Project description:Transcription factor partners can cooperatively bind to DNA composite elements to augment gene transcription. Here, we report a novel protein-DNA binding screening pipeline, termed Spacing Preference Identification of Composite Elements (SPICE), that can systematically predict protein binding partners and DNA motif spacing preferences. SPICE de novo predicted known composite elements, including AP1-IRF composite elements (AICE) and STAT5 tetramers, and also predicted a range of novel binding partners, including JUN-IKZF1 composite elements. We confirmed cooperative binding of JUN and IKZF1 to an upstream conserved noncoding region, CNS9, in the human IL10 gene, that contains a non-canonical IKZF1 site, and the activity of an IL10-luciferase reporter construct depended on both this site and the AP1 binding site within this composite element in primary B and T cells. Our findings reveal an unappreciated global association of IKZF1 and AP1, and establish SPICE as a valuable new pipeline for predicting novel transcription binding complexes.
Project description:The immunomodulatory (IMiD) agents, such as lenalidomide, are highly effective treatment for several B cell lymphomas but have poor efficacy in T cell lymphomas (TCLs). Here, we show that IKZF1 is a key drug target and vulnerability in lenalidomide sensitive TCL cells. However, TCLs are largely resistant and become less dependent on IKZF1. Instead, ZPF91 functions as a transcription factor (TF) and coregulates cell survival with IKZF1 in TCL cells that develop resistance to lenalidomide. Aberrant upregulation of CSNK2B, which leads to c-Jun inactivation, contributes to an enhanced TF activity of ZFP91 and suppresses immune activation triggered by lenalidomide. Although ZFP91 can be better targeted by pomalidomide compared to lenalidomide, an inefficient degradation of IKZF1 and ZFP91 widely exists among IMiD-resistance TCLs. A novel CELMoD agent CC-92480, with markedly increased potency and similar substrate selectivity, can overcome IMiD-resistance across multiple TCL subtypes by near complete degradation of IKZF1 and ZFP91.
Project description:Alterations of IKZF1, encoding the lymphoid transcription factor IKAROS, are a hallmark of high risk acute lymphoblastic leukemia (ALL), however the role of IKZF1 alterations in ALL pathogenesis is poorly understood. Here we show that in mouse models of BCR-ABL1 leukemia, Ikzf1 and Arf alterations synergistically promote the development of an aggressive lymphoid leukemia. Ikzf1 alterations were associated with acquisition of stem cell-like features, including self-renewal and increased bone marrow stromal adhesion. Rexinoid receptor agonists reversed this phenotype, in part by inducing expression of IKZF1, resulting in abrogation of adhesion and self-renewal, cell cycle arrest and attenuation of proliferation without direct cytotoxicity. Retinoids potentiated the activity of dasatinib in mouse and human BCR-ABL1 ALL, providing a new therapeutic option in IKZF1-mutated ALL. Significance: The outcome of therapy for high-risk acute lymphoblastic leukemia remains suboptimal despite contemporary chemotherapy and the advent of targeted therapeutic approaches. Recent genomic studies have identified deletions or mutations of IKZF1 as a hallmark of high-risk ALL, but an understanding of how IKZF1 alteration contribute to leukemia development are lacking. Here we show that IKZF1 alterations drive lymphoid lineage, a stem cell-like phenotype, abnormal bone marrow adhesion, and poor responsiveness to tyrosine kinase inhibitor (TKI) therapy. Using a high-content screen, we show that retinoids reverse this phenotype in part by inducing expression of wild type IKZF1, and increase responsiveness to TKIs. These findings provide new insight into the pathogenesis of high-risk ALL and potential new therapeutic approaches. Pre-B mRNA profiles of p185 MIG and IK6 cells, DMSO or drug treated, in 3 or 4 replicates, using Illumina HiSeq 2500.
Project description:Analysis of the effect of Prednisolone in mouse splenocytes with and without Ikzf1 at gene expression level. The hypothesis tested in the present study was that loss of Ikzf1 affects the induction and repression of the Glucocorticoid receptor target genes. Results provide important information of the differentially expressed genes regulated by Ikzf1 upon Prednisolone treatment, explaining the resistance towards Glucocorticoid-induced apoptosis in splenocytes harboring Ikzf1 loss. Total RNA was obtained from WT and Ikzf1+/- splenocytes subjected to 16 hours Prednsiolone treatment compared to untreated cells.
Project description:To further dissect whether and how activated JUN reconfigures the chromatin landscape, we performed Chromatin Immunoprecipitation (ChIP)-seq analyses for H3K4me1 and H3K27ac. Based on the significant increase of H3K27ac levels at H3K4me1+ sites, we identified 3,017 JUN-activated enhancers in JUN WT cells. In contrast, JUN AA fails to significantly induce H3K27ac accumulation at these regions. Their enrichment levels at JUN-activated enhancers were significantly decreased after JNKi treatment. Besides, these enhancers are directly driven by JUN, especially phosphorylated JUN.
Project description:modENCODE_submission_4625 This submission comes from a modENCODE project of Michael Snyder. For full list of modENCODE projects, see http://www.genome.gov/26524648 Project Goal: We are identifying the DNA binding sites for 300 transcription factors in C. elegans. Each transcription factor gene is tagged with the same GFP fusion protein, permitting validation of the gene's correct spatio-temporal expression pattern in transgenic animals. Chromatin immunoprecipitation on each strain is peformed using an anti-GFP antibody, and any bound DNA is deep-sequenced using Solexa GA2 technology. For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf EXPERIMENT TYPE: CHIP-seq. BIOLOGICAL SOURCE: Strain: OP234(official name : OP234 genotype : unc119(ed3);wgIs234(T24H10.7:TY1 EGFP FLAG;unc119) outcross : 3 mutagen : Bombard tags : GFP::3xFlag description : This strain's transgene was constructed by Mihail Sarov at the Max Planck Institute for Cell Biology in Tubiginen using Tony Hyman's recombineering pipeline. The resulting plasmid was used for biolistic transformation of an unc-119(ed3) strain. The JUN-1::EGFP fusion protein is expressed in the correct jun-1 spatio-temporal expression pattern. This strain was used for ChIP-seq experiments to map the in vivo binding sites for the JUN-1 transcription factor. made_by : Unknown ); Developmental Stage: L4; Genotype: unc119(ed3);wgIs234(T24H10.7:TY1 EGFP FLAG;unc119); Sex: Hermaphrodite; EXPERIMENTAL FACTORS: Developmental Stage L4; Target gene jun-1; Strain OP234(official name : OP234 genotype : unc119(ed3);wgIs234(T24H10.7:TY1 EGFP FLAG;unc119) outcross : 3 mutagen : Bombard tags : GFP::3xFlag description : This strain's transgene was constructed by Mihail Sarov at the Max Planck Institute for Cell Biology in Tubiginen using Tony Hyman's recombineering pipeline. The resulting plasmid was used for biolistic transformation of an unc-119(ed3) strain. The JUN-1::EGFP fusion protein is expressed in the correct jun-1 spatio-temporal expression pattern. This strain was used for ChIP-seq experiments to map the in vivo binding sites for the JUN-1 transcription factor. made_by : Unknown ); temp (temperature) 20 degree celsius
Project description:Interferon regulatory factor 4 (IRF4) is an IRF family transcription factor with critical roles in lymphoid development and in regulating the immune response. IRF4 binds DNA weakly owing to a carboxy-terminal auto-inhibitory domain, but cooperative binding with factors such as PU.1 or SPIB in B cells increases binding affinity, allowing IRF4 to regulate genes containing ETS–IRF composite elements (EICEs; 5'-GGAAnnGAAA-3'). Here we show that in mouse CD4+ T cells, where PU.1/SPIB expression is low, and in B cells, where PU.1 is well expressed, IRF4 unexpectedly can cooperate with activator protein-1 (AP1) complexes to bind to AP1–IRF4 composite (5'-TGAnTCA/GAAA-3') motifs that we denote as AP1–IRF composite elements (AICEs). Moreover, BATF–JUN family protein complexes cooperate with IRF4 in binding to AICEs in pre-activated CD4+ T cells stimulated with IL-21 and in TH17 differentiated cells. Importantly, BATF binding was diminished in Irf4-/- T cells and IRF4 binding was diminished in Batf-/- T cells, consistent with functional cooperation between these factors. Moreover, we show that AP1 and IRF complexes cooperatively promote transcription of the Il10 gene, which is expressed in TH17 cells and potently regulated by IL-21. These findings reveal that IRF4 can signal via complexes containing ETS or AP1 motifs depending on the cellular context, thus indicating new approaches for modulating IRF4-dependent transcription. Genome-wide transcription factors mapping and binding of IRF4, BATF, IRF8, STAT3, JUN etc in WT, Irf4-/- and Batf-/- mice in different cell types (B cells, CD4+ T cells and TH17 cells) cultured with or without IL-21 was conducted. RNA-Seq is conducted in mouse B cells, CD4+ T cells, TH1/TH2/TH9/TH17/Treg.
Project description:To examine the effects of phosphorylated JUN-mediated enhancers activation on gene expression, we conducted RNA-seq analysis in JUN wildtype (WT) or JUN inactive mutant (JUN AA) overexpressed MRC5 cells. The expression levels of genes associated with JUN-activated enhancers are significantly upregulated in JUN WT cells rather than in JUN AA cells. To quantify the effects of JUN inactivation on gene expression, we also performed RNA-seq analysis in JNKi-treated induced CAFs (iCAFs). We observed that JNKi significantly reduced expression levels of JUN-activated enhancers-associated genes.