Search PubMedSearch

SEARCH · Search PubMed

Results for “DEAD-box RNA Helicases”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

153 recordsLinked to original sources

Acetic acid-induced translational repression involves eIF2B body formation and Ded1 sequestration into stress granules in yeast.

Elucidating the physiological impact of acetic acid stress and the corresponding yeast responses is essential for advancing fundamental biology and improving industrial alcoholic fermentation. Despite numerous genome-wide studies, information on the effects of acetic acid stress on yeast translational regulation remains limited. We found that a sublethal concentration of acetic acid (35 mM, 0.2% v/v) causes translational repression, accompanied by the formation of eIF2B bodies and the phosphorylation of eIF2α, both of which are involved in the regulation of translation initiation. Acetic acid also caused the sequestration of Ded1, a DEAD-box RNA helicase crucial for translation initiation, into stress granules. Removal of acetic acid restored translational activity and the proper localization of eIF2B and Ded1, indicating the reversibility of acetic acid-induced translational repression. Furthermore, when yeast cells were pretreated with 0.05% acetic acid, translational repression under subsequent 0.2% acetic acid stress was attenuated in wild-type cells but not in hrk1Δ cells. This indicates that Hrk1, a Pma1 activator, is required to sufficiently enhance tolerance to acetic acid-induced translational repression. These findings provide novel insights into the physiological effects of acetic acid stress on translational activity and translation-related factors in yeast cells.

Saccharomyces cerevisiae

Engineering bubble structures as Cas12a activators for highly sensitive monitoring of WRN helicase function.

The Werner syndrome helicase (WRN) is a critical synthetic lethal target in microsatellite instability cancers, essential for resolving complex genomic structures like replication bubbles and R-loops. However, strategies to simultaneously discriminate WRN activity on DNA versus DNA-RNA substrates in living cells are lacking. Here, we developed a structure-specific CRISPR/Cas12a biosensing strategy to visualize WRN functional activity by engineering bubble-structure probes. These probes were rationally designed to structurally mimic DNA replication bubbles and R-loop associated DNA-RNA hybrids. Upon specific unwinding by WRN, the probes release a sequestered activator strand that triggers Cas12a trans-cleavage, effectively converting the unwinding event into an amplified fluorescent signal. This assay achieves low picomolar sensitivity (LODs: 5.6-6.0 pM) and exceptional selectivity against homologous RecQ helicases. Uniquely, this strategy enables the parallel quantification of WRN activity on both substrate types, providing insights into distinct WRN-mediated pathways for resolving genomic stress. We further demonstrated the strategy's utility by visualizing endogenous WRN dynamics in living cells and profiling the efficacy of small-molecule inhibitors. This work offers a powerful molecular toolkit for dissecting WRN biology and facilitating high-throughput drug screening in targeted cancer therapy.

Werner Syndrome Helicase

Genome-Wide Impact of Human DBR1 Depletion on RNA Processing Networks Reveal a Connection Between Pre-mRNA Splicing, mRNA Surveillance and Stress Granule Dynamics.

The RNA lariat debranching enzyme DBR1 is essential for intron turnover and RNA metabolism, yet its broader impact on transcriptome regulation remains incompletely defined. To elucidate the consequences of DBR1 depletion, we performed transcriptome-wide RNA sequencing of DBR1-knockdown and wild-type HEK293 cells. Differential expression analysis revealed widespread perturbations in pathways linked to RNA splicing, mRNA surveillance, translational control, and stress-granule biology. Many of the most significantly altered transcripts encode splicing factors and RNA quality-control components, underscoring DBR1's influence on post-transcriptional regulation. Alternative splicing analysis showed changes across multiple event types, with exon skipping accounting for >50% of events, followed by mutually exclusive exons, alternative 5' and 3' splice sites, and retained introns, indicating that DBR1 depletion induces pervasive splicing defects. Direct spliceosome inhibition using isoginkgetin (blocks tri-snRNP recruitment) and pladienolide B (targets SF3B1) reproduced the DBR1-KD mis-splicing patterns of cell signaling genes and factors involved in RNA metabolism, supporting a functional link between DBR1 activity and alternative splicing. Notably, DBR1 knockdown revealed a subset of transcripts that are both NMD-sensitive and enriched within stress granules. Consistent with this observation, G3BP1 immunopurification and confocal microscopy further support a role for DBR1 and UPF1 in stress-granule dynamics, suggesting that these factors may participate at distinct stages to influence mRNA fate under stress conditions. Together, these findings indicate that DBR1 functions beyond lariat RNA turnover as a common regulator of RNA processing, transcriptome stability, and stress granule homeostasis, revealing intricate crosstalk between RNA splicing and RNA quality control pathways in human cells.

Humans

Biochemical Insights Into the Conserved Interactions of NMD Factors From Budding Yeast to Humans.

Nonsense-mediated mRNA decay (NMD) is one of the most extensively studied pathways of cytoplasmic mRNA degradation. It plays a critical role in diverse cellular processes by eliminating aberrant transcripts containing premature stop codons and by regulating the stability of physiological mRNAs. NMD factors were initially identified through genetic screens in S. cerevisiae (UPF1, 2, 3) and C. elegans (SMG-1, SMG5-7). Subsequent biochemical and genetic studies revealed the composition of NMD complexes and identified additional factors. A major protein hub for NMD is Upf1, an ATP-dependent RNA helicase that is part of two mutually exclusive NMD assemblies, the Upf1-Upf2-Upf3 complex and the Upf1-decapping complex, which contains the decapping enzyme and its co-factors. Here, we discuss recent findings, primarily from budding yeast, on the protein-protein interactions driving NMD complexes dynamics and their similarities to human NMD. Together, the N-terminal cysteine and histidine rich (CH) and helicase domains (HD) of Upf1 act as a hub for binding multiple partners. Upf1 is required for binding to NMD substrates and for the initiation of RNA degradation through decapping (yeast) or endonucleolytic hydrolysis (humans). We focus on the interplay between Upf2, Dcp2 and Nmd4 (yeast SMG6), which ensures the mutually exclusive formation of Upf1-bound subcomplexes modulating Upf1's affinity for RNA. Thus, the study of NMD factors interactions in different organisms sheds new light on the remarkable conservation of NMD molecular mechanisms.

Nonsense Mediated mRNA Decay

A Conserved 3'UTR Stem-loop Directs UPF1/eIF4AIII-Dependent Regulation of GABARAPL1 mRNA.

RNA-binding proteins (RBP) interact with mRNA untranslated regions containing cis-regulatory elements to govern mRNA localization, stability, and translational efficiency. Among these trans-regulatory factors, RNA helicase UPF1 is a central factor which play a role in multiple mRNA decay pathways, including nonsense-mediated mRNA decay (NMD). NMD is triggered when an exon-junction complex (EJC) is located downstream of a premature termination codon. However, in some cases, NMD can be activated in an EJC-independent manner through mechanisms involving the 3'UTR. In the present study, we focused on the GABARAPL1 3'UTR, as previous studies had shown that this region plays a key role in NMD targeting, although the underlying molecular mechanism had not yet been elucidated. Unlike canonical NMD targets such as SC35, we found that the chemical inhibition of eIF4AIII helicase activity did not affect GABARAPL1 transcript levels, indicating that this transcript is regulated through its 3'UTR via an EJC-independent mechanism. We therefore investigated the potential presence of cis-regulatory element within the 3'UTR of GABARAPL1 which can regulate mRNA and protein levels in a UPF1-dependent manner. Furthermore, we identified a conserved RNA region spanning nucleotides 364-421 involved in GABARAPL1 targeting and used biochemical analysis to demonstrate the direct binding of UPF1 and eIF4AIII to this RNA region, to analyse its secondary structure in solution, and to map the protein-binding sites. By complementing these approaches with molecular modelling, we showed that this stem-loop adopts a stable global fold but a local flexibility and dynamic behaviour properties. Together, our results support the role of UPF1 and eIF4AIII as specific regulators of GABARAPL1 transcript and reveal a novel RNA regulatory element within its 3'UTR, which provides a completely unexpected binding site for these factors.

3' Untranslated Regions

Active Site Assembly by SMG5 as a Mechanism for SMG6 Endonuclease Licencing in Nonsense-mediated mRNA Decay.

Nonsense-mediated mRNA decay (NMD) is a conserved eukaryotic surveillance pathway that eliminates transcripts containing premature termination codons (PTCs). Substantial progress has been made in defining the transcript features that mark aberrant translation termination for NMD activation, yet key mechanistic steps remain incompletely understood - including how recruitment of the central NMD factor UPF1 is coupled to the downstream effector phase in which targeted mRNAs are nucleolytically degraded. In metazoans, NMD employs an endonucleolytic route mediated by SMG6, a PIN-domain nuclease, alongside SMG5 and SMG7, which act downstream of PTC recognition. SMG5 has recently been proposed to licence SMG6 activity, yet the molecular basis of this licencing has remained elusive. Here, we combine AlphaFold structural predictions with biochemical assays to investigate interactions among human SMG5, SMG6, and SMG7. Structural models predict a high-confidence interface between SMG5 and SMG6 PIN domains that forms a composite active site: a conserved SMG5 aspartate (D893) complements the SMG6 acidic triad to reinstate the canonical tetrad required for PIN-domain catalysis. In vitro, SMG6 alone exhibits weak endonucleolytic activity, which is enhanced ∼10-fold by the SMG5 PIN domain. Mutational analyses confirm that conserved residues from both proteins are essential for this composite configuration. Our findings reveal that the SMG5 PIN domain, previously considered catalytically inert, plays a critical role in activating SMG6 by completing its active site. This work provides mechanistic insight into the SMG5-dependent licencing step and uncovers a composite PIN nuclease architecture at the heart of the metazoan NMD effector phase.

Nonsense Mediated mRNA Decay

[Study of a patient with azoospermia due to variant of MOV10L1 gene].

OBJECTIVE: To explore the clinical and genotypic characteristics of a patient with Sertoli cell-only syndrome (SCOS) due to variants of MOV10L1 gene. METHODS: A 27-year-old patient with Non-obstructive azoospermia (NOA) underwent routine semen analysis. Serum levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), progesterone (P), estradiol (E2), prolactin (PRL), and testosterone (T) were determined by chemiluminescence assays. Peripheral blood samples were collected for G-banded karyotyping analysis. Multiplex PCR fluorescence detection was used to screen for AZF gene microdeletions. Whole exome sequencing (WES) and Sanger sequencing were performed simultaneously. Testicular biopsy tissues were subjected to Hematoxylin-Eosin (HE) staining to assess seminiferous tubule cell composition, and MOV10L1 protein expression was detected by immunohistochemical staining. Bioinformatics tools were employed to predict the pathogenicity of variants and their impact on protein structure and function. This study was approved by the Medical Ethics Committee of the Guangdong Institute of Reproductive Sciences [Ethics No.: 2023(01)]. RESULTS: The patient's two semen analyses had failed to detect any sperm. Hormone tests indicated elevated FSH (22.32 mIU/mL) and PRL (397.6 mIU/mL), while T (3.68 nmol/L) and E2 (38.32 pmol/L) were reduced. Chromosomal karyotyping revealed 46,XY, and no AZF gene deletion was detected. WES and Sanger sequencing detected compound heterozygous variants of the MOV10L1 gene, including a c.345C>A (p.C115X) nonsense variant and a c.3323C>T (p.T1108I) missense variant, with the former being unreported previously. HE staining showed only Sertoli cells in the seminiferous tubules, confirming the diagnosis of SCOS. Immunohistochemical staining revealed absent MOV10L1 protein expression in the testicular tissue. Based on the guidelines from American College of Medical Genetics and Genomics (ACMG), the c.345C>A (p.C115X) was classified as a pathogenic variant (PVS1+PM2_Supporting+PP4), while the c.3323C>T (p.T1108I) was deemed variant of uncertain significance (PM2_Supporting+PP3_Supporting+PP4). Bioinformatics analysis demonstrated that c.345C>A (p.C115X) may cause premature termination of protein translation, while c.3323C>T (p.T1108I) may disrupt the hydrophobicity of the RNA helicase domain, reducing the active pocket volume and decreasing its affinity for MILI protein. CONCLUSION: This study has diagnosed a case of SCOS due to compound heterozygous variants of the MOV10L1 gene, which also enriched its mutational spectrum.

Humans

Evolutionary architecture and lineage-specific diversification of Forkhead box transcription factors in Perna viridis.

The Forkhead box (Fox) transcription factors are evolutionarily conserved regulators of development, cell cycle, and apoptosis across metazoans. This study provides the first comprehensive genome-wide analysis of the Fox gene family in the Asian green mussel (Perna viridis). We identified 28 Fox genes distributed across 10 chromosomes. Comparative analysis reveals the absence of the FoxI, FoxQ1, FoxR and FoxS subfamily, consistent with other bivalves and indicative of lineage-specific gene loss during molluscan evolution. Notably, gene duplications in the FoxAB, FoxD, FoxH, FoxN1-4, FoxQ2 and FoxQD subfamilies may reflect functional diversification associated with environmental adaptation. Exon-intron structural variability, including intron loss in several paralogues, suggests structural diversification and potential regulatory variation. Phylogenetic reconstruction confirmed the monophyly of core Fox classes while highlighting divergent expansion patterns in lophotrochozoans. Selection analyses showed strong purifying selection across duplicated Fox paralogs, supporting functional conservation after lineage-specific expansion. Gene Ontology enrichment linked Fox genes to stress response, apoptosis, and transcriptional regulation. By integrating phylogenetic, structural, and transcriptomic analyses, this study provides a genomic framework for understanding Fox gene organisation, evolution, and tissue-associated expression patterns in Perna viridis and establishes a comparative resource for future functional studies in bivalves.

Animals

A cooperative regulatory module between TAGL2 and JMJC1 activates specific defense genes against root-knot nematodes in tomato.

Plant-parasitic nematodes (PPNs) threaten global food security. Although epigenetic modifications are crucial for plant immunity, how histone modifiers contribute to root-knot nematodes (RKNs, Meloidogyne incognita) resistance remains unclear. Here, using genetic, molecular and biochemical approaches, we investigated the epigenetic and transcriptional mechanisms underlying RKN resistance mediated by the histone demethylase (HDM) JMJC1 and the MADS-box transcription factor TAGL2 in tomato (Solanum lycopersicum). We identified JMJC1 as an RKN-induced positive defense regulator targeting H3K9me3 and H3K27me3 histone marks. JMJC1 physically interacts with TAGL2, which also positively regulates RKN resistance. Transcriptomic analysis indicated that TAGL2 regulates multiple layers of the plant defense network, transcriptionally activating representative genes from distinct pathways (including PUB10, bHLH98, CCaMK, and SAUR3), which we validated as positive regulators of RKN resistance via virus-induced gene silencing (VIGS). At the chromatin level, TAGL2 and JMJC1 co-regulate these loci, associating with localized H3K9me3 and H3K27me3 reduction. Furthermore, TAGL2 directly activates JMJC1 transcription, establishing a positive feedback loop that amplifies immune signaling. Our findings reveal a cooperative model wherein a HDM and a transcription factor coordinate at specific loci to fine-tune multiple defense layers at both epigenetic and transcriptional levels, providing insights for breeding durable nematode-resistant plants.

Solanum lycopersicum

Integrative machine learning and transcriptomic analysis reveals molecular mechanisms underlying low survival rate in larval Chinese Bahaba (Bahaba taipingensis).

Chinese Bahaba (Bahaba taipingensis) is a Class I protected marine fish endemic to China. Low larvae survival during artificial breeding severely hinder population recovery. To investigate the molecular mechanism of high mortality in larval fish, this study performed RNA-seq on liver from naturally deceased (ND) and mass-dead (MD) individuals, combined with least absolute shrinkage and selection operator (LASSO) regression and random forest (RF) algorithms to screen for core signature genes. A total of 873 differentially expressed genes (DEGs) were identified, including 112 upregulated and 761 downregulated genes. GO and KEGG enrichment analyses revealed significant enrichment in amino acid metabolism disorders, one‑carbon folate pool impairment, PPAR signaling abnormalities, ECM-receptor interaction, focal adhesion pathway, indicating widespread metabolic suppression accompanied by extracellular matrix remodeling and signaling disturbances in the livers of MD fish. MAD pre-filtering combined with dual machine learning algorithms yielded 18 robust core signature genes, among which SLC38A4, MMP1, FADD, FKBP5, and APOB were consistently identified as high-frequency core genes by both algorithms. SLC38A4 exhibited the highest importance score in the RF model and was significantly downregulated, making it the primary molecule distinguishing ND from MD phenotypes. ROC curve analysis showed that both models achieved an AUC of 1.000 (95% CI lower bound: 0.610), confirming the precise discriminatory ability of the core genes. GSEA further demonstrated significant enrichment of this core gene set in ND samples. This study provides the first systematic elucidation of the molecular mechanisms underlying liver dysfunction in low survival rate B. taipingensis, characterized by amino acid transport impairment, metabolic reprogramming, and structural remodeling, offering theoretical foundations for health assessment, early mortality risk warning, and artificial breeding conservation of this species.

Animals

UNCX/SIN3A-Mediated H4K8 decrotonylation suppresses FOXO3 to drive TNBC progression and docetaxel resistance.

Triple-negative breast cancer (TNBC) remains a clinically challenging subtype characterized by aggressive behavior and limited treatment options. Though docetaxel remains a cornerstone chemotherapy for TNBC, the frequent emergence of resistance highlights the urgent need to identify novel therapeutic targets. In this study, we report that uncoordinated homeobox (UNCX) is upregulated in docetaxel-resistant breast cancer cells, genomically amplified in breast cancer, and associated with poor survival in breast carcinoma patients. Functional studies revealed that UNCX promotes breast cancer cell proliferation, migration and reduces the docetaxel sensitivity. Mechanistically, UNCX functions as a transcriptional repressor by recruiting the SIN3A complex. Genome-wide profiling indicated that the UNCX/SIN3A complex directly binds to the promoters of tumor-suppressor genes including FOXO3, and represses their transcription by removing histone H4K8 crotonylation (H4K8cr). Additionally, the UNCX/SIN3A complex enhances FOXO3 phosphorylation and inhibits its nuclear translocation, further inhibiting its activity. Notably, SIN3A knockdown, FOXO3 overexpression, or crotonylation restoration effectively reverses UNCX-induced malignant phenotypes. These findings collectively establish the UNCX/SIN3A-H4K8cr-FOXO3 axis as a pivotal epigenetic regulator of TNBC progression and chemoresistance, revealing new avenues for targeted therapeutic development against this aggressive breast cancer subtype.

Humans

EZH1/2 inhibition selectively targets SMARCA4/2 co-deficient lung cancer cells by suppressing stemness and proliferation.

SMARCA4-deficient thoracic malignancies comprise biologically heterogeneous tumors, ranging from conventional non-small cell lung cancer with SMARCA4 alterations to thoracic SMARCA4-deficient undifferentiated tumor (SMARCA4-UT), an aggressive entity frequently associated with concomitant SMARCA2 loss. However, the extent to which SMARCA4-deficient lung cancer cell lines recapitulate SMARCA4-UT-like biology remains incompletely defined. Here, we characterized lung cancer cell lines across distinct SMARCA4 and SMARCA2 states and identified a subgroup with SMARCA4/2 co-deficiency that exhibited reduced expression of epithelial lineage markers and transcriptional similarity to SMARCA4-UT and other SWI/SNF-deficient malignancies. The EZH1/2 inhibitor HM97662 selectively suppressed growth in SMARCA4/2-deficient cells, with limited effects in SMARCA2-proficient cells. EZH1/2 inhibition broadly reduced H3K27me3 and induced derepression of PRC2 targets regardless of drug sensitivity. However, its biological effects were most pronounced in SMARCA4/2-deficient cells, where it promoted apoptosis, reduced stemness marker expression, attenuated the SMARCA4-UT-associated transcriptional signature, and suppressed proliferative and mTORC1-related programs. Chromatin accessibility analysis further revealed cell-line-specific patterns of accessibility loss, with reduced accessibility at stemness-associated transcription factor motif-enriched regions coupled with transcriptional repression of nearby genes in SMARCA4/2-deficient cells. These findings support dual EZH1/2 inhibition as a potential therapeutic vulnerability in SMARCA4/2-deficient, SMARCA4-UT-like lung cancer cells.

Humans

Probiotic supplementation improves body composition, lipid profiles, and fatty acid metabolism in combat sports athletes during the weight reduction phase.

PURPOSE: Pre-competition weight control for combat sports athletes may alter body composition and fatty acid metabolism. Probiotics have shown potential to regulate overall metabolism; however, their specific effects on fatty acid metabolism during weight control in athletes remain unclear. METHODS: Thirty-two combat sports athletes participating in the 4-week weight reduction period were assigned to either the probiotic group (Group E) or the placebo group (Group C). Body composition, lipid profiles, and fatty acid metabolism were measured before and after the 4-week weight reduction phase. RESULTS: All the athletes experienced a decrease in body weight, body mass index (BMI), body fat percentage, and muscle mass following the 4-week weight loss intervention. Notably, a more significant reduction in body fat percentage (p&#x2009;<&#x2009;0.05) was observed, along with lower levels of triglycerides (TG) and low-density lipoprotein cholesterol (LDL-C), specifically in Group E. Weight loss intervention resulted in increased levels of short-chain fatty acids (SCFAs), specifically acetic acid, propionic acid, and butyric acid. Notably, Group E exhibited higher mean values for SCFAs compared to Group C (p&#x2009;<&#x2009;0.05). Additionally, the serum levels of &#x3b3;-linolenic acid and 8,11,14-eicosatrienoic acid were significantly reduced in Group E (p&#x2009;<&#x2009;0.05). In contrast, the majority of free fatty acids (FFAs) showed significant increases, with greater magnitudes of change observed in Group C (p&#x2009;<&#x2009;0.05). CONCLUSION: Probiotic supplementation can improve body composition, enhance SCFAs levels, and decrease circulating FFAs in combat sports athletes, suggesting that probiotics may have a beneficial impact on pre-competition weight management. TRIAL REGISTRATION NUMBER: chiCTR2400079908 (Reg Date:2024-01-16).

Humans

Transcriptomic responses of gill and intestinal tissues in Nile tilapia (Oreochromis niloticus) to bacterial infection following sequential nanoimmersion and hydrogel-based multivalent vaccination.

Bacterial pathogens, including Flavobacterium oreochromis, Aeromonas veronii, Streptococcus agalactiae, and Edwardsiella tarda, represent major infectious threats to Nile tilapia (Oreochromis niloticus). A multivalent vaccination strategy integrating cationic nanoemulsion immersion with oral hydrogel boosters was developed to investigate tissue-specific immune responses at the transcriptomic level. Gill tissues were collected following immersion challenge and intestinal tissues following intraperitoneal injection challenge, reflecting the physiologically relevant infection biology of each pathogen and the mechanistic rationale of each delivery platform. RNA sequencing (RNA-seq) generated high-quality datasets (mapping rate&#xa0;>&#xa0;81.64%) with strong concordance to quantitative real-time PCR (qRT-PCR) validation (r&#xa0;=&#xa0;0.83). Comparative transcriptomic analysis revealed distinct yet complementary immune signatures between tissues. Gill transcriptomes were enriched in phagosome, focal adhesion, extracellular matrix-receptor interaction (ECM-receptor interaction), and cytokine-cytokine receptor interaction pathways, accompanied by increased expression of major histocompatibility complex class I/II (MHC class I/II), mannose receptor, &#x3b1;V&#x3b2;3 integrin, and calnexin, indicating innate activation, enhanced phagocytic capacity, epithelial barrier reinforcement, and adaptive immune coordination. Intestinal transcriptomes showed predominant enrichment of adaptive immune pathways, including the intestinal immune network for immunoglobulin (Ig) production, Forkhead box O (FoxO) signaling, and mitogen-activated protein kinase (MAPK) signaling, with increased expression of T-cell receptor (TCR), inducible T-cell co-stimulator ligand (ICOS-L), C-X-C chemokine receptor type 4 (CXCR4), and polymeric immunoglobulin receptor (pIgR), reflecting T and B cell coordination, lymphocyte trafficking, and mucosal immunoglobulin transport, alongside innate engagement through phagosome pathway enrichment. Shared upregulation of MHC class II, B-cell receptor (BCR) signaling, integrin alpha M (ITGAM), and immunoglobulin-associated components across both tissues suggests coordinated mucosal immune activation through a conserved immune module, warranting direct experimental validation. Collectively, these findings provide transcriptomic evidence that this vaccination strategy elicits an integrated, tissue-specialized immune response, advancing mechanistic understanding of gill and intestinal immunity in vaccine-induced protection of teleost fish.

Animals

Generation of spCAS9 expressing human mesenchymal stem cell line to study gene function during osteoblast differentiation.

Human bone marrow-derived stromal cells (hMSCs) are a great resource for studying how genes influence cell fate and differentiation into various cell types like osteoblasts, adipocytes, and chondrocytes, among other cell types. However, genetic manipulation of primary hMSCs has been challenging due to their short lifespan and cellular senescence after limited passaging. Their low and unstable transfection efficiency also complicates gene delivery or inactivation, hindering long-term functional studies. The limited lifespan has been effectively solved by immortalizing hMSCs with telomerase reverse transcriptase (hMSCs-TERT). The use of these cells is ideal for functional studies of osteoblast and adipocyte differentiation through genetic manipulation, providing a stable and reliable model. Here, we have engineered a stable CAS9 expressing hMSC-TERT cell line (hMSC-TERTCAS9) via lentiviral transduction. The constitutive expression of spCas9 enables efficient and reproducible gene editing. We demonstrate the potential of these hMSC-TERTCAS9 cells for generating gene disruptions using plasmid delivery of guide RNAs as a fast and efficient strategy for targeted genome editing. The edited cells can be sorted and expanded as single cells to obtain homogenous clonal cell lines with mono- as well as bi-allelic gene deletions, a crucial step for producing reliable experimental results. We further validate this cell line as a powerful tool for studying gene function during hMSC proliferation and differentiation, providing 3 distinct examples of its utility. Through the generation of indels, single-cell sorting, and clonal selection, we have efficiently inactivated the vitamin D receptor and created both larger (256 nucleotides) gene disruptions in Forkhead box protein O1 and precise removals of a small genomic sequence (73 nucleotides) coding for microRNA MIR675. This novel hMSC-TERTCAS9 cell line represents a significant advancement, offering a stable, efficient, and versatile platform for advanced genetic studies, high-throughput screening, and the creation of reliable cellular disease models.

CRISPR-Cas9

A dual-dimensional CRISPR toolkit enables one-step high-efficiency multiplex genome editing in Komagataella phaffii.

Against the backdrop of green biomanufacturing, engineering methanol-utilizing Komagataella phaffii (K. phaffii) represents an effective strategy to expand the one carbon (C1) product profile and speed up the industrialization of C1-based bioeconomy. To address the technical challenges of low efficiency and cumbersome experimental procedures for multiplex gene editing and precise large-fragment integration during the reconstruction of complex metabolic pathways in K. phaffii, this study established a CRISPR toolkit - Efficient Multi-Gene Editing System 3.0 (EMGES 3.0) - which enabled one-step large-fragment integration coupled with multiplex gene knockout. EMGES 3.0 was constructed through the synergistic optimization of a repair-engineered chassis and an episomal CRISPR vector. For chassis engineering, five DNA repair modules: &#x394;lig4 (DNA Ligase IV, non-homologous end joining end ligation), ppMRE11(The endogenous MRE11 gene from Pichia pastoris) overexpression (The Meiotic Recombination 11, DNA double-strand break end resection), &#x394;rad9 (Radiation-Sensitive 9, DNA damage checkpoint regulation), &#x394;mph1 (Mutator Phenotype Helicase 1, improvement of homologous recombinant strand extension), and PapRecT-PaSSB co-expression (stabilization of recombination intermediates) were integrated to generate the highly recombinogenic strain Y09. For vector engineering, cenARS was replaced by panARS and the endogenous promoter PGAP was employed to drive the double hammerhead ribozyme-single guide RNA-hepatitis delta virus ribozyme (double HH-sgRNA-HDV: dHgH)-mediated sgRNA expression, yielding the optimized vector Nov_pGAP_panARS_pLAT1_Cas9. These two features on K. phaffii together enhanced the EMGES 3.0 to a higher standard of transformation rate and editing efficiency. According to our results, EMGES 3.0 achieved dual-functional gene knockout efficiencies between 76.6% and 100%. For insertion of medium-long fragments (>4.5&#x202f;kb), the efficiency achieved 93.3%. In addition, the one-step integration of ultra-long fragments (>16&#x202f;kb) achieved 14.8%, which was reported for the first time. Furthermore, the efficiency of simultaneous long-fragment integration at three neutral loci reached 38.4% (>15&#x202f;kb). We applied the system for one-step production of free fatty acids (FFAs, yield: 5.82 &#x223c; 7.30&#x202f;mg/L/OD600) and resveratrol (yield: 1.14 &#x223c; 1.28&#x202f;mg/L) using methanol as the sole carbon source. EMGES 3.0 provides a robust technical foundation for complex compounds biosynthesis and high-yield industrial strains, while also advancing K. phaffii as an industrial synthetic biology chassis for efficient C1 utilization.

CRISPR-Cas Systems

Synergistic transcriptional modules in Trichoderma asperellum enhance glutathione detoxification to counteract fungal pathogen toxins.

Trichoderma fungi are potent biocontrol agents. However, their defence mechanisms against pathogen-derived toxins remain poorly understood. We identified two synergistic transcription factor modules in T. asperellum that orchestrate the detoxification of cytotoxic secondary metabolites from the poplar blight pathogen Alternaria alternata. Overexpression of the central regulator TasMYB46 reduced disease lesion area by approximately 22% and was associated with decreased pathogen-induced reactive oxygen species (ROS) accumulation. Mechanistically, TasMYB46 directly activates the glutathione S-transferases TasGST61.1 and TasGST56.1 through distinct promoter binding sites (G-box/as-1/MBS), forming dedicated detoxification modules. Crucially, we identified urolithin C as the most abundant phytotoxin in A. alternata metabolites, which is efficiently detoxified through the TasMYB46-TasGST61.1 module. The transcription enhancer TasbHLH53.8 amplifies this system by binding to TasMYB46, boosting TasGST expression and enhancing glutathione-dependent detoxification capacity. This coordinated response elevates glutathione pools and antioxidant enzyme activities (GST/GPx), conferring increased oxidative stress resistance. This study reveals a novel defence mechanism in Trichoderma in which MYB-bHLH-GST modules enable biocontrol agents to neutralise pathogen-derived toxins. Given that Alternaria toxins threaten crops globally (tomatoes, potatoes, citrus), the discovered regulatory synergy represents a strategic advance in developing next-generation biocontrol solutions against toxin-producing plant pathogens.

Alternaria

Whole-transcriptome RNA sequencing and ceRNA network analyses provide novel insights into the antibacterial immune response of Hippocampus abdominalis against Vibrio harveyi.

Long non-coding RNAs (lncRNAs) stand as newly-arisen molecular types that exert regulatory effects, able to operate as competitive endogenous RNAs (ceRNAs) to engage microRNAs (miRNAs) in interaction, resulting in the recovery of target mRNA expression and activity. Increasing evidences indicate that the ceRNA network affects various biological processes in mammals, including development, cellular differentiation, metabolism, immune response, and disease pathogenesis. In teleost fish, the lncRNA-miRNA-mRNA regulatory networks have been reported occasionally. However, up to now, the roles of lncRNAs in the big-belly seahorse (Hippocampus abdominalis) remains unclear. In this study, we reported for the first time, via whole-transcriptome RNA sequencing, the lncRNA mediated ceRNA regulatory network in Vibrio harveyi-infected H. abdominalis. A total of 4197 differentially expressed mRNAs (DE-mRNAs), 1317 DE-lncRNAs, and 183 DE-miRNAs were identified. Furthermore, the crosstalk between miRNAs and lncRNAs as well as between miRNAs and mRNAs was inferred based on the negative correlations between miRNAs and their target lncRNAs/mRNAs. A core immune associated lncRNA-miRNA-mRNA putative regulatory network was thus constructed, comprising 211 lncRNA-miRNA and 224 mRNA-miRNA pairs. In conclusion, our findings provide an integrative overview of the ceRNA regulatory networks on the underlying immune responses to V. harveyi infection in the big-belly seahorse, and offer a solid theoretical foundation for the comparative immunological research of teleost fish.

Animals