Biology subjects

Wang, S.-H.

Publications and source records attributed to Wang, S.-H..

17 recordsLinked to original sources

bioRxiv2026

FM-GPT: Bayesian fine mapping for phenome-wide transcriptome-wide association studies

Transcriptome-wide association studies (TWAS) integrate genome wide association studies with expression quantitative trait locus reference panels to identify genes associated with traits of interest. However, linkage disequilibrium and correlated gene expression can induce spurious TWAS signals, motivating fine mapping methods to prioritize putatively causal genes within associated loci. The rapid growth of large-scale phenomic resources (e.g. electronic health records (EHRs)) has shifted genetic studies from single-trait analyses to phenome-wide investigations that jointly evaluate many closely related phenotypes. We introduce FM-GPT (Fine-mapping of causal Genes for Phenome-wide Transcriptome-wide association studies), a novel Bayesian fine mapping method for prioritizing causal genes across multiple correlated phenotypes with potentially mixed outcome types (e.g., binary, count or continuous) in phenome-wide TWAS. FM-GPT performs gene-guided dimension reduction of the phenotypes and reveals pleiotropic or phenotype-specific effects of the identified genes. In simulations, FM-GPT identified true causal genes more accurately than other fine mapping methods while controlling false positives. We applied FM-GPT to two applications using data from UK Biobank: a brain-wide genetic analysis of MRI data derived regional cortical thickness measures and a phenome-wide genetic analysis of clinical phenotypes derived from EHR data. FM-GPT greatly narrowed down the set size of putatively causal genes and identified: 1. genes with pleiotropic effects on regional cortical thickness across the cerebral cortex, including five genes BCAS3, LRRC37A, NOS2P3, ARL17B and UBB on chromosome 17 regulating neuronal morphology and cortical organization; and 2. genes that influence multiple medical conditions across the circulatory, metabolic, digestive, respiratory and genitourinary systems, revealing two major axes of variation among these conditions that point to a potential trade-off in gene regulation between immune and metabolic functions. These results highlight FM-GPTs power to disentangle complex gene-phenotype relationships in large-scale phenome-wide studies, uncovering shared biological mechanisms across diverse human traits and advancing translational and comorbidity research. Author SummaryWe developed a novel fine mapping method called FM-GPT, to identify putatively causal genes from correlated noise influencing a wide range of human traits and diseases with potentially mixed outcome types (e.g., binary, count or continuous). The rapid expansion of large-scale phenomic datasets has shifted the single-trait genetic studies to phenome-wide analyses, enabling the study of genetic architecture across many related traits simultaneously. FM-GPT performs gene-guided dimension reduction of the phenotypes and reveals pleiotropic or phenotype-specific effects of the identified causal genes. When applied to the UK Biobank data, FM-GPT greatly narrowed down the set size of putatively causal genes compared to other methods. The tool identified genes with pleiotropic effects on regional cortical thickness that regulate neuronal morphology and cortical organization across the cerebral cortex. It also identified genes that influence multiple medical conditions spanning the circulatory, metabolic, digestive, respiratory, and genitourinary systems. Among these conditions, two major axes of variation emerged, revealing a potential trade-off in gene regulation between immune and metabolic functions. This work provides a clearer picture of shared biological mechanisms across traits and diseases, advancing translational research and the understanding of comorbidity.

bioinformatics↗

bioRxiv2026

Breaking β-sheets in FUS prion-like domain preserves phase separation and function but prevents aggregation and toxicity

The RNA-binding protein Fused in Sarcoma (FUS) undergoes phase separation associated with RNA processing. However, the prion-like low complexity (LC) domain of FUS forms solid-like aggregates in neurodegenerative diseases. Whether the formation of {beta}-sheet structure associated with pathology is also physiologically/functionally relevant is debated. Similarly, if mislocalization alone or concomitant aggregation is responsible for FUS gain-of-function toxicity remains to be probed. Here, we introduce {beta}-sheet breaking proline residues into FUS LC with the goal of preventing cross-{beta}-driven aggregation without disrupting essential functions and phase separation. {beta}-sheet-deficient FUS variants maintain native-like global motions, disorder, and phase separation, but no longer show a liquid-to-solid transition (LST). Biochemical partitioning, cellular localization, and auto- and cross-regulatory functions of FUS all remain essentially unchanged. Conversely, FUS-induced neurodegeneration in several Drosophila models is drastically reduced. These findings suggest a strategy for mitigating disease-related toxicity through backbone structure modulation to prevent prion-like domain protein aggregation. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=198 SRC="FIGDIR/small/706410v1_ufig1.gif" ALT="Figure 1"> View larger version (53K): org.highwire.dtl.DTLVardef@d15f63org.highwire.dtl.DTLVardef@1cd6221org.highwire.dtl.DTLVardef@e58126org.highwire.dtl.DTLVardef@181ec67_HPS_FORMAT_FIGEXP M_FIG C_FIG SUMMARYThe RNA-binding protein Fused in Sarcoma (FUS) undergoes phase separation as part of its physiological function but can aberrantly aggregate into solid-like assemblies in amyotrophic lateral sclerosis and frontotemporal dementia. To dissect the role of {beta}-sheets in both function and pathological transition, we engineered {beta}-sheet-preventing FUS variants via targeted proline residue insertions in the prion-like disordered region. These variants retained native structure, motions, and phase behavior yet showed dramatically reduced aggregation, both as an isolated prion-like domain and in full-length FUS. Crucially, these variants maintained a panel of FUS cellular functions that depend on FUS condensation but prevented FUS toxicity in fly models of neurodegeneration. Our findings implicate {beta}-sheets as key drivers of FUS condensate maturation and neuronal toxicity, highlighting {beta}-sheet modulation as a therapeutic strategy against FUS-related neurodegeneration. HIGHLIGHTSO_LITargeted proline additions disrupt {beta}-sheet formation in FUS without altering native conformations, dynamics, or phase separation behavior C_LIO_LI{beta}-sheet-deficient FUS variants prevent aggregation and liquid-to-solid transitions while retaining key biological functions C_LIO_LIIn vivo models reveal attenuated toxicity of {beta}-sheet-deficient FUS in Drosophila C_LIO_LI{beta}-sheets are identified as central drivers of condensate maturation and neuronal death, offering a therapeutic entry point for modulating prion-like domain pathology C_LI

biochemistry↗

bioRxiv2024

Structural details of helix-mediated TDP-43 C-terminal domain multimerization

The primarily disordered C-terminal domain (CTD) of TAR DNA binding protein-43 (TDP-43), a key nuclear protein in RNA metabolism, forms neuronal inclusions in several neurodegenerative diseases. A conserved region (CR, spanning residues 319-341) in CTD forms transient helix-helix contacts important for its higher-order oligomerization and function that are disrupted by ALS-associated mutations. However, the structural details of CR assembly and the explanation for several ALS-associated variants impact on phase separation and function remain unclear due to challenges in analyzing the dynamic association of TDP-43 CTD using traditional structural biology approaches. By employing an integrative approach, combining biophysical experiments, biochemical assays, AlphaFold2-Multimer (AF2-Multimer), and atomistic simulations, we generated structural models of helical oligomerization of TDP-43 CR. Using NMR, we first established that the native state of TDP-43 CR under physiological conditions is -helical. Next, alanine scanning mutagenesis revealed that while hydrophobic residues in the CR are important for CR assembly, phase separation and TDP-43 nuclear retention function, polar residues down regulate these processes. Finally, pairing AF2-Multimer modeling with AAMD simulations indicated that dynamic, oligomeric assemblies of TDP-43 that are stabilized by a methionine-rich core with specific contributions from a tryptophan/leucine pair. In conclusion, our results advance the structural understanding of the mechanisms driving TDP-43 function and provide a window into the initial stages of its conversion into pathogenic aggregates.

biochemistry↗

bioRxiv2024

Impact of the elderly lung mucosa on Mycobacterium tuberculosis metabolic adaptation during infection of alveolar epithelial cells

BackgroundTuberculosis (TB) is one of the top leading causes of death due to a single infectious agent. Upon infection, Mycobacterium tuberculosis (M.tb) is deposited in the alveoli and encounters the lung mucosa or alveolar lining fluid (ALF). We previously determined that increased M.tb replication in human macrophages and alveolar epithelial cells (ATs) is mediated by age-associated changes in human ALF. Here we determine the transcriptional profile of M.tb when exposed to healthy ALF from adult (A-ALF) or elderly (E-ALF) individuals before and during infection of ATs. ResultsPrior to infection, exposure to E-ALF upregulates M.tb genes associated with the ESX-4 secretion system, immunomodulatory proteins from the ESX-5 system, and genes encoding phospholipases, phosphatases, and proteases. During infection, E-ALF exposure upregulates key M.tb genes from the ESX-5 secretion system, genes associated with PDIMs biosynthesis and transport, and genes linked to bacterial oxidative stress defense mechanisms. ConclusionsThese findings demonstrate how altered ALF in old age can impact the metabolic status of M.tb, enabling greater adaptation to the host and potentially explaining Mtbs increased survival within host cells. Importantly, we present the first transcriptomic analysis on the impact of the elderly lung mucosa on M.tb pathogenesis during intracellular replication in ATs.

microbiology↗

bioRxiv2024

Expanding the molecular grammar of polar residues and arginine in FUS prion-like domain phase separation and aggregation

A molecular grammar governing low-complexity prion-like domains phase separation (PS) has been proposed based on mutagenesis experiments that identified tyrosine and arginine as primary drivers of phase separation via aromatic-aromatic and aromatic-arginine interactions. Here we show that additional residues make direct favorable contacts that contribute to phase separation, highlighting the need to account for these contributions in PS theories and models. We find that tyrosine and arginine make important contacts beyond only tyrosine-tyrosine and tyrosine-arginine, including arginine-arginine contacts. Among polar residues, glutamine in particular contributes to phase separation with sequence/position-specificity, making contacts with both tyrosine and arginine as well as other residues, both before phase separation and in condensed phases. For glycine, its flexibility, not its small solvation volume, favors phase separation by allowing favorable contacts between other residues and inhibits the liquid-to-solid (LST) transition. Polar residue types also make sequence-specific contributions to aggregation that go beyond simple rules, which for serine positions is linked to formation of an amyloid-core structure by the FUS low-complexity domain. Hence, here we propose a revised molecular grammar expanding the role of arginine and polar residues in prion-like domain protein phase separation and aggregation.

biochemistry↗

bioRxiv2024

Intra-condensate demixing of TDP-43 inside stress granules generates pathological aggregates

Cytosolic aggregation of the nuclear protein TDP-43 is associated with many neurodegenerative diseases, but the triggers for TDP-43 aggregation are still debated. Here, we demonstrate that TDP-43 aggregation requires a double event. One is up-concentration in stress granules beyond a threshold, and the other is oxidative stress. These two events collectively induce intra-condensate demixing, giving rise to a dynamic TDP-43 enriched phase within stress granules, which subsequently transitions into pathological aggregates. Mechanistically, intra-condensate demixing is triggered by local unfolding of the RRM1 domain for intermolecular disulfide bond formation and by increased hydrophobic patch interactions in the C-terminal domain. By engineering TDP-43 variants resistant to intra-condensate demixing, we successfully eliminate pathological TDP-43 aggregates in cells. We conclude that up-concentration inside condensates and simultaneous exposure to environmental stress could be a general pathway for protein aggregation, with intra-condensate demixing constituting a key intermediate step.

cell biology↗

bioRxiv2024

Dual DNA/RNA-binding factor regulates dynamics of hnRNP splicing condensates

How RNA splicing events are targeted to the correct genomic locations in specific cellular contexts to generate context-specific transcript diversity and prevent deleterious cryptic splicing remains very poorly understood. We show that a functionally conserved GA-rich DNA-binding transcription factor (TF), CLAMP, targets distinct RNA molecules in male and female cells to precisely regulate sex-specific splicing events through physical and functional interactions with RNA and RNA-binding proteins (RBPs). The prion-like domain of CLAMP (PrLD) and a stem-loop region in the target RNA are important for CLAMP-RNA interaction. Moreover, the CLAMP PrLD domain regulates sex-specific splicing by modulating the dynamics of an hnRNPA2/B1 family protein that regulates alternative splicing. Thus, we demonstrate that a TF targets co-transcriptional splicing to the correct genomic locations by directly linking DNA binding sites to RNA targets and modulating the dynamics of RBP partners that drive alternative splicing.

genomics↗

bioRxiv2023

Intrinsically disordered regions and RNA binding domains contribute to protein enrichment in biomolecular condensates in Xenopus oocytes

Proteins containing both intrinsically disordered regions (IDRs) and RNA binding domains (RBDs) can phase separate in vitro, forming bodies similar to cellular biomolecular condensates. However, how IDR and RBD domains contribute to in vivo recruitment of proteins to biomolecular condensates remains poorly understood. Here, we analyzed the roles of IDRs and RBDs in L-bodies, biomolecular condensates present in Xenopus oocytes. We show that a cytoplasmic isoform of hnRNPAB, which contains two RBDs and an IDR, is highly enriched in L-bodies. While both of these domains contribute to hnRNPAB self-association and phase separation in vitro and mediate enrichment into L-bodies in oocytes, neither the RBDs nor the IDR replicate the localization of full-length hnRNPAB. Our results suggest a model where the additive effects of the IDR and RBDs regulate hnRNPAB partitioning into L-bodies. This model likely has widespread applications as proteins containing RBD and IDR domains are common biomolecular condensate residents.

cell biology↗

bioRxiv2023

Structure and position-specific interactions of prion-like domains in transcription factor Efg1 phase separation

Candida albicans, a prominent member of the human microbiome, can make an opportunistic switch from commensal coexistence to pathogenicity accompanied by an epigenetic shift between the white and opaque cell states. This transcriptional switch is under precise regulation by a set of transcription factors (TFs), with Enhanced Filamentous Growth Protein 1 (Efg1) playing a central role. Previous research has emphasized the importance of Egf1s prion-like domain (PrLD) and the proteins ability to undergo phase separation for the white-to-opaque transition of C. albicans. However, the underlying molecular mechanisms of Efg1 phase separation have remained underexplored. In this study, we delved into the biophysical basis of Efg1 phase separation, revealing the significant contribution of both N-terminal (N) and C-terminal (C) PrLDs. Through NMR structural analysis, we found that Efg1 N-PrLD and C-PrLD are mostly disordered though have prominent partial -helical secondary structures in both domains. NMR titration experiments suggest that the partially helical structures in N-PrLD act as hubs for self-interaction as well as Efg1 interaction with RNA. Using condensed-phase NMR spectroscopy, we uncovered diverse amino acid interactions underlying Efg1 phase separation. Particularly, we highlight the indispensable role of tyrosine residues within the transient -helical structures of PrLDs particularly in the N-PrLD compared to the C-PrLD in stabilizing phase separation. Our study provides evidence that the transient -helical structure is present in the phase separated state and highlights the particular importance of aromatic residues within these structures for phase separation. Together, these results enhance the understanding of C. albicans TF interactions that lead to virulence and provide a crucial foundation for potential antifungal therapies targeting the transcriptional switch. Statement of SignificancePhase separated condensates have been found across the domains of life and many types of cells. To understand their varied functions, seeing the residue-by-residue details of the structure and interactions of component protein constituents is essential. A set of transcription factors that phase-separate controls cell fate of the pathogenic yeast Candida albicans. Here, we examine the structural and interaction details of a main regulator of this process, Efg1, using NMR spectroscopy and biochemical assays. We find Efg1s phase-separating domains are not entirely disordered as often assumed but in fact contain helical regions that persist upon phase separation. We also reveal the balance of contacts formed in the condensed phase and the importance of specific residues and regions in phase separation.

biochemistry↗

bioRxiv2023

Structure-based development of new cyclic compoundstargeting PSD-95 PDZ3 domain.

Aberrant BDNF signaling has been proposed to contribute to the pathophysiology of depression and other neurological disorders such as Angelman syndrome. We have previously shown that targeting the TrkB / PSD-95 nexus by peptidomimetic inhibitors is a promising approach for therapeutic intervention. Here we used structure-based knowledge to develop a new peptidomimetic compound series that fuses SynGAP-derived peptides to our prototype compound CN2097. These compounds target the PSD-95 PDZ3 domain and adjoining C helix to achieve bivalent binding that results in up to 7-fold stronger affinity compared to CN2097. These compounds were designed to improve CN2097 specificity for the PDZ3 domain and limited SAR studies have been performed to improve their resistance to proteolysis.

molecular biology↗

bioRxiv2022

Effect of flavonoids hydroxygenkwanin on vascular smooth muscle cell proliferation, migration, and neointimal formation

BackgroundRestenosis and atherosclerosis are chronic inflammatory disease. Abnormal vascular smooth muscle cell (VSMC) proliferation and migration play crucial roles in neointimal hyperplasia and restenosis progression in response to stimulation with various inflammatory cytokines, such as platelet-derived growth factor-BB (PDGF-BB) and tumour necrosis factor- (TNF-). Hydroxygenkwanin (HGK) exerts remarkable anti-inflammatory, antitumour, antiproliferative and antimigratory effects. The aim of the study was to evaluate and elucidate the therapeutic effect and regulatory mechanism of HGK on neointimal hyperplasia. MethodsTo determine the therapeutic effects of HGK in PDGF-BB- or TNF--treated VSMCs, MTT assays, Western blotting analysis, cell cycle analysis, BrdU incorporation assay, wound healing assay and adhesion assay were performed in vitro. A docking assay was also used to elucidate the mechanism underlying the regulatory effect of HGK. Histological and immunohistochemical staining of denuded femoral arteries was conducted to elucidate the therapeutic effect of HGK in an in vivo assay. ResultsHGK inhibited the abnormal proliferation, migration, and inflammation of PDGF-BB- or TNF--treated VSMCs through regulation of the PDK1/AKT/mTOR pathway. In addition, HGK promoted circulating endothelial progenitor cell (EPC) chemotaxis. In an in vivo assay, HGK dramatically enhanced re-endothelization and reduced neointimal hyperplasia after femoral artery denudation with a guide wire in mice. ConclusionsIn the present study, HGK decreased the PDGF-BB- or TNF--induced abnormal proliferation, migration and inflammation in VSMCs and improved re-endothelialization and neointimal hyperplasia in denuded femoral arteries. These results provide a novel potential treatment for restenosis in the future. Graphic abstract O_FIG_DISPLAY_L [Figure 1] M_FIG_DISPLAY HGK decreases VSMC abnormal proliferation, migration and inflammation through PDK1/AKT/mTOR/S6K inhibition and promotes EPC chemotaxis and reendothelialization. HGK is a potential therapeutic candidate for intimal hyperplasia and restenosis. C_FIG_DISPLAY

cell biology↗

bioRxiv2021

D614G Substitution of SARS-CoV-2 Spike Protein Increases Syncytium Formation and Viral Transmission via Enhanced Furin-mediated Spike Cleavage

Since the D614G substitution in the spike (S) of SARS-CoV-2 emerged, the variant strain underwent rapid expansion to become the most abundant strain worldwide. Therefore, this substitution may provide an advantage of viral spreading. To explore the mechanism, we analyzed 18 viral isolates containing S proteins with either G614 or D614. Both the virus titer and syncytial phenotype were significantly increased in S-G614 than in S-D614 isolates. We further showed increased cleavage of S at the furin substrate site, a key event that promotes syncytium, in S-G614 isolates. These functions of the D614G substitution were validated in cells expressing S protein. The effect on syncytium was abolished by furin inhibitor treatment and mutation of the furin-cleavage site, suggesting its dependence on cleavage by furin. Our study provides a mechanistic explanation for the increased transmissibility of S-G614 containing SARS-CoV-2 through enhanced furin-mediated S cleavage, which increases membrane fusion and virus infectivity.

microbiology↗

bioRxiv2020

A single-cell transcriptome atlas during Cashmere goat hair follicle morphogenesis

Cashmere, also known as soft gold, is produced from the secondary hair follicles in Cashmere goats and its therefore of significance to investigate the molecular profiles during Cashmere goat hair follicle development. However, our current understanding of the machinery underlying Cashmere goat hair follicle remains largely unexplored and researches regarding hair follicle development mainly used the mouse as a research model. To provides comprehensively understanding on the cellular heterogeneity and cell lineage cell fate decisions, we performed single-cell RNA sequencing on 19,705 single cells from induction (embryonic day 60), organogenesis (embryonic day 90) and cytodifferentiation (embryonic day 120) stages of fetus Cashmere goat dorsal skin. Unsupervised clustering analysis identified 16 cell clusters and their corresponding cell types were also unprecedentedly characterized. Based on the lineage inference, we revealed detailed molecular landscape along the dermal and epidermal cell lineage developmental pathways. Notably, by cross-species comparasion of single cell data with murine model, we revelaed conserved programs during dermal condensate fate commitment and the heterochrony development of hair follicle development between mouse and Cashmere goat were also discussed here. Our work here delineate unparalleled molecular profiles of different cell populations during Cashmere goat hair follicle morphogenesis and provide a valuable resource for identifying biomarkers during Cashmere goat hair follicle development.

developmental biology↗

bioRxiv2019

Single-cell transcriptome profiling reveals dermal and epithelium cell fate decisions during embryonic hair follicle development

Characterization of the morphological structure during hair follicle development has been well documented, while the current understanding of the molecular mechanisms involved in follicle development remain limited. Here, using unbiased single-cell RNA sequencing, we analyzed 15,086 single cell transcriptome profiles from E13.5 and E16.5 fetal mice, and newborn mouse (postnatal day 0, P0) dorsal skin cells. Based on t-distributed Stochastic Neighbor Embedding (tSNE) clustering, we identified 14 cell clusters from skin cells and delineated their cell identity gene expression profiles. Pseudotime ordering analysis successfully constructed epithelium/dermal cell lineage differentiation trajectory and revealed sequential activation of key regulons involved during cell fate decisions. Along with this, intercellular communication between different cell populations were inferred based on a priori knowledge of ligand-receptor pairs. Together, our findings here provide a molecular landscape during hair follicle epithelium/dermal cell lineage fate decisions, and more importantly, recapitulate sequential activation of core regulatory transcriptional factors for different cell populations during hair follicle morphogenesis.

developmental biology↗

bioRxiv2018

Schizophrenia risk conferred by protein-coding de novo mutations

Protein-coding de novo mutations (DNMs) in the form of single nucleotide changes and short insertions/deletions are significant genetic risk factors for autism, intellectual disability, developmental delay, and epileptic encephalopathy. In contrast, the burden of DNMs has thus far only had a modest documented impact on schizophrenia (SCZ) risk. Here, we analyze whole-exome sequence from 1,695 SCZ affected parent-offspring trios from Taiwan along with DNMs from 1,077 published SCZ trios to better understand the contribution of coding DNMs to SCZ risk. Among 2,772 SCZ affected probands, the increased burden of DNMs is modest. Gene set analyses show that the modest increase in risk from DNMs in SCZ probands is concentrated in genes that are either highly brain expressed, under strong evolutionary constraint, and/or overlap with genes identified as DNM risk factors in other neurodevelopmental disorders. No single gene meets the criteria for genome-wide significance, but we identify 16 genes that are recurrently hit by a protein-truncating DNM, which is a 3.15-fold higher rate than mutation model expectation of 5.1 genes (permuted 95% CI=1-10 genes, permuted p=3e-5). Overall, DNMs explain only a small fraction of SCZ risk, and this risk is polygenic in nature suggesting that coding variation across many different genes will be a risk factor for SCZ in the population.

genetics↗

bioRxiv2018

Acidic microenvironment shaped by lactate accumulation promotes pluripotency through multiple mechanisms

Enhanced glycolysis is a distinct feature associated with numerous stem cells and cancer cells. However, little is known about its regulatory roles in gene expression and cell fate determination. Here we show that acidic environment shaped by lactate accumulation promotes the self-renewal and pluripotency of both mouse and human embryonic stem cells (ESCs). Mechanistically, acidic pH reduces the tri-methylation of H3K27 globally at transcriptional start sites to partially prevent ESC differentiation. In addition, acidic pH stabilizes a large number of mRNAs including pluripotency genes. Furthermore, we found that AGO1 protein is downregulated at acidic conditions, leading to the de-repression of a subset of microRNA targets in low-pH treated ESCs. Altogether, our study provides insights into mechanisms whereby acidic microenvironment produced by enhanced glycolysis regulates gene expression to determine cell fate and has broad implications in the fields of regenerative medicine and cancer biology.

developmental biology↗

bioRxiv2018

Human Puf-A, a Novel Component of 90S Pre-ribosome, Links Ribosome Biogenesis to Cancer Progression

We describe a novel biogenesis factor of the 90S pre-ribosome, Puf-A, which is a negative transcriptional target of p53. The expression of Puf-A is not only upregulated in advanced human lung cancer and tumors of patients especially with TP53 mutation, but also is highly prognostic for stage I lung cancer. Loss of Puf-A expression prevents KrasG12D/p53-/--induced tumor progression in the lungs and induces apoptosis in TP53- mutated cancers and c-Myc/p53-/--transformed cells as well. Overexpression of Puf-A enhances proliferation of normal cells after c-Myc induction and overcomes the cell-cycle checkpoints incurred by p53 expression. Mechanistically, Puf-A interacts with double-stranded structures of the 5.8S sequence within pre-rRNA and maintains the integrity of 90S pre-ribosomes, thereby impacting early ribosome assembly and export of ribosomes from nuclei. Silencing of Puf-A disrupts the assembly of 90S pre-ribosomes and induces the translocation of its associated nucleophosmin (NPM1) from nucleoli to the nucleoplasm, resulting in impairment of ribosome synthesis. Thus, Puf-A is crucial for over-activation of ribosome biogenesis and contributes to tumor progression and cancer growth.

cancer biology↗