Search Results (969)

MicroRNAs (miRNAs), as an integral component of gene regulatory networks, play a critical role in post-transcriptional regulation, maintaining a dynamic balance between miRNA biogenesis and turnover essential for maintaining cellular homeostasis. The regulation of miRNA turnover, particularly through target-directed microRNA degradation (TDMD), is emerging as a key mechanism in gene expression control in response to physiological, developmental, and environmental changes. This process is mediated by the ubiquitin–proteasome system (UPS), where the E3 ligase ZSWIM8 functions as an adaptor to facilitate the recognition and degradation of Argonaute (AGO) proteins, essential components of the miRNA-induced silencing complex (miRISC), thus negatively regulating gene expression. The ZSWIM8–UPS axis contributes to the precise modulation of miRNA levels by targeting AGO proteins for degradation, thereby influencing miRNA stability and function. This review summarizes the mechanisms underlying ZSWIM8-mediated TDMD, its molecular interactions, and the potential therapeutic applications of targeting miRNA turnover pathways. By understanding the regulation of miRNA degradation, we aim to inform future strategies for the clinical manipulation of miRNA-based therapeutics. Full article

Parkinson’s disease (PD) is one of the most rapidly growing neurological disorders globally. The molecular relationship between common respiratory infections (RIs) and idiopathic Parkinson’s disease (iPD) remains a controversial issue. Multiple studies have linked acute respiratory infections to PD, but the molecular mechanism behind this connection is not significantly defined. Therefore, the aim of our study was to investigate potential molecular interactions between RIs and PD. We retrieved eight publicly available RNA-seq datasets from the NCBI Gene Expression Omnibus (NCBI GEO) and performed extensive bioinformatics analysis, including differential gene expression (DGE) analysis, the identification of overlapped differentially expressed genes (DEGs), weighted gene co-expression network analysis (WGCNA), pathway and functional enrichment analysis, the construction of protein–protein networks, and the identification of hub genes. Additionally, we applied a machine learning method, a Random Forest model (RF), to external RIs datasets to identify the most important genes. We found that ribosomal subunits, mitochondrial complex proteins, proteasome subunits, and proteins encoding ubiquitin are simultaneously downregulated and co-expressed in RIs and PD. Dysregulation of these proteins may disturb multiple pathways, such as those responsible for ribosome biogenesis, protein synthesis, autophagy, and apoptosis; the ubiquitin–proteasome system (UPS); and the mitochondrial respiratory chain. These processes have been implicated in PD’s pathology, namely in the aggregation of α-synuclein, mitochondrial dysfunction, and the death of dopaminergic neuron cells. Our findings suggest that there are significant similarities in transcriptional responses and dysfunctional molecular mechanisms between RIs, PD, and aging. RIs may modulate PD-relevant pathways in an age- or immune-dependent manner; longitudinal studies are needed to examine the RIs risk factor. Therefore, future studies should experimentally investigate the influence of age, vaccination status, infection type, and severity to clarify the role of RIs in PD’s pathogenesis. Full article

PROTACs are trimeric small molecules consisting of a specific modulator of the target protein connected to a ligase-recruiting ligand via a suitably flexible linker. Ligase-recruiting ligands deliver ubiquitin ligases like E3 ligase to the Protein of Interest (POI). The vicinity of the POI-PROTAC-E3 ternary complex enables the E3 ligase to ubiquitinate the surface lysine residues of the POI. The Ubiquitin–Proteasome System (UPS) then degrades the POI. However, despite the considerable advances in the design of PROTACs targeting several types of enzymes and receptors, this strategy is still facing the challenges of precision target delivery and duration of action. In this review, we highlight the recent approaches for the development of PROTAC prodrugs or pro-PROTAC to control the delivery of PROTACs and achieve the required on-target exposure. This strategy may facilitate the application of the PROTAC technology and expand its clinical benefits. Full article

Nearly all eukaryotic proteins are turned over by the ubiquitin (Ub)-26S proteasome system (UPS). Despite its broad cellular roles, only a handful of UPS members, particularly the Ub E3 ligases that specifically recognize a protein for ubiquitylation, have been characterized in plants to date. The challenge arises from the transient recognition and rapid degradation of ubiquitylation substrates by the UPS. To tackle this challenge, the emerging biotinylation-based proximity labeling (PL) offers an exciting tool for enriching transient interactors of Ub E3 ligases. In this study, we examined the efficacy of TurboID in identifying substrates of Arabidopsis Skp1-cullin1-F-box (SCF) ligases. We demonstrate that the Arabidopsis Skp1 Like (ASK)1-TurboID is not fully functioning in planta, which led us to discover a novel antagonism between biotinylation and ubiquitylation in regulating protein stability in vivo. This discovery lowers the effectiveness of PL in ubiquitylome studies. However, using one long-known SCF substrate, phytochrome A, we succeeded to apply its TurboID fusion for complementing the far-red-light response of the phyA-211 null mutant allele, suggesting an efficacy of PL in characterizing single ubiquitylation pathways. This study highlighted a limitation of PL in ubiquitylome studies, discovered a new antagonistic pathway of biotinylation, and developed a theoretical guidance for future PL-based characterization of ubiquitylation pathways. Full article

Alzheimer’s disease (AD) and major depressive disorder (MDD) are prevalent central nervous system (CNS) disorders that share overlapping symptoms but differ in underlying molecular mechanisms. Distinguishing these mechanisms is essential for developing targeted diagnostic and therapeutic strategies. In this study, we integrated multi-tissue transcriptomic datasets from brain and peripheral samples to identify differentially expressed microRNAs (miRNAs) in AD and MDD. Functional enrichment analyses (KEGG, GO) revealed that dysregulated miRNAs in AD were associated with MAPK, PI3K–Akt, Ras, and PD-1/PD-L1 signaling, pathways linked to synaptic plasticity, neuroinflammation, and immune regulation. In contrast, MDD-associated miRNAs showed enrichment in Hippo signaling and ubiquitin-mediated proteolysis, implicating altered neurogenesis and protein homeostasis. Network analysis highlighted key disease- and tissue-specific miRNAs, notably hsa-miR-1202 and hsa-miR-24-3p, with potential roles in neuronal survival and molecular network regulation. These findings suggest that miRNAs may serve as non-invasive biomarkers for diagnosis, prognosis, and treatment monitoring in both disorders. While therapeutic targeting of miRNAs offers promise, challenges such as blood–brain barrier penetration and tissue-specific delivery remain. This integrative approach provides a translational framework for advancing miRNA-based strategies in CNS disease research. Full article

The progression of inflammation during sepsis represents a multifaceted biological cascade that requires effective therapeutic interventions to improve survival. In septic neonatal foals, oxidative stress (OS) arises due to a compromised antioxidant defense system. Oxidative stress may disrupt the functionality of redox-sensitive organelles, such as the endoplasmic reticulum (ER). Endoplasmic reticulum stress disorder affects multiple cellular signaling pathways, including redox balance, inflammation, and apoptosis, and contributes to the pathogenesis of sepsis. The study aimed to elucidate whether OS conditions in sepsis influenced gene expression associated with ER stress. Blood samples were collected from 7 healthy and 21 hospitalized neonatal foals and processed for RNA extraction. RNA sequencing was employed to identify ER stress-responsive genes. Novel findings reported here indicate activation of the ER stress pathway in foals with sepsis. Several genes associated with ER stress, such as clusterin (CLU), BCL2-like 1 (BCL2L1), ubiquitin specific peptidase 14 (USP14), bifunctional apoptosis regulator (BFAR), and optic atrophy 1 (OPA1), were upregulated and positively correlated with sepsis scores and negatively correlated with the combined activities of antioxidant enzymes. In contrast, X-box binding protein 1 (XBP1), homocysteine inducible ER protein with ubiquitin-like domain 1 (HERPUD1), leucine-rich repeat kinase 2 (LRRK2), and selenoprotein S (SELENOS) were negatively correlated with sepsis scores and were downregulated in sepsis and positively correlated with the combined activities of antioxidant enzymes. Furthermore, a positive correlation was observed between cAMP responsive element binding protein 3 like 2 (CREB3L2) and BCL2L1, as well as between the expressions of USP14 and YOD1 deubiquitinase (YOD1) in sepsis. Similarly, the expression levels of XBP1 and Herpud1 demonstrated a positive correlation with each other in sepsis. Additionally, the downregulation of genes with protective function against OS, such as XBP1, HERPUD1, and SELENOS, in septic foals also highlights their significance in mitigating OS in sepsis treatment. The study reported here highlights the potential of ER stress as a promising therapeutic target and prognostic marker in septic foals. 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

VEXAS syndrome (Vacuoles, E1-enzyme, X-linked, Autoinflammation, and Somatic) is a recently identified late-onset autoinflammatory disorder characterized by a unique interplay between hematological and inflammatory manifestations. It results from somatic mutations in the UBA1 gene, located on the short arm of the X chromosome. Initially, females were considered mere carriers, with the syndrome primarily affecting males over 50. However, recent evidence indicates that heterozygous females can exhibit symptoms as severe as those seen in hemizygous males. The disease manifests as systemic inflammation, macrocytic anemia, thrombocytopenia, chondritis, neutrophilic dermatoses, and steroid-dependent inflammatory symptoms. Due to its overlap with autoimmune and hematologic disorders such as relapsing polychondritis, Still’s disease, and myelodysplastic syndromes, misdiagnosis is common. At the molecular level, VEXAS syndrome is driven by impaired ubiquitination pathways, resulting in dysregulated immune responses and clonal hematopoiesis. A key diagnostic marker is the presence of cytoplasmic vacuoles in myeloid and erythroid precursors, though definitive diagnosis requires genetic testing for UBA1 mutations. Traditional immunosuppressants and TNF inhibitors are generally ineffective, while JAK inhibitors and IL-6 blockade provide partial symptom control. Azacitidine and decitabine have shown promise in reducing disease burden, but hematopoietic stem cell transplantation (HSCT) remains the only curative treatment, albeit with significant risks. This review provides a comprehensive analysis of VEXAS syndrome, examining its clinical features, differential diagnoses, diagnostic challenges, and treatment approaches, including both pharmacological and non-pharmacological strategies. By enhancing clinical awareness and optimizing therapeutic interventions, this article aims to bridge emerging genetic insights with practical patient management, ultimately improving outcomes for those affected by this complex and often life-threatening disease. Full article

The peach landrace ‘Liuyefeitao’ exhibits the unique reproductive trait of self-compatibility combined with cross-incompatibility, contrasting with typical Prunus species in this way. In preliminary studies involving controlled pollination assays, we showed complete pollen tube arrest in cross-pollinated styles, whereas self-pollination enabled full tube elongation. S-genotyping identified a homozygous S₂S₂ genotype with intact S₂-RNase but a truncated PpSFB2 due to a frameshift mutation. Transcriptome profiling of the styles revealed 7937 differentially expressed genes (DEGs) between self- and cross-pollination treatments, with significant enrichment in plant MAPK signaling, plant–pathogen interactions, and plant hormone signaling transduction pathways (|Fold Change| ≥ 2, FDR < 0.01). Notably, PpSLFL3 (a pollen F-box gene) showed down-regulation in cross-pollinated styles, as validated by means of qRT-PCR. Protein interaction assays revealed direct binding between PpSLFL3 and S₂-RNase via Y2H and BiFC analysis, suggesting its role in mediating SCF complex-dependent degradation. We propose that insufficient PpSLFL3 expression during cross-pollination disrupts SCF ubiquitin ligase complex-mediated degradation of non-self S₂-RNase, leading to the toxic degradation of RNA in pollen tubes by S₂-RNase. This mechanism is mechanistically similar to unilateral reproductive barriers in Solanaceae but represents a novel regulatory module in Rosaceae. Our findings provide critical insights into the evolution of cross-incompatibility systems and molecular breeding strategies for Prunus species. Full article

Class IId bacteriocins are linear, unmodified antimicrobial peptides produced by Gram-positive bacteria, and often display potent, narrow-spectrum inhibition spectra. Garvicin Q (GarQ) is a class IId bacteriocin produced by the lactic acid bacterium Lactococcus garvieae. It stands out for its unusual broad-spectrum antimicrobial activity against various bacterial species, including Listeria monocytogenes, Pediococcus pentosaceus, Carnobacterium maltaromaticum, Enterococcus faecalis, and Lactococcus spp. Its protein target is the mannose phosphotransferase system (Man-PTS) of susceptible bacterial strains, though little is known about the precise molecular mechanism behind GarQ’s unusual broad spectrum of activity. In this work, ¹³C- and ¹⁵N-labelled GarQ was recombinantly produced using our previously described “sandwiched” protein expression system in Escherichia coli. We also developed a protocol to purify a uniformly labelled sample of the small ubiquitin-like modifier His₆-SUMO, which is produced as a byproduct of the expression procedure. We demonstrated its use as a “free” protein standard for 3D NMR experiment calibrations. The GarQ solution structure was solved using triple-resonance nuclear magnetic resonance (NMR) spectroscopy and was compared with the structures of other Man-PTS-targeting bacteriocins. GarQ adopts a helix–hinge–helix fold, which is contrary to its structural predictions according to AlphaFold 3. Full article

Proteolysis-targeting chimeras (PROTACs) selectively degrade target proteins by recruiting intracellular E3 ubiquitin ligases, overcoming the limitations of traditional small-molecule inhibitors that merely block protein function. This approach has garnered significant interest in precision cancer therapy. However, the clinical translation of PROTACs is hindered by their typically high molecular weight, poor membrane permeability, and suboptimal pharmacokinetic properties. Nanodrug delivery technologies represent a promising approach to overcome the limitations of PROTACs. By encapsulating, conjugating, or integrating PROTACs into functionalized nanocarriers, these systems can substantially enhance solubility and biostability, enable tumor-targeted and stimuli-responsive delivery, and thereby effectively alleviate the “hook effect” and minimize off-target toxicity. This review systematically outlines the primary design strategies for current nano-PROTAC delivery systems, including physical encapsulation, chemical conjugation, carrier-free self-assembly systems, and intelligent “split-and-mix” delivery platforms. We provide an overview and evaluation of recent advances in diverse nanomaterial carriers—such as lipid-based nanoparticles, polymeric nanoparticles, inorganic nanoparticles, biological carriers, and hybrid nanoparticles—highlighting their synergistic therapeutic potential for PROTACs delivery. The clinical translation prospects of these innovative systems are also discussed. This comprehensive analysis aims to deepen the understanding of this rapidly evolving field, address current challenges and opportunities, promote the advancement of nano-PROTACs, and offer insights into their future development. Full article

Background: The candidate therapeutic peptide TnP demonstrates broad, system-level regulatory capacity, revealed through integrated network analysis from transcriptomic data in zebrafish. Our study primarily identifies TnP as a multifaceted modulator of drug metabolism, wound healing, proteolytic activity, and pigmentation pathways. Results: Transcriptomic profiling of TnP-treated larvae following tail fin amputation revealed 558 differentially expressed genes (DEGs), categorized into four functional networks: (1) drug-metabolizing enzymes (cyp3a65, cyp1a) and transporters (SLC/ABC families), where TnP alters xenobiotic processing through Phase I/II modulation; (2) cellular trafficking and immune regulation, with upregulated myosin genes (myhb/mylz3) enhancing wound repair and tlr5-cdc42 signaling fine-tuning inflammation; (3) proteolytic cascades (c6ast4, prss1) coupled to autophagy (ulk1a, atg2a) and metabolic rewiring (g6pca.1-tg axis); and (4) melanogenesis-circadian networks (pmela/dct-fbxl3l) linked to ubiquitin-mediated protein turnover. Key findings highlight TnP’s unique coordination of rapid (protease activation) and sustained (metabolic adaptation) responses, enabled by short network path lengths (1.6–2.1 edges). Hub genes, such as nr1i2 (pxr), ppara, and bcl6aa/b, mediate crosstalk between these systems, while potential risks—including muscle hypercontractility (myhb overexpression) or cardiovascular effects (ace2-ppp3ccb)—underscore the need for targeted delivery. The zebrafish model validated TnP-conserved mechanisms with human relevance, particularly in drug metabolism and tissue repair. TnP’s ability to synchronize extracellular matrix remodeling, immune resolution, and metabolic homeostasis supports its development for the treatment of fibrosis, metabolic disorders, and inflammatory conditions. Conclusions: Future work should focus on optimizing tissue-specific delivery and assessing genetic variability to advance clinical translation. This system-level analysis positions TnP as a model example for next-generation multi-pathway therapeutics. Full article

Background: During infection with the cytomegalovirus (CMV), the membrane system of the infected cell is remodelled into a megastructure called the assembly compartment (AC). These extensive changes may involve the manipulation of the host cell proteome by targeting a pleiotropic function of the cell such as ubiquitination (Ub). In this study, we investigate whether the Ub system is required for the establishment and maintenance of the AC in murine CMV (MCMV)-infected cells Methods: NIH3T3 cells were infected with wild-type and recombinant MCMVs and the Ub system was inhibited with PYR-41. The expression of viral and host cell proteins was analyzed by Western blot. AC formation was monitored by immunofluorescence with confocal imaging and long-term live imaging as the dislocation of the Golgi and expansion of Rab10-positive tubular membranes (Rab10 TMs). A cell line with inducible expression of hemagglutinin (HA)-Ub was constructed to monitor ubiquitination. siRNA was used to deplete host cell factors. Infectious virion production was monitored using the plaque assay. Results: The Ub system is required for the establishment of the infection, progression of the replication cycle, viral gene expression and production of infectious virions. The Ub system also regulates the establishment and maintenance of the AC, including the expansion of Rab10 TMs. Increased ubiquitination of WASHC1, which is recruited to the machinery that drives the growth of Rab10 TMs, is consistent with Ub-dependent rheostatic control of membrane tubulation and the continued expansion of Rab10 TMs. Conclusions: The Ub system is intensively utilized at all stages of the MCMV replication cycle, including the reorganization of the membrane system into the AC. Disruption of rheostatic control of the membrane tubulation by ubiquitination and expansion of Rab10 TREs within the AC may contribute to the development of a sufficient amount of tubular membranes for virion envelopment. Full article

RNA-seq analysis of the highly differentiated human retinal pigment epithelial (RPE) cell-line ARPE-19, cultured on transwells for ≥4 months, yielded 44,909 genes showing 83.35% alignment with the human reference genome. These included mRNA transcripts of RPE-specific genes and those involved in retinopathies. Monolayers were fed photoreceptor outer segments (POS), designed to be synchronously internalised, mimicking homeostatic RPE activity. Cells were subsequently fixed at 4, 6, 24 and 48 h when POS were previously shown to maximally co-localise with Rab5, Rab7, LAMP/lysosomes and LC3b/autophagic compartments. A comprehensive analysis of differentially expressed genes involved in proteolysis revealed a pattern of gene orchestration consistent with POS breakdown in the autophagy-lysosomal pathway. At 4 h, these included elevated upstream signalling events promoting early stages of cargo transport and endosome maturation compared to RPE without POS exposure. This transcriptional landscape altered from 6 h, transitioning to promoting cargo degradation in autolysosomes by 24–48 h. Longitudinal scrutiny of mRNA transcripts revealed nuanced differences even within linked gene networks. POS exposure also initiated transcriptional upregulation in ubiquitin proteasome and chaperone-mediated systems within 4–6 h, providing evidence of cross-talk with other proteolytic processes. These findings show detailed evidence of transcriptome-level responses to cargo trafficking and processing in RPE cells. Full article

A series of eleven new N-alkyl 3-(3-benzyloxyquinoxalin-2-yl) propanamides were prepared based on the azide coupling of 3-(3-benzyloxyquinoxalin-2-yl) propanhydrazide with a variety of primary and secondary amines and the consequent conjunction of a broad spectrum of lipophile and hydrophile characters to a quinoxaline ring system. 3-(3-benzyloxyquinoxalin-2-yl) propanhydrazide was produced in a two-step reaction of methyl 3-(3-oxo-3,4-dihydroquinoxalin-2-yl) propanoate with benzyl chloride followed by the hydrazinolysis of the corresponding ester. The antiproliferative activity of the compounds was tested in various cancer cell lines, including PC-3, Hela, HCT-116, and MCF-7; they showed a wide spectrum of activity for most of the tested compounds. Compound 6k exhibited the highest activity, which was comparable to that of doxorubicin, with IC₅₀ (µM) values of 12.17 ± 0.9, 9.46 ± 0.7, 10.88 ± 0.8, and 6.93 ± 0.4 µM compared to 8.87 ± 0.6, 5.57 ± 0.4, 5.23 ± 0.3, and 4.17 ± 0.2 µM for doxorubicin against Hela, HCT-116, and MCF-7, respectively. The in silico mechanistic study revealed the inhibition of HDAC-6 through the binding of the unique zinc finger ubiquitin-binding domain (HDAC6 Zf-UBD). The docking results showed a specific binding pattern that emphasized the crucial role of the quinoxaline ring and its substituents. The newly developed derivatives were evaluated for antitumor effects against four cancer cell lines PC-3, HeLa, HCT-116, and MCF-7. This research led to the identification of a quinoxaline-based scaffold exhibiting broad-spectrum antiproliferative activity and a distinct mechanism involving binding to HDAC6 Zf-UBD. The findings highlight its potential for further optimization and preclinical studies to support future anticancer drug development. Full article