Project description:Arabidopsis plants grown in vitro on control media on a nylon mesh; transfered after 7days either to control or 0.2mM 3-Methoxybenzamide (3MB) containing media were sampled after 24, 48, 96 and 168h to obtain data if/how PARP inhibition changes transcription of plants in respect to the observed growth enhancement
Project description:Poly(ADP-ribose) polymerase-2 (PARP-2) is acknowledged as a DNA repair enzyme; however, recently metabolic properties had been attributed to it. Hereby, we examined the metabolic consequences of PARP-2 ablation in liver. Microarray analysis of PARP-2 knockdown HepG2 cells revealed the dysregulation of lipid and cholesterol metabolism genes. Induction of cholesterol biosynthesis genes stemmed from the enhanced expression of sterol-regulatory element binding protein (SREBP)-1. We revealed that PARP-2 is a suppressor of the SREBP-1 promoter, therefore ablation of PARP-2 induces SREBP-1 expression and consequently cholesterol synthesis. PARP-2-/- mice had higher SREBP-1 expression that was translated into enhanced hepatic and serum cholesterol levels. PARP-2 silencing was performed employing shPARP-2 (small hairpin) and scPARP-2 (scrambled) shRNA by lentiviral delivery (Sigma) using 40 MOI lentiviruses coding shRNA sequence against PARP-2.
Project description:PARP-6, a member of a family of enzymes (17 in humans) known as poly-ADP- ribose polymerases (PARPs), is a neuronally enriched PARP. While previous studies from our group show that PARP-6 is a regulator of dendrite morphogenesis in hippocampal neurons, its function in the nervous system in vivo is poorly understood. Here, we describe the generation of a PARP-6 loss-of-function mouse model for examining the function of PARP-6 during neurodevelopment in vivo. Using CRISPR-Cas9 mutagenesis, we generated a mouse line that expresses a PARP-6 truncated variant (PARP-6TR) in place of PARP-6WT. Unlike PARP-6WT, PARP-6TR is devoid of catalytic activity. Homozygous PARP-6TR do not exhibit obvious neuromorphological defects during development, but nevertheless die perinatally. This suggests that PARP-6 catalytic activity is important for postnatal survival. We also report PARP-6 mutations in six patients with several neurodevelopmental disorders, including microencephaly, intellectual disabilities, and epilepsy. The most severe mutation in PARP-6 (C563R) results in the loss of catalytic activity. Expression of the PARP-6C563R mutant in hippocampal neurons decreases dendrite morphogeneis. Taken together, these results suggest that PARP-6 is an essential gene in mice, and the loss of PARP-6 catalytic activity has detrimental effects on neuronal function in humans.
Project description:Poly (ADP-ribose) polymerase 7 (PARP-7) has emerged as a critically important member of a large enzyme family that catalyze ADP-ribosylation in mammalian cells. PARP-7 is a critical regulator of the innate immune response. What remains unclear is the mechanism by which PARP-7 regulates this process, namely because the protein targets of PARP-7 mono-ADP-ribosylation (MARylation) are largely unknown. Here, we combine chemical genetics, proximity labeling, and proteome-wide amino acid ADP- ribosylation site profiling for identifying the direct targets and sites of PARP-7-mediated MARylation in a cellular context. We found that the inactive PARP family member, PARP13 (a critical regulator of the antiviral innate immune response) is a major target of PARP-7. PARP-13 is preferentially MARylated on cysteine residues in its RNA binding zinc finger domain. Proteome-wide ADP-ribosylation analysis reveals cysteine as a major MARylation acceptor of PARP-7. This study provides insight into PARP-7 targeting and MARylation site preference.
Project description:NMNAT-1 and PARP-1, two key enzymes in the NAD+ metabolic pathway, localize to the nucleus where integration of their enzymatic activities has the potential to control a variety of nuclear processes. Using a variety of biochemical, molecular, cell-based, and genomic assays, we show that NMNAT-1 and PARP-1 physically and functionally interact at target gene promoters in MCF-7 cells. Specifically, we show that PARP-1 recruits NMNAT-1 to promoters, where it produces NAD+ to support PARP-1 catalytic activity, but also enhances the enzymatic activity of PARP-1 independent of NAD+ production. Furthermore, using two-photon excitation microscopy, we show that NMNAT-1 catalyzes the production of NAD+ in a nuclear pool that may be distinct from other cellular compartments. In expression microarray experiments, depletion of NMNAT-1 or PARP-1 alters the expression of about 200 protein-coding genes each, with about 10% overlap between the two gene sets. NMNAT-1 enzymatic activity is required for PARP-1-dependent PARylation at the promoters of commonly regulated target genes, as well as the expression of those target genes. Collectively, our studies link the enzymatic activities of NMNAT-1 and PARP-1 to the regulation of a set of common target genes through functional interactions at target gene promoters. We examined the co-localization of NMNAT-1 and PARP-1 at RefSeq promoters in MCF-7 cells using ChIP-chip Five samples:(1) two FLAG-NMNAT-1 IP'd with FLAG antibody from MCF-7 cells ectopically expressig FLAG-NMNAT-1 and (2) three native PARP-1 IP'd from parental MCF-7 cells with PARP-1 antibody
Project description:In order to determine whether dis-regulation of a genetic pathway could explain the increased apoptosis of parp-2-/- double positive thymocytes, the gene expression profiles in double positive thymocytes derived from wild-type and parp-2-/- mice were analysed using Affymetrix oligonucleotide chips (mouse genome 430 2.0).
Project description:Plant homeodomain (PHD) finger proteins affect growth and development by regulating transcription and reading epigenetic modifications of histones, but their functions in abiotic stress responses remain largely unclear. Here we characterize seven Arabidopsis thaliana Alfin1-like PHD finger proteins (ALs) in the response to abiotic stresses. ALs localize to the nucleus and repress transcription. Except AL6, all the ALs bind to G-box element. Changes of the amino acids at positions 34 and 35 in AL6 cause the loss of G-box binding ability. Expression of the ALs responded differently to osmotic stress, salt, cold and abscisic acid treatments. AL5 was induced by multiple stresses, and AL5-overexpressing plants showed higher tolerance to salt, drought and freezing stress than Col-0. Also, al5 mutants showed reduced stress tolerance. ChIP-Seq assay helps find the direct targets of AL5. Polyclonal antibody of AL5 protein was used to perform ChIP experiment. Two samples were analyzed, AL5 OE sample and its knock out mutant. Data was analyzed as OE sample Vs mutant sample and help find targets of AL5 protein.
Project description:Plants engineered for abiotic stress tolerance may soon be commercialized. The engineering of these plants typically involves the manipulation of complex multigene networks and may therefore have a greater potential to introduce pleiotropic effects than the simple monogenic traits that currently dominate the plant biotechnology market. Drought- tolerant Arabidopsis thaliana were engineered through overexpression of the transcription factor ABF3 in order to investigate unintended pleiotropic effects. In order to eliminate position effects, the Cre/lox recombination system was used to create control plant lines that contain identical T-DNA insertion sites but with the ABF3 transgene excised. This additionally allowed us to determine if Cre recombinase can cause unintended effects that impact the transcriptome. Microarray analysis of control plant lines that underwent Cre-mediated excision of the ABF3 transgene revealed only two genes that were differentially expressed in more than one plant line, suggesting that the impact of Cre recombinase on the transcriptome was minimal. In the absence of drought stress, overexpression of ABF3 had no effect on the transcriptome, but following drought stress, differences were observed in the gene expression patterns of plants overexpressing ABF3 relative to control plants. Examination of the functional distribution of the differentially expressed genes revealed strong similarity indicating that unintended pathways were not activated. In response to drought stress, overexpression of ABF3 results in a reprogramming of the drought response, which is characterized by changes in the timing or strength of expression of some drought response genes, without activating any unexpected gene networks. These results illustrate that important gene networks are highly regulated in Arabidopsis and that engineering stress tolerance may not necessarily cause extensive changes to the transcriptome.
Project description:Primary T cells were isolated from spleen of Parp-1-/- and wild-type mice by magnetic depletion of non-T cells using a MACS Pan-T Cell isolation kit, according to the manufacturer´s instruction (Mintenyi Biotec, Bergisch Gladbach, Germany). Purity was assessed by flow cytometry analysis using antibodies against CD3, CD4 and CD8 and all preparations were more than 98% pure of T cells. The cells were activated with plate-bound anti-mouse CD3 (clone 145-2C11) (5 microg/ml) in the absence or the presence of anti-mouse CD28 (clone 37.51) (5microg/ml) both from BD PharMingen (San Diego, CA) and culture for 3.5 h in RPMI 1640 medium (BioWhittaker) supplemented with 10% FCS, 2mM L-glutamine, 5x10-5 M 2-mercaptoethanol (Sigma), 2.5 microg/ml fungizone, 100 IU/ml penicillin, and 10 microg/ml streptomycin.
Project description:Brassinosteroids (BRs) are endogenous plant hormones and essential for normal plant growth and development. MicroRNAs (miRNAs) of Arabidopsis thaliana are involved in mediating cell proliferation in leaves, stress tolerance, and root development. The specifics of BRs mechanisms involving miRNAs are unknown. To explore the role of miRNAs in BR-mediated pathways, we analyzed differences in miRNA profiles between control (mock solution) and 24-epibrassinolide (EBR) treatments from customized miRNA microarrays. Seedlings were separately cultured under exogenous 10 nM EBR treatments for 30 (EBR30) or 180 (EBR180) minutes, and total RNAs of all seedlings were extracted after seven days of growth. Two independent experiments were performed at each time (30 or 180 minutes).