Project description:We developed RBS-ID, which greatly simplifies the RNA moiety by chemical cleavage, reducing the complexity of MS/MS search space to accurately identify and localize RBS in peptides. RBS-ID comprehensively and robustly identifies RNA-binding sites at both proteome and single protein level.
Project description:Roberts syndrome (RBS) is a human developmental disorder caused by mutations in the cohesin acetyltransferase ESCO2. We previously reported that mTORC1 was inhibited and overall translation was reduced in RBS cells. Treatment of RBS cells with L-leucine partially rescued mTOR function and protein synthesis, correlating with increased cell division. In this study, we use RBS as a model for mTOR inhibition and analyze transcription and translation with ribosome profiling to determine genome-wide effects of L-leucine. The translational efficiency of many genes is increased with Lleucine in RBS cells including genes involved in ribosome biogenesis, translation, and mitochondrial function. snoRNAs are strongly upregulated in RBS cells, but decreased with L-leucine. Imprinted genes, including H19 and GTL2, are differentially expressed in RBS cells consistent with contribution to mTORC1 control. This study reveals dramatic effects of L-leucine stimulation of mTORC1 and supports that ESCO2 function is required for normal gene expression and translation.
Project description:Roberts syndrome (RBS) is a human developmental disorder caused by mutations in the cohesin acetyltransferase ESCO2. We previously reported that mTORC1 was inhibited and overall translation was reduced in RBS cells. Treatment of RBS cells with L-leucine partially rescued mTOR function and protein synthesis, correlating with increased cell division. In this study, we use RBS as a model for mTOR inhibition and analyze transcription and translation with ribosome profiling to determine genome-wide effects of L-leucine. The translational efficiency of many genes is increased with Lleucine in RBS cells including genes involved in ribosome biogenesis, translation, and mitochondrial function. snoRNAs are strongly upregulated in RBS cells, but decreased with L-leucine. Imprinted genes, including H19 and GTL2, are differentially expressed in RBS cells consistent with contribution to mTORC1 control. This study reveals dramatic effects of L-leucine stimulation of mTORC1 and supports that ESCO2 function is required for normal gene expression and translation. 42 samples of human fibroblast cell lines with various genotypes (wt, corrected, and esco2 mutants) are treated with l-leucine or d-leucine (control) for 3 or 24 hours. Biological replicates are present.
Project description:Peripheral sensory neurons are a critical part of the nervous system that transmit a multitude of sensory stimuli to the central nervous system. During larval and juvenile stages in zebrafish, this function is mediated by Rohon-Beard somatosensory neurons (RBs). RBs are optically accessible and amenable to experimental manipulation, making them a powerful system for mechanistic investigation of sensory neurons. Previous studies provided evidence that RBs fall into multiple subclasses; however, the number and molecular make up of these potential RB subtypes have not been well defined. Using a single-cell RNA sequencing (scRNA-seq) approach, we demonstrate that larval RBs in zebrafish fall into three, largely non-overlapping classes of neurons. We also show that RBs are molecularly distinct from trigeminal neurons in zebrafish. Cross-species transcriptional analysis indicates that one RB subclass is similar to a mammalian group of A-fiber sensory neurons. Another RB subclass is predicted to sense multiple modalities, including mechanical stimulation and chemical irritants. We leveraged our scRNA-seq data to determine that the fibroblast growth factor (Fgf) pathway is active in RBs. Pharmacological and genetic inhibition of this pathway led to defects in axon maintenance and RB cell death. Moreover, this phenotype can be phenocopied by treatment with an FDA-approved Fgf inhibitor dovitinib, which is used in clinic and causes peripheral neuropathy. Importantly, dovitinib-mediated axon loss can be suppressed by loss of Sarm1, a positive regulator of neuronal cell death and axonal injury. This offers a molecular target for future clinical intervention to fight neurotoxic effects of this drug.
Project description:Peripheral sensory neurons are a critical part of the nervous system that transmit a multitude of sensory stimuli to the central nervous system. During larval and juvenile stages in zebrafish, this function is mediated by Rohon-Beard somatosensory neurons (RBs). RBs are optically accessible and amenable to experimental manipulation, making them a powerful system for mechanistic investigation of sensory neurons. Previous studies provided evidence that RBs fall into multiple subclasses; however, the number and molecular make up of these potential RB subtypes have not been well defined. Using a single-cell RNA sequencing (scRNA-seq) approach, we demonstrate that larval RBs in zebrafish fall into three, largely non-overlapping classes of neurons. We also show that RBs are molecularly distinct from trigeminal neurons in zebrafish. Cross-species transcriptional analysis indicates that one RB subclass is similar to a mammalian group of A-fiber sensory neurons. Another RB subclass is predicted to sense multiple modalities, including mechanical stimulation and chemical irritants. We leveraged our scRNA-seq data to determine that the fibroblast growth factor (Fgf) pathway is active in RBs. Pharmacological and genetic inhibition of this pathway led to defects in axon maintenance and RB cell death. Moreover, this phenotype can be phenocopied by treatment with an FDA-approved Fgf inhibitor dovitinib, which is used in clinic and causes peripheral neuropathy. Importantly, dovitinib-mediated axon loss can be suppressed by loss of Sarm1, a positive regulator of neuronal cell death and axonal injury. This offers a molecular target for future clinical intervention to fight neurotoxic effects of this drug.
2024-03-01 | GSE240721 | GEO
Project description:RBS high-throughput sequencing raw data
Project description:Our study in zebrafish is the first to use an animal model to understand the biology of the developmental disorder Roberts Syndrome (RBS). RBS is caused by mutations in the ESCO2 gene. We have used morpholinos (MO) to knock down esco2 in zebrafish to better understand the pathology of this rare human syndrome. Our zebrafish model nicely phenocopies the developmental defects observed in RBS.
Project description:Here we use bisulfite conversion of RNA combined with high-throughput IIlumina sequencing (RBS-seq) to identify single-nucleotide resolution of m5C sites in ribosomal RNAs of all three sub-cellular transcriptomes in Arabidopsis thaliana. m5C sites in rRNAs were also anlyzed in Arabidopsis T-DNA knockouts for the RNA methyltransferases TRM4A, TRM4B, TRDMT1, NSUN5, NOP2A, NOP2B and NOP2C.
Project description:Here we use bisulfite conversion of rRNA depleted RNA combined with high-throughput Illumina sequencing (RBS-seq) to identify single-nucleotide resolution of m5C sites transcriptome-wide in Arabidopsis thaliana siliques. m5C sites were also analyzed in an Arabidopsis T-DNA knockout for the RNA methyltransferase TRM4B.
Project description:Both prokaryotic and eukaryotic organisms take deterministic decisions to reprogram cell fates. A macroscopic manifestation of such an event is the remodelling of the cellsâ morphology and it typically is governed at the molecular scale by massive reorganization of the cellular transcriptome. With the regulation at the level of transcription initiation representing the most common form for such developmental reprogramming, cells typically rely on one or several master regulators to coordinate the the activity of hundreds of genes simultaneously by directly binding to their promoters. Despite the apparent simplicity of prokaryotes and their reduced genome size compared to that of their eukaryotic counterparts, free-living bacteria typically encode hundreds of transcription factors (TFs) in their genomes that could act as master TFs. By contrast, obligate intracellular bacteria such as Chlamydiae have a drastically reduced genome due to their intimate association with the host and thus a smaller number of TF genes. The genomes of members of the Chlamydiaceae family, which include the well-known bacterial pathogens Chlamydia trachomatis and Chlamydia pneumoniae, are only 1-1.2 Mbp. By contrast, members of the environmental Chlamydiae Waddlia chondrophila and Parachlamydia acanthamoebae have a 2-fold and 3-fold larger genome, respectively, likely allowing for an expansion of the host range while still retaining their host dependence and parasitic life style. Moreover, they all exhibit a characteristic chlamydial developmental cycle via two functionally specialized morphotypes, the infectious non-dividing elementary bodies (EBs) and the non-infectious dividing reticulate bodies (RBs). This developmental cycle is usually divided in three stages: the early stage during which EBs enter host cells and differentiate into RBs; the mid-stage where RBs proliferate inside a vacuole called inclusion and the late stage where RBs differentiate back into EBs and are released after exocytosis or cell lysis. Chlamydial genes are thus classified into three different temporal classes (early, mid and late expressed genes), likely reflecting the need of these transcripts in each of the three developmental stages. W. chondrophila, an emerging pathogen implicated in abortion in bovine and miscarriage in humans, encodes less than 20 TFs, 10 of which are conserved among the Chlamydiae. In light of this low TF multiplicity in the chlamydial pan-genome along with the common developmental cycle and parasitic life style, we aimed to define the regulatory pan-genome of each these conserved TFs to identify the elusive chlamydial master regulator and to characterize underling specificity for its target promoters using chromatin-immunoprecipitation followed by deep-sequencing (ChIP-Seq) of chlamydial cells growing inside the host. The immunochemistry of ChIP-Seq has the advantage of minimizing the contaminating nucleic acids compared to chlamydial transcriptome studies, it has the added benefit of providing the first unambiguous glimpse into the regulatory landscape of a bacterium inside host, offering a solid framework in understanding the stochastic and/or deterministic switches that bacteria rely on during infections. Examination of the regulatory network of an intracellular pathogen