Project description:To gain further insight into the root clock mechanism, we performed a mutagenesis screen in plants carrying DR5::Luciferase in combination with markers for subsequent LR organogenesis (pWOX5::ER-YFP and pSCR::ER-GFP12). Out of this screening, we identified a mutant with increased expression of DR5::Luciferase in the OZ and PBS distributed throughout the primary root axis without evident spacing. We further refer to this mutant as potent.
Project description:Retinoic Acid Receptors (RARs) bind RA-response elements in regulatory regions of their target genes. While canonical RAREs comprise direct repeats of the consensus 5’-RGKTCA-3’ sequence separated by 1, 2 or 5 nucleotides (DR1, DR2, DR5), we show that shortly after RA treatement of mouse embryoid bodies or F9 cells, RARs occupy a large repertoire of DR0, DR2, DR5, DR8 and IR0 elements. In vitro, RAR-RXR bind these non-canonical spacings with comparable affinities to DR2 and DR5. Most DR8 elements comprise three half sites with DR2 and DR0 spacings. This specific half site organisation constitutes a previously unrecognised, but frequent signature of RAR binding elements and acts as an RARE. At later stages of embryoid body differentiation, RARs relocalise to a restricted repertoire of sites comprising predominantly DR5 elements. Differentiation thus involves genomic relocalisation of RARs, and a switch from DR0 and DR8 at early times to DR5 at later stages. Examination of genomic localisation of RAR in differentiating embryoid bodies.
Project description:Apo2L/TRAIL stimulates cancer-cell death through the proapoptotic receptors DR4 and DR5, but the determinants of tumor susceptibility to this ligand are not fully defined. mRNA expression of the peptidyl O-glycosyl transferase GALNT14 correlated with Apo2L/TRAIL sensitivity in pancreatic carcinoma, non-small cell lung carcinoma and melanoma cell lines (P < 0.00009; n=83), and up to 30% of samples from various human malignancies displayed GALNT14 overexpression. RNA interference of GALNT14 reduced cellular Apo2L/TRAIL sensitivity, whereas overexpression increased responsiveness. Biochemical analysis of DR5 identified several ectodomain O-GalNAc-Gal-Sialic acid structures. Sequence comparison predicted conserved extracellular DR4 and DR5 O-glycosylation sites; progressive mutation of the DR5 sites attenuated apoptosis signaling. O-glycosylation promoted ligand-stimulated clustering of DR4 and DR5, which mediated recruitment and activation of the apoptosis-initiating protease caspase-8. These results uncover a novel link between death receptor O-glycosylation and apoptosis signaling, providing potential predictive biomarkers for Apo2L/TRAIL-based cancer therapy. Keywords: cell type comparison
Project description:Retinoic Acid Receptors (RARs) bind RA-response elements in regulatory regions of their target genes. While canonical RAREs comprise direct repeats of the consensus 5’-RGKTCA-3’ sequence separated by 1, 2 or 5 nucleotides (DR1, DR2, DR5), we show that shortly after RA treatement of mouse embryoid bodies or F9 cells, RARs occupy a large repertoire of DR0, DR2, DR5, DR8 and IR0 elements. In vitro, RAR-RXR bind these non-canonical spacings with comparable affinities to DR2 and DR5. Most DR8 elements comprise three half sites with DR2 and DR0 spacings. This specific half site organisation constitutes a previously unrecognised, but frequent signature of RAR binding elements and acts as an RARE. At later stages of embryoid body differentiation, RARs relocalise to a restricted repertoire of sites comprising predominantly DR5 elements. Differentiation thus involves genomic relocalisation of RARs, and a switch from DR0 and DR8 at early times to DR5 at later stages.
Project description:Apo2L/TRAIL stimulates cancer-cell death through the proapoptotic receptors DR4 and DR5, but the determinants of tumor susceptibility to this ligand are not fully defined. mRNA expression of the peptidyl O-glycosyl transferase GALNT14 correlated with Apo2L/TRAIL sensitivity in pancreatic carcinoma, non-small cell lung carcinoma and melanoma cell lines (P < 0.00009; n=83), and up to 30% of samples from various human malignancies displayed GALNT14 overexpression. RNA interference of GALNT14 reduced cellular Apo2L/TRAIL sensitivity, whereas overexpression increased responsiveness. Biochemical analysis of DR5 identified several ectodomain O-GalNAc-Gal-Sialic acid structures. Sequence comparison predicted conserved extracellular DR4 and DR5 O-glycosylation sites; progressive mutation of the DR5 sites attenuated apoptosis signaling. O-glycosylation promoted ligand-stimulated clustering of DR4 and DR5, which mediated recruitment and activation of the apoptosis-initiating protease caspase-8. These results uncover a novel link between death receptor O-glycosylation and apoptosis signaling, providing potential predictive biomarkers for Apo2L/TRAIL-based cancer therapy. Experiment Overall Design: Gene expression for untreated cell lines analyzed. Some cell lines have one replicate profile, some two (Samples with 2 CEL files). Normalized data for replicates was averaged. Analysis involved a regularized t-test to identify genes with expression differences between Apo2L sensitive and resistant lines.
Project description:To understand regulation of the in-phase and the antiphase oscillations by IAA18/POTENT and ARF7, we performed next-generation sequencing (NGS). OZ samples were taken at the minimum of DR5::Luciferase expression for the wild type, and simultaneously for arf7-1 and iaa18/potent regardless of DR5::Luciferase expression to avoid bias.
Project description:We report the application of ChIP-Seq of H4ac and H3K27me3 histone modifications to jasmonate-treated wild type (DR5) and HDA6 mutant (axe1-5) whole A. thaliana seedlings
Project description:Retinoic Acid Receptors (RARs) as a functional heterodimer with Retinoid X Receptors (RXRs), bind a diverse series of RA-response elements (RAREs) in regulated genes. Among them, the non-canonical DR0 elements are bound by RXR-RAR with comparable affinities to DR5 elements but DR0 elements do not act transcriptionally as independent RAREs. In this work, we present structural insight for the recognition of DR5 and DR0 elements by RXR-RAR heterodimer using x-ray crystallography, small angle x-ray scattering, and hydrogen/deuterium exchange coupled to mass spectrometry. We solved the crystal structure of RXR-RAR DNA-binding domain in complex with the Rarb2 DR5 and RXR DNA-binding domain in complex with Hoxb13 DR0. While cooperative binding was observed on DR5, on DR0 the two molecules bound non-cooperatively on opposite sides of the DNA. In addition, our data unveil the structural organization and dynamics of the multi-domain RXR-RAR DNA complexes providing evidence for DNA-dependent allosteric communication between domains. Differential binding mode between DR0 and DR5 were observed leading to differences in the conformation and structural dynamics of the multi-domain RXR-RAR DNA complex. These results reveal that the topological organization of the RAR binding element confer regulatory information by modulating the overall topology and structural dynamics of the RXR-RAR heterodimers.
Project description:The purpose of the trial is to evaluate the safety of GEN1029 (HexaBody-DR5/DR5) in a mixed population of patients with specified solid tumors
Project description:We have performed a transcriptomics study in which we first transfected LNA GapmeRs against DR5-AS lncRNA to silence it in HeLa cells. Total RNA was isolated from control as well as transfected cells and silencing was confirmed by qPCR. Total RNAs were subjected to deep-sequencing to identify differentially expressed mRNAs. We then took advantage of bioinformatic tools to identify which pathways are affected by DR5-AS knock-down.