UNASSIGNED: Head and Neck Squamous Cell Carcinoma (HNSCC) is a malignancy characterized by a high incidence and recurrence rate. 5-methylcytosine (m5C) RNA modification is a common alteration affecting cancer progression; however, how m5C operates within the tumor microenvironment of HNSCC remains to be elucidated.
UNASSIGNED: We conducted Nanopore sequencing on 3 pairs of cancer and paracancerous tissues from mid- and late-stage HNSCC, obtaining 132 upregulated genes (transcriptomically upregulated, m5C elevated) and 129 downregulated genes (transcriptomically downregulated, m5C reduced). Subsequent Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed; a differential gene interaction network (PPI) was constructed, revealing the interactions of each gene with others in the network. Co-expression analysis was performed on the genes within the PPI, unveiling their expression and regulatory relationships. Through GSVA analysis, variations in related pathways under different states were identified. Furthermore, results of m5C in lncRNA were screened, followed by target gene prediction.
UNASSIGNED: Sequencing results from the 3 pairs of mid- and late-stage HNSCC cancer and paracancerous tissues demonstrated that RPS27A, RPL8, and the lncRNAs including differentiation antagonizing nonprotein coding RNA (DANCR), DCST1 antisense RNA 1 (CCDC144NL-AS1), Growth Arrest-Specific Transcript 5 (GAS5), Nuclear Paraspeckle Assembly Transcript 1 (NEAT1), and Small Nucleolar RNA Host Gene 3 (SNHG3), etc., under m5Cregulation, have close connections with surrounding genes. The differentially m5Cmodified genes are primarily involved in ribosomal protein synthesis, oxidative stress response, metabolic reprogramming, immunity, and other life processes; pathways like mitochondrial protein import and photodynamic therapy induced unfolded protein response are upregulated in the tumor, while pathways, including the classic P53, are suppressed. Analysis on m5C-regulated long non-coding RNAs (lncRNAs) revealed tight associations with RPS27A and RPL8 as well.
UNASSIGNED: Our study identifies the key factors and signaling pathways involving m5C in HNSCC. The findings suggest that ribosome-related genes might regulate ribosomal protein synthesis, oxidative stress response, metabolic reprogramming, and immune response through m5C RNA modification by means like hypoxia and ferroptosis, thereby playing a pivotal role in the onset and progression of HNSCC. Hence, attention should be paid to the role of ribosomes in HNSCC. These findings may facilitate the precision and individualized treatment of patients with mid- and late-stage HNSCC in clinical settings.

Microsatellite instability-high (MSI-H) tumors are malignant tumors that, despite harboring a high mutational burden, often have intact TP53. One of the most frequent mutations in MSI-H tumors is a frameshift mutation in RPL22, a ribosomal protein. Here, we identified RPL22 as a modulator of MDM4 splicing through an alternative splicing switch in exon 6. RPL22 loss increases MDM4 exon 6 inclusion and cell proliferation and augments resistance to the MDM inhibitor Nutlin-3a. RPL22 represses the expression of its paralog, RPL22L1, by mediating the splicing of a cryptic exon corresponding to a truncated transcript. Therefore, damaging mutations in RPL22 drive oncogenic MDM4 induction and reveal a common splicing circuit in MSI-H tumors that may inform therapeutic targeting of the MDM4-p53 axis and oncogenic RPL22L1 induction.

Ribosomes are regulated by evolutionarily conserved ubiquitination/deubiquitination events. We uncover the role of the deubiquitinase OTUD6 in regulating global protein translation through deubiquitination of the RPS7/eS7 subunit on the free 40 S ribosome in vivo in Drosophila. Coimmunoprecipitation and enrichment of monoubiquitinated proteins from catalytically inactive OTUD6 flies reveal RPS7 as the ribosomal substrate. The 40 S protein RACK1 and E3 ligases CNOT4 and RNF10 function upstream of OTUD6 to regulate alkylation stress. OTUD6 interacts with RPS7 specifically on the free 40 S, and not on 43 S/48 S initiation complexes or the translating ribosome. Global protein translation levels are bidirectionally regulated by OTUD6 protein abundance. OTUD6 protein abundance is physiologically regulated in aging and in response to translational and alkylation stress. Thus, OTUD6 may promote translation initiation, the rate limiting step in protein translation, by titering the amount of 40 S ribosome that recycles.

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.

The tumor suppressor p53 and its antagonists MDM2 and MDM4 integrate stress signaling. For instance, dysbalanced assembly of ribosomes in nucleoli induces p53. Here, we show that the ribosomal protein L22 (RPL22; eL22), under conditions of ribosomal and nucleolar stress, promotes the skipping of MDM4 exon 6. Upon L22 depletion, more full-length MDM4 is maintained, leading to diminished p53 activity and enhanced cellular proliferation. L22 binds to specific RNA elements within intron 6 of MDM4 that correspond to a stem-loop consensus, leading to exon 6 skipping. Targeted deletion of these intronic elements largely abolishes L22-mediated exon skipping and re-enables cell proliferation, despite nucleolar stress. L22 also governs alternative splicing of the L22L1 (RPL22L1) and UBAP2L mRNAs. Thus, L22 serves as a signaling intermediate that integrates different layers of gene expression. Defects in ribosome synthesis lead to specific alternative splicing, ultimately triggering p53-mediated transcription and arresting cell proliferation.

Programmed death-ligand 1 interacts with fungal ribosomal Rpl20b in phagosomes and induces interleukin-10 secretion.

Aminoglycoside antibiotics target ribosomes and are effective against a wide range of bacteria. Here, we demonstrated that knockout strains related to energy metabolism in Escherichia coli showed increased tolerance to aminoglycosides during the mid-exponential growth phase. Contrary to expectations, these mutations did not reduce the proton motive force or aminoglycoside uptake, as there were no significant changes in metabolic indicators or intracellular gentamicin levels between wild-type and mutant strains. Our comprehensive proteomics analysis unveiled a noteworthy upregulation of proteins linked to the tricarboxylic acid (TCA) cycle in the mutant strains during the mid-exponential growth phase, suggesting that these strains compensate for the perturbation in their energy metabolism by increasing TCA cycle activity to maintain their membrane potential and ATP levels. Furthermore, our pathway enrichment analysis shed light on local network clusters displaying downregulation across all mutant strains, which were associated with both large and small ribosomal binding proteins, ribosome biogenesis, translation factor activity, and the biosynthesis of ribonucleoside monophosphates. These findings offer a plausible explanation for the observed tolerance of aminoglycosides in the mutant strains. Altogether, this research provides valuable insights into the mechanisms of aminoglycoside tolerance, paving the way for novel strategies to combat such cells.
Bacteria that are resistant to antibiotic drugs pose a significant challenge to human health around the globe. They have acquired genetic mutations that allow them to survive and grow in the presence of one or more antibiotics, making it harder for clinicians to eliminate such bacteria from human patients with life-threatening infections. Some bacteria may be able to temporarily develop tolerance to an antibiotic by altering how they grow and behave, without acquiring any new genetic mutations. Such drug-tolerant bacteria are more likely to survive long enough to gain mutations that may promote drug resistance. Recent studies suggest that genes involved in processes collectively known as energy metabolism, which convert food sources into the chemical energy cells need to survive and grow, may play a role in both tolerance and resistance. For example, Escherichia coli bacteria develop mutations in energy metabolism genes when exposed to members of a family of antibiotics known as the aminoglycosides. However, it remains unclear what exact role energy metabolism plays in antibiotic tolerance. To address this question, Shiraliyev and Orman studied how a range of E. coli strains with different genetic mutations affecting energy metabolism could survive in the presence of aminoglycosides. The experiments found that most of the mutant strains had a higher tolerance to the drugs than normal E. coli. Unexpectedly, this increased tolerance did not appear to be due to the drugs entering the mutant bacterium cells less than they enter normal cells (a common strategy of drug resistance and tolerance). Further experiments using a technique, known as proteomics, revealed that many genes involved in energy metabolism were upregulated in the mutant bacteria, suggesting these cells were compensating for the genetic abnormalities they have. Furthermore, the mutant bacteria had lower levels of the molecules the antibiotics target than normal bacteria. The findings of Shiraliyev and Orman offer critical insights into how bacteria become tolerant of aminoglycoside antibiotics. In the future, this may guide the development of new strategies to combat bacterial diseases.

Growth retardation for more than 2 SD below the average population or presumed familial target height is classified as a short stature and may be a clinical manifestation of a large number of disorders. The use of the latest methods of molecular genetic analysis in recent years has allowed for a better understanding of the pathogenesis of inherited forms of a short stature. One of the recently discovered mechanisms of this pathology was monoallelic mutations in RPL13 gene, leading to the development of Isidor-Toutain type spondyloepimetaphyseal dysplasia (SEDM). Characteristic phenotypic features for this form are normal birth length, early postnatal growth deficiency, platyspondyly, proximal femoral epiphyseal changes, coxa vara, genu varum. This study presents the clinical and radiological characteristics of the first patient in the Russian -Federation with SEMD caused by a mutation in RPL13 gene.

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.

Ribosomes are not totally globular machines. Instead, they comprise prominent structural protrusions and a myriad of tentacle-like projections, which are frequently made up of ribosomal RNA expansion segments and N- or C-terminal extensions of ribosomal proteins. This is more evident in higher eukaryotic ribosomes. One of the most characteristic protrusions, present in small ribosomal subunits in all three domains of life, is the so-called beak, which is relevant for the function and regulation of the ribosome\'s activities. During evolution, the beak has transitioned from an all ribosomal RNA structure (helix h33 in 16S rRNA) in bacteria, to an arrangement formed by three ribosomal proteins, eS10, eS12 and eS31, and a smaller h33 ribosomal RNA in eukaryotes. In this review, we describe the different structural and functional properties of the eukaryotic beak. We discuss the state-of-the-art concerning its composition and functional significance, including other processes apparently not related to translation, and the dynamics of its assembly in yeast and human cells. Moreover, we outline the current view about the relevance of the beak\'s components in human diseases, especially in ribosomopathies and cancer.