Project description:LincRNA-EPS is a long noncoding RNA that is expressed in macrophages and downregulated upon exposure to diverse microbial products. Analysis of macrophages from lincRNA-EPS-deficient mice revealed a specific role for this lincRNA in restraining immune response gene (IRG) expression. Mechanistically, lincRNA-EPS associates with chromatin at regulatory regions of IRGs to repress their transcription. To gain insight into the molecular function of lincRNA-EPS on chromatin, we generated ATAC-Seq libraries from wildtype and lincRNA-EPS-deficient macrophages stimulated with LPS.
Project description:An inducible program of inflammatory gene expression is central to antimicrobial defenses. This response is controlled by a collaboration involving signal-dependent activation of transcription factors, transcriptional co-regulators, and chromatin-modifying factors. We have identified a long noncoding RNA (lncRNA) that acts as a key regulator of this inflammatory response. Pattern recognition receptors such as the Toll-like receptors induce the expression of numerous lncRNAs. One of these, lincRNA-Cox2, mediates both the activation and repression of distinct classes of immune genes. Transcriptional repression of target genes is dependent on interactions of lincRNA-Cox2 with heterogeneous nuclear ribonucleoprotein A/B and A2/B1. Collectively, these studies unveil a central role of lincRNA-Cox2 as a broad-acting regulatory component of the circuit that controls the inflammatory response
Project description:Long noncoding RNA (lncRNA) refers to the family of RNA transcripts with more than 200 nucleotides in length, but cannot encode proteins. lincRNA (long intergenic noncoding RNA) is a subset of lncRNA that do not overlap with known genes. Increasing evidences have shown that some of these transcripts do in fact contain open reading frames (ORFs) to code short peptides, and do have significant functional roles within the cells. However, many of these peptides remain unannotated and uncharacterized. This study proposes a workflow integrating proteomics, transcriptomics and bioinformatics specifically for lincRNA-encoded peptide discovery. The workflow was tested on the mouse kidney inner medulla (IM), a region that contains the collecting duct system responsible for regulated water transport. In brief, short peptides (from 2 to 20 kDa) were enriched by tricine protein gel and in-gel trypsinized into peptides, then analyzed using high resolution mass spectrometry. However, to match mass fragment ion spectra to peptide sequences requires a reference peptide sequence database which are not available for the noncoding transcripts, and must be generated de novo in the sample of interest. We modified the RNA-Seq mapping workflow by filtering out coding reads first to better quantitate the noncoding transcript expressions. Also, a rule-based ORF prediction was implemented to select one best predicted ORF per noncoding transcript to construct the peptide library. Candidates were further evaluated using several quality control criteria and bioinformatics tools. Three candidates, conserved in rat and human, passed all criteria, maybe truly novel coding genes. In summary, we present a workflow based on the modern transcriptomics and proteomics technologies for lincRNA-encoded peptide discovery. A computational challenge is to generate a hypothetical lincRNA-encoded peptide database for peptide-mass spectra matching. With this workflow, we discovered three previously unannotated peptides in the mouse kidney inner medulla. The same workflow can be applied in any cell or tissue type of interest to quickly advance this research field.
Project description:The p53-regulated long non-coding RNA, lincRNA-p21, has been proposed to promote apoptosis and to repress in trans the expression of genes in the p53 transcriptional network. Here, we report the generation of a conditional knockout mouse model developed to further examine lincRNA-p21 function. Using this genetic approach, we find that the primary function of lincRNA-p21 is to activate in cis the expression of its neighboring gene, the cyclin-dependent kinase inhibitor p21. Mechanistically, we show that lincRNA-p21 acts in concert with hnRNP-K as a co-activator for p53-dependent transcription of p21. Additional phenotypes of lincRNA-p21 deficiency, including deregulated expression and altered chromatin state of a set of Polycomb target genes, defective G1/S checkpoint, increased proliferation rates, and enhanced reprogramming efficiency could be attributed to diminished p21 levels. This study reveals a novel paradigm, whereby the long non-coding RNA lincRNA-p21 affects global gene expression and influences events in the p53 tumor suppressor pathway by acting in cis as a locus-restricted transcriptional co-activator for p53-mediated expression of p21. Examination of 2 different histone modifications (H3K4me3 and H3K27me3) in 2 cell types (WT and lincRNA-p21 KO) in the presence and absence of Doxorubicin.
Project description:The p53-regulated long non-coding RNA, lincRNA-p21, has been proposed to promote apoptosis and to repress in trans the expression of genes in the p53 transcriptional network. Here, we report the generation of a conditional knockout mouse model developed to further examine lincRNA-p21 function. Using this genetic approach, we find that the primary function of lincRNA-p21 is to activate in cis the expression of its neighboring gene, the cyclin-dependent kinase inhibitor p21. Mechanistically, we show that lincRNA-p21 acts in concert with hnRNP-K as a co-activator for p53-dependent transcription of p21. Additional phenotypes of lincRNA-p21 deficiency, including deregulated expression and altered chromatin state of a set of Polycomb target genes, defective G1/S checkpoint, increased proliferation rates, and enhanced reprogramming efficiency could be attributed to diminished p21 levels. This study reveals a novel paradigm, whereby the long non-coding RNA lincRNA-p21 affects global gene expression and influences events in the p53 tumor suppressor pathway by acting in cis as a locus-restricted transcriptional co-activator for p53-mediated expression of p21. mRNAseq in 2 cell types (WT and lincRNA-p21 KO) in the presence and absence of Doxorubicin performed in biological triplicate.
Project description:The p53-regulated long non-coding RNA, lincRNA-p21, has been proposed to promote apoptosis and to repress in trans the expression of genes in the p53 transcriptional network. Here, we report the generation of a conditional knockout mouse model developed to further examine lincRNA-p21 function. Using this genetic approach, we find that the primary function of lincRNA-p21 is to activate in cis the expression of its neighboring gene, the cyclin-dependent kinase inhibitor p21. Mechanistically, we show that lincRNA-p21 acts in concert with hnRNP-K as a co-activator for p53-dependent transcription of p21. Additional phenotypes of lincRNA-p21 deficiency, including deregulated expression and altered chromatin state of a set of Polycomb target genes, defective G1/S checkpoint, increased proliferation rates, and enhanced reprogramming efficiency could be attributed to diminished p21 levels. This study reveals a novel paradigm, whereby the long non-coding RNA lincRNA-p21 affects global gene expression and influences events in the p53 tumor suppressor pathway by acting in cis as a locus-restricted transcriptional co-activator for p53-mediated expression of p21.
Project description:The p53-regulated long non-coding RNA, lincRNA-p21, has been proposed to promote apoptosis and to repress in trans the expression of genes in the p53 transcriptional network. Here, we report the generation of a conditional knockout mouse model developed to further examine lincRNA-p21 function. Using this genetic approach, we find that the primary function of lincRNA-p21 is to activate in cis the expression of its neighboring gene, the cyclin-dependent kinase inhibitor p21. Mechanistically, we show that lincRNA-p21 acts in concert with hnRNP-K as a co-activator for p53-dependent transcription of p21. Additional phenotypes of lincRNA-p21 deficiency, including deregulated expression and altered chromatin state of a set of Polycomb target genes, defective G1/S checkpoint, increased proliferation rates, and enhanced reprogramming efficiency could be attributed to diminished p21 levels. This study reveals a novel paradigm, whereby the long non-coding RNA lincRNA-p21 affects global gene expression and influences events in the p53 tumor suppressor pathway by acting in cis as a locus-restricted transcriptional co-activator for p53-mediated expression of p21.