Project description:Interventions: Case series:None
Primary outcome(s): exon genes;transcriptional expression;proteome;protein phosphorylation group
Study Design: Sequential
Project description:Dynamic post-translational modification of RNA polymerase II (RNAPII) coordinates the co-transcriptional recruitment of enzymatic complexes that regulate chromatin states and co-transcriptional processing of nascent RNA. Extensive phosphorylation of serine residues occurs at the structurally-disordered C-terminal domain (CTD) of the largest RNAPII subunit, which is composed of multiple heptapeptide repeats with consensus sequence Y1-S2-P3-T4-S5-P6-S7. Serine-5 and Serine-7 phosphorylation mark transcription initiation, whereas Serine-2 phosphorylation coincides with productive elongation. In vertebrates, the CTD has eight non-canonical substitutions of Serine-7 into Lysine-7, which can be acetylated (K7ac). Here, we describe for the first time mono- and di-methylation of CTD Lysine-7 residues (K7me1 and K7me2). K7me1 and K7me2 are observed during the earliest transcription stages and precede or accompany Serine-5 and Serine-7 phosphorylation. Genome wide mapping of 2 novel RNAPII post-translational modifications (CTD-K7me1 and CTD-K7me2) in mouse ES cells.
Project description:<p> Human disorders of mitochondrial oxidative phosphorylation (OXPHOS) represent a devastating collection of inherited diseases. These disorders impact at least 1:5000 live births, and are characterized by multi-organ system involvement. They are characterized by remarkable locus heterogeneity, with mutations in the mtDNA as well as in over 77 nuclear genes identified to date. It is estimated that additional genes may be mutated in these disorders. </p> <p>To discover the genetic causes of mitochondrial OXPHOS diseases, we performed targeted, deep sequencing of the entire mitochondrial genome (mtDNA) and the coding exons of over 1000 nuclear genes encoding the mitochondrial proteome. We applied this 'MitoExome' sequencing to 124 unrelated patients with a wide range of OXPHOS disease presentations from the Massachusetts General Hospital Mitochondrial Disorders Clinic. </p> <p>The 2.3Mb targeted region was captured by hybrid selection and Illumina sequenced with paired 76bp reads. The total set of 1605 targeted nuclear genes included 1013 genes with strong evidence of mitochondrial localization from the MitoCarta database, 377 genes with weaker evidence of mitochondrial localization from the MitoP2 database and other sources, and 215 genes known to cause other inborn errors of metabolism. Approximately 88% of targeted bases were well-covered (>20X), with mean 200X coverage per targeted base. </p>
Project description:Here we report systems-wide identification of serine ADP-ribosylation sites and quantification of their cellular changes in human cells upon oxidative stress. High-resolution mass spectrometry and unrestricted data processing confirmed that serine residues are the major target of ADP-ribosylation in HeLa cells. Proteome-wide analyses identified 3,090 serine ADP-ribosylation sites, with 97 percent of acceptor sites modulated more than 2-fold upon oxidative stress, while treatment with PARP inhibitor Olaparib abrogates induction (part 1, ADP-ribosylation data, PXD009208). Consistent with the nuclear expression of ARTD1/PARP1 and ARTD2/PARP2, serine ADP-ribosylation prominently occurred on nuclear proteins. Structural-predictive analyses revealed that serine ADP-ribosylation preferentially resides in disordered regions, and identified serine ADP-ribosylation sites to significantly overlap with known phosphorylation sites. Large-scale phosphoproteomics analysis supported these observations (part 2, phosphorylation data), hereby providing first evidence for site-specific crosstalk between serine ADP-ribosylation and phosphorylation. Collectively, we demonstrate that serine ADP-ribosylation is a widespread modification and a major nuclear responder to oxidative stress, and that its regulatory scope is comparable to other posttranslational modifications.
Project description:RNA Polymerase II transcribes protein-coding and many non-coding RNA genes in eukaryotes. The largest subunit of RNA Polymerase II, Rpb1, contains a hepta-peptide repeat on its C-terminal tail with three potential phosphorylation sites (Serine 2, Serine 5 and Serine 7). Mammalian Rpb1 contains 52 repeats. The phosphorylation events are catalyzed by specific protein kinases where the phosphorylation of specific residues is coupled to the transcription cycle. For example, the Cdk7 subunit of TFIIH phosphorylates both Serine 5 and Serine 7 during intiation and the Cdk9 subunit of P-TEFb phosphorylates Serine 2 during the transition into productive elongation. The dataset presented here is the genome-wide distribution of RNA Pol II with Serine 7 of the CTD phosphorylated in murine embryonic stem cells. This data, in addition to phospho-specific datasets generated in the same cell type in Rahl et al. Cell 2010 and Seila et al. Science 2008, represents the genome-wide distribution of multiple RNA Pol II isoforms in murine embryonic stem cells: total Pol II, hypophosphorylated CTD Pol II, Serine 2 phosphorylated CTD Pol II, Serine 5 phosphorylated CTD Pol II and Serine 7 phosphorylated CTD Pol II. An antibody specific to RNA Pol II Serine 7 phosphorylated CTD (gift of Dirk Eick; Chapman et al. Science 2008) was used to enrich for DNA fragments associated with this Pol II isoform in murine embryonic stem cells. DNA was purified and prepared for Illumina/Solexa sequencing following their standard protocol. This is a single dataset but together with datasets from Rahl et al. Cell 2010 and Seila et al. Science 2008, these datasets represent the genome-wide distribution of multiple RNA Pol II isoforms in murine embryonic stem cells: total Pol II, hypophosphorylated CTD Pol II, Serine 2 phosphorylated CTD Pol II, Serine 5 phosphorylated CTD Pol II and Serine 7 phosphorylated CTD Pol II.
Project description:Autism spectrum disorders such as Rett syndrome (RTT) have been hypothesized to arise from defects in experience-dependent synapse maturation. RTT is caused by mutations in MECP2, a nuclear protein that becomes phosphorylated at S421 in response to neuronal activation. We show here that disruption of MeCP2 S421 phosphorylation in vivo results in defects in synapse development and behavior, implicating activity-dependent regulation of MeCP2 in brain development and RTT. We investigated the mechanism by which S421 phosphorylation regulates MeCP2 function and show by chromatin immunoprecipitation-sequencing that this modification occurs on MeCP2 bound across the genome. The phosphorylation of MeCP2 S421 appears not to regulate the expression of specific genes; rather, MeCP2 functions as a histone-like factor whose phosphorylation may facilitateM-CM-^BM-BM- a genome-wide response of chromatin to neuronal activity during nervous system development. We propose that RTT results in part from a loss of this experience-dependent chromatin remodeling. To examine MeCP2 binding across the neuronal genome and where on the genome MeCP2 is phosphorylated at Serine 421 in response to neuronal activity we performed anti-total MeCP2 and anti-phospho-Serine 421 specific Chromatin immunoprecipitation from cultured cortical neurons that were either left unstimulated or membrane depolarized for 2 hours by addition of 55mM KCl to the media. ChIP DNA was verified for successful IP by qPCR then cloned and sequenced using ABI SOLiD system 4. ChIP was performed from E16 +7DIV disociated cortical cultures from one or two independent dissections using an anti-c-terminal antiserum recognizing MeCP2 independent of its phosphorylation state or with an anti-pS421 antiserum that specifically immunoprecipitates MeCP2 phosphorylated at serine 421. Samples were qPCR validated and sequenced using ABI SOLiD system 4 library preparation and sequencing.
Project description:ADP-ribosylation (ADPr) is a reversible posttranslational modification involved in a range of cellular processes. Here, we report system-wide identification of serine ADPr in human cells upon oxidative stress. High-resolution mass spectrometry and unrestricted data processing confirm that serine residues are the major target of ADPr in HeLa cells. Proteome-wide analysis identifies 3,090 serine ADPr sites, with 97% of acceptor sites modulating more than 2-fold upon oxidative stress, while treatment with the poly (ADP-ribose) polymerase (PARP) inhibitor olaparib abrogates this induction. Serine ADPr predominantly targets nuclear proteins, while structural-predictive analyses reveal that serine ADPr preferentially targets disordered protein regions. The identified ADP-ribosylated serines significantly overlap with known phosphorylated serines, and large-scale phosphoproteomics analysis provides evidence for the site-specific crosstalk between serine ADPr and phosphorylation. Collectively, we demonstrate that serine ADPr is a widespread modification and a major nuclear signaling response to oxidative stress, with a regulatory scope comparable to other extensive posttranslational modifications - Part 1, ADP-ribosylation data.
Project description:Transcriptional elongation by RNA polymerase II (Pol II) is regulated by positive transcription elongation factor b (P-TEFb) in association with Bromodomain-containing protein 4 (BRD4). We used genome-wide chromatin immunoprecipitation sequencing in primary human CD4+ T cells to reveal that BRD4 co-localizes with Ser2-phosphorylated Pol II (Pol II Ser2) at both enhancers and promoters of active genes. Disruption of bromodomain:histone acetylation interactions by JQ1, a small-molecule bromodomain inhibitor, resulted in decreased BRD4 binding, reduced Pol II Ser2, and reduced expression of lineage-specific genes in primary human CD4+ T cells. A large number of JQ1-disrupted BRD4 binding regions exhibited di-acetylated H4 (lysine-5 and -8) and H3K27 acetylation (H3K27ac), which correlated with the presence of histone acetyltransferases and deacetylases. Genes associated with BRD4/H3K27ac co-occupancy exhibited significantly higher activity than those associated with H3K27ac or BRD4 binding alone. Comparison of BRD4 binding in T cells and in human embryonic stem cells revealed that enhancer BRD4 binding sites were predominantly lineage-specific. Our findings suggest that BRD4-driven Pol II phosphorylation at serine 2 plays an important role in regulating lineage-specific gene transcription in human CD4+ T cells. Examination of BRD4, total Pol II, serine 2 phosphorylated Pol II and serine 5 phosphorylated Pol II binding in CD4+ T cells (with and without JQ1 treatment) and BRD4 binding in human embryonic stems cell; PolyA RNA expression in CD4+ T cells( with and without JQ1 treatment) using RNA-seq
Project description:RNA Polymerase II transcribes protein-coding and many non-coding RNA genes in eukaryotes. The largest subunit of RNA Polymerase II, Rpb1, contains a hepta-peptide repeat on its C-terminal tail with three potential phosphorylation sites (Serine 2, Serine 5 and Serine 7). Mammalian Rpb1 contains 52 repeats. The phosphorylation events are catalyzed by specific protein kinases where the phosphorylation of specific residues is coupled to the transcription cycle. For example, the Cdk7 subunit of TFIIH phosphorylates both Serine 5 and Serine 7 during intiation and the Cdk9 subunit of P-TEFb phosphorylates Serine 2 during the transition into productive elongation. The dataset presented here is the genome-wide distribution of RNA Pol II with Serine 7 of the CTD phosphorylated in murine embryonic stem cells. This data, in addition to phospho-specific datasets generated in the same cell type in Rahl et al. Cell 2010 and Seila et al. Science 2008, represents the genome-wide distribution of multiple RNA Pol II isoforms in murine embryonic stem cells: total Pol II, hypophosphorylated CTD Pol II, Serine 2 phosphorylated CTD Pol II, Serine 5 phosphorylated CTD Pol II and Serine 7 phosphorylated CTD Pol II.
Project description:Post-translational regulation of the MYC Transcription Factor (TF), including its phosphorylation and ubiquitination, plays an important role in determining cell proliferation and apoptosis and has been implicated in tumorigenesis. Using a computational systems biology approach, followed by biochemical and functional validation, we have characterized the role of the STK38 kinase, an NDR family serine-threonine kinase, as a key modulator of MYC transcriptional activity in human B cells, affecting MYC protein stability in a signal-dependent fashion. Specifically, we show that in human B lymphoma ST486 cells STK38 is a key mediator of BCR pathway signaling, affecting MYC protein turnover and its phosphorylation at Ser62 in kinase-activity-dependent manner. STK38 inactivation abrogates apoptosis following BCR activation while its silencing mediates MYC protein degradation via canonical proteolytic pathways. This suggests that STK38 could provide an effective therapeutic target in MYC-dependent malignancies. ST486 human Burkitt's lymphoma cells were transduced with STK38 shRNA lentiviral vectors.