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Yatsenko, A.

Publications and source records attributed to Yatsenko, A..

5 recordsLinked to original sources

Argonaute 1 associates with nucleolar snoRNP machinery and regulates pre-rRNA levels and cell growth

Argonaute proteins are best known as cytoplasmic effectors of small-RNA-mediated gene silencing, although their compartment-specific functions remain incompletely understood. Here, we identify a previously unrecognized nucleolar role for Drosophila Argonaute 1 (AGO1). We observed stress-induced redistribution of AGO1 into cytoplasmic and nuclear ribonucleoprotein assemblies, whereas a distinct AGO1 pool consistently localized to Fibrillarin-positive nucleoli. Co-immunoprecipitation further showed that AGO1 associates with Fibrillarin-containing complexes in vivo. Re-analysis of AGO1-associated small-RNA sequencing data revealed snoRNAs, particularly C/D box snoRNAs, among AGO1-bound RNA species and increased snoRNA representation following AGO1 overexpression. Structural modelling demonstrated that simultaneous molecular interaction of AGO1 and the Fibrillarin-containing snoRNP machinery with the same snoRNA is stereochemically feasible, providing a structural framework for their potential association within a nucleolar snoRNP assembly. Functionally, AGO1 depletion reduced pre-rRNA levels and decreased both nucleolar and cell size in the follicular epithelium. Depletion of Dicer-1 did not reproduce these growth defects, arguing against a general consequence of impaired miRNA biogenesis. Together, these findings identify AGO1 as a nucleolar regulator that associates with snoRNP machinery and links small-RNA biology to pre-rRNA homeostasis and cell growth.

cell biology↗

The RNA helicase DDX53 (CAGE) contributes to RNA metabolism in a human germ cell model

DDX53 (DEAD-box helicase 53, known also as CAGE) is an intronless gene on the X chromosome, which expression shows strong testis specificity. It belongs to the group of cancer-testis (CT) antigens, with most studies to date focusing on its role in cancer, but the precise biological function of DDX53 remains unclear. Previous reports identifying rare DDX53 variants in infertile men provided the rationale for investigating the role of DDX53 in the context of human spermatogenesis. By using the human seminoma cell line (TCam-2) as an in vitro male germline model, we aimed to investigate the function and molecular targets of DDX53 protein. Our eCLIP and RNA-seq data show that DDX53 protein directly interacts with numerous RNA molecules, drives transcriptome changes in human cells, and is involved in alternative splicing of RNA. Moreover, we identified potential DDX53 protein interactors using Co-IP-MS approach. Subcellular localization analysis by confocal microscopy indicated a predominantly cytoplasmic distribution of DDX53, with partial nuclear presence in TCam-2 cells. We also identified DDX53-positive structures that may correspond to germ granule-like assemblies, although their precise nature remains to be determined. Additionally, we confirmed DDX53 presence in human testis using a specific, commercially available anti-DDX53 antibody. Our data indicate that DDX53 protein acts as a regulator of RNA metabolism in human cells. Collectively, we show that DDX53 participates in transcriptome regulation (including splicing) in male germ cells and exhibits transcriptomewide RNA interactions, but its wider biological role remains to be clarified.

molecular biology↗

Multi-omic screening identifies RBMXL3 as a primate-specific RNA-binding protein and candidate regulator of RNA metabolism in human spermatogenesis

BackgroundRBMXL3 is a primate-specific gene localized on the X chromosome, which expression is detectable mainly in the male gonad. So far, very little is known about the RBMXL3 protein function and its molecular interactions. However, recent reports mention the RBMXL3 gene in the context of human spermatogenesis, cancer, and a breathing disorder that affects newborns. In this study, we investigate the RBMXL3s molecular network on a genome-wide scale using the human seminoma cell line (TCam-2) as a male germline in vitro model. MethodsBy using transcriptomic (RNA sequencing (RNA-seq) and enhanced crosslinking and immunoprecipitation (eCLIP)) and proteomic (Co-immunoprecipitation coupled with Mass Spectrometry, (Co-IP-MS)) approaches we show RBMXL3 importance in RNA metabolism. Additionally, Western Blot, qRT-PCR, immunostaining, and confocal imaging were used in order to investigate the function of RBMXL3. Finally, we used a plasmid-based L1 retrotransposition assay to demonstrate the suppressive effect of RBMXL3 on human Long Interspersed Nuclear Element-1 (LINE-1, L1) retrotransposition. ResultsOur RNA-seq data show that RBMXL3 expression drives gene expression changes and influence alternative splicing in human cells. Moreover, by performing eCLIP we provide a proof that RBMXL3 binds to a wide range of RNA transcripts. Additionally, we confirmed the nuclear localization of RBMXL3 in TCam-2 cells and its presence in spermatogonia and spermatocytes within the human testis. Finally, we report for the first time that RBMXL3 restricts human LINE-1 retrotransposition. ConclusionsOur findings for the first time identify primate-specific RBMXL3 protein as a new upstream regulator of RNA metabolism, characterized by broad RNA-binding activity in human TCam-2 cells. Finally, we show that RBMXL3 expression heavily reduces LINE-1 retrotransposition in human cells, underlying RBMXL3 importance in maintaining genome integrity. Our data suggest that RBMXL3 may contribute to the regulation of transcriptome dynamics in male germ cells, while its broader functional implications remain to be determined. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=56 SRC="FIGDIR/small/677621v3_ufig1.gif" ALT="Figure 1"> View larger version (21K): org.highwire.dtl.DTLVardef@8bf116org.highwire.dtl.DTLVardef@180fe82org.highwire.dtl.DTLVardef@1c52960org.highwire.dtl.DTLVardef@11f7519_HPS_FORMAT_FIGEXP M_FIG C_FIG Created with BioRender.com

cell biology↗

Unraveling the link between Neuropathy Target Esterase NTE/SWS, lysosomal storage diseases, inflammation, and abnormal fatty acid metabolism

Mutations in Drosophila Swiss Cheese (SWS) gene or its vertebrate orthologue Neuropathy Target Esterase (NTE) lead to progressive neuronal degeneration in flies and humans. Despite its enzymatic function as a phospholipase is well-established, the molecular mechanism responsible for maintaining nervous system integrity remains unclear. In this study, we found that SWS is present in surface glia that form the blood-brain-barrier (BBB) and that SWS is important to maintain its structure and permeability. Importantly, BBB glia-specific expression of Drosophila SWS or human NTE in the sws mutant background fully rescues surface glial organization and partially restores BBB integrity, suggesting a conserved function of NTE/SWS. Interestingly, sws mutant glia showed abnormal organization of plasma membrane domains and tight junction rafts accompanied by the accumulation of lipid droplets, lysosomes, and multilamellar bodies. Since the observed cellular phenotypes closely resemble the characteristics described in a group of metabolic disorders known as lysosomal storage diseases (LSDs), our data established a novel connection between NTE/SWS and these conditions. We found that mutants with defective BBB exhibit elevated levels of fatty acids, which are precursors of eicosanoids and are involved in the inflammatory response. Also, as a consequence of a permeable BBB, several innate immunity factors are upregulated. Treatment with anti-inflammatory agents prevents the abnormal architecture of the BBB, suggesting that inflammation contributes to the maintenance of a healthy brain barrier. Since a defective BBB is associated with many neurodegenerative diseases, a better understanding of the molecular mechanisms of inflammation may help to promote the use of anti-inflammatory therapy for age-related neurodegeneration.

neuroscience↗

GCNA preserves genome integrity and fertility across species

The propagation of species depends on the ability of germ cells to protect their genome in the face of numerous exogenous and endogenous threats. While these cells employ a number of known repair pathways, specialized mechanisms that ensure high-fidelity replication, chromosome segregation, and repair of germ cell genomes remain incompletely understood. Here, we identify Germ Cell Nuclear Acidic Peptidase (GCNA) as a highly conserved regulator of genome stability in flies, worms, zebrafish, and humans. GCNA contains a long acidic intrinsically disordered region (IDR) and a protease-like SprT domain. In addition to chromosomal instability and replication stress, GCNA mutants accumulate DNA-protein crosslinks (DPCs). GCNA acts in parallel with a second SprT domain protein Spartan. Structural analysis reveals that while the SprT domain is needed to limit meiotic and replicative damage, most of GCNAs function maps to its IDR. This work shows GCNA protects germ cells from various sources of damage, providing novel insights into conserved mechanisms that promote genome integrity across generations.\n\nHighlightsGCNA ensures genomic stability in germ cells and early embryos across species\n\nGCNA limits replication stress and DNA double stranded breaks\n\nGCNA restricts DNA-Protein Crosslinks within germ cells and early embryos\n\nThe IDR and SprT domains of GCNA govern distinct aspects of genome integrity\n\nGraphic Abstract\n\nO_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=189 SRC=\"FIGDIR/small/570804_ufig1.gif\" ALT=\"Figure 1\">\nView larger version (54K):\norg.highwire.dtl.DTLVardef@1928d82org.highwire.dtl.DTLVardef@885ff2org.highwire.dtl.DTLVardef@15322c9org.highwire.dtl.DTLVardef@110c615_HPS_FORMAT_FIGEXP M_FIG C_FIG

developmental biology↗