Project description:Poly(ADP-ribose) polymerase 3 (PARP3) is a member of the PARP family of enzymes. It is structurally related to the well characterized type member PARP1 that orchestrates DNA strand break repair and cell death by the synthesis of poly(ADP-ribose). In contrast, the functions of PARP3 are undefined. We have used several in vitro and in vivo approaches to examine the possible functions of PARP3 as a transcriptional regulator, a function suggested from its previously reported association with several Polycomb group (PcG) proteins. A ChIP-chip analysis of PARP3 gene occupancy in the human neuroblastoma cell line SK-N-SH reveals that PARP3 is preferentially associated with developmental genes and is significantly enriched around the transcriptional start site of several genes encoding neuronal and sensory placodes specifiers, such as SOX9, DLX3 and DLX4. Using zebrafish as a vertebrate animal model, we demonstrate that Parp3 plays a key role in ectodermal and neural crest specification. Morpholino oligonucleotide-directed inhibition of parp3 expression in zebrafish impairs the expression of the neural crest cell specifier sox9a and of dlx3b/dlx4b, the formation of cranial sensory placodes, inner ears and pectoral fins. It delays pigmentation and severely impedes the development of the median fin fold and tail bud. Our findings demonstrate that Parp3 is crucial in the early stages of zebrafish development, possibly by exerting its transcriptional regulatory functions as early as during the specification of the neural plate border.
Project description:Poly(ADP-ribose) polymerase 3 (PARP3) is a member of the PARP family of enzymes. It is structurally related to the well characterized type member PARP1 that orchestrates DNA strand break repair and cell death by the synthesis of poly(ADP-ribose). In contrast, the functions of PARP3 are undefined. We have used several in vitro and in vivo approaches to examine the possible functions of PARP3 as a transcriptional regulator, a function suggested from its previously reported association with several Polycomb group (PcG) proteins. A ChIP-chip analysis of PARP3 gene occupancy in the human neuroblastoma cell line SK-N-SH reveals that PARP3 is preferentially associated with developmental genes and is significantly enriched around the transcriptional start site of several genes encoding neuronal and sensory placodes specifiers, such as SOX9, DLX3 and DLX4. Using zebrafish as a vertebrate animal model, we demonstrate that Parp3 plays a key role in ectodermal and neural crest specification. Morpholino oligonucleotide-directed inhibition of parp3 expression in zebrafish impairs the expression of the neural crest cell specifier sox9a and of dlx3b/dlx4b, the formation of cranial sensory placodes, inner ears and pectoral fins. It delays pigmentation and severely impedes the development of the median fin fold and tail bud. Our findings demonstrate that Parp3 is crucial in the early stages of zebrafish development, possibly by exerting its transcriptional regulatory functions as early as during the specification of the neural plate border. ChIP were conducted as described (Rodrigue et al. 2006). PARP3 was immunoprecipitated from 3 x 10^7 SK-N-SH cells with a commercial anti-PARP3 (Enzo Life Sciences ALX-210-541). In control ChIP, PARP3 antibodies were replaced by rabbit IgG. Two independent PARP3 and control ChIP-chip experiments were achieved. The DNA was amplified using LM-PCR and labelled with Cy5 (PARP3) and Cy3 (IgG) before hybridization on Agilent Human promoter arrays (two 244k chip per ChIP for a total of 4 chips). Detailed protocols can be found at http://www.ircm.qc.ca/microsites/francoisrobert/en. Regions significantly enriched for PARP3 relative to IgG were identified as described (Lee et al. 2006).
Project description:HS-10502 is a Poly(ADP-ribose) polymerase 1 (PARP1)-specific selective inhibitor. The purpose if this study is to assess the safety, tolerability, pharmacokinetics (PK), and efficacy of HS-10502 in subjects with homologous recombination repair (HRR) gene mutant or homologous recombination deficiency (HRD) positive advanced solid tumors.
Project description:The autosomal recessive immunodeficiency, centromeric instability and facial anomalies (ICF) syndrome is a genetically heterogeneous disorder. Despite recent successes in the identification of the underlying gene defects, it is currently unclear how mutations in any of the four known ICF genes cause a primary immunodeficiency. Here we demonstrate that loss of ZBTB24 in B cells from ICF2 patients impairs non-homologous end-joining (NHEJ) during immunoglobulin class-switch recombination and consequently impairs immunoglobulin production and subtype balance. Mechanistically, we found that ZBTB24 associates with poly(ADP-ribose) polymerase 1 (PARP1) and stimulates auto-poly(ADP-ribosyl)ation of this enzyme. The zinc finger in ZBTB24 binds PARP1-associated poly(ADP-ribose) chains and mediates the PARP1-dependent recruitment of ZBTB24 to DNA breaks. Moreover, by binding to poly(ADP-ribose) chains ZBTB24 protects these moieties from degradation by poly(ADP-ribose) glycohydrolase (PARG). This enhances the poly(ADP-ribose)-dependent interaction between PARP1 and the LIG4/XRCC4 NHEJ complex and promotes NHEJ by facilitating the assembly of this repair complex at DNA breaks. Thus, we uncover ZBTB24 as a regulator of PARP1-dependent NHEJ and class-switch recombination, providing a molecular basis for the immunodeficiency in ICF syndrome.
Project description:Poly(ADP-ribose) polymerase-1 (PARP-1) and poly(ADP-ribose) glycohydrolase (PARG) are enzymes that modify target proteins in the nucleus by the addition and removal, respectively, of ADP-ribose polymers. Although a role for PARP-1 in gene regulation has been well established, the role of PARG is less clear. To investigate how PARP-1 and PARG coordinately regulate global patterns of gene expression, we used short hairpin RNAs (shRNAs) to stably knockdown PARP-1 or PARG in MCF-7 cells, followed by expression microarray analyses.
Project description:The histone variant macroH2A1 and the poly(ADP-ribose) polymerase PARP-1 both regulate gene transcription by modulating chromatin structure and function. Of the two macroH2A1 splice variants, macroH2A1.1 and macroH2A1.2, the former is often suppressed in cancer and has the unique ability to interact with poly(ADP-ribose). Using ChIP-seq in primary lung fibroblasts, we demonstrate that macroH2A1 is incorporated into either of two spatially and functionally distinct types of chromatin; the first is marked by H3 K27 trimethylation, while the second contains a set of nine histone acetylations. MacroH2A1-regulated genes are involved in cancer progression are specifically found in macroH2A1-containing acetylated chromatin. Through the recruitment of PARP-1, macroH2A1.1 promotes the acetylation of H2B K12 and K120 which plays a key role in the regulation of macroH2A1 target genes in primary cells. The macroH2A1/PARP-1 pathway regulating H2B K12 and K120 acetylation is disrupted in cancer cells, in part, explaining macroH2A1M-bM-^@M-^Ys role in cancer suppression. Two biological replicates of the macroH2A1 ChIP and two corresponding input samples were sequenced
Project description:The histone variant macroH2A1 and the poly(ADP-ribose) polymerase PARP-1 both regulate gene transcription by modulating chromatin structure and function. Of the two macroH2A1 splice variants, macroH2A1.1 and macroH2A1.2, the former is often suppressed in cancer and has the unique ability to interact with poly(ADP-ribose). Using ChIP-seq in primary lung fibroblasts, we demonstrate that macroH2A1 is incorporated into either of two spatially and functionally distinct types of chromatin; the first is marked by H3 K27 trimethylation, while the second contains a set of nine histone acetylations. MacroH2A1-regulated genes are involved in cancer progression are specifically found in macroH2A1-containing acetylated chromatin. Through the recruitment of PARP-1, macroH2A1.1 promotes the acetylation of H2B K12 and K120 which plays a key role in the regulation of macroH2A1 target genes in primary cells. The macroH2A1/PARP-1 pathway regulating H2B K12 and K120 acetylation is disrupted in cancer cells, in part, explaining macroH2A1’s role in cancer suppression. Three biological replicates of RNA-seq from cells expressing shRNA directed against macroH2A1 or luciferase as a control
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 skeletal muscle.
Project description:Cockayne syndrome (CS) is an accelerated aging disorder, caused by mutations in the CSA or CSB genes. In CSB-deficient cells, poly (ADP ribose) polymerase (PARP) is persistently activated by unrepaired DNA damage and PARP consumes and depletes cellular nicotinamide adenine dinucleotide (NAD), which leads to mitochondrial dysfunction. Here, the distribution of poly (ADP ribose) (PAR) was determined in CSB-deficient cells using ADPr-ChAP (ADP ribose-chromatin affinity purification), and the results show striking enrichment of PAR at transcription start sites (TSS), depletion of heterochromatin, and downregulation of H3K9me3-specific methyltransferases SUV39H1 and SETDB1. Induced-expression of SETDB1 in CSB-deficient cells downregulated PAR and normalized mitochondrial function. The results suggest that defects in CSB are strongly associated with loss of heterochromatin, downregulation of SETDB1, increased PAR in highly-transcribed regions, and mitochondrial dysfunction.