Search Results (392)

Abalone are highly susceptible to haliotid herpesvirus 1 (HaHV1), the causative agent of abalone viral ganglioneuritis (AVG), a re-emerging disease responsible for significant mortality events in both wild and farmed populations. Currently, there are no effective antiviral treatments or preventive measures available against HaHV1, which is partly due to the limited understanding of the immune responses and viral pathogenesis in this non-model marine invertebrate. This highlights the urgent need for novel intervention strategies, including investigations into the molecular mechanisms underlying HaHV1 infection. In other herpesviruses, the large tegument protein UL36 plays a crucial role in transporting the viral capsid to the host cell’s nuclear pore complex (NPC), mediated by N-terminal nuclear localization signals (NLSs). However, the nuclear import mechanism of UL36 homologue (UL36h) in HaHV1 remains largely uncharacterized. In this study, we identified and functionally characterized the NLS motif within HaHV1 UL36h and elucidated its interactions with the importin alpha (IMPα) nuclear import receptor. Through a combination of high-resolution crystallography and quantitative binding assays, we determined the key residues responsible for binding to IMPα and demonstrated isoform-specific variations in binding affinity. Our biochemical and structural analyses confirmed key interactions within the NLS that are essential for IMPα interactions. These findings advance our molecular understanding of HaHV1 host interactions and pave the way for the development of targeted antiviral strategies against abalone herpesvirus infection. Full article

Several transient receptor potential vanilloid (TRPV) ion channels are proton-sensitive, and recent structural studies have identified poorly conserved mechanisms for the proton sensitivity of TRPV1, TRPV2 and TRPV5. While such detailed studies are lacking for TRPV3, three distinct intracellular motifs were suggested to be required for a direct channel activation by cytosolic acidification. In this study, we investigated if these mechanisms are also relevant for the activation of TRPV3 by weak acids. Wildtype (WT) and several mutants of human TRPV3 transiently expressed in HEK 293T cells were investigated by whole-cell patch clamp electrophysiology. Cells expressing TRPV3-WT generated membrane currents induced by acetic acid (HOAc), formic acid and carbonic acid at pH 5.0. Activation induced by HOAc was concentration-dependent and increased with decreasing pH values. HOAc also strongly potentiated TRPV3-mediated responses to carvacrol and heat. Among the three suggested motifs for the binding of intracellular protons, only the mutant TRPV3-Asp512Ala exhibited an almost complete loss of HOAc sensitivity. The mutation of two C-terminal charged residues (Gln689/Asp727) even resulted in a clear gain of function for both HOAc and heat, and the mutation of the 2-APB-binding site His426 did not significantly abrogate HOAc sensitivity. Finally, insertion of the recently identified binding site in TRPV2 for the weak acid probenecid into TRPV3 (Glu216His) resulted in an increased HOAc sensitivity. To conclude, our data confirm that TRPV3 is sensitized and activated by several weak acids. While Asp512 appears to be a critical intracellular proton-modulating site, a more profound understanding of the mechanisms dictating the proton sensitivity of TRPV3 may require structural studies. Full article

N, as plants’ most essential nutrient, profoundly shapes root system architecture (RSA), with LRs being preferentially regulated. This review synthesizes the intricate molecular mechanisms underpinning N sensing, signaling, and its integration into developmental pathways governing LR initiation, primordium formation, emergence, and elongation. We delve deeply into the roles of specific transporters (NRT1.1, nitrate transporter 2.1 (NRT2.1)), transcription factors (Arabidopsis nitrate regulated 1 (ANR1), NLP7, TGACG motif-binding factor (TGA), squamosa promoter-binding protein-like 9 (SPL9)) and intricate hormone signaling networks (auxin, abscisic acid, cytokinins, ethylene) modulated by varying N availability (deficiency, sufficiency, excess) and chemical forms (NO₃⁻, NH₄⁺, organic N). Emphasis is placed on the systemic signaling pathways, including peptide-mediated long-distance communication (CEP—C-terminally encoded peptide receptor 1 (CEPR1)) and the critical role of the shoot in modulating root responses. Furthermore, we explore the emerging significance of carbon–nitrogen (C/N) balance, post-translational modifications (ubiquitination, phosphorylation), epigenetic regulation, and the complex interplay with other nutrients (phosphorus (P), sulfur (S)) and environmental factors in shaping N-dependent LR plasticity. Recent advances utilizing single-cell transcriptomics and advanced imaging reveal unprecedented cellular heterogeneity in LR responses to N. Understanding this sophisticated regulatory network is paramount for developing strategies to enhance nitrogen use efficiency (NUE) in crops. This synthesis underscores how N acts as a master regulator, dynamically rewiring developmental programs through molecular hubs that synchronize nutrient sensing with root morphogenesis—a key adaptive strategy for resource acquisition in heterogeneous soils. Full article

Galectin-9 (Gal-9, LGALS9) is a member of the family of carbohydrate-binding lectins known as galectins. Galectins bind a diverse repertoire of galactose-bearing glycoprotein receptors expressed across multiple cell types. These interactions elicit a broad spectrum of pleiotropic effects important in both normal physiology and disease pathogenesis. Gal-9 contains two separate carbohydrate recognition domains with overlapping yet also divergent binding affinities for distinct glycostructures. This tandem repeat motif enables fine-tuning of its various biological functions. Additional control of Gal-9 activity is provided via multiple gene variants, protein isoforms, tissue distribution, and cell type-associated glycoprotein binding profiles. Within the tumor microenvironment, Gal-9 interacts with immune, non-immune, and cancer cells to influence malignant progression. Its binding of the premier immune checkpoint glycoreceptors, T-cell immunoglobulin and mucin-domain-containing-3 (TIM-3) and programmed cell death protein 1 (PD-1), places Gal-9 apart as a burgeoning target for immunotherapy. In this review, we delve into important aspects of Gal-9 immunobiology in tumorigenesis, including glycobiological and lineage-dependent functions. We further examine Gal-9 as a promising new glyco-immune checkpoint target for cancer therapy. Full article

While calcium (Ca²⁺) is a universal cellular messenger, the ionic properties of magnesium (Mg²⁺) make it less suited for rapid signaling and more for structural integrity. Still, besides being a passive player, Mg²⁺ is the only active Ca²⁺ antagonist, essential for tuning the efficacy of Ca²⁺-dependent cardiac excitation–contraction coupling (ECC) and for ensuring cardiac function robustness and stability. This review aims to provide a comprehensive framework to link the structural and molecular mechanisms of Mg²⁺/Ca²⁺ antagonistic binding across key proteins of the cardiac ECC machinery to their physiopathological relevance. The pervasive “dampening” effect of Mg²⁺ on ECC activity is exerted across various players and mechanisms, and lies in the ions’ physiological competition for multiple, flexible binding protein motifs across multiple compartments. Mg²⁺ profoundly modulates the cardiac action potential waveform by inhibiting the L-type Ca²⁺ channel Cav1.2, i.e., the key trigger of cardiac ryanodine receptor (RyR2) opening. Cytosolic Mg²⁺ favors RyR2 closed or inactive conformations not only through physical binding at specific sites, but also indirectly through modulation of RyR2 phosphorylation by Camk2d and PKA. RyR2 is also potently inhibited by luminal Mg²⁺, a vital mechanism in the cardiac setting for preventing excessive Ca²⁺ release during diastole. This mechanism, able to distinguish between Ca²⁺ and Mg²⁺, is mediated by luminal partners Calsequestrin 2 (CASQ2) and Triadin (TRDN). In addition, Mg²⁺ favors a rearrangement of the RyR2 cluster configuration that is associated with lower Ca²⁺ spark frequencies. Full article

C-C motif chemokine receptor-like 2 (CCRL2) is an atypical chemokine receptor (ACKR) that binds chemerin with high affinity but lacks classical G protein-coupled signaling. Instead, it functions as a non-signaling presenter of chemerin to CMKLR1-expressing cells, modulating antitumor immunity. CCRL2 is highly expressed in the tumor microenvironment and various human cancers, and its expression has been linked to delayed tumor growth in mouse models, primarily through the chemerin/CMKLR1 axis. While CCRL2’s role in immune surveillance is well established, its tumor cell-intrinsic functions remain less clear. Here, we investigated the impact of CCRL2 overexpression and knockout on tumor cell behavior in vitro. Although CCRL2 did not affect proliferation, migration, or clonogenicity in B16F0 melanoma and LLC cells, it significantly influenced spheroid morphology in B16F0 cells. Transcriptomic analysis revealed that CCRL2 modulates innate immune signaling pathways, including TLR4 and IFN-γ/STAT1, with context-dependent downstream effects. These findings suggest that CCRL2 shapes tumor architecture by rewiring inflammatory signaling networks in a cell-intrinsic manner. Further studies in other cancer types and cell models are needed to determine whether CCRL2’s regulatory role is broadly conserved and to explore its potential as a therapeutic target in solid tumors. Full article

Glioblastoma multiforme (GBM) remains one of the most aggressive and treatment-resistant brain tumors, with poor prognosis and limited therapeutic options. Background/Objectives: Integrin α_vβ₃, a cell surface receptor overexpressed in GBM, specifically binds to cyclic arginine-glycine-aspartate-D-phenylalanine-lysine (c(RGDfK)) motif, making it a valuable target for tumor-specific delivery and PET imaging. This study explores a novel radiotheranostic agent, [⁶⁴Cu]Cu-NOTA-TP-c(RGDfK), which combines the imaging and therapeutic capabilities of copper-64 (⁶⁴Cu) and the cytotoxic activity of a terpyridine-platinum (TP) complex, conjugated to c(RGDfK). Methods: A robust protocol was developed for the small-scale preparation of NOTA-TP-c(RGDfK). Comparative cellular studies were conducted using U87 MG glioblastoma (GBM) cells and SVG p12 human astrocytes to evaluate the performance of [⁶⁴Cu]Cu-NOTA-TP-c(RGDfK) relative to [⁶⁴Cu]Cu-NOTA-c(RGDfK), [⁶⁴Cu]Cu-NOTA-TP, ^natCu-NOTA-TP-c(RGDfK), cisplatin, and temozolomide. Results: ⁶⁴Cu-radiolabeling of NOTA-TP-c(RGDfK) was achieved with >99% radiochemical purity, and competition assays confirmed high binding affinity to integrin α_vβ₃ (IC₅₀ = 16 ± 8 nM). Cellular uptake, internalization, and retention studies demonstrated significantly higher accumulation of [⁶⁴Cu]Cu-NOTA-TP-c(RGDfK) in U87 MG cells compared to control compounds, with 38.8 ± 1.8% uptake and 28.0 ± 1.0% internalization at 24 h. Nuclear localization (6.0 ± 0.5%) and stable intracellular retention further support its therapeutic potential for inducing localized DNA damage. Importantly, [⁶⁴Cu]Cu-NOTA-TP-c(RGDfK) exhibited the highest cytotoxicity in U87 MG cells (IC₅₀ = 10 ± 2 nM at 48 h), while maintaining minimal toxicity in normal SVG p12 astrocytes. Conclusions: These results highlight [⁶⁴Cu]Cu-NOTA-TP-c(RGDfK) as a promising targeted radiotheranostic agent for GBM, warranting further preclinical development Full article

Many vertebrates have evolved resistance to snake venom as a result of coevolutionary chemical arms races. In Australian skinks (family Scincidae), who often encounter venomous elapid snakes, the frequency, diversity, and molecular basis of venom resistance have been unexplored. This study investigated the evolution of neurotoxin resistance in Australian skinks, focusing on mutations in the muscle nicotinic acetylcholine receptor (nAChR) α1 subunit’s orthosteric site that prevent pathophysiological binding by α-neurotoxins. We sampled a broad taxonomic range of Australian skinks and sequenced the nAChR α1 subunit gene. Key resistance-conferring mutations at the toxin-binding site (N-glycosylation motifs, proline substitutions, arginine insertions, changes in the electrochemical state of the receptor, and novel cysteines) were identified and mapped onto the skink organismal phylogeny. Comparisons with other venom-resistant taxa (amphibians, mammals, and reptiles) were performed, and structural modelling and binding assays were used to evaluate the impact of these mutations. Multiple independent origins of α-neurotoxin resistance were found across diverse skink lineages. Thirteen lineages evolved at least one resistance motif and twelve additional motifs evolved within these lineages, for a total of twenty-five times of α-neurotoxic venoms resistance. These changes sterically or electrostatically inhibit neurotoxin binding. Convergent mutations at the orthosteric site include the introduction of N-linked glycosylation sites previously known from animals as diverse as cobras and mongooses. However, an arginine (R) substitution at position 187 was also shown to have evolved on multiple occasions in Australian skinks, a modification previously shown to be responsible for the Honey Badger’s iconic resistance to cobra venom. Functional testing confirmed this mode of resistance in skinks. Our findings reveal that venom resistance has evolved extensively and convergently in Australian skinks through repeated molecular adaptations of the nAChR in response to the enormous selection pressure exerted by elapid snakes subsequent to their arrival and continent-wide dispersal in Australia. These toxicological findings highlight a remarkable example of convergent evolution across vertebrates and provide insight into the adaptive significance of toxin resistance in snake–lizard ecological interactions. Full article

Oxidative stress overwhelms cellular antioxidant defenses, causing DNA damage and pro-tumorigenic signaling that accelerate cancer initiation and progression. Electron shuttles (ESs) from phytocompounds offer precise redox control but lack quantitative benchmarks. This study aims to give a clearer definition to electron shuttles by characterizing mulberry’s electrochemical capabilities via the three defined ES criteria and deciphering its mechanism against oxidative stress-related cancer. Using double-chambered microbial-fuel-cell power metrics, cyclic voltammetry, and compartmental fermentation modeling, we show that anthocyanin shows a significant difference (p < 0.05) in power density at ≥500 µg/mL (maximum of 2.06-fold power-density increase) and reversible redox cycling (ratio = 1.65), retaining >90% activity over four fermentation cycles. Molecular docking implicates meta-dihydroxyl motifs within the core scaffold in receptor binding, overturning the view that only ortho- and para-substituents participate in bioactivity. In vitro, anthocyanins both inhibit nitric oxide release and reduce DU-145 cell viability dose-dependently. Overall, our findings establish mulberry anthocyanins as robust electron shuttles with potential for integration into large-scale bio-electrochemical platforms and targeted redox-based cancer therapies. Full article

Background/Objectives: Neuropilin-1 (NRP1) is a key co-receptor for SARS-CoV-2, complementing the ACE2 receptor. Several investigations have documented highly conserved sequences in this receptor, supporting the implication of NRP1 as a key mediator in SARS-CoV-2 cellular entry mechanisms. Methods: To investigate this hypothesis, we examined 104,737 SARS-CoV-2 genome fastas from GISAID genomic data, corresponding to isolates collected between 2020 and 2025 in Mexico. Specifically, we focused on the RRAR motif, a known furin-binding site for NRP-1 and the binding site for ACE2 with the spike protein. Our analysis revealed high conservation (>98%) of the RRAR domain compared to a rapidly diminishing ACE2-binding domain. A complementary analysis, using Data from Gene Expression Omnibus (GEO, GSE150316), showed that NRP1 expression in lung tissue remains relatively stable, whereas ACE2 displayed high inter-individual variability and lower abundance compared to NRP1. Based on this evidence, we designed two humans–rats NRP1 siRNAs that were tested in vivo using a melittin-induced lung injury model. Results: The RT-PCR assays confirmed an effective NRP1 knockdown, and the siRNA-treated group showed a significant reduction in the lesions severity. These findings highlight NRP1 as a stable and relevant therapeutic target and suggest the protective potential of siRNA-mediated gene silencing. Conclusions: The evidence presented here supports the rational design of NRP1-directed therapies for multiple circulating SARS-CoV-2 variants in Mexico. Full article

It is becoming evident that the therapeutic effect of reawakening the immune response is to limit tumor cell growth and expansion. The use of immune checkpoint inhibitors, like blocking antibodies against programmed cell death receptor (PD) 1 and/or cytotoxic T lymphocyte antigen (CTLA) 4 alone or in combination with other drugs, has led to unexpected positive results in some tumors but not all. Several other molecules inhibiting lymphocyte antitumor effector subsets have been discovered in the last 30 years. Herein, we focus on the leukocyte-associated immunoglobulin (Ig)-like receptor 1 (LAIR1/CD305). LAIR1 represents a typical immunoregulatory molecule expressed on almost all leukocytes, unlike other regulatory receptors expressed on discrete leukocyte subsets. It bears two immunoreceptor tyrosine-based inhibitory motifs (ITIMs) in the intracytoplasmic protein domain involved in the downregulation of signals mediated by activating receptors. LAIR1 binds to several ligands, such as collagen I and III, complement component 1Q, surfactant protein D, adiponectin, and repetitive interspersed families of polypeptides expressed by erythrocytes infected with Plasmodium malariae. This would suggest LAIR1 involvement in several cell-to-cell interactions and possibly in metabolic regulation. The presence of both cellular and soluble forms of LAIR would indicate a fine regulation of the immunoregulatory activity, as happens for the soluble/exosome-associated forms of PD1 and CTLA4 molecules. As a consequence, LAIR1 appears to play a role in some autoimmune diseases and the immune response against tumor cells. The finding of LAIR1 expression on hematological malignancies, but also on some solid tumors, could open a rationale for the targeting of this molecule to treat neoplasia, either alone or in combination with other therapeutic options. Full article

Background/Objectives: Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most prevalent chronic liver disease worldwide, contributing to metabolic dysfunction and increased healthcare costs. The green Mediterranean diet reduces intrahepatic fat and elevates the plasma levels of 2,5-dihydroxybenzoic acid (2,5-DHBA), suggesting a mechanistic role for 2,5-DHBA in hepatic lipid metabolism. This study aimed to evaluate the therapeutic potential of 2,5-DHBA in MASLD and elucidate its molecular mechanism. Methods: Lipid accumulation was assessed in oleic acid-treated HepG2 cells and a high-fat diet (HFD)-induced MASLD mouse model. RNA sequencing, molecular docking, and immunohistochemical staining were performed to investigate the molecular mechanisms, focusing on the chemokine (C-C motif) ligand 2 (CCL2)–CCL2 receptor (CCR2) axis. Results: 2,5-DHBA significantly reduced hepatic lipid accumulation in both HepG2 cells and HFD-fed mice in a dose-dependent manner. RNA sequencing revealed the marked downregulation of CCL2, a key proinflammatory mediator in MASLD pathogenesis. Molecular docking predicted that 2,5-DHBA competed with CCL2 for binding at the CCR2 axis. Immunohistochemistry further confirmed that 2,5-DHBA treatment lowered hepatic CCL2 expression, suppressed nuclear factor-κB activation, and reduced inflammatory cell infiltration. These findings suggest that 2,5-DHBA exerted anti-steatotic effects by modulating the CCL2-CCR2 signaling pathway. Conclusions: This is the first study to demonstrate that 2,5-DHBA attenuates hepatic steatosis via targeting the CCL2-CCR2 axis. These findings highlight its potential as a novel nutraceutical strategy for MASLD treatment. Full article

20-hydroxyecdysone (20E) is essential for insect development and diapause. Ecdysone receptor (EcR) and ultraspiracle (USP) proteins are crucial regulators of 20E signaling. To explore their potential roles in the development of Sitodiplosis mosellana, a major wheat pest that undergoes obligatory diapause as a larva, one SmEcR and two SmUSPs (SmUSP-A and SmUSP-B) from this species were isolated and characterized. The deduced SmEcR and SmUSP-A/B proteins contained a conserved DNA-binding domain with two zinc finger motifs that bind to specific DNA sequences. Expression of SmEcR and the SmUSPs was developmentally controlled, as was 20E induction. Their transcription levels increased as the larvae entered pre-diapause, followed by downregulation during diapause and upregulation during the shift to post-diapause quiescence, which is highly consistent with ecdysteroid titers in this species. Topical application of 20E to diapausing larvae also elicited a dose-dependent expression of the three genes. Expression of SmEcR and SmUSPs decreased markedly during the pre-pupal stage and was higher in adult females compared to males. These findings suggested that 20E-induced expression of SmEcR and SmUSPs has key roles in diapause initiation and maintenance, post-diapause quiescence, and adult reproduction, while the larval–pupal transformation may be associated with a decrease in their expression levels. Full article

Introduction: Rice, a cornerstone of global food security, faces escalating demands for enhanced yield and disease resistance. We collected 300 high-quality genomes, representing both cultivated (Oryza sativa indica, O. sativa japonica, and O. sativa aus) and wild species (O. rufipogon, O. glaberrima, and O. barthii). Methods: Leveraging HMMER, NLR-Annotator, and OrthoFinder, we systematically identified 148,077 leucine-rich repeat (LRR) and 143,459 nucleotide-binding leucine-rich repeat (NLR) genes, with LRR receptor-like kinases (LRR-RLKs) dominating immune receptor proportions, followed by coiled-coil domain containing (CNL)-type NLRs and LRR receptor-like proteins (LRR-RLPs). Results: Benchmarking Universal Single-Copy Orthologs (BUSCO) assessments confirmed robust genome quality (average score: 94.78). Strikingly, 454 TIR-NB-LRR (TNL) genes—typically rare in monocots—were detected, challenging prior assumptions. Phylogenetic analysis with Arabidopsis TNLs highlighted five O. glaberrima genes clustering with dicot TNLs; these genes featured truncated PLN03210 motifs fused to nucleotide-binding adaptor shared by APAF-1, R proteins, and CED-4 (NB-ARC) and LRR domains. Conclusions: By bridging structural genomics, evolutionary dynamics, and domestication-driven adaptation, this work provides a foundation for targeted breeding strategies and advances functional studies of plant immunity in rice. Full article

m⁶A methylation modification is an important genetic modification involved in biological processes such as sexual maturation, antibacterial, and antiviral in aquatic animals. However, few studies have been conducted in aquatic animals on the relationship between m⁶A methylation modification and autophagy-inflammation induced by lipid metabolism disorders. In the present study, a high-fat (HF) group and HF-MLP group (1 g mulberry leaf polysaccharides (MLPs)/1 kg HF diet) were set up. The mid-hind intestines of Megalobrama amblycephala juveniles from the two groups were collected for MeRIP-seq and RNA-seq after an 8-week feeding trial. The m⁶A peaks in the HF and HF-MLP groups were mainly enriched in the 3′ Untranslated Region (3′UTR), Stop codon, and coding sequence (CDS) region. Compared with the HF group, the m⁶A peaks in the HF-MLP group were shifted toward the 5′UTR region. ‘RRACH’ was the common m⁶A methylation motif in the HF and HF-MLP groups. Methyltransferase mettl14 and wtap expression in the intestines of the HF-MLP group were significantly higher compared with the HF group (p < 0.05). A total of 21 differentially expressed genes(DEGs) with different peaks were screened by the combined MeRIP-seq and RNA-seq analysis. Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis enriched BCL2 interacting protein 3 (bnip3) to autophagy–animal and mitophagy–animal signaling pathways, etc., and nucleotide-binding domain leucine-rich repeat protein 1 (nlrp1) was enriched to the Nucleotide-binding oligomerization domain (NOD)-like receptor signaling pathway. Combined MeRIP-seq and RNA-seq analysis indicated that the expression pattern of bnip3 was hyper-up and that of nlrp1 was hyper-down. Gene Set Enrichment Analysis (GSEA) analysis confirmed that the intestinal genes of HF-MLP group positively regulate lysosomal and autophagy–animal signaling pathways. In the present study, we demonstrated that m⁶A methylation modification plays a role in regulating autophagy-inflammatory responses induced by HF diets by MLPs, and further explored the molecular mechanisms by which MLPs work from the epigenetic perspective. Full article