Analysis of the implication of the DBIRD complex (DBC1 and ZNF326/ZIRD) in gene expression and alternative splicing
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ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: close pierre
PROVIDER: S-ECPF-GEOD-35480 | biostudies-other |
REPOSITORIES: biostudies-other
Similar Datasets
Project description:Alternative mRNA splicing is the main reason vast mammalian proteomic complexity can be achieved with a limited number of genes. Splicing is physically and functionally coupled to transcription and the rate of transcript elongation has a profound effect on splicing. As the nascent pre-mRNA emerges from transcribing RNA polymerase II (RNAPII), it is assembled into a messenger ribonucleoprotein (mRNP) particle that represents its functional form, and the composition of which determines the fate of the mature transcript4. However, factors that connect the transcribing polymerase with the mRNP particle and help integrate transcript elongation with mRNA splicing remain obscure. Here, we characterized the interactome of chromatin-associated mRNP particles and thereby identified Deleted in Breast Cancer 1 (DBC1) and a protein we named ZIRD. These proteins are subunits of a novel protein complex, named DBIRD, which binds directly to RNAPII. DBIRD regulates alternative splicing of a large set of exons embedded in A/T-rich DNA, and is present at the affected exons. RNAi-mediated DBIRD depletion results in region-specific decreases in transcript elongation, particularly across areas encompassing affected exons. These data indicate that DBIRD complex acts at the interface between mRNP particles and RNAPII, integrating transcript elongation with regulation of alternative splicing. HEK 293 cells were transfected with CTR-, DBC1- and ZIRD (ZNF326)- specific stealth siRNAs. Total RNAs from three independent experiments were extracted after 48 hours. All conditions were analyzed in triplicate.
2012-03-20 | E-GEOD-35480 | biostudies-arrayexpress
Project description:Alternative mRNA splicing is the main reason vast mammalian proteomic complexity can be achieved with a limited number of genes. Splicing is physically and functionally coupled to transcription and the rate of transcript elongation has a profound effect on splicing. As the nascent pre-mRNA emerges from transcribing RNA polymerase II (RNAPII), it is assembled into a messenger ribonucleoprotein (mRNP) particle that represents its functional form, and the composition of which determines the fate of the mature transcript4. However, factors that connect the transcribing polymerase with the mRNP particle and help integrate transcript elongation with mRNA splicing remain obscure. Here, we characterized the interactome of chromatin-associated mRNP particles and thereby identified Deleted in Breast Cancer 1 (DBC1) and a protein we named ZIRD. These proteins are subunits of a novel protein complex, named DBIRD, which binds directly to RNAPII. DBIRD regulates alternative splicing of a large set of exons embedded in A/T-rich DNA, and is present at the affected exons. RNAi-mediated DBIRD depletion results in region-specific decreases in transcript elongation, particularly across areas encompassing affected exons. These data indicate that DBIRD complex acts at the interface between mRNP particles and RNAPII, integrating transcript elongation with regulation of alternative splicing.
2012-03-20 | GSE35480 | GEO
Project description:BACKGROUND: Human sex hormone-binding globulin (SHBG) regulates free sex steroid concentrations in plasma and modulates rapid, membrane based steroid signaling. SHBG is encoded by an eight exon-long transcript whose expression is regulated by a downstream promoter (P(L)). The SHBG gene was previously shown to express a second major transcript of unknown function, derived from an upstream promoter (P(T)), and two minor transcripts. RESULTS: We report that transcriptional expression of the human SHBG gene is far more complex than previously described. P(L) and P(T) direct the expression of at least six independent transcripts each, resulting from alternative splicing of exons 4, 5, 6, and/or 7. We mapped two transcriptional start sites downstream of P(L) and P(T), and present evidence for a third SHBG gene promoter (P(N)) within the neighboring FXR2 gene; PN regulates the expression of at least seven independent SHBG gene transcripts, each possessing a novel, 164-nt first exon (1N). Transcriptional expression patterns were generated for human prostate, breast, testis, liver, and brain, and the LNCaP, MCF-7, and HepG2 cell lines. Each expresses the SHBG transcript, albeit in varying abundance. Alternative splicing was more pronounced in the cancer cell lines. P(L)- P(T)- and P(N)-derived transcripts were most abundant in liver, testis, and prostate, respectively. Initial findings reveal the existence of a smaller immunoreactive SHBG species in LNCaP, MCF-7, and HepG2 cells. CONCLUSION: These results extend our understanding of human SHBG gene transcription, and raise new and important questions regarding the role of novel alternatively spliced transcripts, their function in hormonally responsive tissues including the breast and prostate, and the role that aberrant SHBG gene expression may play in cancer.
| S-EPMC2694190 | biostudies-literature
Project description:BackgroundUltra-fast pseudo-alignment approaches are the tool of choice in transcript-level RNA sequencing (RNA-seq) analyses. Unfortunately, these methods couple the tasks of pseudo-alignment and transcript quantification. This coupling precludes the direct usage of pseudo-alignment to other expression analyses, including alternative splicing or differential gene expression analysis, without including a non-essential transcript quantification step.ResultsIn this paper, we introduce a transcriptome segmentation approach to decouple these two tasks. We propose an efficient algorithm to generate maximal disjoint segments given a transcriptome reference library on which ultra-fast pseudo-alignment can be used to produce per-sample segment counts. We show how to apply these maximally unambiguous count statistics in two specific expression analyses - alternative splicing and gene differential expression - without the need of a transcript quantification step. Our experiments based on simulated and experimental data showed that the use of segment counts, like other methods that rely on local coverage statistics, provides an advantage over approaches that rely on transcript quantification in detecting and correctly estimating local splicing in the case of incomplete transcript annotations.ConclusionsThe transcriptome segmentation approach implemented in Yanagi exploits the computational and space efficiency of pseudo-alignment approaches. It significantly expands their applicability and interpretability in a variety of RNA-seq analyses by providing the means to model and capture local coverage variation in these analyses.
| S-EPMC6693274 | biostudies-literature
Project description:Alternative splicing generates an enormous amount of functional and proteomic diversity in metazoan organisms. This process is probably central to the macromolecular and cellular complexity of higher eukaryotes. While most studies have focused on the molecular mechanism triggering and controlling alternative splicing, as well as on its incidence in different species, its maintenance and evolution within populations has been little investigated. Here, we propose to address these questions by comparing the structural characteristics as well as the functional and transcriptional profiles of genes with monomorphic or polymorphic splicing, referred to as MS and PS genes, respectively. We find that MS and PS genes differ particularly in the number of tissues and cell types where they are expressed.We find a striking deficit of PS genes on the sex chromosomes, particularly on the Y chromosome where it is shown not to be due to the observed lower breadth of expression of genes on that chromosome. The development of a simple model of evolution of cis-regulated alternative splicing leads to predictions in agreement with these observations. It further predicts the conditions for the emergence and the maintenance of cis-regulated alternative splicing, which are both favored by the tissue specific expression of splicing variants. We finally propose that the width of the gene expression profile is an essential factor for the acquisition of new transcript isoforms that could later be maintained by a new form of balancing selection.
| S-EPMC2575406 | biostudies-literature
Project description:Aberrant alternative splicing events play a critical role in cancer biology, contributing to tumor invasion, metastasis, epithelial-mesenchymal transition, and drug resistance. Recent studies have shown that alternative splicing is a key feature for transcriptomic variations in colorectal cancer, which ranks third among malignant tumors worldwide in both incidence and mortality. Long non-coding RNAs can modulate this process by acting as trans-regulatory agents, recruiting splicing factors, or driving them to specific targeted genes. LncH19 is a lncRNA dis-regulated in several tumor types and, in colorectal cancer, it plays a critical role in tumor onset, progression, and metastasis. In this paper, we found, that in colorectal cancer cells, the long non-coding RNA H19 can bind immature RNAs and splicing factors as hnRNPM and RBFOX2. Through bioinformatic analysis, we identified 57 transcripts associated with lncH19 and containing binding sites for both splicing factors, hnRNPM, and RBFOX2. Among these transcripts, we identified the mRNA of the GTPase-RAC1, whose alternatively spliced isoform, RAC1B, has been ascribed several roles in the malignant transformation. We confirmed, in vitro, the binding of the splicing factors to both the transcripts RAC1 and lncH19. Loss and gain of expression experiments in two colorectal cancer cell lines (SW620 and HCT116) demonstrated that lncH19 is required for RAC1B expression and, through RAC1B, it induces c-Myc and Cyclin-D increase. In vivo, investigation from biopsies of colorectal cancer patients showed higher levels of all the explored genes (lncH19, RAC1B, c-Myc and Cyclin-D) concerning the healthy counterpart, thus supporting our in vitro model. In addition, we identified a positive correlation between lncH19 and RAC1B in colorectal cancer patients. Finally, we demonstrated that lncH19, as a shuttle, drives the splicing factors RBFOX2 and hnRNPM to RAC1 allowing exon retention and RAC1B expression. The data shown in this paper represent the first evidence of a new mechanism of action by which lncH19 carries out its functions as an oncogene by prompting colorectal cancer through the modulation of alternative splicing.
| S-EPMC11299361 | biostudies-literature
Project description:BackgroundMultiple Sclerosis (MS) is an autoimmune neurodegenerative disease affecting approximately 3 million people globally. Despite rigorous research on MS, aspects of its development and progression remain unclear. Understanding molecular mechanisms underlying MS is crucial to providing insights into disease pathways, identifying potential biomarkers for early diagnosis, and revealing novel therapeutic targets for improved patient outcomes.MethodsWe utilized publicly available RNA-seq data (GSE138614) from post-mortem white matter tissues of five donors without any neurological disorder and ten MS patient donors. This data was interrogated for differential gene expression, alternative splicing and single nucleotide variants as well as for functional enrichments in the resulting datasets.ResultsA comparison of non-MS white matter (WM) to MS samples yielded differentially expressed genes involved in adaptive immune response, cell communication, and developmental processes. Genes with expression changes positively correlated with tissue inflammation were enriched in the immune system and receptor interaction pathways. Negatively correlated genes were enriched in neurogenesis, nervous system development, and metabolic pathways. Alternatively spliced transcripts between WM and MS lesions included genes that play roles in neurogenesis, myelination, and oligodendrocyte differentiation, such as brain enriched myelin associated protein (BCAS1), discs large MAGUK scaffold protein 1 (DLG1), KH domain containing RNA binding (QKI), and myelin basic protein (MBP). Our approach to comparing normal appearing WM (NAWM) and active lesion (AL) from one donor and NAWM and chronic active (CA) tissues from two donors, showed that different IgH and IgK gene subfamilies were differentially expressed. We also identified pathways involved in white matter injury repair and remyelination in these tissues. Differentially spliced genes between these lesions were involved in axon and dendrite structure stability. We also identified exon skipping events and spontaneous single nucleotide polymorphisms in membrane associated ring-CH-type finger 1 (MARCHF1), UDP glycosyltransferase 8 (UGT8), and other genes important in autoimmunity and neurodegeneration.ConclusionOverall, we identified unique genes, pathways, and novel splicing events affecting disease progression that can be further investigated as potential novel drug targets for MS treatment.
| S-EPMC11343266 | biostudies-literature
Project description:ObjectiveOsteoarthritis (OA) is the most prevalent joint disease characterized by the degeneration of articular cartilage and the remodeling of its underlying bones, resulting in pain and loss of function in the knees and hips. As far as we know, no curative treatments are available except for the joint replacement. The precise molecular mechanisms which are involved in the degradation of cartilage matrix and development of osteoarthritis are still unclear.DesignBy analyzing RNA-seq data, we found the molecular changes at the transcriptome level such as alternative splicing, gene expression, and molecular pathways in OA knees cartilage.ResultsExpression analysis have identified 457 differential expressed genes including 266 up-regulated genes such as TNFSF15, ST6GALNAC5, TGFBI, ASPM, and TYM, and 191 down-regulated genes such as ADM, JUN, IRE2, PIGA, and MAFF. Gene set enrichment analysis (GSEA) analysis identified down-regulated pathways related to translation, transcription, immunity, PI3K/AKT, and circadian as well as disturbed pathways related to extracellular matrix and collagen. Splicing analysis identified 442 differential alternative splicing events within 284 genes in osteoarthritis, including genes involved in extracellular matrix (ECM) and alternative splicing, and TIA1 was identified as a key regulator of these splicing events.ConclusionsThese findings provide insights into disease etiology, and offer favorable information to support the development of more effective interventions in response to the global clinical challenge of osteoarthritis.
| S-EPMC10416206 | biostudies-literature
Project description:The exosome is a complex with exoribonuclease activity that regulates RNA surveillance and turnover. The exosome also plays a role in regulating the degradation of precursor mRNAs to maintain the expression of splicing variants. In Neurospora, the silencing of rrp44, which encodes the catalytic subunit of the exosome, changed the expression of a set of spliceosomal snRNA, snRNP genes and SR protein related genes. The knockdown of rrp44 also affected the assembly of the spliceosome. RNA-seq analysis revealed a global change in bulk splicing events. Exosome-mediated splicing may regulate alternative splicing of NCU05290, NCU07421 and the circadian clock gene frequency (frq). The knockdown of rrp44 led to an increased ratio of splicing variants without intron 6 (I-6) and shorter protein isoform small FRQ (s-FRQ) as a consequence. These findings suggest that the exosome controls splicing events by regulating the degradation of precursor mRNAs and the gene expression, assembly and function of the spliceosome.
| S-EPMC4549623 | biostudies-literature
Project description:BackgroundMembers of the Sox gene family isolated from both vertebrates and invertebrates have been proved to participate in a wide variety of developmental processes, including sex determination and differentiation. Among these members, Sox30 had been considered to exist only in mammals since its discovery, and its exact function remains unclear.ResultsSox30 cDNA was cloned from the Nile tilapia by RT-PCR and RACE. Screening of available genome and EST databases and phylogenetic analysis showed that Sox30 also exists in non-mammalian vertebrates and invertebrates, which was further supported by synteny analyses. Tissue expression in human, mouse and tilapia suggested that Sox30 was probably a gonad-specific gene, which was also supported by the fact that Sox30 EST sequences were obtained from gonads of the animal species. In addition, four alternatively spliced isoforms were isolated from tilapia gonad. Their temporal and spatial expression patterns during normal and sex reversed gonadal development were investigated by RT-PCR and in situ hybridization. Our data suggest that expressions of Sox30 isoforms are related to stage and phenotypic-sex, observed in the germ cells of male gonad and in somatic cells of the female gonad.ConclusionsSox30 is not a gene only existed in mammals, but exists widely throughout the animal kingdom as supported by our bioinformatic, phylogenetic and syntenic analyses. It is very likely that Sox30 is expressed exclusively in gonads. Expression analyses revealed that Sox30 may be involved in female and male gonadal development at different stages by alternative splicing.
| S-EPMC3004900 | biostudies-literature