Project description:The goal of this study was to identify genomic binding sites of the NRSF/REST transcription factor under conditions of basal and increased SF-1 dosage in the H295R human adrenocortical tumor cell line. 4 samples: input DNA (2 replicates) - NRSF/REST ChIP basal SF-1 dosage - NRSF/REST ChIP increased SF-1 dosage
Project description:SF-1 is a nuclear receptor transcription factor playing a key role in adrenogonadal development and in adrenocortical tumorigenesis when overexpressed. NRSF/REST is a transcriptional repressor that represses expression of neuronal genes in non-neural tissues. Some data suggest that SF-1 and NRSF/REST can functionally interact in adrenocortical cancer cells. We studied gene expression profiles using Affymetrix microarrays in the H295R/TR SF-1 adrenocortical cancer cell line. In this cell line, SF-1 expression can be increased in a doxycycline-dependent manner (Mol. Endocrinol. 21: 2968–2987, 2007). The effects of a control siRNA and sRNAs specific for SF-1 and for NRSF/REST (in basal or increased SF-1 expression conditions) on gene expression were measured.
Project description:SF-1 is a nuclear receptor transcription factor playing a key role in adrenogonadal development and in adrenocortical tumorigenesis when overexpressed. NRSF/REST is a transcriptional repressor that represses expression of neuronal genes in non-neural tissues. Some data suggest that SF-1 and NRSF/REST can functionally interact in adrenocortical cancer cells. We studied gene expression profiles using Affymetrix microarrays in the H295R/TR SF-1 adrenocortical cancer cell line. In this cell line, SF-1 expression can be increased in a doxycycline-dependent manner (Mol. Endocrinol. 21: 2968–2987, 2007). The effects of a control siRNA and sRNAs specific for SF-1 and for NRSF/REST (in basal or increased SF-1 expression conditions) on gene expression were measured. In H295R/TR SF-1 cells SF-1 and NRSF/REST (in conditions of basal and increased SF-1 dosage) expression were knocked down by Amaxa nucleofection. RNA was extracted and hybridized to Human Gene 1.0 ST Affymetrix microarrays.
Project description:The goal of this study was to identify genomic binding sites of the NRSF/REST transcription factor under conditions of basal and increased SF-1 dosage in the H295R human adrenocortical tumor cell line.
Project description:Analysis of HeLa cell with overexpression of an EGFP-tagged dominant-negative truncation (73- 563 a.a.) of human REST/NRSF. RNA polymerase II and DNA damage repair factor γ-H2AX binding data provide insight into the molecular bases of how REST/NRSF perturbation impairs genome stability.
Project description:The molecular mechanisms that lead to the cognitive defects characteristic of Down syndrome (DS), the most frequent cause of mental retardation, have remained elusive. Here we use a transgenic DS mouse model to show that DYRK1A gene dosage imbalance deregulates chromosomal clusters of genes located near neuron-restrictive silencer factor (REST/NRSF) binding sites. We found that DYRK1A binds the SWI/SNF-complex known to interact with REST/NRSF. Mutation of a REST/NRSF binding site in the promoter of the REST/NRSF target gene L1cam modifies the transcriptional effect of Dyrk1A-dosage imbalance on L1cam. DyrkA dosage imbalance perturbs Rest/Nrsf levels with decreased Rest/Nrsf expression in embryonic neurons and increased expression in adult neurons. We identified a coordinated deregulation of multiple genes that are responsible for the cellular phenotypic traits present in DS such as dendritic growth impairment and microcephaly during prenatal cortex development. Dyrk1a overexpression in primary mouse cortical neurons reduced the neuritic complexity. In the postnatal hippocampus, DYRK1A overexpression suppresses a form of synaptic plasticity that may be sufficient to cause DS cognitive defects. We propose that DYRK1A overexpression-related neuronal gene deregulation generates the brain phenotypic changes that characterize DS, with an accessory role for the gene dosage imbalance of other chromosome 21 genes.
Project description:The molecular mechanisms that lead to the cognitive defects characteristic of Down syndrome (DS), the most frequent cause of mental retardation, have remained elusive. Here we use a transgenic DS mouse model to show that DYRK1A gene dosage imbalance deregulates chromosomal clusters of genes located near neuron-restrictive silencer factor (REST/NRSF) binding sites. We found that DYRK1A binds the SWI/SNF-complex known to interact with REST/NRSF. Mutation of a REST/NRSF binding site in the promoter of the REST/NRSF target gene L1cam modifies the transcriptional effect of Dyrk1A-dosage imbalance on L1cam. DyrkA dosage imbalance perturbs Rest/Nrsf levels with decreased Rest/Nrsf expression in embryonic neurons and increased expression in adult neurons. We identified a coordinated deregulation of multiple genes that are responsible for the cellular phenotypic traits present in DS such as dendritic growth impairment and microcephaly during prenatal cortex development. Dyrk1a overexpression in primary mouse cortical neurons reduced the neuritic complexity. In the postnatal hippocampus, DYRK1A overexpression suppresses a form of synaptic plasticity that may be sufficient to cause DS cognitive defects. We propose that DYRK1A overexpression-related neuronal gene deregulation generates the brain phenotypic changes that characterize DS, with an accessory role for the gene dosage imbalance of other chromosome 21 genes.
Project description:Transcription profiling of transgenic down syndrome mouse model to show the role of DYRK1A gene. The molecular mechanisms that lead to the cognitive defects characteristic of Down syndrome (DS), the most frequent cause of mental retardation, have remained elusive. Here we use a transgenic DS mouse model to show that DYRK1A gene dosage imbalance deregulates chromosomal clusters of genes located near neuron-restrictive silencer factor (REST/NRSF) binding sites. We found that DYRK1A binds the SWI/SNF-complex known to interact with REST/NRSF. Mutation of a REST/NRSF binding site in the promoter of the REST/NRSF target gene L1cam modifies the transcriptional effect of Dyrk1Adosage imbalance on L1cam. DyrkA dosage imbalance perturbs Rest/Nrsf levels with decreased Rest/Nrsf expression in embryonic neurons and increased expression in adult neurons. We identified a coordinated deregulation of multiple genes that are responsible for the cellular phenotypic traits present in DS such as dendritic growth impairment and microcephaly during prenatal cortex development. Dyrk1a overexpression in primary mouse cortical neurons reduced the neuritic complexity. In the postnatal hippocampus, DYRK1A overexpression suppresses a form of synaptic plasticity that may be sufficient to cause DS cognitive defects. We propose that DYRK1A overexpression-related neuronal gene deregulation generates the brain phenotypic changes that characterize DS, with an accessory role for the gene dosage imbalance of other chromosome 21 genes.
Project description:Repressor element-1 silencing transcription factor (REST) or neuron-restrictive silencer factor (NRSF) is a zinc-finger (ZF) containing transcriptional repressor that recognizes thousands of neuron-restrictive silencer elements (NRSEs) in mammalian genomes. How REST/NRSF regulates gene expression remains incompletely understood. Here, we investigate the binding pattern and regulation mechanism of REST/NRSF in the clustered protocadherin (PCDH) genes. We find that REST/NRSF directionally forms base-specific interactions with NRSEs via tandem ZFs in an anti-parallel manner but with striking conformational changes. In addition, REST/NRSF recruitment to the HS5-1 enhancer leads to the decrease of long-range enhancer-promoter interactions and downregulation of the clustered PCDH alpha genes. Thus, REST/NRSF represses PCDH alpha gene expression through directional binding to a repertoire of NRSEs within the distal enhancer and variable target genes.
Project description:The molecular mechanisms that lead to the cognitive defects characteristic of Down syndrome (DS), the most frequent cause of mental retardation, have remained elusive. Here we use a transgenic DS mouse model to show that DYRK1A gene dosage imbalance deregulates chromosomal clusters of genes located near neuron-restrictive silencer factor (REST/NRSF) binding sites. We found that DYRK1A binds the SWI/SNF-complex known to interact with REST/NRSF. Mutation of a REST/NRSF binding site in the promoter of the REST/NRSF target gene L1cam modifies the transcriptional effect of Dyrk1A-dosage imbalance on L1cam. DyrkA dosage imbalance perturbs Rest/Nrsf levels with decreased Rest/Nrsf expression in embryonic neurons and increased expression in adult neurons. We identified a coordinated deregulation of multiple genes that are responsible for the cellular phenotypic traits present in DS such as dendritic growth impairment and microcephaly during prenatal cortex development. Dyrk1a overexpression in primary mouse cortical neurons reduced the neuritic complexity. In the postnatal hippocampus, DYRK1A overexpression suppresses a form of synaptic plasticity that may be sufficient to cause DS cognitive defects. We propose that DYRK1A overexpression-related neuronal gene deregulation generates the brain phenotypic changes that characterize DS, with an accessory role for the gene dosage imbalance of other chromosome 21 genes. Experiment Overall Design: Agilent Whole Mouse Genome oligomicroarrays (GEO accession no. GPL2872, Agilent Technologies, Palo Alto, CA) were used. They contain 60-mer DNA probes synthesized in situ in a 44k format. Of 44,290 spots, 2756 are controls. The remaining 41,534 spots represent 33,661 unique transcripts which correspond to 20,202 unique human genes. Five independent (Dyrk1A overexpression, five individual samples) measurements were carried out for each group of biological conditions using exchanged dye-labeled RNA targets (i.e., Cy3 and Cy5 dye-swapping experiments).