ABSTRACT: ChIP-chip time-course from DmD8 cells with Pol II (Ser 2 and Ser 5 phosphorylated) antibody after 0, 10, 20, 30 40, 60 and 100 minutes Notch activation
Project description:ChIP-chip time-course from DmD8 cells with Pol II (Ser 2 and Ser 5 phosphorylated) antibody or Su(H) antibody after Notch activation
Project description:Cellular responses to signalling pathways are often highly dynamic, however most analyses of developmental signalling pathways focus on a single endpoint. We have analyzed the temporal changes in transcription following a short Notch activation treatment and related these to the recruitment of the Notch pathway transcription factor, CSL [Suppressor of Hairless, Su(H), in Drosophila], and to the state of RNA Polymerase II (Pol II) binding. A total of 154 genes showed significant differential expression over time and their expression profiles stratified into 14 clusters based on temporal and quantitative differences in their responses. These differences were partially reflected in the profiles of Pol II and Su(H) binding. However, neither could fully account for the different response profiles. Furthermore, the timing of the different responses was unaffected by more prolonged Notch activation. Instead our data suggest that regulatory relationships between genes that segregate into different response clusters can partially account for the stratification. Thus, feed-forward repression, where products of early responding Enhancer of split bHLH genes (E(spl)bHLH) inhibit expression of endogenous repressors, is one mechanism that explains the profile of genes that exhibit delayed up-regulation. E(spl)bHLH genes may therefore be responsible for co-ordinating the Notch response of a wide spectrum of other targets, explaining their critical functions in many developmental and disease contexts. DmD8 cells were collected at 7 time points (0M-bM-^@M-^Y, 10M-bM-^@M-^Y, 20M-bM-^@M-^Y, 30M-bM-^@M-^Y, 40M-bM-^@M-^Y, 60M-bM-^@M-^Y and 100M-bM-^@M-^Y) after a 5 minute Notch stimulation as 3 independent replicates. Immunoprecipitation was performed with Pol II (Ser 2 and Ser 5 phosphorylated) antibody and compared to the total input DNA. Samples from replicates #1 and #3 were labelled with Cy5, and replicate #2 was labelled with Cy3 as a dye-swap.
Project description:We report changes in GR and Pol II binding profiles genome-wide upon treatment with corticosterone (Cort) for 20 minutes, treatment with Cort for 20 minutes followed by hormone withdrawal for 40 minutes, 60 minutes continuous stimulation with Cort, and 60 minutes continuous stimulation with Dexamethasone (Dex).
Project description:The transcription factor Twist is a critical cooperating factor that confers transcriptional specificity to the Notch pathway in muscle progenitor cells (DmD8) ChIP analysis of Twi show that Twist binding is significantly enriched in Notch responsive region in DmD8 cells
Project description:The transcription factor Twist is a critical cooperating factor that confers transcriptional specificity to the Notch pathway in muscle progenitor cells (DmD8) ChIP analysis of Twi show that Twist binding is significantly enriched in Notch responsive region in DmD8 cells 3 replicates of Twist ChIP after30 min. Notch activation.
Project description:We report changes in GR and Pol II binding profiles genome-wide upon treatment with corticosterone (Cort) for 20 minutes, treatment with Cort for 20 minutes followed by hormone withdrawal for 40 minutes, 60 minutes continuous stimulation with Cort, and 60 minutes continuous stimulation with Dexamethasone (Dex). We examine GR binding upon following treatments: 0' Cort, 20' Cort, 60' Cort Pulsed, 60' Cort Constant; Pol II binding upon following treatments: 0' Cort, 20' Cort, 60' Cort Pulsed, 60' Cort Constant, 60' Dex Constant; Pol II binding upon Mock treatments simulating 0' Cort, 20' Cort, 60' Cort Pulsed, 60' Cort Constant; CTCF binding profile of untreated cells.
Project description:To identify genes upregulated in response to Notch signalling in DmD8 cells. To identify genes upregulated in response to Notch signalling in KC cells. Keywords: Expression analysis at a single timepoint (30' after Notch activation)
Project description:Release of promoter-proximal paused RNA polymerase II (Pol II) during early elongation is a critical step in transcriptional regulation in metazoan cells. Paused Pol II release is thought to require the kinase activity of cyclin-dependent kinase 9 (CDK9) for the phosphorylation of DRB sensitivity-inducing factor, negative elongation factor, and C-terminal domain (CTD) serine-2 of Pol II. We found that Pol II-associated factor 1 (PAF1) is a critical regulator of paused Pol II release, that positive transcription elongation factor b (P-TEFb) directly regulates the initial recruitment of PAF1 complex (PAF1C) to genes, and that the subsequent recruitment of CDK12 is dependent on PAF1C. These findings reveal cooperativity among P-TEFb, PAF1C, and CDK12 in pausing release and Pol II CTD phosphorylation. Comparison of the chromatin occupancy of [1] PAF1, CDC73, LEO1, CTR9, total Pol II, and CTD serine 2-phosphorylated Pol II by ChIP-seq in THP1 cells; [2] PAF1, Pol II, Pol II (ser-5p), CDK12, and CDK9 by ChIP-seq in control and PAF1 knockdown cells; [3] LEO1 and Pol II by ChIP-seq in control and flavopiridol treated THP1 cells.
