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Glaesserella parasuis is the pathogen that causes Glässer's disease in pigs, which is characterized by fibrinous polyserositis, arthritis and meningitis. Research on ribosomal protein L32 in microorganisms has mainly focused on regulating gene transcription and translation, but its effect on bacterial virulence is unclear. The role of L32 gene in G. parasuis is not clear, and in order to study the function of L32 gene, a suicide plasmid-mediated natural transformation method was used to construct a L32 gene deletion mutant. We found that although L32 was shown to be non-essential for cell proliferation, the growth curve of ΔL32 is clearly different compared with that of ZJ1208. ΔL32 produced more outer membrane vesicles (OMVs) with a variety of irregular shapes, but produced similar biofilm to the parental strain. ΔL32 is more sensitive to osmotic pressure, oxidation pressure and heat shock stress. Meanwhile, ΔL32 is significantly more susceptible to antimicrobials such as spectinomycin, apramycin, sulfafurazole, but not to other antibiotics used in this study. In the mouse challenge experiment, the mortality of mice infected with the mutant strain decreased by 40% compared to those infected with the wild-type strain, indicating that L32 is a virulence-associated factor which contributes to bacterial fitness in host environments. The above results show that L32 is important for the growth, stress resistance and virulence of G. parasuis, and this study also confirms for the first time that L32 plays an important role in antibiotic resistance against aminoglycosides and sulfonamides.

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Ribosomal protein SA (RPSA) plays multiple roles in cells, including ribosomal biogenesis and translation, cellular migration, and cytoskeleton reorganization. RPSA is crucial in the process of pathogen infection. Extensive research has examined RPSA's role in pathogen adhesion and invasion, but its broader functions, particularly its anti-infective capabilities, have garnered increasing attention in recent years. This dual role is closely related to its structural domains, which influence its localization and function. This review summarizes key research findings concerning the functional domains of RPSA and analyzes the relationship between its membrane localization and structural domains. Additionally, the functional implications of RPSA are categorized based on its different localizations during pathogen infection. Specifically, when RPSA is located on the cell surface, it promotes pathogen adhesion and invasion of host cells; conversely, when RPSA is located intracellularly, it exhibits anti-infective properties. Overall, RPSA shows a dual nature, both in facilitating pathogen invasion of the host and in possessing the ability to resist pathogen infection. This review comprehensively examines the dual role of RPSA in pathogen infection by analyzing its structural domains, localization, and interactions with cellular and pathogen molecules. Our aim is to update and deepen researchers' understanding of the various functions of RPSA during pathogen infection.

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Eukaryotic chromatin consisting of nucleosomes connected by linker DNA is organized into higher order structures, which is facilitated by linker histone H1. Formation of chromatin compacts and protects the genome, but also hinders DNA transactions. Cells have evolved mechanisms to modify/remodel chromatin resulting in chromatin states suitable for genome functions. The high mobility group box (HMGB) proteins are non-histone chromatin architectural factors characterized by one or more HMGB motifs that bind DNA in a sequence nonspecific fashion. They play a major role in chromatin dynamics. The Saccharomyces cerevisiae (yeast hereafter) HMGB protein Hmo1 contains two HMGB motifs. However, unlike a canonical HMGB protein that has an acidic C-terminus, Hmo1 ends with a lysine rich, basic, C-terminus, resembling linker histone H1. Hmo1 exhibits characteristics of both HMGB proteins and linker histones in its multiple functions. For instance, Hmo1 promotes transcription by RNA polymerases I and II like canonical HMGB proteins but makes chromatin more compact/stable like linker histones. Recent studies have demonstrated that Hmo1 destabilizes/disrupts nucleosome similarly as other HMGB proteins in vitro and acts to maintain a common topological architecture of genes in yeast genome. This minireview reviews the functions of Hmo1 and the underlying mechanisms, highlighting recent discoveries.

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Elastin, a key structural protein essential for the elasticity of the skin and elastogenic tissues, degrades with age. Replenishing elastin holds promise for anti-aging cosmetics and the supplementation of elastic activities of the cardiovascular system. We employed RiboScreenTM, a technology for identifying molecules that enhance the production of specific proteins, to target the production of tropoelastin. We make use of RiboScreenTM in two crucial steps: first, to pinpoint a target ribosomal protein (TRP), which acts as a switch to increase the production of the protein of interest (POI), and second, to identify small molecules that activate this ribosomal protein switch. Using RiboScreenTM, we identified ribosomal protein L40, henceforth eL40, as a TRP switch to boost tropoelastin production. Drug discovery identified a small-molecule hit that binds to eL40. In-cell treatment demonstrated activity of the eL40 ligand and delivered increased tropoelastin production levels in a dose-dependent manner. Thus, we demonstrate that RiboScreenTM can successfully identify a small-molecule hit capable of selectively enhancing tropoelastin production. This compound has the potential to be developed for topical or systemic applications to promote skin rejuvenation and to supplement elastic functionality within the cardiovascular system.

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Potato late blight is the most devastating pre- and post-harvest crop disease in the world, which is widespread and difficult to control, causing serious economic losses. Cultivating resistant varieties is a major way to prevent and control late blight in a green way. However, due to the rapid evolution of pathogens, the plant resistance is losing. Therefore, mining effective and durable genes involved in disease resistance is crucial for breeding resistant varieties against late blight. In this study, we took "potato-Phytophthora infestans" as the "host-pathogen" model system to discover the potential disease resistance-related genes and elucidate their molecular functional mechanism. Through yeast two-hybridization, bimolecular fluorescence complementation, Co-immunoprecipitation assays, and gene function validation etc., we found that ribosomal protein S6 kinase 2 (StS6K2) is a key resistant protein, which is interacted with StWRKY59 transcription factor. Overexpression of StS6K2 and StWRKY59 both enhanced the plants resistance to P. infestans, and promoted the host immune response, such as ROS burst and callose deposition. In OEStWRKY59 lines, DEGs involved in secondary metabolites synthesis, plant hormone signaling transduction and plant-pathogen interaction were significantly enriched. These findings provide novel genetic resources for the breeding of resistant varieties.

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The identification of therapeutic target genes that are functionally involved in stemness is crucial to effectively cure patients with metastatic carcinoma. We have previously reported that inhibition of ribosomal protein L9 (RPL9) expression suppresses the growth of colorectal cancer (CRC) cells by inactivating the inhibitor of DNA-binding 1 (ID-1) signaling axis, which is functionally associated with cancer cell survival. In addition to cell proliferation, ID-1 is also involved in the maintenance of cancer stemness. Thus, we aimed in this study to investigate whether the function of RPL9 could correlate with CRC stem cell-like properties. Here, we demonstrated that siRNA silencing of RPL9 reduced the invasiveness and migrative capabilities of HT29 and HCT116 parental cell populations and the capacity for sphere formation in the HT29 parental cell population. CD133+ cancer stem cells (CSCs) were then separated from CD133- cancer cells of the HT29 parental cell culture and treated with RPL9-specific siRNAs to verify the effects of RPL9 targeting on stemness. As a result, knockdown of RPL9 significantly suppressed the proliferative potential of CD133+ colorectal CSCs, accompanied by a reduction in CD133, ID-1, and p-IκBα levels. In line with these molecular alterations, targeting RPL9 inhibited the invasion, migration, and sphere-forming capacity of CD133+ HT29 CSCs. Taken together, these findings suggest that RPL9 promotes CRC stemness via ID-1 and that RPL9 could be a potential therapeutic target for both primary CRC treatment and the prevention of metastasis and/or recurrence.

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Antimicrobial peptides (AMPs), characterized by their cationic nature and amphiphilic properties, play a pivotal role in inhibiting the biological activity of microbes. Currently, only a fraction of the antimicrobial potential within the ribosomal protein family has been explored, despite its extensive membership and resemblance to AMPs. Herein we demonstrated that amphioxus RPL17 (BjRPL17) exhibited not only upregulated expression upon bacterial stimulation but also possessed bactericidal capabilities against both Gram-negative and -positive bacteria through combined action mechanisms including interaction with cell surface molecules LPS, LTA, and PGN, disruption of cell membrane integrity, promotion of membrane depolarization, and induction of intracellular ROS production. Furthermore, a peptide derived from residues 127-141 of BjRPL17 (termed BjRPL17-1) showed antibacterial activity against Staphylococcus aureus and its methicillin-resistant strain via the same mechanism observed for the full-length protein. Additionally, the rpl17 gene was highly conserved in Metazoa, hinting it may play a universal role in the antibacterial defense system in different animals. Importantly, neither BjRPL17 nor peptide BjRPL17-1 exhibited toxicity towards mammalian cells thereby offering prospects for designing novel AMP agents based on these findings. Collectively, our results establish RPL17 as a novel member of AMPs with remarkable evolutionary conservation.

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Sheep body size can directly reflect the growth rates and fattening rates of sheep and is also an important index for measuring the growth performance of meat sheep.Inner Mongolia Cashmere Goat is a local excellent breed of cashmere and meat dual-purpose, which is a typical heterogeneous indumentum. The hair follicles cycle through periods of vigorous growth (anagen), a regression caused by apoptosis (catagen), and relative rest (telogen). At present, it is not clear which genes affect the cycle transformation of hair follicles and unclear how proteins impact the creation and expansion of hair follicles.we using multi-omics joint analysis methodologies to investigated the possible pathways of transformation and apoptosis in goat hair follicles. The results showed that 917,1,187, and 716 proteins were specifically expressed in anagen, catagen andtelogen. The result of gene ontology (GO) annotation showed that differentially expressed proteins (DEPs) are in different growth cycle periods, and enriched GO items are mostly related to the transformation of cells and proteins. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment result indicated that the apoptosis process has a great impact on hair follicle's growth cycle. The results of the protein interaction network of differential proteins showed that the ribosomal protein family (RPL4, RPL8, RPS16, RPS18, RPS2, RPS27A, RPS3) was the core protein in the network. The results of combined transcriptome and proteomics analysis showed that there were 16,34, and 26 overlapped DEGs and DEPs in the comparison of anagen VS catagen, catagen VS telogen and anagen VS telogen, of which API5 plays an important role in regulating protein and gene expression levels. We focused on API5 and Ribosomal protein and found that API5 affected the apoptosis process of hair follicles, and ribosomal protein was highly expressed in the resting stage of hair follicles. They are both useful as molecular marker candidate genes to study hair follicle growth and apoptosis,and they both have an essential function in the cycle transition process of hair follicles. The results of this study may provide a theoretical basis for further research on the growth and development of hair follicles in Inner Mongolian Cashmere goats.

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Despite advancements in therapeutic strategies, the development of drug resistance and metastasis remains a serious concern for the efficacy of chemotherapy against colorectal cancer (CRC). We have previously demonstrated that low expression of ribosomal protein uL3 positively correlates with chemoresistance in CRC patients. Here, we demonstrated that the loss of uL3 increased the metastatic capacity of CRC cells in chick embryos. Metabolomic analysis revealed large perturbations in amino acid and glutathione metabolism in resistant uL3-silenced CRC cells, indicating that uL3 silencing dramatically triggered redox metabolic reprogramming. RNA-Seq data revealed a notable dysregulation of 108 genes related to ferroptosis in CRC patients. Solute Carrier Family 7 Member 11 (SLC7A11) is one of the most dysregulated genes; its mRNA stability is negatively regulated by uL3, and its expression is inversely correlated with uL3 levels. Inhibition of SLC7A11 with erastin impaired resistant uL3-silenced CRC cell survival by inducing ferroptosis. Of interest, the combined treatment erastin plus uL3 enhanced the chemotherapeutic sensitivity of uL3-silenced CRC cells to erastin. The antimetastatic potential of the combined strategy was evaluated in chick embryos. Overall, our study sheds light on uL3-mediated chemoresistance and provides evidence of a novel therapeutic approach, erastin plus uL3, to induce ferroptosis, establishing individualized therapy by examining p53, uL3 and SLC7A11 profiles in tumors.

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Diamond-Blackfan anemia (DBA) is a rare genetic disorder affecting the bone marrow's ability to produce red blood cells, leading to severe anemia and various physical abnormalities. Approximately 75% of DBA cases involve heterozygous mutations in ribosomal protein (RP) genes, classifying it as a ribosomopathy, with RPS19 being the most frequently mutated gene. Non-RP mutations, such as in GATA1, have also been identified. Current treatments include glucocorticosteroids, blood transfusions, and hematopoietic stem cell transplantation (HSCT), with HSCT being the only curative option, albeit with challenges like donor availability and immunological complications. Gene therapy, particularly using lentiviral vectors and CRISPR/Cas9 technology, emerges as a promising alternative. This review explores the potential of gene therapy, focusing on lentiviral vectors and CRISPR/Cas9 technology in combination with non-integrating lentiviral vectors, as a curative solution for DBA. It highlights the transformative advancements in the treatment landscape of DBA, offering hope for individuals affected by this condition.

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In the present study, we compared the genetic variability of fragments from the internal transcribed spacer region (ITS) and the small subunit ribosomal DNA (SSUrDNA) as nuclear markers, in contrast with the ribosomal protein large two (rpl2) loci, placed in the mitochondrion-related organelles (MROs) within and among human fecal samples with Blastocystis. Samples were analyzed using polymerase chain reaction (PCR)-sequencing, phylogenies, and genetics of population structure analyses were performed. In total, 96 sequences were analyzed, i.e., 33 of SSUrDNA, 35 of rpl2, and 28 of ITS. Only three subtypes (STs) were identified, i.e., ST1 (11.4%), ST2 (28.6%), and ST3 (60%); in all cases, kappa indexes were 1, meaning a perfect agreement among ST assignations. The topologies of phylogenetic inferences were similar among them, clustering to each ST in its specific cluster; discrepancies between phylogeny and assignment of STs were not observed. The STRUCTURE v2.3.4 software assigned three subpopulations corresponding to the STs 1-3, respectively. The population indices were consistent with those previously reported by other groups. Our results suggest the potential use of the ITS and rpl2 genes as molecular markers for Blastocystis subtyping as an alternative approach for the study of the genetic diversity observed within and between human isolates of this microorganism.

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Glucan-dependent biofilm formation is a crucial process in the establishment of Streptococcus mutans as a cariogenic oral microbe. The process of glucan formation has been investigated in great detail, with glycosyltransferases GtfB, GtfC, and GtfD shown to be indispensable for the synthesis of glucans from sucrose. Glucan production can be visualized during biofilm formation through fluorescent labeling, and its abundance, as well as the effect of glucans on general biofilm architecture, is a common phenotype to study S. mutans virulence regulation. Here, we describe an entirely new phenotype associated with glucan production, caused by a mutation in the open reading frame SMU_848, which is located in an operon encoding ribosome-associated proteins. This mutation led to the excess production and accumulation of glucan-containing droplets on the surface of biofilms formed on agar plates after prolonged incubation. While not characterized in S. mutans, SMU_848 shows homology to the phage-related ribosomal protease Prp, essential in cleaving off the N-terminal extension of ribosomal protein L27 for functional ribosome assembly in Staphylococcus aureus. We present a further characterization of SMU_848/Prp, demonstrating that the deletion of this gene leads to significant changes in S. mutans gtfBC expression. Surprisingly, it also profoundly impacts the interkingdom interaction between S. mutans and Candida albicans, a relevant dual-species interaction implicated in severe early childhood caries. The presented data support a potential broader role for SMU_848/Prp, possibly extending its functionality beyond the ribosomal network to influence important ecological processes. IMPORTANCE: Streptococcus mutans is an important member of the oral biofilm and is implicated in the initiation of caries. One of the main virulence mechanisms is the glucan-dependent formation of biofilms. We identified a new player in the regulation of glucan production, SMU_848, which is part of an operon that also encodes for ribosomal proteins L27 and L21. A mutation in SMU_848, which encodes a phage-related ribosomal protease Prp, leads to a significant accumulation of glucan-containing droplets on S. mutans biofilms, a previously unknown phenotype. Further investigations expanded our knowledge about the role of SMU_848 beyond its role in glucan production, including significant involvement in interkingdom interactions, thus potentially playing a global role in the virulence regulation of S. mutans.

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Although alternative splicing (AS) is a major mechanism that adds diversity to gene expression patterns, its precise role in generating variability in ribosomal proteins, known as ribosomal heterogeneity, remains unclear. The ribosomal protein S24 (RPS24) gene, encoding a ribosomal component, undergoes AS; however, in-depth studies have been challenging because of three microexons between exons 4 and 6. We conducted a detailed analysis of RPS24 AS isoforms using a direct approach to investigate the splicing junctions related to these microexons, focusing on four AS isoforms. Each of these isoforms showed tissue specificity and relative differences in expression among cancer types. Significant differences in the proportions of these RPS24 AS isoforms between cancerous and normal tissues across diverse cancer types were also observed. Our study highlighted a significant correlation between the expression levels of a specific RPS24 AS isoform and the epithelial-mesenchymal transition process in lung and breast cancers. Our research contributes to a better understanding of the intricate regulatory mechanisms governing AS of ribosomal protein genes and highlights the biological implications of RPS24 AS isoforms in tissue development and tumorigenesis.

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Hepatitis C virus (HCV) infects the human liver, and its chronic infection is one of the major causes of Hepatocellular carcinoma. Translation of HCV RNA is mediated by an Internal Ribosome Entry Site (IRES) element located in the 5'UTR of viral RNA. Several RNA Binding proteins of the host interact with the HCV IRES and modulate its function. Here, we demonstrate that PSPC1 (Paraspeckle Component 1), an essential paraspeckle component, upon HCV infection is relocalized and interacts with HCV IRES to prevent viral RNA translation. Competition UV-crosslinking experiments showed that PSPC1 interacts explicitly with the SLIV region of the HCV IRES, which is known to play a vital role in ribosomal loading to the HCV IRES via interaction with Ribosomal protein S5 (RPS5). Partial silencing of PSPC1 increased viral RNA translation and, consequently, HCV replication, suggesting a negative regulation by PSPC1. Interestingly, the silencing of PSPC1 protein leads to an increased interaction of RPS5 at the SLIV region, leading to an overall increase in the viral RNA in polysomes. Overall, our results showed how the host counters viral infection by relocalizing nuclear protein to the cytoplasm as a survival strategy.

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Accurate gene expression is fundamental for sustaining life, enabling adaptive responses to routine tasks and management of urgent cellular environments. RNA polymerases (RNAP I, RNAP II, and RNAP III) and ribosomal proteins (RPs) play pivotal roles in the precise synthesis of proteins from DNA sequences. In this review, we briefly examined the structure and function of their constituent proteins and explored to characterize these proteins and the genes encoding them, particularly in terms of their expression quantitative trait loci (eQTL) associated with complex human traits. We gathered a comprehensive set of 4007 genome-wide association study (GWAS) signal-eQTL pairs, aligning GWAS Catalog signals with eQTLs across various tissues for the genes involved. These pairs spanned 16 experimental factor ontology (EFO) parent terms defined in European Bioinformatics Institute (EBI). A substantial majority (83.4%) of the pairs were attributed to the genes encoding RPs, especially RPS26 (32.9%). This large proportion was consistent across all tissues (15.5~81.9%), underscoring its extensive impact on complex human traits. Notably, these proportions of EFO terms differed significantly (p < 0.0031) from those for RNAPs. Brain-specific pairs for POLR3H, a component of RNAP III, were implicated in neurological disorders. The largest number of pairs in RNAP I was found for POLR1H, encoding RPA12, a built-in transcription factor essential for high transcriptional efficiency of RNAP I. RNAP II-related pairs were less abundant, with unique structural organization featuring minimal subunits for flexible transcription of a diverse range of genes with customized dissociable subunits. For instance, RPB4 encoded by POLR2D, the RNAP II gene with the most pairs, forms its dissociable stalk module with RPB7. This study provides insightful genetic characteristics of RPs and RNAPs, with a priority emphasis on RPS26, POLR1H, POLR2D, and POLR3H, for future studies on the impact of individual genetic variation on complex human traits.

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Protein kinase B (AKT1) is a serine/threonine kinase that regulates fundamental cellular processes, including cell survival, proliferation, and metabolism. AKT1 activity is controlled by two regulatory phosphorylation sites (Thr308, Ser473) that stimulate a downstream signaling cascade through phosphorylation of many target proteins. At either or both regulatory sites, hyperphosphorylation is associated with poor survival outcomes in many human cancers. Our previous biochemical and chemoproteomic studies showed that the phosphorylated forms of AKT1 have differential selectivity toward peptide substrates. Here, we investigated AKT1-dependent activity in human cells, using a cell-penetrating peptide (transactivator of transcription, TAT) to deliver inactive AKT1 or active phospho-variants to cells. We used enzyme engineering and genetic code expansion relying on a phosphoseryl-transfer RNA (tRNA) synthetase (SepRS) and tRNASep pair to produce TAT-tagged AKT1 with programmed phosphorylation at one or both key regulatory sites. We found that all TAT-tagged AKT1 variants were efficiently delivered into human embryonic kidney (HEK 293T) cells and that only the phosphorylated AKT1 (pAKT1) variants stimulated downstream signaling. All TAT-pAKT1 variants induced glycogen synthase kinase (GSK)-3α phosphorylation, as well as phosphorylation of ribosomal protein S6 at Ser240/244, demonstrating stimulation of downstream AKT1 signaling. Fascinatingly, only the AKT1 variants phosphorylated at S473 (TAT-pAKT1S473 or TAT-pAKT1T308,S473) were able to increase phospho-GSK-3ß levels. Although each TAT-pAKT1 variant significantly stimulated cell proliferation, cells transduced with TAT-pAKT1T308 grew significantly faster than with the other pAKT1 variants. The data demonstrate differential activity of the AKT1 phospho-forms in modulating downstream signaling and proliferation in human cells.

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Inter-regulation between related genes, such as ribosomal protein (RP) paralogs, has been observed to be important for genetic compensation and paralog-specific functions. However, how paralogs communicate to modulate their expression levels is unknown. Here, we report a circular RNA involved in the inter-regulation between RP paralogs RpL22 and RpL22-like during Drosophila spermatogenesis. Both paralogs are mutually regulated by the circular stable intronic sequence RNA (sisRNA) circRpL22(NE,3S) produced from the RpL22 locus. RpL22 represses itself and RpL22-like. Interestingly, circRpL22 binds to RpL22 to repress RpL22-like, but not RpL22, suggesting that circRpL22 modulates RpL22's function. circRpL22 is in turn controlled by RpL22-like, which regulates RpL22 binding to circRpL22 to indirectly modulate RpL22. This circRpL22-centric inter-regulatory circuit enables the loss of RpL22-like to be genetically compensated by RpL22 upregulation to ensure robust male germline development. Thus, our study identifies sisRNA as a possible mechanism of genetic crosstalk between paralogous genes.

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Objectives: To investigate the potential role of Ribosomal protein L35 (RPL35) in regulating chondrocyte catabolic metabolism and to examine whether osteoarthritis (OA) progression can be delayed by overexpressing RPL35 in a mouse compression loading model. Methods: RNA sequencing analysis was performed on chondrocytes treated with or without 20 % elongation strain loading for 24 h. Experimental OA in mice was induced by destabilization of the medial meniscus and compression loading. Mice were randomly assigned to a sham group, an intra-articular adenovirus-mediated overexpression of the negative group, and an intra-articular adenovirus-mediated overexpression of the RPL35 operated group. The Osteoarthritis Research Society International score was used to evaluate cartilage degeneration. Immunostaining and western blot analyses were conducted to detect relative protein levels. Primary mouse chondrocytes were treated with 20 % elongation strain loading for 24 h to investigate the role of RPL35 in modulating chondrocyte catabolic metabolism and regulating cellular senescence in chondrocytes. Results: The protein expression of RPL35 in mouse chondrocytes was significantly reduced when excessive mechanical loading was applied, while elevated protein levels of RPL35 protected articular chondrocytes from degeneration. In addition, the RPL35 knockdown alone induced chondrocyte senescence, decreased the expression of anabolic markers, and increased the expression of catabolic markers in vitro in part through the hedgehog (Hh) pathway. Conclusions: These findings demonstrated a functional pathway important for OA development and identified intra-articular injection of RPL35 as a potential therapy for OA prevention and treatment. The translational potential of this article: It is necessary to develop new targeted drugs for OA due to the limitations of conventional pharmacotherapy. Our study explores and demonstrates the protective effect of RPL35 against excessive mechanical stress in OA models in vivo and in vitro in animals. These findings might provide novel insights into OA pathogenesis and show its translational potential for OA therapy.

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ATAD3A is a mitochondrial membrane protein belonging to the ATPase family that contains the AAA+ domain. It is widely involved in mitochondrial metabolism, protein transport, cell growth, development and other important life processes. It has previously been reported that the deletion of ATAD3A causes growth and development defects in humans, mice and Caenorhabditis elegans. To delve into the mechanism underlying ATAD3A defects and their impact on development, we constructed a Bombyx mori ATAD3A (BmATAD3A) defect model in silkworm larvae. We aim to offer a reference for understanding ATAD3A genetic defects and elucidating the molecular regulatory mechanisms. The results showed that knockout of the BmATAD3A gene significantly affected the weight, survival rate, ATPase production and mitochondrial metabolism of individuals after 24 h of incubation. Combined metabolomics and transcriptomics analysis further demonstrated that BmATAD3A knockout inhibits amino acid biosynthesis through the regulation of mitochondrial ribosomal protein expression. Simultaneously, our findings indicate that BmATAD3A knockout impeded mitochondrial activity and ATPase synthesis and suppressed the mitochondrial oxidative phosphorylation pathway through B. mori mitochondrial ribosomal protein L11 (BmmRpL11). These results provide novel insights into the molecular mechanisms involved in the inhibition of development caused by ATAD3A deficiency, offering a potential direction for targeted therapy in diseases associated with abnormal ATAD3A expression.

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The exosomal pathway is an essential mechanism that regulates the abnormal content of microRNAs (miRNAs) in hepatocellular carcinoma (HCC). The directional transport of miRNAs requires the assistance of RNA­binding proteins (RBPs). The present study found that RBPs participate in the regulation of miRNA content through the exosomal pathway in HCC cells. First, differential protein expression profiles in the serum exosomes of patients with HCC and benign liver disease were detected using mass spectrometry. The results revealed that ribosomal protein L9 (RPL9) was highly expressed in serum exosomes of patients with HCC. In addition, the downregulation of RPL9 markedly suppressed the proliferation, migration and invasion of HCC cells and reduced the biological activity of HCC­derived exosomes. In addition, using miRNA microarrays, the changes in exosomal miRNA profiles in HCC cells caused by RPL9 knockdown were examined. miR­24­3p and miR­185­5p were most differentially expressed, as verified by reverse transcription­quantitative PCR. Additionally, using RNA immunoprecipitation, it was found that RPL9 was directly bound to the two miRNAs and immunofluorescence assays confirmed that RPL9 was able to carry miRNAs into recipient cells via exosomes. Overexpression of miR­24­3p in cells increased the accumulation of miR­24­3p in exosomes and simultaneously upregulated RPL9. Excessive expression of miR­24­3p in exosomes also increased their bioactivity. Exosome­mediated miRNA regulation and transfer require the involvement of RBPs. RPL9 functions as an oncogene, can directly bind to specific miRNAs and can be co­transported to receptor cells through exosomes, thereby exerting its biological functions. These findings provide a novel approach for modulating miRNA profiles in HCC.

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