanisms underlying the hair growth-promoting effects of rhamnose. These findings highlight the potential for the therapeutic application of rhamnose in the treatment of alopecia.

pharmacology and toxicology↗

bioRxiv2025

Single-Cell Genomics Elucidates Molecular Variations and Regulatory Mechanisms in Circulating Immune Cells

The human peripheral blood displays diverse molecular characteristics across populations, understanding the drivers and underlying mechanisms of which remains challenging. Here, we introduce the Chinese Immune Multi-Omics Atlas (CIMA), elucidating sex-, age-, and genetic-related molecular variations by analyzing multi-omics data from 428 adults with over 10 million immune cells. CIMA generated an enhancer-driven gene regulatory network, identifying 237 high-quality regulons and revealing cell type-specific regulatory mechanisms. Additionally, 11,521 lead cis-expression quantitative trait loci (eQTLs) and 46,339 chromatin accessibility QTLs (caQTLs) were identified at cell type level. CIMA also uncovered pleiotropic associations among immune-related disease risk loci, eQTLs, and caQTLs in a cell type-specific manner. Lastly, a novel cell language model, CIMA-CLM, was developed to predict chromatin accessibility and noncoding variant effects using chromatin sequences and gene expressions. This work represents a population-scale multi-omics resource of human immune cells, providing a valuable reference for future investigation of immune-related diseases.

immunology↗

bioRxiv2025

Avoidance of fratricide and improved efficacy of CD33-MSLN CAR-iNK cells in treating acute myeloid leukemia

Acute myeloid leukemia (AML) patients are often older, which brings challenges of endurance and persistent efficacy of autologous CAR-T cell therapies. Allogenic CAR-NK cell therapies may offer reduced toxicities and enhanced anti-leukemic potential against AML. In this study, we designed a novel CD33-mesothelin loop CAR (Loop CAR) and evaluated its anti-tumor efficacy in human umbilical cord blood-derived NK (UCB-NK) cells and human pluripotent stem cell-derived NK (hPSC-iNK) cells. The Loop CAR exhibited superior cytotoxicity against dual-antigen-positive tumor cell lines and primary AML cells. To further avoid fratricide caused by endogenous CD33 expression in NK cells, we established a hPSC-derived cell line via knockout of CD33 gene (CD33KO) and engineered Loop CAR. Rather than enforced expression of exogenous CD16, we generated abundant mature CD33KO-Loop CAR-iNK cells highly expressing endogenous CD16 via an organoid induction approach. This innovative strategy effectively mitigated NK cell fratricide and significantly enhanced CD33 and mesothelin-mediated specific cytotoxicity. Moreover, the CD33KO-Loop CAR-iNK cells demonstrated superior tumor-killing activity in AML xenograft mice and significantly prolonged survival. hPSC-derived CD33KO-Loop CAR-iNK cells possess unique advantages and translational potential for treating AML.

cancer biology↗

bioRxiv2025

Engineered CRO-CD7 CAR-NK cells derived from pluripotent stem cells avoid fratricide and efficiently suppress human T-cell malignancies

BackgroundT cell malignancies are highly aggressive hematological tumors with limited effective treatment options. CAR-NK cell therapy targeting CD7 has emerged as a promising approach for treating T-cell malignancies. However, conventional CAR-NK cell therapy faces the challenges of cell fratricide due to CD7 expression on both malignant cells and normal NK cells. Additionally, engineering CARs into human tissue-derived NK cells demonstrates heterogeneity, low transduction efficiency, and high manufacturing costs. MethodsThe human pluripotent stem cells (hPSCs) were genetically modified by knocking out the CD7 gene and introducing the CD7 CAR expression cassette to generate CD7 KO-CD7 CAR-hPSCs. These modified hPSCs were subsequently differentiated into CD7 KO-CD7 CAR-iNK cells using an efficient organoid induction method. The cytotoxicity of CD7 KO-CD7 CAR-iNK cells against CD7+ tumor cells was evaluated. Furthermore, we overexpressed the CXCR4 gene in CD7 KO-CD7 CAR-hPSCs and derived CXCR4-expressing CD7 KO-CD7 CAR-iNK (CRO-CD7 CAR-iNK) cells. The dynamics of CRO-CD7 CAR-iNK cells in vivo were tracked, and their therapeutic efficacy was assessed using human T-cell acute lymphoblastic leukemia (T-ALL) xenograft models. ResultsThe CD7 KO-CD7 CAR-iNK cells derived from CD7 KO-CD7 CAR-hPSCs effectively avoided fratricide, demonstrated normal expansion, and exhibited potent and specific anti-tumor activity against CD7+ T-cell tumor cell lines and primary T-ALL cells. CXCR4 overexpression in CRO-CD7 CAR-iNK cells improved their homing capacity and extended their persistence in vivo. The CRO-CD7 CAR iNK cells significantly suppressed tumor growth and prolonged the survival of T-ALL tumor-bearing mice. ConclusionsOur study provides a reliable strategy for the large-scale generation of fratricide-resistant CD7 CAR-iNK cells with robust anti-tumor effects from hPSCs, offering a promising cell product to treat T-cell malignancy.

cancer biology↗

bioRxiv2025

Fasting-induced hepatic gluconeogenesis is compromised in Anxa6-/- mice

Maintaining constant blood glucose levels is essential for energizing glucose-dependent tissues. During the fed state, insulin lowers elevated blood glucose, while in the fasted state, glucagon maintains blood glucose levels through hepatic stimulation of fatty acid oxidation, glycogenolysis, and gluconeogenesis (GNG). The liver plays a crucial role in these metabolic adaptations. Deregulation of GNG is a hallmark of type 2 diabetes mellitus (T2DM), driven by hepatic insulin resistance, elevated glucagon levels, and excess circulating free fatty acids. Despite normal insulin-sensitive control of glucose levels and effective glycogen mobilization, Anxa6 knockout (Anxa6-/-) mice display rapid hypoglycaemia during fasting. This metabolic disarrangement, in particular during the early stages of fasting is characterized by a low respiratory exchange ratio (RER) and increased lipid oxidation during the diurnal period, indicating a reliance on lipid oxidation due to hypoglycaemia. Elevated glucagon levels during fasting suggest deficiencies in GNG. Further analysis reveals that Anxa6-/- mice are unable to utilize alanine for hepatic GNG, highlighting a specific impairment in the glucose-alanine cycle in fasted Anxa6-/- mice, underscoring the critical role of ANXA6 in maintaining glucose homeostasis under metabolic stress. During fasting, slightly reduced expression levels of alanine aminotransferase 2 (Gpt2) and lactate dehydrogenase (Ldha2), enzymes converting alanine to pyruvate, and the hepatic alanine transporter SNAT4 might contribute to these observations in the Anxa6-/- mice. These findings identify that ANXA6 deficiency causes an inability to maintain glycolytic metabolism under fasting conditions due to impaired alanine-dependent GNG.

physiology↗

bioRxiv2025

Hyperacute Response Proteins (HARPs) synthesized on γ-tubulin-FTO-MARK4 translation microdomains upon exposure to stress, regulate stressresponse in cancer.

Compared to normal, cancer cells are particularly resistant to stress, and their immediate response to stress is critical for their subsequent multilayered adaptation programs which pose a major clinical challenge. With unbiased proteomics and transcriptomics analysis, we identified a list of HARPs synthesized from pre-existing mRNAs within 20 min of diverse stresses in A549 cancer cells, despite the known suppressed global translation in stress. HARP mRNAs were translated on microtubule-associated translation microdomains (MATMs) located on {gamma}-tubulin, that host FTO and specialized cytoskeletal ribosomes, structurally and functionally distinct from ER and cytosolic ribosomes. FTO exited the nucleus immediately after stress and was activated by the microtubule-associated stress kinase MARK4 via T6 phosphorylation. Activated FTO demethylated a translation-inhibiting mRNA methylation (m6A) signature, facilitating compartmentalized HARP translation on MATMs, while non-HARP mRNA remained inhibited. FTO or MARK4 inhibition suppressed HARP synthesis and increased apoptosis post various stresses, including chemotherapy. These data were confirmed in 4 additional cancer cell lines and normal fibroblasts. Using the Protein Atlas database, we found that high levels of our identified HARPs had on average a 35% decrease on patient 5-year survival in prevalent and resistant cancers (breast, lung, liver, pancreas). {gamma}-tubulin, FTO and MARK4 are therapeutic targets for many cancers, through their ability to comprehensively promote HARPs translation, a potential Achilles heel for cancers resistance to physiologic or therapeutic stress, offering a new window in stress biology.

cancer biology↗

bioRxiv2025

Co-Conservation of Synaptic Gene Expression and Circuitry in Collicular Neurons

The superior colliculus (SC), a midbrain sensorimotor hub, is anatomically and functionally similar across vertebrates, but how its cell types have evolved is unclear. Using single-nucleus transcriptomics, we compared the SCs molecular and cellular organization in mice, tree shrews, and humans. Despite over 96 million years of evolutionary divergence, we identified [~]30 consensus neuronal subtypes, including Cbln2+ neurons that form the SC-pulvinar circuit in mice and tree shrews. Synapse-related genes were among the most conserved, unlike neocortex, suggesting co-conservation of synaptic genes and circuitry. In contrast, cilia-related genes diverged significantly across species, highlighting the potential importance of the neuronal primary cilium in SC evolution. Additionally, we identified a novel inhibitory SC neuron in tree shrews and humans but not mice. Our findings reveal that the SC has evolved by conserving neuron subtypes, synaptic genes, and circuitry, while diversifying ciliary gene expression and an inhibitory neuron subtype.

neuroscience↗

bioRxiv2025

Single-cell spatial transcriptome reveals pathological features of human hippocampus with sclerosis

More than half of epileptic patients ultimately turned to intractable epilepsy. Mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS), the most common type of intractable epilepsies, whose pathological mechanism remains elusive. Here, using 42 human hippocampal samples from surgical donors of MTLE (32 with and 10 without HS) through single-cell resolution Stereo-seq and histologcial experiments, we revealed spatially pathological changes of gene expression and cell type composition with HS systematically. After precise parcellation of hippocampal subregions and differentially expressed gene (DEG) analysis between each region with and without sclerosis, we found Cornu Ammonis (CA) subregions with higher number of DEGs were vulnerable to sclerosis, especially CA1 and CA3. Within CA1, we found that CA1-superficial and proximal areas were more vulnerable than CA1-deep and distal areas in sclerosis. Meanwhile, after analyzing 350,795 segmented cells from Stereo-seq, we found dramatically increasing density of astrocyte accompanied with significantly decreasing density of excitatory neurons in CA1, especially superficial and proximal CA1, and CA3 in sclerosis. In these two vulnerable subregions, proliferative astrocyte (P_astrocyte) and reactive astrocyte (R_astrocyte) were found to be enriched whereas apoptotic subtype of astrocyte (A_astrocyte), related with apoptotic pathway, was mainly located in alveus, which strengthened cell communication with reactive microglia (R_microglia) in HS, revealing the novel pathological feature in our work. The pseudotime analysis indicated that CA excitatory neurons underwent synaptic impairment, energy dysfunction, aging, and finally losing cell identity until death through autophagy or apoptosis. Besides, we also found a resilient subtype, EX_CA2-4.3, highly expressed extracellular matrix related genes including PDYN, and was increasing the interaction of BDNF-NTRK, NFASC-CNTN1 to withstand the damage from sclerosis. Together, our study provided a reference of human hippocampus with and without HS caused by MTLE, and highlighted the potential pathological mechanism on molecular and cellular level of MTLE-HS.

neuroscience↗

bioRxiv2025

Tool-use brain representations are independent of the acting body part and motor experience

The sensorimotor system is broadly organized somatotopically. However, an action-type organization has also been found: a division based on action-type independent of acting body parts has been shown for reaching and grasping actions. Does this generalization extend to non-ethological actions? Here, we examined fMRI responses for tool-use actions that participants performed with their hands or feet. We additionally tested individuals born without hands to control for hand motor imagery when performing foot actions. We show that the primary sensorimotor cortices have hand and foot selectivity, consistent with a somatotopic organization. In contrast, higher-level motor areas within the tool-use network, such as the premotor cortex, supplementary motor area, and superior parietal cortices, showed a shared preference for tool-use independent of the executing body part and sensorimotor experience. Multivariate decoding of action-type in these areas generalized between controls hand and foot and was successful in individuals born without hands. Finally, the temporal dynamics pattern in primary and association areas carried effector-specific and action-type information, respectively. Altogether, we show that the tool-use network in motor association areas represents higher-order action information beyond concrete motor parameters associated with specific effectors, and regardless of hand motor experience. This suggests that an action-type, effector-independent organization extends beyond ethological actions, supporting a hierarchical organization in the action domain. Further, it shows that functional organization in congenital handlessness is based on the hierarchical organization of the intact cortex.

neuroscience↗

bioRxiv2025

The epigenetic factor Zrf1 regulates intestinal stem cell proliferation during midgut regeneration

Stem cells are essential for tissue maintenance and regeneration, balancing self-renewal and differentiation to support homeostasis and repair. Through an RNAi screen in the Drosophila midgut, we identified the epigenetic factor Zrf1 as a critical regulator of intestinal stem cell (ISC) proliferation. Functional analyses reveal that Zrf1 integrates inputs from multiple signaling pathways and interacts with components of the RNA-induced silencing complex (RISC). Zrf1 mutants exhibit elevated expression of transposable elements (TEs) and chromatin disruption, highlighting a broader role in genome stability. Single-nuclei RNA sequencing (snRNA-seq) further demonstrated the influence of Zrf1 on chromatin organization and TE repression, particularly within stem cell progenitors. Our findings suggest that Zrf1 is potentially a key chromatin regulator necessary for maintaining stem cell proliferation and genome integrity, enhancing our understanding of the molecular controls underlying stem cell function and chromatin dynamics.

genetics↗

bioRxiv2025

ESMAdam: a plug-and-play all-purpose protein ensemble generator

Proteins often adopt multiple ensemble conformations to perform essential functions such as catalysis, transport, and signal transduction. Traditional physics-based methods for generating these conformations, including molecular dynamics and Monte Carlo simulations, are computationally expensive and time-consuming, limiting their practicality for high-throughput applications like screening. Recent advances in machine learning, particularly deep generative models, offer a promising alternative for protein conformation ensemble generation. However, these models are often task-specific or rely on strong assumptions to generalize. Here, we introduce ESMAdam, a versatile and efficient framework for protein conformation ensemble generation. Using the ESMFold protein language model ESMFold and ADAM stochastic optimization in the continuous protein embedding space, ESMAdam addresses a wide range of ensemble generation tasks. In this work, we demonstrate several basic applications of ESMAdam, including conditional ensemble generation and CG-to-all-atom backmapping. In addition, we showcase advanced applications, such as screening alternative binding modes of protein multimers and reconstructing 3D structures from cryo-EM images. Compared to traditional physics-based methods, ESMAdam significantly reduces computational time. Unlike deep-generative-model-based approaches, it requires no retraining and easily adapts to diverse ensemble restraint conditions, making it exceptionally suited for various structure prediction and screening tasks. This plug-and-play framework represents a step toward efficient and flexible protein ensemble generation for applications in structural biology and drug discovery.

biochemistry↗