Search Results (4,506)

This study reports the synthesis and comprehensive spectroscopic characterization of 4-indolylcyanamide (4ICA), a novel indole-derived infrared (IR) probe designed for assessing local microenvironments in biological systems. 4ICA was synthesized via a two-step procedure with an overall yield of 43%, and its structure was confirmed using high-resolution mass spectrometry and ¹HNMR. Fourier Transform Infrared (FTIR) spectroscopy revealed that the cyanamide group stretching vibration of 4ICA exhibits exceptional solvent-dependent frequency shifts, significantly greater than those of conventional cyanoindole probes. A strong linear correlation was observed between the vibrational frequency and the combined Kamlet–Taft parameter, underscoring the dominant role of solvent polarizability and hydrogen bond acceptance in modulating its spectroscopic behavior. Quantum chemical calculations employing density functional theory (DFT) with a conductor-like polarizable continuum model (CPCM) provided further insight into the solvatochromic shifts and suppression of Fermi resonance in high-polarity solvents such as DMSO. Additionally, IR pump–probe measurements revealed short vibrational lifetimes (~1.35 ps in DMSO and ~1.13 ps in ethanol), indicative of efficient energy relaxation. With a transition dipole moment nearly twice that of traditional nitrile-based probes, 4ICA demonstrates enhanced sensitivity and signal intensity, establishing its potential as a powerful tool for site-specific environmental mapping in proteins and complex biological assemblies using nonlinear IR techniques. Full article

Transcription factors (TFs) are important gene transcription regulators involved in myriad functions such as development, metabolism, and stress response. TFs are found in all eukaryotes, with many families of TFs unique to plants and algae. Algae are of interest due to a wide range of novel metabolites, of which TFs play an important role in regulating their biosynthesis. In particular, the red algae (phylum Rhodophyta) are a source of several important metabolites that are a current focus of further research. However, to date, investigations of TF families in rhodophytes have been limited due to the relative lack of genomic resources available and the small number of in silico analyses of their TFs. In this study, we used genomic and transcriptomic data to identify rhodophyte TFs. We found that the general proportion of TFs in rhodophytes was overall consistent with previous research. However, for the first time in the rhodophyte class Florideophyceae, we report the presence of a putative TF within the trihelix TF (TTF) family, which are light-sensitive TFs associated with growth and stress response. In particular, we demonstrate evidence suggesting the presence of putative TTFs in three Asparagopsis taxiformis genomes, as well as in several other florideophyte assemblies. This was supported by analyses including Neighbour-Joining phylogeny, protein structure prediction, and motif analysis. In summary, this research reported the repertoire of TFs in rhodophyte algae across a much greater range than previously reported and identified putative TTFs in several algae from the class Florideophyceae. This opens an avenue for further research into the evolution of various TFs in early plants, as well as key regulatory factors in rhodophyte metabolism, though future research, such as functional characterisation, will be required to confirm these findings. Full article

Pre-mRNA splicing is catalyzed by the ribonucleoprotein (RNP) complex known as the spliceosome. The spliceosomes are dynamic and undergo constant rearrangement, leading to the formation of the different spliceosomal complexes A, B, B^act, C, C*, and P. Isolation of the spliceosomal complex at a specific intermediate stage requires a means to enrich it. This study describes a strategy for studying intermediate spliceosomal complexes by combining BioID with splicing assays. The MINX splicing substrate with a mutation at the 3′ splice site was utilized to arrest and capture the spliceosomal C* complex before the second catalytic step of splicing. The splicing substrate also contains binding sites for the MS2 coat protein, which facilitates the pull-down of assembled complex by FLAG-MS2-tagged RNP immunoprecipitation and determines the captured proximal proteins by mass spectrometry. Full article

The plasma membrane (PM) of eukaryotic cells plays a key role in the response to stress, acting as the first line of defense against environmental changes and protecting cells against intracellular perturbations. In this work, we explore how membrane-bound chaperones and membrane lipid domains work together to shape plasma membrane properties—a partnership we refer to as the “epichaperome–plasma membrane lipid axis.” This axis influences membrane fluidity, curvature, and domain organization, which in turn shapes the spatial and temporal modulation of signaling platforms and pathways essential for maintaining cellular integrity and homeostasis. Changes in PM fluidity can modulate the activity of ion channels, such as transient receptor potential (TRP) channels. These changes also affect processes such as endocytosis and mechanical signal transduction. The PM proteome undergoes rapid changes in response to membrane perturbations. Among these changes, the expression of heat shock proteins (HSPs) and their accumulation at the PM are essential mediators in regulating the physical state and functional properties of the membrane. Because of the pivotal role in stress adaptation, HSPs influence a wide range of cellular processes, which we grouped into three main categories: (i) mechanistic insights, differentiating in vitro (liposome, reconstituted membrane systems) and in vivo evidence for HSP-PM recruitment; (ii) functional outputs, spanning how ion channels are affected, changes in membrane fluidity, transcytosis, and the process of endocytosis and exosome release; and (iii) pathological effects, focusing on how rewired lipid–chaperone crosstalk in cancer drives resistance to drugs through altered membrane composition and signaling. Finally, we highlight Membrane Lipid Therapy (MLT) strategies, such as nanocarriers targeting specific PM compartments or small molecules that inhibit HSP recruitment, as promising approaches to modulate the functional stability of epichaperome assembly and membrane functionality, with profound implications for tumorigenesis. Full article

Virus-like particles (VLPs) formed as a result of self-assembly of viral capsid proteins are widely used as a platform for antigen presentation in vaccine development. However, since the inclusion of a foreign peptide into the capsid protein can alter its spatial structure and interfere with VLP assembly, such insertions are usually limited to short peptides. In this study, we have demonstrated the potential of capsid protein (CP) of single-stranded RNA phage PQ465 to present long peptides using green fluorescent protein (GFP) as a model. GFP was genetically linked to either the N- or C-terminus of PQ465 CP. Hybrid proteins were expressed in Escherichia coli and Nicotiana benthamiana plants. Spherical virus-like particles (~35 nm according to transmission electron microscopy) were successfully formed by both N- and C-terminal fusions expressed in E. coli, and by plant-produced CP with GFP fused to the C-terminus. ELISA revealed that GFP in VLPs was accessible for specific antibodies suggesting that it is exposed on the surface of PQ465-GFP particles. VLPs carrying GFP were recognized by anti-CP antibodies with less efficiency than VLPs formed by empty CP, which indicates shielding of the CP core in PQ465-GFP particles. Therefore, PQ465 CP can be used as a chimeric VLP platform for the display of relatively large protein antigens, which can operate in bacterial and plant expression systems. Full article

Acquired Immunodeficiency Syndrome (AIDS) is caused by Human Immunodeficiency Virus (HIV), and continues to be responsible for a substantial number of deaths worldwide each year. Development of a robust and efficient HIV-1 vaccine remains a critical priority. Structural analysis of viral proteins provides a foundational approach to designing peptide-based immunogenic vaccines. In the current experiment, we used computational prediction approaches alongside molecular docking and molecular dynamics (MD) simulations to identify potential epitopes within gp120 and Nef proteins. The selected co-epitopes were fused with the HBsAg-binding protein (SBP), a 344-amino acid protein previously identified in our laboratory through screening of a human liver cDNA expression library against HBsAg, to facilitate efficient delivery to and uptake by dendritic cells (DCs), thereby enhancing antigen (Ag) presentation. Flexible linkers are used to connect B cells, Helper T Lymphocytes (HTLs), and Cytotoxic T Lymphocytes (CTLs) in a sequential manner. The assembled vaccine construct comprises 757 amino acids, corresponding to a recombinant protein of 83.64 kDa molecular weight. Structural analysis through docking studies, MD simulations, and 3D structure validation revealed that the designed protein exhibits high structural stability and potential for interaction with Toll-like receptors (TLRs). These findings support the vaccine’s ability to enhance cellular and humoral feedback, including the stimulation of T and B cells and induction of antibody (Ab) production. The results underscore the promise of this in silico designed co-epitope vaccine as a viable candidate for HIV-1 prevention and suggest that such constructs may serve as effective immunogens in future HIV-1 vaccine strategies. Full article

Background/Objectives: In response to the COVID-19 pandemic, we developed a vaccine candidate against SARS-CoV-2. Spike Ferritin Nanoparticle (SpFN) comprises 24 identical prefusion-stabilized spike proteins anchored to a self-assembled nanoparticle. Organized along the three-fold axis of the ferritin particle, eight SARS-CoV-2 spike trimers are presented per nanoparticle. Methods: Here, we describe the CGMP processes for manufacturing SpFN using transient transfection of Expi293F cells. Results: The final yield of SpFN was ~10 mg per liter of media supernatant. The resulting protein is stable in cold storage for two years at −20 °C, as well as for a month at room temperature, and can withstand multiple freeze/thaw cycles. SpFN material produced using the CGMP protocols adjuvanted with Army Liposomal Formulation-QS-21 (ALFQ) elicited potent neutralizing antibodies against WA-1, Alpha, Beta, and Delta variants in mice as measured by a pseudovirus neutralization assay. Conclusions: This work demonstrates rapid development and scaled-up production of clinical-grade SARS-CoV-2 vaccine protein material, allowing permissive storage and transport conditions, and serves as a framework for recombinant protein production for future emergent pathogens. Full article

Andrenidae is a major pollinator lineage with considerable ecological importance, yet limited molecular resources have impeded comprehensive understanding of its evolutionary history. This study sequenced and assembled five mitogenomes of Andrenidae, which were collected from Xizang, Tibet. Analyses included sequence size, nucleotide composition, Ka/Ks ratios, and gene rearrangements. The assembled mitogenomes ranged from 15,631 to 18,506 bp in length. AT content (%) varied between 74.46 and 79.85. Relative synonymous codon usage analysis revealed that AUU, UUA, UUU, and UUA were the most frequently preferred codons. All 13 protein-coding genes displayed Ka/Ks values below one, with ATP8 showing the highest ratio and COX1 the lowest. Gene rearrangements occurred in all mitogenomes, and three distinct tRNA rearrangement patterns were detected. This study provided more available molecular data for future evolutionary biology studies of Andrenidae. Additionally, 24 previously published Apoidea mitogenomes (three outgroups and 26 ingroups) were incorporated to infer phylogenetic relationships using Maximum Likelihood and Bayesian Inference methods. The results supported Melittidae as the basal lineage of bees, while Andrenidae was recovered as the sister clade to Halictidae + Colletidae. Full article

The investigation and comparison of chloroplast genomes facilitate our deeper elucidation of the evolutionary dynamics and phylogenetics of plant species, particularly non-model plants. Opisthopappus is a genus of Asteraceae that is endemic to the Taihang Mountains in China, which includes Opisthopappus taihangensis and Opisthopappus longilobus. Although certain chloroplast genomic data are available, the comprehensive evolutionary relationships of chloroplast genomes in this genus are not yet fully understood. In this study, the assembled O. taihangensis chloroplast genomes exhibited a quadripartite structure with 131 genes, encompassing 86 protein-coding, 37 tRNA, and eight rRNA genes. The basic phylogenetic relationships of 275 Asteraceae species were consistent with preceding studies. Opisthopappus with Ajania and Chrysanthemum were gathered together in Trib. Anthemideae. However, O. taihangensis and O. longilobus were not clustered into a group. Six and eight variable hotspots were detected in Opisthopappus and Asteraceae respectively. A total of 18 optimal codons were identified in two species. Differentiation in codon usage patterns was primarily influenced by natural selection between O. taihangensis and O. longilobus. Thereinto, GCU (Ala) was specific to O. taihangensis, while ACU (Thr) was to O. longilobus. Most of the codons preferentially ended with A/U, with only two genes (rpl16 and matK) being subjected to positive selection in Opisthopappus. Under salt stress, 25 editing sites were detected in O. longilobus, and 34 editing sites were found in O. taihangensis. All editing sites were C to U transitions. Distinct editing events occurred in the two species. During the evolution of chloroplast genomes, the genes that undergo positive selection may help two Opisthopappus species to adapt the harsh cliff environment of the Taihang Mountains and ensure their normal growth and development. In response to stress, O. taihangensis and O. longilobus tended to utilize different codons and initiate unique RNA editing events. These will facilitate further work on taxonomy, phylogenetics, and adaptive evolution of Opisthopappus, even Anthemideae or Asteraceae. Full article

Bacterial microcompartments (BMCs) are intracellular structures for compartmentalizing specific metabolic pathways in bacteria. As a unique type of BMCs, carboxysomes utilize protein shells to sequester ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and carbonic anhydrase for efficient carbon dioxide (CO₂) fixation. This study aims to reconstruct an α-carboxysome in Saccharomyces cerevisiae and investigate its metabolic effects. Here, genes of the cso operon from Halothiobacillus neapolitanus, Calvin cycle-related enzyme phosphoribulokinase (PRK) from Spinacia oleracea, and two S. cerevisiae chaperone genes, HSP60 and HSP10, were introduced into S. cerevisiae. The engineered yeast strain demonstrated assembled and enzymatically active Rubisco, significant increase in ethanol production and reduction in the byproduct glycerol. Formation of the α-carboxysome structures was observed after purification by sucrose density gradient centrifugation. The engineered yeast strain harboring functional α-carboxysome has the potential for enhancing bioethanol production. Full article

Bacteriophages have been widely investigated as a promising treatment of food, medical equipment, and humans colonized by antibiotic-resistant bacteria. Phages pose particular interest in combating those bacteria which form biofilms, such as the medically important human pathogen Pseudomonas aeruginosa and several plant pathogens, including P. syringae. In an undergraduate lab course, P. putida was used as the host to isolate novel anti-pseudomonal bacteriophages. Environmental samples of soil and water were collected, and purified phage isolates were obtained. After Illumina sequencing, genomes of these phages were assembled de novo and annotated. Assembled genomes were compared with known genomes in the literature and GenBank to identify taxonomic relations and to refine their functional annotations. The thirteen phages described are sipho-, myo-, and podoviruses in several families of Caudoviricetes, spanning several novel genera, with genomes ranging from 40,000 to 96,000 bp. One phage (DDSR119) is unique and is the first reported P. putida siphovirus. The remaining 12 can be clustered into four distinct groups. Six are highly related to each other and to previously described Autotranscriptaviridae phages: Waldo5, PlaquesPlease, and Laces98 all belong to the Waldovirus genus, whereas Stalingrad, Bosely, and Stamos belong to the Troedvirus genus. Zuri was previously classified as the founding member of a new genus Zurivirus within the family Schitoviridae. Ebordelon and Holyagarpour each represent different species within Zurivirus, whereas Meara is a more distantly related member of the Schitoviridae. Dolphis and Jeremy are similar enough to form a genus but have only a few distant relatives among sequenced phages and are notable for being temperate. We identified the lysis cassettes in all 13 phages, compared tail spike structures, and found auxiliary metabolic genes in several. Studies like these, which isolate and characterize infectious virions, enable the identification of novel proteins and molecular systems and also provide the raw materials for further study, evaluation, and manipulation of phage proteins and their hosts. Full article

Oleosomes are submicron oil bodies of a triacylglycerol core enveloped by a phospholipid monolayer and embedded proteins, forming a naturally assembled nanocarrier with exceptional oxidative resilience, interfacial stability, and biocompatibility. Their unique architecture supports solvent-free extraction, self-emulsification, and near-complete encapsulation of highly lipophilic compounds (log P > 4), including curcumin and cannabidiol, with reported efficiencies exceeding 95%. These plant-derived droplets enhance oral bioavailability through lymphatic uptake and enable targeted delivery strategies such as magnetically guided chemotherapy, which has reduced tumor burden by approximately 70% in vivo. The review critically examines recent advances in oleosome research, spanning botanical sourcing, green extraction technologies, interfacial engineering, xenobiotic encapsulation, pharmacokinetics, and therapeutic applications across oncology, dermatology, metabolic disease, and regenerative medicine. Comparative analyses demonstrate that oleosomes rival or surpass synthetic lipid nanocarriers in encapsulation efficiency, oxidative stability, and cost efficiency while offering a sustainable, clean-label alternative. Remaining challenges, including low loading of hydrophilic drugs, allergenicity, and regulatory standardization, are addressed through emerging strategies such as hybrid oleosome–liposome systems, recombinant oleosin engineering, and stimulus-responsive coatings. These advances position oleosomes as a versatile and scalable platform with significant potential for food, cosmetic, and pharmaceutical applications. Full article

The microhylid frog Microhyla fissipes is a protected terrestrial wildlife species in China, recognized for its ecological, economic, and scientific value. However, its mitochondrial genome remains poorly characterized. To address this gap, we sequenced and annotated the complete mitogenome of M. fissipes to elucidate its structural organization and phylogenetic placement within Microhylidae. The assembled mitogenome is 16,723 bp in length and contains 37 genes, including 13 protein-coding genes, 2 rRNAs, and 22 tRNAs, along with one control region and the origin of heavy-strand replication. We also identified eight overlapping regions and eleven intergenic spacers. The overall base composition showed an A + T bias (59.91%) with negative AT-skew (−0.04) and GC-skew (−0.27). All tRNAs displayed typical cloverleaf secondary structures, except for trnS1, which lacked the D-arm. Phylogenetic reconstruction using both maximum likelihood and Bayesian inference strongly supported the monophyly of Microhylidae and revealed a sister-group relationship between Microhyla and Kaloula. Within Microhyla, M. fissipes was most closely related to M. heymonsi, with which it formed a well-supported clade that also included Microhyla okinavensis, Microhyla mixtura, and Microhyla beilunensis. Selection pressure analysis on protein-coding genes indicated widespread purifying selection (Ka/Ks < 1) across most genes, except for ATP8, COX2, and COX3, which may be under relaxed selective constraints. These findings offer valuable genomic resources for the conservation of M. fissipes and provide new insights into the phylogeny and evolution of microhylid frogs. Full article

Lignocellulosic agricultural residues represent a rich source of potential feedstock for biorefinery applications, but their valorization remains challenging. The white-rot fungus Irpex lacteus J2 exhibited a promising degradation effect, but its molecular mechanisms of lignocellulose degradation remained largely uncharacterized. Here, we performed high-quality whole-genome sequencing and untargeted metabolomic profiling of I. lacteus J2 during the degradation of corn straw as the sole carbon source. The assembled I. lacteus J2 genome contained 14,647 protein-coding genes, revealing a rich genetic repertoire for biomass degradation and secondary metabolite synthesis. Comparative genomics showed high synteny (mean amino acid sequence identity 92.28%) with I. lacteus Irplac1. Untargeted metabolomic analysis unveiled a dynamic metabolic landscape during corn straw fermentation. Dominant metabolite classes included organic acids and derivatives (27.32%) and lipids and lipid-like molecules (25.40%), as well as heterocyclic compounds (20.41%). KEGG pathway-enrichment analysis highlighted significant activation of core metabolic pathways, with prominent enrichment in global metabolism (160 metabolites), amino acid metabolism (99 metabolites), carbohydrate metabolism (24 metabolites), and lipid metabolism (19 metabolites). Fermentation profiles at 3 and 15 days demonstrated substantial metabolic reprogramming, with up to 210 upregulated and 166 downregulated metabolites. Correlation analyses further revealed complex metabolic interdependencies and potential regulatory roles of key compounds. These integrated multi-omics insights significantly expand our understanding of the genetic basis and metabolic versatility, enabling I. lacteus J2 to efficiently utilize lignocellulose. Our findings position I. lacteus J2 as a robust model strain and provide a valuable foundation for developing advanced fungus-based strategies for sustainable bioprocessing and valorization of agricultural residues. Full article

A pathogenic fungus was isolated from the leaves of strawberry black spot in Zhengzhou China. Based on morphological and phylogenetic analysis, the isolate was identified as Alternaria alstroemeriae. Hybrid sequencing and assembly yielded a high-quality 38.7 Mb genome with 12,781 predicted genes and 99.6% Benchmarking Universal Single-Copy Orthologs (BUSCO) completeness. Functional annotation revealed enrichment in carbohydrate metabolism, secondary metabolite biosynthesis, and virulence-associated genes. Strain L6 harbored 45 biosynthetic gene clusters(BGCs), including 12 clusters for terpenes, 7 for non-ribosomal peptide synthetases, and 7 for polyketide synthases. Six BGCs showed high similarity to known pathways producing alternariol (phytotoxic/mycotoxic compound), alternapyrone (phytotoxin), choline (osmoprotectant), terpestacin (anti-angiogenic agent), clavaric acid (anticancer terpenoid), and betaenone derivatives (phytotoxins). CAZyme analysis identified 596 carbohydrate-active enzymes, aligning with L6’s biotrophic lifestyle. Additionally, 996 secreted proteins were predicted, of which five candidate effectors contained the conserved RxLx [EDQ] host-targeting motif, suggesting potential roles in virulence. This genome resource highlights L6’s exceptional secondary metabolites (SMs) diversity, featuring both plant-pathogenic toxins and pharmacologically valuable compounds, indicating that this endophytic fungus is a potential producer of metabolites meriting further exploration and development. Full article