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PubMed2026

RNA dysregulation as a determinant of aging and neurodegenerative vulnerability.

In the nervous system, aging causes deterioration of cellular and molecular processes that are associated with declines in cognition, sensory perception, and motor coordination. Aging is also the strongest risk factor for neurodegenerative disease, yet the mechanisms by which aging predisposes neurons to dysfunction remain incompletely understood. While genomic instability, proteostasis decline, mitochondrial dysfunction, and chronic inflammation have dominated prevailing models, recent evidence highlights RNA dysregulation as a central component of age-associated decline. In this review, we summarize recent findings suggesting that aging progressively erodes RNA regulatory fidelity through alterations in RNA-binding protein abundance, localization, biophysical behavior, and RNA interactions. We argue that age-dependent RNA dysregulation represents an important mechanism that converges with genetic risk to drive neuronal vulnerability and neurodegeneration.

RNA dysregulation↗

PubMed2026

Exploring precision risk in pediatric vesicoureteral reflux: Innate immune gene variations and reflux outcomes in the RIVUR cohort.

INTRODUCTION: Children with vesicoureteral reflux (VUR) are at increased risk for morbidity from recurrent urinary tract infections (UTIs), yet the factors influencing spontaneous VUR resolution remain poorly defined. This study evaluates whether genetic variations in key urinary innate immune effectors (DEFA1A3, DMBT1, and RNASE7) influences VUR resolution and interacts with prophylaxis to alter clinical response. METHODS: We conducted a secondary analysis of 303 RIVUR participants with available DEFA1A3 and DMBT1 copy number variation (CNV) data and RNASE7 rs1263872 genotype. Primary outcomes were (1) VUR improvement (decrease in grade) and (2) VUR resolution at study exit. Multivariable logistic regression models included genotype, treatment, and their interactions, adjusting for age, sex, baseline grade (high vs low), laterality, bowel/bladder dysfunction, and any UTI. Internal validation used 2000-sample bootstrap with bias-corrected and accelerated confidence intervals and influence diagnostics. RESULTS: Clinical covariates did not significantly predict VUR improvement. Children with DEFA1A3 CNV >5 had higher odds of improvement (OR 2.36, 95% CI 1.12-4.96, p = 0.023), an effect that remained significant in bootstrap analyses. High-grade VUR was associated with lower odds of resolution (OR 0.34, 95% CI 0.12-0.94, p = 0.038). A significant interaction was observed between prophylaxis and high DMBT1 copy number for VUR resolution (interaction OR 2.99, 95% CI 1.11-8.04, p = 0.031); no interaction was seen for improvement. RNASE7 rs1263872 was not associated with either outcome. CONCLUSION: Innate immune gene variation may contribute to heterogeneity in VUR outcomes. High DEFA1A3 copy number was associated with reflux improvement and a DMBT1-prophylaxis interaction was associated with reflux resolution. The results of this study is hypothesis-generating and prompt further evaluation to assess whether a subset of children may experience structural benefit from prophylaxis or have a more favorable natural history based on their innate immune genotype.

Humans↗

PubMed2026

Light regulates capsaicinoid biosynthesis via the CaHY5-CaBBX2-CaACS8 module in pepper.

Capsaicinoids are a class of unique alkaloids that confer the pungent taste to pepper fruits. However, it remains largely unknown how light regulates the biosynthesis of capsaicinoids. We conducted a metabolic analysis on light- and dark-adapted pepper fruits. The results showed that dark-adapted pepper fruits had lower capsaicinoid contents and correspondingly downregulated transcription of capsaicinoid biosynthetic genes (CBGs), indicating that light plays a crucial role in capsaicinoid biosynthesis. Furthermore, silencing of CaHY5, a pivotal transcription factor gene in the light signaling pathway, decreased the content of capsaicinoid and suppressed the expression of CBGs, whereas transient overexpression of CaHY5 generated exactly opposite results. CaHY5 can bind to the G-box motif in the promoters of CaBBX2 and CaACS8, thereby enhancing their transcriptional levels. The activated CaBBX2 then binds to the T/G-box in the CaACS8 promoter to stimulate its expression. CaBBX2 or CaACS8 silencing led to decreased levels of capsaicinoids, while their transient overexpression produced increased capsaicinoid contents. Collectively, our results indicated that the light-activated CaHY5-CaBBX2-CaACS8 regulatory module plays a pivotal role in capsaicinoid biosynthesis. These findings provide new insights into the influence of light on capsaicinoid biosynthesis and potential targets for activation of this biosynthetic pathway in pepper.

Capsicum↗

PubMed2026

Induced degradation of Ufd1 reveals regulation of cohesin by the VCP/p97Ufd1-Npl4 complex.

The AAA ATPase VCP/p97 has emerged as a critical regulator of ubiquitin and chromatin-associated processes but progress in understanding has been hampered by the complexity of p97 functions and the various p97 cofactors involved. Here, we combined ubiquitin profiling with acutely induced degradation of the Ufd1 subunit of the p97 ubiquitin adapter, Ufd1-Npl4, in human cells. We identified a set of chromatin regulators, HUS1, XRCC1, MORF4L1, and the cohesin subunit RAD21 as targets of p97Ufd1-Npl4 We find that RAD21 is ubiquitylated and targeted by p97Ufd1-Npl4 specifically in S phase to remove a subpopulation of cohesin from chromatin. Acute degradation of Ufd1 in S phase, after replication licensing is completed, impedes replication and leads to replication-associated DNA damage. Our findings suggest that a fraction of cohesin rings need to be removed by p97Ufd1-Npl4 from DNA to allow unhindered replication and reveal a critical function of p97 that ensures genome stability.

Cell Cycle Proteins↗

PubMed2026

Antennal transcriptome analysis of chemosensory proteins in the raspberry weevil, Aegorhinus superciliosus (Coleoptera: Curculionidae).

Aegorhinus superciliosus (Coleoptera: Curculionidae) is a polyphagous pest of economic importance in southern Chile, the chemical ecology of which remains poorly characterized. Across insect species, chemosensory proteins, including odorant receptors (ORs), gustatory receptors (GRs), ionotropic receptors (IRs), odorant-binding proteins (OBPs), chemosensory proteins (CSPs), and sensory neuron membrane proteins (SNMPs), mediate the detection of chemical cues involved in host selection, reproduction, and other ecologically relevant behaviors. In this study, the antennal transcriptome of adult A. superciliosus was sequenced and analyzed using a de novo RNA-seq approach. Three independent biological replicates per sex were used for RNA-seq, and the same number of independent biological replicates was used for RT-qPCR validation; sequencing yielded 147,409,936 high-quality reads after quality filtering. A total of 112 candidate chemosensory genes were identified, comprising 43 ORs, 34 OBPs, 10 CSPs, 18 IRs, 5 GRs, and 2 SNMPs. Phylogenetic analyses assigned these candidate proteins to established clades, providing a comparative framework for functional inference for ORs and OBPs. Sex- and tissue-biased expression analyses revealed that several ORs, including AsupOR4, AsupOR19, and AsupOBP13, exhibit antennal enrichment and sex-specific expression patterns. Notably, AsupOR19 and AsupOBP13 displayed strong female-biased expression. In addition, transcripts of selected ORs and OBPs were detected in non-antennal tissues, such as the rostrum and legs, suggesting potential functional versatility beyond canonical olfaction. Together, these findings represent the first molecular identification of the chemosensory repertoire of A. superciliosus. This study establishes a foundation for reverse chemical ecology approaches aimed at identifying behaviorally active volatile organic compounds (VOCs) toward environmentally sustainable strategies for integrated pest management.

Animals↗

PubMed2026

Exploring sex differences in endocannabinoid system biomarkers and their relationship with antidepressant treatment outcomes in major depressive disorder: a CAN-BIND 1 secondary analysis.

BACKGROUND: Sex differences in major depressive disorder (MDD) are well documented, but it remains unclear whether sex-related variation in peripheral endocannabinoid system (ECS)-related biomarkers is detectable in MDD. OBJECTIVES: To examine baseline sex differences in ECS-related mRNA expression, DNA methylation, and single nucleotide polymorphisms (SNPs) in MDD, and associations between baseline ECS markers and antidepressant outcomes in sex-stratified analyses. METHODS: Among 178 participants with MDD from CAN-BIND-1, all received escitalopram for 8 weeks; non-responders then received adjunctive aripiprazole from Weeks 8-16.Response was defined as ≥ 50% reduction in MADRS score, and remission as MADRS ≤ 10. ANCOVAs examined baseline sex differences and sex-stratified biomarker associations with percent MADRS reduction at Weeks 8 and 16, as well as categorical response and remission outcomes. Covariates included site, baseline MADRS, age, and ethnicity. False discovery rate correction was applied. RESULTS: Baseline sex differences in methylation were observed for CACNA1H, GABRB2, MAGL, and GABRR2, though none survived correction. No baseline sex differences in mRNA expression or SNPs were detected after correction. Lower baseline DAGLA mRNA in males was associated with greater Week 8 symptom improvement (FDR corrected). This association was not observed in females. No associations with response or remission at Weeks 8 or 16 survived correction. IMPLICATIONS: Baseline sex differences in peripheral ECS-related markers were not detected in this sample. Larger studies are needed to verify whether ECS-related biomarkers, particularly DAGLA, contribute to antidepressant outcomes in a sex-specific manner.

Humans↗

PubMed2026

Lipid-mediated activation of BLT2 promotes membrane repair to prevent cell death.

Various pathogenic microorganisms produce toxins that create pores in cell membranes, causing cell damage and disrupting the host epithelial barrier. Recently, we reported that mice lacking the G protein-coupled receptor leukotriene B4 receptor 2 (BLT2), which is expressed in vascular endothelial and alveolar epithelial cells, are highly susceptible to pneumolysin (PLY), a pneumococci-generated toxin. Although we clarified the protective roles of BLT2 in vascular endothelial cells, those in alveolar epithelial cells have not been elucidated. Here, we report that lipid mediator 12-hydroxyheptadecatrienoic acid (12-HHT), which is produced by membrane-damaged epithelial cells, prevents cell death by promoting membrane repair through BLT2. BLT2 promoted the release of PLY-bound plasma membranes as extracellular vesicles in a sphingomyelinase-dependent manner. Additionally, BLT2 activated Rac1 and subsequent actin polymerization, leading to resistance to cell death. Furthermore, inhibition of 12-HHT production by aspirin and treatment with a BLT2 antagonist abolished the protective effect of BLT2. These findings provide a new therapeutic strategy for bacterial infection.

Receptors, Leukotriene B4↗

PubMed2026

Genome-wide identification and characterization of ABC transporters and their expression in response to saline-alkaline stress and WSSV infection in Fenneropenaeus chinensis.

ATP-binding cassette (ABC) transporters play crucial roles in stress responses across organisms, yet their functions in Fenneropenaeus chinensis remain largely unknown. In this study, we identified 42 FcABC genes (FcABCs) in the F. chinensis genome and analyzed their phylogenetic relationships, gene structures, and chromosomal distributions. Phylogenetic analysis grouped the FcABCs into eight subfamilies (ABCA-ABCH), with conserved motif and domain compositions within each subfamily. Expression analysis showed that several FcABC genes, including FcABCG5, FcABCA1, and FcABCC3, were significantly induced under saline-alkaline stress in gill and hepatopancreas tissues. In contrast, most FcABCs were downregulated after WSSV challenge, though a subset (e.g., FcABCB1, FcABCC1) exhibited early upregulation. Functional validation via RNA interference demonstrated that knockdown of FcABCG5 increased shrimp mortality under saline-alkaline stress. Cis-regulatory element analysis revealed an enrichment of stress- and immune-related elements in FcABC promoters. Protein-protein interaction network predictions indicated potential roles for FcABCs in cholesterol metabolism and organic anion transport. Our findings provide insights into the roles of FcABC genes in stress adaptation and immune defense, offering candidate genes for the breeding of stress-resistant shrimp varieties.

Animals↗

PubMed2026

Molecular characterization and biological characteristics of a highly pathogenic recombinant ALV-J strain (HUE2023) with cross-clade gp85 recombination.

Avian leukosis virus subgroup J (ALV-J) has undergone extensive diversification into phylogenetically distinct clades, yet whether recombination between these clades within the gp85 envelope glycoprotein generates variants with altered pathogenicity has received little direct investigation. A field strain (HUE2023) was recovered from breeding roosters displaying vascular tumors. The viral genome was sequenced and subjected to phylogenetic and recombination analyses. The three-dimensional structure of gp85 was predicted with AlphaFold3; electrostatic surface potentials and surface hydrophobicity were computed using the Adaptive Poisson-Boltzmann Solver and the Eisenberg hydrophobicity scale, respectively. Pathogenicity and immunosuppressive effects were assessed in Hy-Line Brown chickens. Recombination analysis revealed that HUE2023 is an inter-clade recombinant derived from Clade 1.1 (major parent: JS14NT01) and Clade 1.2 (minor parent: JS09GY3). A single-residue deletion at position 61 within receptor-binding domain 1 (RBD-1), unique to the recombinant, induced a localized conformational rearrangement that generated a concentrated electronegative surface patch and a contiguous hydrophobic pocket not observed in either parental gp85. Animal challenge showed that HUE2023 is highly pathogenic: female chickens in the high-dose group reached only 61% survival and displayed significant growth retardation (P < 0.05) together with marked immunosuppression. The recombination in the RBD-1 led to local conformational rearrangement, resulting in a concentrated and negatively charged surface area as well as a continuous hydrophobic pocket, which were never present in any of the parental gp85 sequences. These results indicate that gp85 recombination across clades can yield variants with fundamentally altered receptor-binding surfaces and argue for integrating structural surveillance into ALV-J monitoring programmes.

Animals↗

PubMed2026

Functions of tandem-repeat galectins and domain coordination governs galectin-4 activity in grass carp (Ctenopharyngodon idella).

Galectins are β-galactoside-binding lectins that play essential roles in innate immunity. Among them, tandem-repeat galectins (TrGals), typically composed of two distinct carbohydrate-recognition domains (CRDs) connected by a linker peptide, are well established as key regulators of pathogen recognition and host defense in mammals. However, their structural diversity and immunological functions in teleost fish remain poorly understood. In this study, five TrGals (Gal-4, Gal-8a, Gal-8b, Gal-9, and Gal-9like) were identified in grass carp. Sequence and structural analysis revealed that Gal-8a/b, Gal-9, and Gal-9like possess the canonical two-CRD architecture, whereas Gal-4 uniquely contains four highly similar tandem-repeat domains. All five TrGals were broadly expressed across examined tissues, with predominant expression in the liver. Upon Aeromonas hydrophila infection, Gal-4, Gal-8a, Gal-8b, and Gal-9 were rapidly up-regulated at early time points (3-6 h). To elucidate the functional significance of CRD number, recombinant full-length CiGal-4 (CiGal4-full) and three truncated variants containing one, two, or three CRDs (CiGal4-1CRD, CiGal4-2CRD, and CiGal4-3CRD) were generated and systematically characterized. All recombinant proteins contained the conserved β-sheet structure typical of galectin CRDs. Functional assays revealed that CiGal4-full displayed the strongest growth-inhibitory activity against all tested bacteria, whereas CiGal4-1CRD showed the weakest effect. Notably, CiGal4-2CRD exhibited the most potent bactericidal activity, surpassing the full-length protein, while CiGal4-3CRD showed no further enhancement. CiGal4-full and CiGal4-2CRD showed superior carbohydrate-binding activities compared with the other variants. Collectively, these results reveal that CRD copy number alone does not linearly determine galectin function. Instead, domain organization and conformational coordination are critical for optimizing antimicrobial activity. This study provides new insights into the structure-function relationships and evolutionary diversification of galectins in teleosts and highlights their potential as novel antimicrobial and immunomodulatory agents in aquaculture.

Animals↗

PubMed2026

Viral community in Aspergillus spp. isolated from commercially available fermented dried bonito.

Katsuobushi is a traditional processed seafood product used in Japanese-style cooking, and when it is produced through fermentation by fungi, it is called karebushi. The fungi involved in katsuobushi fermentation are collectively referred to as katsuobushi molds. We previously discovered seven novel viruses from katsuobushi molds and determined their genome sequences. However, our previous explorations used only nine fungal strains available from culture collections, leaving the diversity of viruses infecting fungi involved in katsuobushi fermentation unclear. Therefore, in this study, we aimed to isolate fungi from commercially available karebushi and clarify the prevalence of viruses in the isolates. Karebushi produced by three manufacturers was obtained, and 30 fungal strains (including Aspergillus spp.) were isolated from each. Double-stranded RNA (dsRNA) fractions were prepared from the mycelia of the isolated strains. Electrophoresis suggested that a relatively high proportion of the isolates harbored dsRNA elements consistent with RNA virus infection (30-70% per manufacturer; 59% overall). Furthermore, dsRNA sequencing identified four novel viruses in isolates of Aspergillus chevalieri and Aspergillus montevidensis: a beny-like virus, a gammapartitivirus, a narnavirus, and a victorivirus, in addition to two previously reported viruses. Notably, this represents the first report of a beny-like virus in Aspergillus spp. This study provides insights into the diversity of viruses infecting fungi involved in katsuobushi fermentation.

Aspergillus↗

PubMed2026

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↗

PubMed2026

eIF5A and polyamines restrict mRNA levels in response to ribosome stalls.

Obstacles to translation elongation stall ribosomes and allow deleterious proteins to accumulate, which threatens cellular health. Cells recognize and clear stalled ribosomes via several interrelated pathways, although the mechanisms by which cells distinguish stalled from normally elongating ribosomes and mount an appropriate response are incompletely understood. While recent work highlights how ribosome collisions help cells to recognize stalled ribosomes, how other factors contribute to detection remains unclear. Here, we report a requirement for the translational factor eIF5A in the mRNA decay response to ribosomal stalling, i.e., No-Go mRNA Decay (NGD). We identified the Caenorhabditis elegans polyamine transporter, catp-6, via a forward genetic screen as a factor required for NGD. During our mechanistic dissection of the catp-6 phenotype, we uncovered a role for cellular polyamines and the translation elongation factor eIF5A in NGD, and we show this requirement is conserved from C. elegans to Saccharomyces cerevisiae. Our analyses support the idea that cells use eIF5A to identify ribosomal stalls and execute NGD and uncover a molecular function for a core protein synthesis factor in limiting expression from stall-inducing mRNAs. Our work offers insight into how cells identify and remove problematic mRNAs from the translational pool. Our work also raises the possibility that dysregulated mRNA decay is an unrecognized pathophysiology associated with polyaminopathies and eIF5A disorders, of relevance to varied neurodegenerative and aging phenotypes and efforts to pharmacologically inhibit eIF5A.

Animals↗

PubMed2026

Inducible flocculation in Komagataella phaffii enables enhanced biomass separation for biopharmaceutical production.

Biomass separation represents a critical bottleneck in Komagataella phaffii-based biopharmaceutical processes, as typically high cell densities of 40 - 50 % create significant operational, technical and economic challenges for harvest operations. Yeast cell aggregation (flocculation) provides a solution to accelerate cell sedimentation by increasing particle size, thus allowing to improve biomass-supernatant separation efficiency during both natural gravity settling and (continuous) centrifugation operations. This study demonstrates successful engineering of K. phaffii strains with an inducible flocculation phenotype using CRISPR/Cas9-based genome editing to integrate the Saccharomyces cerevisiae FLO1 (ScFLO1) gene under control of various regulatory elements, including methanol-inducible and derepressible promoters. Flocculation strength could be enhanced by implementing transcriptional positive feedback circuits based on the methanol-inducible AOX1 promoter. To address methanol-free production requirements, we developed alternative systems to retrofit PAOX1-based ScFLO1 expression and exploited the derepressible PDF promoter, offering broader compatibility with biopharmaceutical manufacturing facilities. Flocculating cells cultivated in a bioreactor demonstrated significantly improved sedimentation behavior, with considerably lower supernatant turbidity after short low-speed centrifugation or gravity sedimentation compared to non-flocculating controls. Crucially, cell flocculation had no negative impact on product amount and quality when expressing a multivalent NANOBODY® VHH molecule with pharmaceutical relevance. Thus, this work establishes the first genetically engineered flocculation system in K. phaffii compatible with recombinant protein production, providing the basis for an innovative approach to streamline harvest operations in biopharmaceutical processes.

Flocculation↗

PubMed2026

Genetic regulation of CPEB3-mediated alternative polyadenylation associated with survival of patients with hepatocellular carcinoma.

BACKGROUND: Alternative polyadenylation (APA) is a key post-transcriptional mechanism that regulates gene expression by modulating 3'UTR length, its dysregulation has been implicated in carcinogenesis. How genetic variants influence APA to affect hepatocellular carcinoma (HCC) prognosis remains unclear. METHODS: Prognosis-APA quantitative trait loci (apaQTL) were performed using genotype and APA profiling from TCGA data. A two-stage survival analysis in 848 Chinese and 369 TCGA LIHC patients and functional validation were used to identify prognostic apaQTL in HCC progression. RESULTS: A total of 2,025 and 817 significant APA events were identified in Chinese and TCGA cohort, respectively. Besides, 859 events were associated with poor prognosis in HCC and enriched in RNA splicing / metabolism pathways. We detected 32,034 significant apaQTLs, predominantly enriched in 3'UTRs and RBP-binding regions. CPEB3 was prioritized as a key APA regulator RBP; its low expression correlated with poor patient survival and promoted proliferation, migration, and invasion in HCC cells. Notably, a functional apaQTL variant rs2037547, located in GSK3B and mediated by CPEB3, demonstrated a poor survival of HCC patients in both cohort (pooled HR=1.29, p=0.016). Mechanistically, rs2037547 promoted aberrant APA at proximal poly(A) sites of GSK3B through CPEB3, leading to increased expression of short 3'UTR isoform. This regulatory alteration enhanced HCC cell proliferation, invasion, and migration, and contributed to HCC progression. CONCLUSION: These findings elucidated the distinct role of apaQTL-mediated APA dysregulation in HCC prognosis, providing insights for prognostic stratification and potential targets for personalized therapy in HCC.

RNA-binding proteins↗

PubMed2026

The Homozygous p.(Arg215Ter) Variant in XRCC2 Is Associated With Atypical Fanconi Anemia Without Major Hematological Abnormalities in Childhood.

Fanconi Anemia (FA) is the most frequent inherited bone marrow failure syndrome. A role for the XRCC2 gene in FA was suspected in 2012 and confirmed in 2016, but only two affected individuals have been described thus far, and no long-term follow-up is available. Here we present two young related adults born to consanguineous parents, in whom we identified the homozygous p.(Arg215Ter) variant in XRCC2. Both patients presented with mild intellectual disability, microcephaly, distinctive facial features, short stature, thumb abnormalities, and abnormal skin pigmentation. Unlike in FA, DEB test resulted negative in peripheral blood during childhood and no cytopenia, clonal evolution, or other hematological complications were detected until the age of 19 and 20 years, respectively. Our report suggests that the homozygous p.(Arg215Ter) variant in XRRC2 causes a distinctive FA-like disorder, characterized by the typical physical characteristics seen in FA, but a lack of major hematological manifestations in childhood, and the presence of a more pronounced neurodevelopmental phenotype than that seen in FA.

Humans↗

PubMed2026

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↗

PubMed2026

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↗