Influence of IWS1 TND-interacting motifs (TIMs) on chromatin localization patterns [ChIP-seq]
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ABSTRACT: To reveal the influence of TND-interacting motifs (TIMs), which bind TFIIS N-terminal domains (TNDs), we prepared KELLY cells expressing either wild-type IWS1-FLAG or IWS1-FLAG containing disruptive mutations in the unstructured TIM3 region. Following lentiviral transduction of either WT or M3 IWS1-FLAG, we performed ChIP using anti-FLAG antibodies from these samples and performed chromatin occupancy profiling using ChIP-seq. Analysis of locations reveal that both WT and M3 samples are highly enriched in at transcribed gene bodies.
Project description:To reveal the influence of TND-interacting motifs (TIMs), which bind TFIIS N-terminal domains (TNDs), we prepared KELLY cells expressing either wild-type IWS1-FLAG or IWS1-FLAG containing disruptive mutations in the unstructured TIM3 region. Following lentiviral transduction of either WT or M3 IWS1-FLAG, we prepared mRNA from these samples and performed expression profiling using RNA-seq. Analysis of differential gene expression provided markers that are differentially regulated by TIM3 of IWS1.
Project description:To reveal the influence of TND-interacting motifs (TIMs), which bind TFIIS N-terminal domains (TNDs), we prepared KELLY cells expressing either wild-type IWS1-FLAG or IWS1-FLAG containing disruptive mutations in the unstructured TIM3 region. Following lentiviral transduction of either WT or M3 IWS1-FLAG, we prepared PRO-seq libraries from these samples and examined elongation profiles. Analysis of elongation profiles revealed that TIM3 disruption induces pervasive defects of transcription elongation.
Project description:Toxoplasma gondii secretes various virulence effector molecules into host cells to disrupt host interferon-γ (IFN-γ)-dependent immunity. Among the effectors, ROP18 directly phosphorylates and inactivates IFN-inducible GTPases, such as immunity-related GTPases (IRGs) and guanylate-binding proteins (GBPs), leading to subversion of IFN-inducible GTPase-induced cell-autonomous immunity. The modes of action of ROP18 have been studied extensively; however, little is known about the molecular mechanism of how ROP18 is produced in the parasite itself. Here, we report a role of T. gondii transcription factor IWS1 in ROP18 mRNA expression in the parasite. Compared with wild-type virulent type I T. gondii, IWS1-deficient parasites showed dramatically increased loading of IRGs and GBPs onto the parasitophorous vacuole membrane (PVM). Moreover, IWS1-deficient parasites displayed decreased virulence in wild-type mice but retained normal virulence in mice lacking the IFN-γ receptor. Furthermore, IWS1-deficient parasites showed severely decreased ROP18 mRNA expression. Ectopic expression of ROP18 in IWS1-deficient parasites restored the decreased loading of effectors onto the PVM and in vivo virulence in wild-type mice. Taken together, these data demonstrate that T. gondii IWS1 regulates ROP18 mRNA expression to determine fitness in IFN-γ-activated host cells and mice.
Project description:Known pyrophosphorylation substrates NOLC1, TCOF1, IWS1 were overexpressed in IP6K1-/- double KO HEK293T cells, along with active WT or kinase-dead IP6K1 i.e. background high or low in inositol pyrophosphates. the three proteins were pulled down via their SFB-tag and submitted to a pyrophosphoproteomics workflow. This was to demonstrate the dependence of pyrophosphorylation on PP-InsPs.
Project description:Spn1/Iws1 is an essential eukaryotic transcription elongation factor that is conserved from yeast to humans. Several studies have shown that Spn1 functions as a histone chaperone to control transcription, RNA splicing, genome stability, and histone modifications as an integral member of the RNA polymerase II elongation complex. However, the precise role of Spn1 is not understood, and there is little understanding of why it is essential for viability. To address these issues, we have isolated eight suppressor mutations that bypass the essential requirement for Spn1 in Saccharomyces cerevisiae. Unexpectedly, the suppressors identify several functionally distinct complexes and activities, including the histone chaperone FACT, the histone methyltransferase Set2, the Rpd3S histone deacetylase complex, the histone acetyltransferase Rtt109, the nucleosome remodeler Chd1, and a member of the SAGA co-activator complex, Sgf73. The identification of these distinct groups and their analysis suggests that there are multiple mechanisms by which Spn1 bypass can occur, including changes in histone acetylation and alterations of other histone chaperones. Thus, Spn1 may participate in multiple functions during transcription. Our results suggest that bypass of a subset of these functions allows viability in the absence of Spn1.