Project description:This study analyzed the effect of RBM5 gene deletion in cortical brain tissue on differential gene expression/splicing changes 48h after a traumatic brain injury (TBI). TBI was induced in WT vs. KO mice by controlled cortical impact (CCI) injury. The four grouops included: (1) Sham-WT, (2) CCI-WT, (3) Sham-KO, and (4) CCI-KO. The objective of this study was to test if RBM5 KO decreased the expression of cell death mediators in the contused brain 48h post-injury.
Project description:RNA-binding proteins (RBPs) are key players regulating RNA processing and are associated with disorders ranging from cancer to neurodegeneration. Here, we present a proteomics workflow for large-scale identification of RBPs and their RNA-binding regions in the mammalian brain identifying 526 RBPs including 86 previously undescribed. Analysing brain tissue from the Huntington’s disease (HD) R6/2 mouse model uncovered differential RNA-binding of the alternative splicing regulator RBM5. Combining several omics workflows, we show that RBM5 binds differentially to transcripts enriched in pathways of neurodegeneration in R6/2 brain tissue. We further find these transcripts to undergo changes in splicing and demonstrate that RBM5 directly regulates these changes in human neurons derived from embryonic stem cells. Finally, we reveal that RBM5 interacts differently with several known huntingtin interactors and components of huntingtin aggregates. Collectively, we demonstrate the applicability of our method for capturing RNA interactor dynamics in the contexts of tissue and disease.
Project description:Using the Cross-linking immuno-precipitation (CLIP) methodology combined with high throughput sequencing analysis, we have identified the RNA targets of the RNA-binding protein RBM5 in the brain of wild-type and R6/2 (Huntington's disease model) adult mice. In parallel, transcriptome analysis was performed by RNA-sequencing using brain samples from the same animals.
Project description:RNA Binding Motif 5 (RBM5) is a nuclear splicing factor. Prior studies show that RBM5 overexpression in cancer cells alters gene splicing, gene expression, and induces cell death and/or growth arrest. The role of RBM5 in primary neurons is unknown, and its potential mRNA targets have not been identified. Using lentivirus based approaches we tested if RBM5 knockdown (i.e. by shRNA) or RBM5 overexpression (DDK-tagged rat open reading frame) alters whole genome expression in primary rat cortical neurons. We used microarrays to examine genes that are up-regulated vs. down-regulation in cortical neurons after RBM5 knockdown vs. overexpression.
Project description:Background: The oncogenic protein HOXA9 plays a critical role in leukemia transformation and maintenance, and its aberrant expression is a hallmark of most aggressive acute leukemia. Although inhibiting the upstream regulators of HOXA9 has been proven as a significant therapeutic intervention, the comprehensive regulation network controlling HOXA9 expression in leukemia has not been systematically investigated. Results: Here, we perform genome-wide CRISPR/Cas9 screening in the HOXA9-driven reporter acute leukemia cells. We identify a poorly characterized RNA-binding protein, RBM5, as the top candidate gene required to maintain leukemia cell fitness. RBM5 is highly overexpressed in acute myeloid leukemia (AML) patients compared to healthy individuals. RBM5 loss triggered by CRISPR knockout and shRNA knockdown significantly impairs leukemia maintenance in vitro and in vivo. Through domain CRISPR screening, we reveal that RBM5 functions through a noncanonical transcriptional regulation circuitry rather than RNA splicing, such an effect depending on DNA-binding domains. By integrative analysis and functional assays, we identify HOXA9 as the downstream target of RBM5. Ectopic expression of HOXA9 rescues impaired leukemia cell proliferation upon RBM5 loss. Importantly, acute protein degradation of RBM5 through auxin-inducible degron system immediately reduces HOXA9 transcription. Conclusions: We identify RBM5 as a new upstream regulator of HOXA9 and reveal its essential role in controlling the survival of AML. These functional and molecular mechanisms further support RBM5 as a promising therapeutic target for myeloid leukemia treatment. Keywords: Acute myeloid leukemia; CRISPR screen; Genome editing; HOXA9; RBM5.
Project description:RBM5 and RBM10 are RNA-binding proteins and splicing regulators. These two proteins are putative paralogs in mammalian cells, sharing common domain organization and extensive protein sequence similarity, but their RNA-binding preferences differ. We developed a sensitive system to identify splicing events regulated by RBM5 and/or RBM10, deleting all RBM5 alleles in 293Flp-In cells, and reducing the expression of RBM10, which is partially rescued by activation of a cryptic exon (CE) in one of the RBM10 alleles. RBM5 or RBM10 transgenes were then introduced in these RBM5-null, RBM10 mutant cells (RBM5-/-;RBM10-/CE), allowing controlled protein expression, induced with Doxycycline. Using this system we identify thousands of RBM5 and RBM10-regulated cassette exons, and note a substantial overlap between the two sets.
Project description:RBM5, a regulator of alternative splicing of apoptotic genes, and its close homologues, RBM6 and RBM10, are RNA binding proteins frequently deleted or mutated in lung cancer. We report that RBM5/6 and RBM10 antagonistically regulate the proliferative capacity of cancer cells and display distinct positional effects in alternative splicing regulation. We identify the Notch pathway regulator NUMB as a key target of these factors in the control of cell proliferation. NUMB alternative splicing, which is frequently altered in lung cancer, can regulate colony and xenograft tumor formation and its modulation recapitulates or antagonizes the effects of RBM5, 6 and 10 in cell colony formation. RBM10 mutations identified in lung cancer cells disrupt NUMB splicing regulation to promote cell growth. Our results reveal a key genetic circuit in the control of cancer cell proliferation. CLIP-Seq analysis of RBM5, RBM6 and RBM10, with 2 biological replicates and one non-specific control for each protein.
Project description:RBM5, a regulator of alternative splicing of apoptotic genes, and its close homologues, RBM6 and RBM10, are RNA binding proteins frequently deleted or mutated in lung cancer. We report that RBM5/6 and RBM10 antagonistically regulate the proliferative capacity of cancer cells and display distinct positional effects in alternative splicing regulation. We identify the Notch pathway regulator NUMB as a key target of these factors in the control of cell proliferation. NUMB alternative splicing, which is frequently altered in lung cancer, can regulate colony and xenograft tumor formation and its modulation recapitulates or antagonizes the effects of RBM5, 6 and 10 in cell colony formation. RBM10 mutations identified in lung cancer cells disrupt NUMB splicing regulation to promote cell growth. Our results reveal a key genetic circuit in the control of cancer cell proliferation. RNA from 3 biological replicates of knockdowns of RBM5, 6 and 10 and a control set were used. Changes between the control and knockdowns were measured based on using a splice-junction array (Affymetrix HJAY).