Search Results (786)

Background/Objectives: The Arabidopsis thaliana GDS1 (Growth, Development and Splicing 1) gene has recently been identified as a key regulator linking nitrate signaling to leaf senescence. However, a systematic analysis of the GDS1 gene family in maize (Zea mays L.) is lacking. This study aims to identify and characterize the ZmGDS1 gene family in maize, providing a foundation for functional studies on their roles in growth, development, and low-nitrogen-induced leaf senescence. Methods: Putative ZmGDS1 family members were identified by searching the maize B73 reference genome using BLASTP (version 2.11.0+) and HMMER (version 3.4), with the Arabidopsis GDS1 protein sequence as the query. Candidate sequences were verified for the presence of the conserved zf-CCCH domain using NCBI CD-Search and SMART. Phylogenetic relationships, gene structures, conserved motifs, chromosomal distribution, collinearity, and promoter cis elements were comprehensively analyzed using MEGA 11, TBtools (version 1.098), MEME (version 5.5.9), and PlantCARE. Phylogenetic trees were constructed using the maximum likelihood (ML) method with the LG+G+I model and 1000 bootstrap replicates. Results: Thirteen ZmGDS1 genes were identified, distributed unevenly across eight maize chromosomes. Phylogenetic analysis classified the ZmGDS1 proteins into four distinct groups (A–D), revealing a lineage-specific expansion in group D. While all members contained the conserved zf-CCCH domain, their motif compositions varied considerably; ZmGDS1.1 exhibited the most complex structure, whereas ZmGDS1.12 had the most simplified. Subcellular localization predictions indicated that most ZmGDS1 proteins are targeted to the nucleus, consistent with a potential role as transcription factors. Promoter analysis revealed an abundance of cis elements associated with light response, hormone signaling (methyl jasmonate, abscisic acid, auxin), and stress responses. Notably, phylogenetically related genes tended to share similar cis-element profiles. Conclusions: This genome-wide analysis provides the first characterization of the ZmGDS1 gene family in maize. The observed structural conservation and diversity, together with regulatory elements linked to senescence-associated signals, support the hypothesis that ZmGDS1 genes may contribute to leaf senescence, particularly under low-nitrogen conditions. These findings provide a basis for future functional validation studies. Full article

Sigma factors (SIGs) are nuclear-encoded regulators of chloroplast gene transcription. We conducted a genome-wide analysis in Brassica napus, identifying 23 SIG genes that were phylogenetically classified into six distinct subfamilies. Characterization of gene structure, conserved motifs, and chromosomal locations indicated family expansion primarily through segmental duplication under purifying selection. Promoter analysis identified cold-responsive elements enriched in BnSIG5A. Expression profiling showed that BnSIG5 subfamily members, particularly BnSIG5A, are strongly induced by cold stress. Analysis of Arabidopsis SIG5 mutants confirmed previously reported roles of AtSIG5 in cold tolerance. Heterologous expression in yeast, and the strong cold induction of BnSIG5A together with its chloroplast localization, suggest that BnSIG5A may play a conserved role, providing a foundation for future functional studies in B. napus. This work establishes a genomic framework for the SIG family in rapeseed and identifies BnSIG5A as a high-priority candidate for further investigation. Subcellular localization confirmed chloroplast targeting of BnSIG5A. Heterologous expression in yeast and analysis of Arabidopsis SIG5 mutants suggest conserved functions in cold tolerance, providing a foundation for future functional studies in B. napus. This work establishes a genomic framework for understanding SIG-mediated stress responses in rapeseed and identifies BnSIG5A as a promising candidate for further investigation. Full article

Seeds of Paeonia lactiflora Pall. ‘Hangshao’ contain over 20% oil, of which more than 90% are unsaturated fatty acids, showing its high potential as an oil crop. Triacylglycerol (TAG) is the main storage form of fatty acids, and diacylglycerol acyltransferase 2 (DGAT2) is a key enzyme in TAG biosynthesis. In this study, the full-length cDNA of PlDGAT2 (326 amino acids) was cloned. Subcellular localization assays further indicated that it localized in the endoplasmic reticulum. Functional verification showed that silencing PlDGAT2 in herbaceous peony decreased the level of total fatty acids, palmitic acid (C16:0, PA) and α-linolenic acid (C18:3, ALA), but increased linoleic acid (C18:2, LA) in leaves. Overexpressing PlDGAT2 in tobacco elevated the content of total fatty acids, PA, and ALA in seeds, while also enlarging the seed sizes, but it reduced the LA content in tobacco seeds. This study suggests that PlDGAT2 contributes to the accumulation of ALA and total fatty acids, offering a potential gene target for improving the oil quality of herbaceous peony seeds. Full article

Background: Apocynum venetum L., a saline–alkali-tolerant plant, is a valuable resource for forage, textile, and medicinal purposes. This study aimed to identify the AQP gene family in A. venetum genome-wide and explore their potential functions under abiotic stress. Methods: Gene identification, phylogenetic relationships, structural features, and evolutionary patterns were analyzed, along with gene expression patterns and correlations with physiological traits. Results: Phylogenetic analysis classified the 25 candidate AvAQP genes into five distinct subgroups, with members exhibiting conserved gene structures, motifs, and phosphorylation patterns. Subcellular localization predictions indicate targeting primarily to the plasma membrane or the vacuole, with one isoform (AvTIP5;1) predicted to localize to both. Synteny analysis revealed three intraspecific and multiple interspecific gene pairs (26 with Arabidopsis thaliana and 34 with Medicago truncatula). In silico promoter analysis identified 49 cis-regulatory elements associated with phytohormone response, stress signaling, and development, providing preliminary clues for their possible involvement in diverse biological processes. qPCR profiling under abiotic stress demonstrated tissue-specific expression patterns among AvAQP members under different stress conditions. Correlation analyses between gene expression and physiological indicators (growth- and water-related traits) were predominantly positive, with only a few negative correlations under stress conditions, suggesting that AvAQP expression may be associated with plant physiological status. Conclusions: This study presents a comprehensive analysis of the AQP family in A. venetum providing a foundation for further functional characterization of these genes in response to abiotic stress. Full article

Interferon-induced transmembrane proteins (IFITMs) are broad-spectrum antiviral factors that restrict the entry of many enveloped viruses, including HIV-1, by modifying host membrane properties and trapping fusion at the hemifusion stage. Beyond blocking entry in target cells, IFITMs also reduce the infectivity of virions produced from IFITM-expressing cells, a phenomenon termed “negative imprinting”. Conserved motifs, such as the amphipathic helix and oligomerization motifs, have been reported to be essential for IFITM-mediated protection of target cells from viral infection. Yet, the impact of IFITM incorporation on progeny virion infectivity remains poorly defined. Here, we show that IFITM3 mutants defective in target cell protection activity still markedly impair HIV-1 fusion/infection upon incorporating into virions, without affecting viral maturation or Env incorporation. Immunofluorescence studies suggest mislocalization of the IFITM3 mutants as the reason for the lack of antiviral activity in target cells. Testing the antiviral activity of chimeras between antiviral and non-antiviral IFITM orthologs failed to clearly identify a domain responsible for reduction of HIV-1 infectivity, suggesting that multiple domains may be required for negative imprinting. Interestingly, co-incorporation of non-antiviral dog IFITM1 with human IFITM3 did not interfere with IFITM3’s negative imprinting activity, despite forming mixed hetero-oligomers. This finding implies a dominant, oligomerization-independent antiviral phenotype of IFITM3 in virions. Our findings suggest that IFITMs may protect target cells and negatively imprint progeny virions through distinct mechanisms, underscoring the need to further characterize the molecular basis for the reduced fusion competence of IFITM-containing HIV-1 particles. Full article

Polyamines, such as spermidine (Spd), are small aliphatic amines that play critical roles in plant growth, fruit development, and stress responses. Spermidine synthase (SPDS) is the enzyme responsible for catalyzing Spd biosynthesis. However, the functional characterization of SPDS genes in tomato (Solanum lycopersicum) has been less studied. In this study, four SlSPDS genes (SlSPDS1-4) were identified and analyzed for their physicochemical properties, phylogenetic relationships, promoter cis-acting elements, subcellular localization, responses to various abiotic stresses, and effects on polyamine content in tomato leaves. Promoter analysis revealed the presence of multiple hormone and stress-responsive elements. Simultaneously, the overexpressing lines were subjected to osmotic stress treatment. Subcellular localization experiments demonstrated that SlSPDS1 and SlSPDS2 were distributed in both the nucleus and cytoplasm, while SlSPDS3 and SlSPDS4 were specifically localized to the nucleus. SlSPDS1-3 exhibited significant responses to high/low temperature stress, salt stress, and ABA stress. Meanwhile, only SlSPDS1 and SlSPDS4 exhibited responses to drought stress. Transient expression of SlSPDSs in tomato revealed changes in the accumulation levels of spermine, putrescine, tyramine, and tryptamine, whereas the contents of spermidine and phenethylamine showed no significant changes. Simultaneously, we successfully obtained four SlSPDS-overexpressing transgenic tomato lines, OE-SPDS1-4. Phenotypic analysis confirmed that these transgenic lines exhibited significantly reduced wilting and chlorosis compared with WT plants under drought and salt stress. Functional validation indicates that overexpression of these genes enhances reactive oxygen species (ROS) scavenging capacity in transgenic tomatoes, thereby potentially improving their tolerance to drought and salt stress. These findings highlighted the potential function of SlSPDS genes in tomato, providing valuable targets for improving stress tolerance. Full article

Epstein–Barr virus (EBV) is a human pathogenic and oncogenic herpesvirus, with worldwide importance, at times associated with serious to life-threatening symptoms, especially in immunocompromised hosts. The available preventive options against EBV disease are limited to medically elaborate and cost-intensive measures of cell-based immunotherapy. The development of novel options of anti-EBV drug targeting is currently a matter of intense international efforts. A putative target of the antiviral therapy approach is the EBV-encoded protein kinase BGLF4, which fulfills a multifaceted role in productive viral replication. So far, viral BGLF4 interactor proteins and phosphorylated substrates have occasionally been reported, but in particular cellular interactors await further characterization concerning both, their relevance for BGLF4 functionality and their accessibility to antiviral drugs. In this study, we have analyzed host cell–BGLF4 interaction, BGLF4 kinase properties, and BGLF4-directed small molecules. The main results are as follows: (i) a mass spectrometry-based interactomic study was performed with EBV-producing Akata-BX1 cells, thereby identifying the human pyruvate dehydrogenase (PDH) as a relevant BGLF4 interactor; (ii) BGLF4–PDH interaction was confirmed by protein coimmunoprecipitation, subcellular cofractionation, and confocal imaging; (iii) the BGLF4-mediated phosphorylation of PDH was demonstrated by an in vitro kinase assay (IVKA); (iv) a reduction in PDH phosphorylation was shown for selected kinase inhibitors, which also exerted BGLF4-directed inhibitory potential in a quantitative qSox-IVKA, and (v) these hit compounds showed anti-EBV activity in lytically induced P3HR-1 cells using qPCR measurement, as well as PDH-inhibitory activity using standardized PDH assays. These data lead to an improved understanding of EBV–host interaction that may open novel anti-EBV preventive opportunities. Combined, the findings point to PDH as a new cellular interactor of the EBV kinase BGLF4. Also, notably, the data on pharmacological intervention with kinase activity or substrate phosphorylation may possibly provide as yet untapped options of antiviral drug targeting. Full article

Coumarin-based compounds are recognized for their chemical versatility and diverse biological activities, yet clinical applications remain largely confined to 4-hydroxycoumarin anticoagulants. To bridge this translational gap, coumarin scaffolds have been increasingly employed in prodrug design to enable controlled activation, targeted delivery, and theranostic functionality. This review critically evaluates whether coumarin-based prodrugs fulfill their therapeutic promise or remain primarily preclinical tools across oncology, inflammation, infectious diseases, and cardiovascular disorders. Strategies including enzymatic-, pH-, redox-, and light-triggered activation, as well as subcellular targeting and multifunctional hybrids, are discussed. Preclinical studies demonstrate improved bioavailability, reduced off-target toxicity, and real-time fluorescence monitoring, yet most compounds remain at the in vitro or small-animal model stage. Despite their mechanistic and conceptual potential, clinical translation is constrained by molecular complexity, pharmacokinetics, safety, and regulatory challenges. Overall, coumarins constitute a versatile multifunctional platform whose therapeutic impact relies on rigorous in vivo validation and strategic optimization. Full article

The WRKY transcription factors (TFs) are key regulators of plant responses to biotic and abiotic stresses. However, their roles in Amaranthus palmeri remain unexplored. In this study, 32 ApWRKYs were identified through bioinformatics and gene expression analyses. Subcellular localization predictions placed ApWRKYs in the nucleus, and transient expression assays of ApWRKY2 and ApWRKY5 confirmed nuclear targeting, supporting their role as transcriptional regulators. ApWRKYs are distributed across 15 genomic scaffolds, and phylogenetic analysis grouped them into three subfamilies, with conserved motifs identified within specific clades. Interaction analysis suggested potential post-transcriptional regulation by miRNAs. Gene expression profiling of ApWRKYs under glufosinate ammonium, NaCl, and PEG-induced osmotic stress treatments revealed potential distinct regulatory roles. Furthermore, transient overexpression in Arabidopsis thaliana found that ApWRKY1, ApWRKY2, and ApWRKY5 potentially regulate chlorophyll fluorescence and photosynthetic efficiency under glufosinate treatment. These findings establish ApWRKYs as central regulators of stress adaptation in A. palmeri, provide novel insights into WRKY-mediated regulation, and lay a foundation for future functional investigations aimed at enhancing stress resilience and herbicide management in horticultural systems. Full article

Advances in regenerative medicine have positioned platelets and their derivatives—including platelet-rich plasma, platelet-rich fibrin, platelet lysate, extracellular vesicles, and purified growth factors—as promising interventions specifically for skin and bone aging, two clinically accessible tissues with robust preclinical and clinical evidence for platelet-derived component-based rejuvenation and regeneration. Because much of the available evidence comes from injury models or age-associated inflammatory/degenerative diseases, we explicitly distinguish pathology-targeted inflammation resolution/repair from rejuvenation under physiological aging. This review summarizes the composition and core bioactivities of platelet-derived products and delineates their putative anti-aging mechanisms, encompassing proangiogenic signaling, immunomodulation, attenuation of oxidative stress, regulation of extracellular matrix turnover, and stimulation of osteogenesis. We further evaluate emerging applications that expand therapeutic performance, such as platelet-mimetic delivery vehicles, engineered and sustained-release formulations, and targeted use of subcellular structures. Evidence from recent preclinical and clinical studies indicates favorable safety profiles and signals of efficacy across cutaneous rejuvenation and skeletal regeneration, while underscoring persistent challenges related to product standardization, dosing, and outcome measures. Collectively, platelet-based therapeutics represent a versatile platform with broad applicability to anti-aging interventions in skin and bone and strong potential for translation through continued bioengineering and clinical validation. However, because most available evidence comes from injury models or age-associated diseases (e.g., photoaging, chronic wounds, osteoarthritis, osteoporosis), direct extrapolation to physiological aging is limited; throughout, we explicitly contrast these contexts, specify their indication-specific endpoints, and summarize the main translational limitations. Full article

Drug repurposing in oncology is often framed as a drug–target matching exercise, yet many candidates with plausible biological rationales fail in the clinic. In solid tumors, therapeutic outcomes are constrained not only by pharmacological target relevance but also by limited tumor accessibility, heterogeneous intratumoral exposure, loss of context-dependent activity, and dose-limiting systemic toxicity. This perspective argues that repurposing strategies should treat exposure engineering as a design principle alongside molecular selectivity. Peptides that bind cell- or matrix-associated molecules at the tumor site have the potential to implement spatial, temporal, and subcellular control over where and when a drug engages its pharmacological target, thereby enabling confinement of polypharmacology to tumor contexts. Mechanistic modes of peptide-enabled exposure selectivity (homing, anchoring/retention, conditional activation, penetration enhancement, and subcellular biasing), key failure modes, and translational constraints are discussed, together with an exposure-centric screening workflow to prioritize repurposed agents most amenable to peptide-guided rescue. Emphasizing the combination of exposure control and the addressing-element layer clarifies when and how pharmacologically promiscuous drugs may be repurposed safely and effectively. Full article

Background/Objectives: Leishmaniasis is a disease affecting millions of people caused by parasites of the genus Leishmania. The GP63 protein of Leishmania infantum (LiGP63) is one of its major surface antigens and a main virulence factor, playing a role in the adhesion of extracellular promastigote stages to macrophages and in the survival of intracellular amastigotes. Methods: Here, DNA aptamers have been developed against LiGP63 through the systematic evolution of ligands by exponential enrichment. Results: Twenty individual aptamer sequences were characterized using confocal fluorescence microscopy and flow cytometry analysis, and 14 of them had targeting to more than 70% of L. infantum promastigotes with different subcellular localization patterns. Subsequent dot blot analyses narrowed down the selection to five candidates for further characterization through an aptamer-linked immobilized sorbent assay where it was possible to detect endogenous LiGP63 in L. infantum promastigote lysates. The five selected aptamers recognized the recombinant LiGP63 protein with binding affinities ranging from 0.3 to 2.1 µM. Promastigotes preincubated with LiGP63Apt-4, -27 and -28 exhibited a significantly reduced adhesion to and infection of RAW 264.7 macrophages. Moreover, when LiGP63Apt-4 and -28 were conjugated to liposomes, these two aptamers significantly enhanced the targeting to L. infantum promastigotes compared to plain liposomes. Conclusions: Given their improved stability and cost-effectiveness over antibodies, the aptamers evolved here represent promising candidates for new therapeutic and diagnostic approaches and for future nanoparticle-based drug delivery strategies in leishmaniasis. Full article

Aquaporins are key membrane proteins that mediate water transport in plants and are indispensable for maintaining cellular water homeostasis and normal physiological processes. This study investigated the function of SbPIP1-3, an aquaporin gene isolated from drought-tolerant Sorghum bicolor. Bioinformatics analysis, subcellular localization, and heterologous expression of SbPIP1-3 were performed in Saccharomyces cerevisiae, Arabidopsis thaliana, and rapeseed. Sequence analysis revealed that SbPIP1-3 encodes a basic hydrophobic protein targeted to the plasma membrane, a finding further corroborated by subcellular localization assays. In yeast expression assays, SbPIP1-3-transformed strains retained viability under osmotic stress induced by 1.2 M mannitol, whereas non-transgenic control strains failed to survive. In Arabidopsis and rapeseed experiments, the SbPIP1-3 overexpression enhanced drought tolerance (improved germination, root growth, antioxidant enzyme activity, proline content, PSII repair capacity, and survival after drought–rewatering) and reduced intracellular H₂O₂ accumulation. Transcriptome profiling of drought-stressed transgenic Arabidopsis and control plants demonstrated significant upregulation of mostly stress-responsive pathways (e.g., MAPK signaling pathway and hormone signaling pathways) and key drought-tolerance genes (e.g., SNRK2-2, SOD1, APX3, GPX3, P5CS1). Collectively, these findings suggest that SbPIP1-3 enhances plant drought tolerance through the following mechanisms: improving transmembrane water transport efficiency to sustain cellular osmotic balance; activating the antioxidant defense system to increase enzyme activity and mitigate reactive oxygen species (ROS) accumulation; optimizing photosynthetic protection mechanisms to preserve the structural and functional integrity of PSII; and regulating the expression of stress-responsive signaling pathways and associated functional genes. Full article

Myocardial ischemia–reperfusion injury remains a major unresolved challenge in cardiovascular medicine. Although timely restoration of blood flow is essential to limit ischemic damage, reperfusion triggers a complex network of maladaptive biological responses, including oxidative stress, calcium overload, mitochondrial dysfunction, metabolic impairment, and sterile inflammation. These processes converge on cardiomyocyte death, adverse ventricular remodeling, and long-term functional deterioration. Mesenchymal stem cells have been widely investigated as cardioprotective agents; however, accumulating evidence indicates that their beneficial effects are predominantly mediated by paracrine mechanisms. Among these, extracellular vesicles released by mesenchymal stem cells have emerged as key biological effectors. Experimental studies demonstrate that mesenchymal stem cell–derived extracellular vesicles modulate multiple signaling pathways involved in ischemia–reperfusion injury, including activation of the phosphoinositide 3-kinase (PI3K) and protein kinase B (PKB) axis, regulation of signal transducer and activator of transcription 3 (STAT3) signaling in a cell-specific manner, suppression of nuclear factor kappa B (NF-κB)-driven inflammatory responses, and stabilization of hypoxia-inducible factor-1α (HIF-1α)–dependent adaptive programs. At the subcellular level, these vesicles preserve mitochondrial structure and function, support energy metabolism, regulate mitophagy, and limit oxidative damage. Their molecular cargo, comprising regulatory microRNAs, metabolic enzymes, and stress-response proteins, enables coordinated modulation of survival, inflammatory, and reparative pathways rather than single-target effects. This review synthesizes current experimental evidence on the mechanistic basis of mesenchymal stem cell–derived extracellular vesicle–mediated cardioprotection and discusses their potential as cell-free, mechanism-based therapeutic strategies to limit myocardial ischemia–reperfusion injury. Full article

Minute virus of canines (MVC) is an autonomous canine parvovirus that causes severe pathological outcomes, including embryo mortality, spontaneous abortion, and congenital malformations in neonatal puppies. Although MVC infection has been shown to induce host cell cycle arrest and apoptosis, the underlying regulatory mechanisms that coordinate cell proliferation and control apoptotic responses during viral replication remain poorly understood. Sirtuin 1 (SIRT1) is an NAD⁺-dependent deacetylase that plays a critical role in regulating cell cycle progression, DNA damage responses, and apoptosis. However, its involvement in MVC infection has not been fully elucidated. Herein, we show that MVC infection markedly upregulates the mRNA and protein expression levels of SIRT1 in a time-dependent manner. MVC infection activates the SIRT1-p53 signaling axis and modulates the acetylation status of p53. In addition, MVC alters the subcellular distribution of SIRT1, promoting its nuclear translocation and colocalization with the viral protein VP2. Functional analyses demonstrated that pharmacological activation of SIRT1 enhanced the viability of MVC-infected WRD cells (virus-tropic cell), promoting viral replication, prolonging S-phase arrest, and reducing apoptosis. Conversely, inhibition of SIRT1 produced the opposite effects, which were closely associated with regulation of the SIRT1-p53 signaling axis. Moreover, SIRT1 knockdown accelerated apoptosis and attenuated S-phase arrest, whereas SIRT1 overexpression further strengthened S-phase retention. Collectively, our findings identify the SIRT1-p53 signaling axis as an important regulator of cell cycle progression and apoptosis during MVC infection, highlighting SIRT1 as a key host factor that supports viral replication and persistence and a potential target for antiviral intervention. Full article