Project description:We identified a novel muscle-specific lncRNA, lncFAM71E1-2:2 (lncFAM), which increased robustly during early human myogenesis. Overexpression of lncFAM promoted differentiation of human myoblasts into myotubes, while silencing lncFAM suppressed this process. A nucleus-resident lncRNA, lncFAM was studied using chromatin isolation by RNA purification followed by mass spectrometry (ChIRP-ms) analysis to identify the molecular mechanisms whereby it might promote myogenesis. Analysis of lncFAM-interacting proteins revealed that lncFAM recruited the RNA-binding protein HNRNPL to the promoter of MYPBPC2, in turn increasing MYBPC2 mRNA transcription and enhancing production of the myogenic protein MYPBPC2. These results highlight a mechanism whereby a novel ribonucleoprotein complex, lncFAM-HNRNPL promotes MYBPC2 expression transcriptionally to increase myogenesis.
Project description:We identified a novel muscle-specific lncRNA, lncFAM71E1-2:2 (lncFAM), which increased robustly during early human myogenesis. Overexpression of lncFAM promoted differentiation of human myoblasts into myotubes, while silencing lncFAM suppressed this process. A nucleus-resident lncRNA, lncFAMwas studied using chromatin isolation by RNA purification followed by mass spectrometry (ChIRP-ms) analysis to identify the molecular mechanisms whereby it might promote myogenesis. Analysis of lncFAM-interacting proteins revealed that lncFAM recruited the RNA-binding protein HNRNPL to the promoter of MYPBPC2, in turn increasing MYBPC2 mRNA transcription and enhancing production of the myogenic protein MYPBPC2. These results highlight a mechanism whereby a novel ribonucleoprotein complex, lncFAM-HNRNPL promotes MYBPC2 expression transcriptionally to increase myogenesis
Project description:The mammalian transcriptome comprises a vast family of long noncoding (lnc)RNAs implicated in physiologic processes such as myogenesis, through which muscle forms during embryonic development and regenerates in the adult. However, the specific molecular mechanisms by which lncRNAs regulate human myogenesis are poorly understood. Here, we identified a novel muscle-specific lncRNA, lncFAM71E1-2:2 (lncFAM), which increased robustly during early human myogenesis. Overexpression of lncFAM promoted differentiation of human myoblasts into myotubes, while silencing lncFAM suppressed this process. As lncFAM resides in the nucleus, chromatin isolation by RNA purification followed by mass spectrometry (ChIRP-MS) analysis was employed to identify the molecular mechanisms whereby it might promote myogenesis. Analysis of lncFAM-interacting proteins revealed that lncFAM recruited the RNA-binding protein HNRNPL to the promoter of MYBPC2, in turn increasing MYBPC2 mRNA transcription and enhancing production of the myogenic protein MYBPC2. These results highlight a mechanism whereby a novel ribonucleoprotein complex, lncFAM-HNRNPL, elevates MYBPC2 expression transcriptionally to promote myogenesis.
Project description:In the current project with aim to unequivocally characterize a novel splicing-regulatory network that proves to be a central mediator of endothelial barrier function and vascular integrity. At the core of this network is the endothelial enriched lncRNA NTRAS (annotated as RP11-354k1.1) is shown to control alternative splicing decisions in HUVECs through interplaying with splicing factor hnRNPL. Specifically, in the project we show that NTRAS sequesters the splicing factor hnRNPL through a CA dinucleotide motif, to enhance TJP1 exon 20 usage, thereby TJP1α+ isoform. In turn disrupting TJP1α+ isoform expression impaired endothelial barrier function. Collectively, this splicing-regulatory network might prove fundamental in unlocking new interventions strategic to prevent or reverse vascular leakage.
Project description:Evidence of widespread transcription at active enhancers became apparent. However, our understanding about the functions of enhancer RNAs (eRNAs) and their mechanistic roles remains incomplete. Here, we study eRNA regulation and function using skeletal myoblast differentiation as a paradigm. We provide a panoramic view of enhancer transcription and uncover reprogramming in enhancer transcription occurring during myogenic differentiation. We demonstrate the critical role of MyoD in activating eRNAs production. Results from in depth dissection of two eRNAs transcribed from super enhancers (seRNA-1 and -2) suggest that seRNAs can promote myogenic differentiation in vitro and in vivo; the induction of the seRNAs is in coordination with the activation of the neighboring genes and seRNA loss largely impairs their expression. Mechanistically, we elucidate these seRNAs specifically bind to heterogeneous nuclear ribonucleoprotein L (hnRNPL) and modulate hnRNPL binding to the target promoter. A CAAA tract on the seRNA was identified to be essential in mediating the interaction between seRNA-1 and hnRNPL. Disruption of seRNA-hnRNPL interaction attenuates Pol II and H3K36me3 deposition at the target genes, in coincidence with the reduction of their expression. Furthermore, analyses of hnRNPL binding transcriptome-wide reveals its association with eRNAs is a general phenomenon in multiple cells. Collectively, we propose that eRNA-hnRNPL interaction contributes to target mRNA activation.
Project description:Evidence of widespread transcription at active enhancers became apparent. However, our understanding about the functions of enhancer RNAs (eRNAs) and their mechanistic roles remains incomplete. Here, we study eRNA regulation and function using skeletal myoblast differentiation as a paradigm. We provide a panoramic view of enhancer transcription and uncover reprogramming in enhancer transcription occurring during myogenic differentiation. We demonstrate the critical role of MyoD in activating eRNAs production. Results from in depth dissection of two eRNAs transcribed from super enhancers (seRNA-1 and -2) suggest that seRNAs can promote myogenic differentiation in vitro and in vivo; the induction of the seRNAs is in coordination with the activation of the neighboring genes and seRNA loss largely impairs their expression. Mechanistically, we elucidate these seRNAs specifically bind to heterogeneous nuclear ribonucleoprotein L (hnRNPL) and modulate hnRNPL binding to the target promoter. A CAAA tract on the seRNA was identified to be essential in mediating the interaction between seRNA-1 and hnRNPL. Disruption of seRNA-hnRNPL interaction attenuates Pol II and H3K36me3 deposition at the target genes, in coincidence with the reduction of their expression. Furthermore, analyses of hnRNPL binding transcriptome-wide reveals its association with eRNAs is a general phenomenon in multiple cells. Collectively, we propose that eRNA-hnRNPL interaction contributes to target mRNA activation.
Project description:Evidence of widespread transcription at active enhancers became apparent. However, our understanding about the functions of enhancer RNAs (eRNAs) and their mechanistic roles remains incomplete. Here, we study eRNA regulation and function using skeletal myoblast differentiation as a paradigm. We provide a panoramic view of enhancer transcription and uncover reprogramming in enhancer transcription occurring during myogenic differentiation. We demonstrate the critical role of MyoD in activating eRNAs production. Results from in depth dissection of two eRNAs transcribed from super enhancers (seRNA-1 and -2) suggest that seRNAs can promote myogenic differentiation in vitro and in vivo; the induction of the seRNAs is in coordination with the activation of the neighboring genes and seRNA loss largely impairs their expression. Mechanistically, we elucidate these seRNAs specifically bind to heterogeneous nuclear ribonucleoprotein L (hnRNPL) and modulate hnRNPL binding to the target promoter. A CAAA tract on the seRNA was identified to be essential in mediating the interaction between seRNA-1 and hnRNPL. Disruption of seRNA-hnRNPL interaction attenuates Pol II and H3K36me3 deposition at the target genes, in coincidence with the reduction of their expression. Furthermore, analyses of hnRNPL binding transcriptome-wide reveals its association with eRNAs is a general phenomenon in multiple cells. Collectively, we propose that eRNA-hnRNPL interaction contributes to target mRNA activation.