Project description:To identify the RNA targets of the RNA binding proteins NONO and SFPQ in two different cell types, PARCLIP was carried out (Photoactivatable Ribonucleoside-Enhanced Crosslinking and Immunoprecipitation) using a monoclonal antibody that recognises a NONO/SFPQ heterodimer. In this analysis, only the target gene NEAT1 was analysed, to show the binding sites for NONO and SFPQ in this transcript in the two cell lines.
Project description:siRNA knockdown of NONO mRNA followed by RNA-seq was carried out in the KELLY neuroblasotma cell line. In order to determine potential regulatory targets of NONO protein, we performed differential expression analysis. To identify the RNA targets of NONO in neuroblastoma, we carried out PAR-CLIP (Photoactivatable Ribonucleoside-Enhanced Crosslinking and Immunoprecipitation) using an antibody recognising NONO protein.
Project description:A large swath of the human proteome is dedicated to mRNA homeostasis, but most RNA-binding proteins lack chemical probes. Here, we report the discovery through phenotypic screening of electrophilic small molecules that swiftly (within 4 h) and stereospecifically decrease transcripts encoding the androgen receptor (AR) and its major V7 splice variant in human prostate cancer cells. We show by chemical proteomics that these compounds covalently engage cysteine-145 of the RNA-binding protein NONO. Broader profiling revealed that covalent NONO ligands suppress a discrete set of transcripts and proteins, including multiple oncogenic transcription factors, and impair the proliferation of cancer cells. These effects were not observed following genetic disruption of NONO, which instead blocked ligand activity. The covalent ligands promote accumulation of NONO in nuclear foci and at the first 5’ splice site of immature transcripts, pointing to a trapping mechanism that may prevent the compensatory action of the paralogous proteins PSPC1 and SFPQ, which were found to increase in cancer cells following genetic or chemical perturbation of NONO. These findings, taken together, designate NONO as a druggable RNA-binding protein that can be co-opted by covalent small molecules to suppress pro-tumorigenic transcriptional networks.
Project description:Sorting U2OS and HeLa cells genetically modified with the Fucci System allowed us to separate cells according to cell cycle progression followed by RNA Sequencing to characterize the oscillating transcriptome in cells without the need for chemical synchronization.
Project description:Phenotypic characterisation of our zebrafish sfpq homozygous mutants revealed a restricted set of specific defects, unexpected for a protein expressed ubiquitously and involved in such general mechanisms. The CNS was prominently affected, showing brain boundary and axonal defects associated with absence of motility. To investigate a possible specificity in SFPQ functional targets by microarray RNA profiling analysis, comparing the transcriptome of the sfpq homozygous mutants with its wild type and heterozygous siblings at the earliest stage at which the phenotype is robustly recognizable.
Project description:Circular RNAs (circRNAs) represent an abundant and conserved entity of non-coding RNAs, however the principles of biogenesis are currently not fully understood. To elucidate features important for circRNA production, we performed global analyses of RNA-binding proteins associating with the flanking introns of circRNAs, and we identified two factors, SFPQ and NONO, to be highly enriched with circRNAs. We observe a subclass of circRNAs, coined DALI circRNAs, with distal inverted Alu elements and long introns to be highly deregulated upon SFPQ knockdown. Moreover, SFPQ depletion leads to increased intron retention with concomitant induction of cryptic splicing prevalent for long introns causing in some cases premature transcription termination and polyadenylation. Aberrant splicing in the upstream and downstream regions of circRNA producing exons are critical for shaping the circRNAome, and specifically, we identify a conserved impact of missplicing in the immediate upstream region to drive circRNA biogenesis. Collectively, our data show that SFPQ plays an important role in maintaining intron integrity by ensuring accurate splicing of long introns, and disclose novel features governing Alu-independent circRNA production.
Project description:Identifying causes of sporadic intellectual disability remains a considerable medical challenge. Here, we demonstrate that null mutations in the NONO gene, a member of the Drosophila Behavior Human Splicing (DBHS) protein family, are a novel cause of X-linked syndromic intellectual disability. Comparing humans to Nono-deficient mice revealed related behavioral and craniofacial anomalies, as well as global transcriptional dysregulation. Nono-deficient mice also showed deregulation of a large number of synaptic transcripts, causing a disorganization of inhibitory synapses, with impaired postsynaptic scaffolding of gephyrin. Alteration of gephyrin clustering could be rescued by over-expression of Gabra2 in NONO-compromised neurons. These findings link NONO to intellectual disability and first highlight the key role of DBHS proteins in functional organization of GABAergic synapses.
Project description:Identifying causes of sporadic intellectual disability remains a considerable medical challenge. Here, we demonstrate that null mutations in the NONO gene, a member of the Drosophila Behavior Human Splicing (DBHS) protein family, are a novel cause of X-linked syndromic intellectual disability. Comparing humans to Nono-deficient mice revealed related behavioral and craniofacial anomalies, as well as global transcriptional dysregulation. Nono-deficient mice also showed deregulation of a large number of synaptic transcripts, causing a disorganization of inhibitory synapses, with impaired postsynaptic scaffolding of gephyrin. Alteration of gephyrin clustering could be rescued by over-expression of Gabra2 in NONO-compromised neurons. These findings link NONO to intellectual disability and first highlight the key role of DBHS proteins in functional organization of GABAergic synapses.
Project description:To investigate the RNA binding proterties of NONO and NONO-delta-ER in testis; we collected adult NONO and NONO-delta-ER mice testis We then performed eCLIP-seq respectively and convey subsequent bioinformatic analysis.