Search Results (477)

Telomeres are terminal regions of chromosomes that protect and stabilize chromosome structures. Telomeres are usually composed of specific DNA repeats (motifs) that are maintained by telomerase and a complex of specific proteins. Telomeric DNA sequences are generally highly conserved throughout the evolution of different groups of eukaryotes. The most common motif in insects is TTAGG, but it is not universal, including in the large order Hemiptera. In particular, several derived telomeric motifs were identified in this order by analyzing chromosome-level genome assemblies or by FISH screening the chromosomes of target species. Here, we analyzed chromosome-level genome assemblies of 16 species from three hemipteran suborders, including Sternorrhyncha (Coccoidea: Planococcus citri, Acanthococcus lagerstroemiae, and Trionymus diminutus; Aphidoidea: Tuberolachnus salignus, Metopolophium dirhodum, Rhopalosiphum padi, and Schizaphis graminum), Auhenorrhyncha (Cicadomorpha: Allygus modestus, Arthaldeus pascuellus, Aphrophora alni, Cicadella viridis, Empoasca decipiens, and Ribautiana ulmi), and Heteroptera (Gerromorpha: Gerris lacustris; Pentatomomorpha: Aradus depressus and A. truncatus). In addition, scaffold-level genome assemblies of three more species of Heteroptera (Gerromorpha: Gerris buenoi, Microvelia longipes, and Hermatobates lingyangjiaoensis) were examined. The presumably ancestral insect motif TTAGG was found at the ends of chromosomes of all species studied using chromosome-level genome assembly analysis, with four exceptions. In Aphrophora alni, we detected sequences of 4 bp repeats of TGAC, which were tentatively identified as a telomeric motif. In Gerris lacustris, from the basal true bug infraorder Gerromorpha, we found a 10 bp motif TTAGAGGTGG, previously unknown not only in Heteroptera or Hemiptera but also in Arthropoda in general. Blast screening of the scaffold-level assemblies showed that TTAGAGGTGG is also likely to be a telomeric motif in G. buenoi and Microvelia. longipes, while the results obtained for H. lingyangjiaoensis were inconclusive. In A. depressus and A. truncatus from the basal for Pentatomomorpha family Aradidae, we found a 10 bp motif TTAGGGATGG. While the available data allowed us to present two alternative hypotheses about the evolution of telomeric motifs in Heteroptera, further data are needed to verify them, especially for the yet unstudied basal infraorders Enicocephalomorpha, Dipsocoromorpha, and Leptopodomorpha. Full article

Flammulina velutipes is a widely cultivated edible mushroom in East Asia, recognized for its nutritional benefits and distinct morphology characterized by a long stipe and a compact, hemispherical pileus. The pileus not only plays a critical biological role in reproduction through spore formation but also serves as a key commercial trait influencing consumer preference and market value. Despite its economic importance, pileus development in F. velutipes is highly sensitive to environmental factors, among which carbon dioxide (CO₂) concentration is particularly influential under indoor cultivation conditions. While previous studies have reported that elevated CO₂ levels can inhibit pileus expansion in other mushroom species, the molecular mechanisms by which CO₂ affects pileus growth in F. velutipes remain poorly understood. In this study, we investigated the impact of CO₂ concentration on pileus morphology and gene expression in F. velutipes by cultivating fruiting bodies under two controlled atmospheric conditions: low (1000 ppm) and high (10,000 ppm) CO₂. Morphometric analysis revealed that elevated CO₂ levels significantly suppressed pileus expansion, reducing the average diameter by more than 50% compared to the low CO₂ condition. To elucidate the underlying genetic response, we conducted RNA sequencing and identified 102 differentially expressed genes (DEGs), with 78 being downregulated under elevated CO₂. Functional enrichment analysis highlighted the involvement of cyclin-dependent protein kinase regulatory pathways in this response. Two cyclin genes were found to be significantly downregulated under elevated CO₂ conditions, and their suppression was validated through quantitative real-time PCR. These genes, possessing conserved cyclin_N domains, are implicated in the regulation of the eukaryotic cell cycle, particularly in mitotic growth. These results indicate that CO₂-induced downregulation of cyclin genes may underlie cell cycle arrest, contributing to inhibited pileus development. This study is the first to provide transcriptomic evidence that elevated CO₂ concentrations specifically repress PHO80-like cyclin genes in F. velutipes, revealing a molecular mechanism by which CO₂ stress inhibits pileus development. These findings suggest that elevated CO₂ triggers a morphogenetic checkpoint by repressing PHO80-like cyclins, thereby modulating cell cycle progression during fruiting body development. This study provides the first evidence of such a transcriptional response in edible mushrooms and offers promising molecular targets for breeding CO₂-resilient strains and optimizing commercial cultivation conditions. Full article

Parasitoid venom significantly influences host physiology and development. Our previous research identified high levels of insulin-binding protein IMP-L2 in the venom of Scleroderma guani. IMP-L2 may inhibit the insulin/insulin-like growth factor signaling (IIS) cascade by competitively binding insulin-like peptides (ILPs) with insulin receptor (InR). However, how to regulate IIS transduction is unclear. We speculate that venom-derived IMP-L2 may bind ILPs to inhibit IIS transduction. Consequently, we investigated the regulation of the IIS/TOR pathway by venom-derived IMP-L2. An expression analysis of IIS/TOR pathway genes across various developmental stages of Tenebrio molitor demonstrated that this pathway governs the entire developmental process. By examining gene expression before and after parasitism, we determined that S. guani predominantly inhibits TOR pathway signaling in T. molitor post-parasitism. Bioinformatics and expression analyses revealed that IMP-L2 is critically involved in Hymenoptera insects, exhibiting high expression in the venom apparatus, and is upregulated in response to S. guani parasitism factors. Additionally, recombinant IMP-L2 was produced via eukaryotic expression. Finally, the recombinant IMP-L2 was found to inhibit the TOR and IIS/TOR signaling pathways at early (6 h) and late (24 h) stages post-injection. Knockdown of IMP-L2 in S. guani parasitized T. molitor pupae, resulting in accelerated death of T. molitor. During parasitism, S. guani may suppress host growth and development by modulating the IIS/TOR signaling pathway through venom-derived IMP-L2, potentially affecting host lifespan. Full article

Autophagy is an essential eukaryotic catabolic process through which damaged or superfluous cellular components are degraded and recycled via the formation of double-membrane autophagosomes. In plants, autophagy-related genes (ATGs) are primarily expressed in the cytoplasm and are responsible for orchestrating distinct stages of autophagosome biogenesis. Among these, ATG8 proteins, orthologous to the mammalian LC3 family, are conserved ubiquitin-like modifiers that serve as central hubs in selective autophagy regulation. Although ATG8 proteins are localized in both the cytoplasm and nucleus, their functions within the nucleus remain largely undefined. In the present study, the ATG8-interacting motif (AIM) was identified and functionally characterized in the potato ATG8 homolog (StATG8), demonstrating its capacity for selective target recognition. StATG8 was shown to form both homodimeric and heterodimeric complexes with other ATG8 isoforms, implying a broader regulatory potential within the ATG8 family. Notably, StATG8 was found to interact with the Ralstonia solanacearum type III effector PopP2, a nuclear-localized acetyltransferase, suggesting a possible role in effector recognition within the nucleus. In addition, interactions between StATG8 and transcription factors AtWRKY40 and AtWRKY60 were detected in both cytoplasmic autophagosomes and the nuclear compartment. These observations provide novel insights into the noncanonical, nucleus-associated roles of plant ATG8 proteins. The nuclear interactions with pathogen effectors and transcriptional regulators suggest that ATG8 may function beyond autophagic degradation, contributing to the regulation of nuclear signaling and plant immunity. These findings offer a foundational basis for further investigation into the functional diversification of ATG8 in plant cellular compartments. Full article

Membrane transporters are vital for solute movement and localisation across cellular compartments, particularly in extremophilic organisms such as Galdieriales. These red algae thrive in geothermal and metal-rich environments, where adaptive transporter systems contribute to their metabolic flexibility. While inventories of transporter genes in the species Galdieria sulphuraria have previously been compiled, their phylogenetic origins remain incompletely resolved. Here, we conduct a comparative phylogenetic analysis of three transporter families—Major Facilitator Superfamily (MFS). Amino acid–Polyamine–Organocation (APC) and the natural resistance–associated macrophage protein (Nramp)—selected from overexpressed transcripts in G. sulphuraria strain SAG 107.79. Using sequences from six Galdieriales species and orthologs from diverse taxa, we reconstructed maximum likelihood trees to assess conservation and potential horizontal gene transfer (HGT). The MFS subfamilies revealed contrasting patterns: sugar porters (SPs) exhibited polyphyly and fungal affinity, suggesting multiple HGT events, while phosphate:H⁺ symporters (PHSs) formed a coherent monophyletic group. APC sequences were exclusive in G. sulphuraria and extremophilic prokaryotes, indicating a likely prokaryotic origin. In contrast, Nramp transporters were broadly conserved across eukaryotes and prokaryotes, showing no signs of recent HGT. Together, these findings highlight the mosaic evolutionary history of membrane transporters in Galdieriales, shaped by a combination of vertical inheritance and taxon-specific gene acquisition events, and provide new insight into the genomic strategies underpinning environmental resilience in red algae. Full article

The 26S proteasome is a large, ATP-dependent proteolytic complex responsible for degrading ubiquitinated proteins in eukaryotic cells. It plays a crucial role in maintaining cellular protein homeostasis by selectively eliminating misfolded, damaged, or regulatory proteins marked for degradation. In this study, whole-exome sequencing (WES) was performed on an individual presenting with developmental delay and mild intellectual disability, as well as on both of his unaffected parents. This analysis identified a de novo variant, c.959C>G (p.Pro320Arg), in the PSMC5 gene. As predicted, this gene shows a very likely autosomal dominant inheritance pattern. Notably, PSMC5 has not previously been associated with any phenotype in the OMIM database. This variant was recently submitted to the ClinVar database as a variant of uncertain significance (VUS) and remains absent in both gnomAD and dbSNP. Notably, it has been identified in six unrelated individuals presenting with clinical features comparable to those observed in the patient described in this study. Multiple in silico prediction tools classified the variant as pathogenic, and a PhyloP conservation score supports strong evolutionary conservation of the mutated nucleotide. Protein structure predictions using the AlphaFold3 algorithm revealed notable structural differences between the mutant and wild-type PSMC5 proteins. We hypothesize that the p.Pro320Arg substitution alters the structure and function of PSMC5 as a regulatory subunit of the 26S proteasome, potentially impairing the stability and activity of the entire complex. Although functional studies are imperative, this study contributes to a deeper understanding of PSMC5, expands the spectrum of associated neurodevelopmental phenotypes, and highlights its potential as a therapeutic target. Furthermore, this study resulted in the submission of the identified variant to the ClinVar database (SCV006083352), where it was classified as pathogenic. Full article

Drinking water biofilm ecosystems harbor complex and dynamic prokaryotic and eukaryotic microbial communities. However, little is known about the impact of copper corrosion on microbial community functions in metabolisms and resistance. This study was conducted to evaluate the impact of upstream Cu pipe materials on downstream viable community structures, pathogen populations, and metatranscriptomic responses of the microbial communities in drinking water biofilms. Randomly transcribed cDNA was generated and sequenced from downstream biofilm samples of either unplasticized polyvinylchloride (PVC) or Cu coupons. Diverse viable microbial organisms with enriched pathogen-like organisms and opportunistic pathogens were active in those biofilm samples. Cu-influenced tubing biofilms had a greater upregulation of genes associated with potassium (K) metabolic pathways (i.e., K-homeostasis, K-transporting ATPase, and transcriptional attenuator), and a major component of the cell wall of mycobacteria (mycolic acids) compared to tubing biofilms downstream of PVC. Other upregulated genes on Cu influenced biofilms included those associated with stress responses (various oxidative resistance genes), biofilm formation, and resistance to toxic compounds. Downregulated genes included those associated with membrane proteins responsible for ion interactions with potassium; respiration–electron-donating reactions; RNA metabolism in eukaryotes; nitrogen metabolism; virulence, disease, and defense; and antibiotic resistance genes. When combined with our previous identification of biofilm community differences, our studies reveal how microbial biofilms adapt to Cu plumbing conditions by fine-tuning gene expression, altering metabolic pathways, and optimizing their structural organization. This study offers new insights into how copper pipe materials affect the development and composition of biofilms in premise plumbing. Specifically, it highlights copper’s role in inhibiting the growth of many microbes while also contributing to the resistance of some microbes within the drinking water biofilm community. Full article

The large portion of the eukaryotic genomes was considered non-functional and called the “dark matter” of the genome, now appearing as regulatory hubs coding for RNAs without the potential for making proteins, known as non-coding RNA. Long non-coding RNA (lncRNA) is defined as functional RNA molecules having lengths larger than 200 nucleotides without the potential for coding for proteins. Thousands of lncRNAs are identified in different plants and animals. LncRNAs are characterized by a low abundance, fewer exons than mRNA, tissue-specific expression, and low sequence conservation compared to protein-coding genes (PCGs). LncRNAs, like PCGs, are regulated by promoters and enhancers with characteristic chromatin signatures, DNA methylation, multiple exons, introns, and alternate splicing. LncRNAs interact with DNA, mRNA, microRNA, and proteins, including chromatin/histone modifiers, transcription factors/repressors, epigenetic regulators, spliceosomal, and RNA-binding proteins. Recent observations indicate that lncRNAs code for small peptides, also called micropeptides (<100 amino acids), and are involved in the development and growth of plants, suggesting the bi-functional activities of lncRNAs. LncRNAs have emerged as the major regulators of diverse functions, principally by altering the transcription of target genes. LncRNAs are involved in plant growth, development, immune responses, and various physiological processes. Abiotic, biotic, nutrient, and other environmental stresses alter the expressions of numerous lncRNAs. Understanding the mechanisms of actions of lncRNAs opens up the possibility of improving agronomic traits by manipulating lncRNAs. However, further studies are required in order to find the interactions among the deregulated lncRNAs and validate the findings from high-throughput studies to harness their potential in crop improvement. Full article

Background: Casein kinase I-like (CKL) protein is a member of the serine/threonine kinase CKI family and plays a pivotal regulatory role in various eukaryotic cellular processes, including stress responses. Objectives: This study aims to systematically identify the CKL gene family in the tomato genome and investigate its responsiveness to abiotic stress. Methods: Members of SlCKL were identified through genome-wide bioinformatics analysis, and their physicochemical properties, chromosomal localization, gene structure, conserved domains, phylogenetic relationships, cis-acting elements, cross-species collinearity, and tissue expression profiles were comprehensively analyzed. The expression patterns of SlCKL genes under abiotic stress were validated using real-time quantitative PCR. Results: A total of 16 SlCKL genes were identified and classified into three subfamilies (I–III), which are unevenly distributed across nine chromosomes, predominantly clustered at the ends. The gene structure, motifs, and functional domains exhibit high conservation. Collinearity analysis revealed stronger synteny between tomato and Arabidopsis thaliana or pepper compared to rice, maize, or tobacco, suggesting a common ancestral origin. The tissue expression profile indicates that SlCKLs are preferentially transcribed in roots. Promoter analysis and qRT-PCR validation demonstrated differential responses of SlCKLs to various abiotic stresses, such as drought, salt, heat, cold, and ABA treatment. Conclusions: This study represents the first systematic identification of the tomato SlCKL gene family, elucidating its evolutionary relationships, structural characteristics, tissue-specific expression patterns, and differential responsiveness to abiotic stress, thereby providing a critical foundation for further investigation into the molecular mechanisms underlying CKL-mediated abiotic stress adaptation in tomatoes. Full article

Photosynthetic eukaryotes have shaped the Earth’s biosphere by producing oxygen and organic compounds using light energy in specialized organelles called plastids. Plastids evolved from free-living cyanobacteria ingested by heterotrophic unicellular eukaryotes. Two such independent engulfment processes, called cyanobacterial endosymbioses, have been reported. The first gave rise to primary plastids and three Archaeplastida lineages: glaucophytes, red algae, and green algae with land plants, whereas the second resulted in chromatophores in the rhizarian amoeba Paulinella. Importantly, Archaeplastidans donated their plastids to many protist groups, further spreading photosynthesis across the tree of life. To reveal complex plastid evolution, we performed comprehensive phylogenetic and molecular clock analyses using new fossil calibrations and the largest number yet of plastid-encoded proteins from 108 taxa, representing diverse photosynthetic organisms. Our results indicate that primary plastids evolved prior to 2.1–1.8 Ga, i.e., before glaucophytes diverged from other Archaeplastidans, and Paulinella chromatophores were likely before 292–266 Ma. Red and green algae were engulfed by cryptophyte and chlorarachniophyte ancestors between 1.7–1.4 Ga and 1.1–1.0 Ga, respectively; the former subsequently triggered plastid transfers to other eukaryotes. We also examined the impact of molecular clocks and calibration sets on age estimates, showing that clocks are the main source of variation. Full article

Eukaryotic transcription involves a complex interplay of protein factors that dynamically engage with chromatin at distinct stages. Among these, the histone chaperone FACT (Facilitates Chromatin Transcription) plays a unique role in nucleosome disassembly and reassembly during transcription, replication, and repair. While its functional importance is well established, the underlying structural mechanisms involved in these activities remain incompletely understood. The remarkable functional versatility of FACT in regulating genetic information processing likely stems from its distinctive structural and mechanical properties. This review focuses on the structural organization of FACT and analysis of the mechanisms involved in chromatin reorganization by this unusual histone chaperone. Full article

In eukaryotes, the mitogen-activated protein kinase (MAPK) cascade pathway is a highly conserved cell signaling mechanism that is essential for stress response, growth, and development. MAPK cascade genes have currently been identified and characterized in a wide range of fungi, although they have not been fully understood in early divergent fungal lineages like the Mucoromycota, which contains Mucoromycotina, Glomeromycotina, and Mortierellomycotina. In this study, a genome-wide investigation of Blakeslea trispora (Mucorales, Choanephoraceae) revealed a total of 19 MAPK cascade genes, including 9 BtMAPKKKs, 4 BtMAPKKs, and 6 BtMAPKs genes. Using phylogenetic analysis, it was found that the kinase domain sequences and motif composition of the three MAPK, MAPKK, and MAPKKK lineages are substantially conserved in fungi. Whole genome duplication analysis indicated that B. trispora has four and nine duplication pairs in the MAPK and MAPKKK genes, respectively, which are expanded by segmental replication events. BtHog2, the orthologous protein of Hog1, exhibits a substantial rise in transcription levels under blue light irradiation, indicating its function in light signal response and transduction. Several sets of interacting protein pairs were found using molecular docking analysis and yeast two-hybrid assay, providing a comprehensive MAPK cascade signaling network in B. trispore. Furthermore, MAPK cascade proteins show varying transcription levels in response to blue light and sex hormone stimulation, as well as variable treatment duration. BtMAPKKK9 and BtBck1 are strongly induced during sexual interaction, indicating their involvement in the response to trisporic acid and the subsequent alterations in hyphal cell wall structure. These findings shed light on the evolution of MAPK cascade genes and the functional mechanisms underlying MAPK cascade genes in response to light and sex hormone signaling pathways in B. trispore. Full article

The eukaryotic translation elongation factor 1 (eEF1) family exhibits critical roles in RNA viral infection beyond its canonical function in protein synthesis. This review analyzes the structural characteristics of eEF1A and the eEF1B complex, and their regulatory mechanisms during viral infection. eEF1A impacts viral replication by stabilizing viral RNA-dependent RNA polymerase (RdRp) complexes, modulating genomic RNA synthesis, and facilitating viral assembly through cytoskeletal regulation. eEF1B subunits contribute through enhancing viral mRNA translation, regulating nuclear transport of viral components, and mediating post-translational modifications. The high conservation of eEF1 proteins across species and their involvement in multiple stages of viral replication establish them as promising broad-spectrum antiviral targets. Current eEF1-targeting compounds like plitidepsin demonstrate efficacy against diverse viral families, though therapeutic development faces challenges in balancing antiviral activity with host toxicity. This review provides a theoretical foundation for developing novel antiviral strategies targeting host–virus interaction interfaces and offers insights into addressing emerging infectious diseases. Full article

Trypanosomatids constitute a family of parasitic protozoa that cause significant human and veterinary diseases that are classified as neglected zoonotic diseases (NZDs). In a rapidly evolving world, these diseases have the potential to become a world health problem no longer solely associated with low-income countries. Therefore, the development of new strategies to control and restrain the dissemination of trypanosomatids is imperative. Extracellular vesicles (EVs) are a heterogeneous group of membrane-enclosed vesicles released by prokaryotic and eukaryotic cells. They can be found in diverse body fluids that carry biologically active molecules, including proteins, nucleic acids, lipids, and carbohydrates. EVs participate in cell-to-cell communication by delivering their cargo content to recipient cells. Thus, EVs play a role in regulating normal physiological processes, including immune surveillance and tissue repair, as well as being involved in pathological conditions, like cancer. In recent years, EVs have attracted significant attention from the scientific community, mainly due to their immune regulatory properties. Therefore, this review examines the role played by trypanosomatid-derived EVs in leishmaniases and trypanosomiasis, highlighting their biological role in host–parasite communication and exploring their potential future applications in controlling NZDs, especially those caused by trypanosomatids. Full article

Microalgae represent a promising platform for the synthesis of recombinant proteins, particularly in the context of biopharmaceutical applications. Their unique combination of eukaryotic cellular machinery and prokaryotic-like simplicity offers several advantages, including the ability to perform complex post-translational modifications, rapid growth rates, and cost-effective culture conditions. Advances in genome sequencing, genetic engineering tools, and omics technologies have significantly enhanced the feasibility and efficiency of using microalgae for therapeutic protein production. These advancements, coupled with the development of well-established transformation methods and optimized vectors, have enabled the successful expression of various biopharmaceuticals, ranging from vaccines to enzymes. Here, the main stages and current status of the production of exogenic recombinant proteins dedicated to human therapy are presented. Full article