Similar Datasets
Project description:The homeodomain transcription factor Prep1 was previously shown to regulate insulin sensitivity. Our aim was to study the specific role of Prep1 for the regulation of energy metabolism in skeletal muscle. Muscle specific ablation of Prep1 resulted in increased expression of respiratory chain subunits. This finding was consistent with an increase in mitochondrial enzyme activity without affecting mitochondrial volume fraction as assessed by electron microscopy. Metabolic phenotyping revealed no differences in daily energy expenditure or body composition. However, during treadmill exercise challenge, Prep1 ablation resulted in a higher maximal oxidative capacity and better endurance. Elevated PGC-1α expression was identified as a cause for increased mitochondrial capacity in Prep1-ablated mice. Prep1 stabilizes p160 Mybbp1a, a known inhibitor of PGC-1α activity. Thereby, P160 protein levels were significantly lower in muscle of Prep1-ablated mice. By a ChIPseq approach, PREP1-binding sites in genes encoding mitochondrial components (e.g. Ndufs2) were identified that might be responsible for elevated OXPHOS proteins in the muscle of Prep1 nullmutants. These results suggest that Prep1 exhibits additional direct effects on regulation of mitochondrial proteins. We therefore conclude that Prep1 is a regulator of oxidative phosphorylation components via direct and indirect mechanisms.
2014-01-01 | GSE52424 | GEO
Project description:The homeodomain transcription factor Prep1 was previously shown to regulate insulin sensitivity. Our aim was to study the specific role of Prep1 for the regulation of energy metabolism in skeletal muscle. Muscle specific ablation of Prep1 resulted in increased expression of respiratory chain subunits. This finding was consistent with an increase in mitochondrial enzyme activity without affecting mitochondrial volume fraction as assessed by electron microscopy. Metabolic phenotyping revealed no differences in daily energy expenditure or body composition. However, during treadmill exercise challenge, Prep1 ablation resulted in a higher maximal oxidative capacity and better endurance. Elevated PGC-1α expression was identified as a cause for increased mitochondrial capacity in Prep1-ablated mice. Prep1 stabilizes p160 Mybbp1a, a known inhibitor of PGC-1α activity. Thereby, P160 protein levels were significantly lower in muscle of Prep1-ablated mice. By a ChIPseq approach, PREP1-binding sites in genes encoding mitochondrial components (e.g. Ndufs2) were identified that might be responsible for elevated OXPHOS proteins in the muscle of Prep1 nullmutants. These results suggest that Prep1 exhibits additional direct effects on regulation of mitochondrial proteins. We therefore conclude that Prep1 is a regulator of oxidative phosphorylation components via direct and indirect mechanisms. Consequence of Prep1 ablation in skeletal muscle was investigated in Prep1deltaSM mice and compared to Prep1 flox mice, both on C57BL/6 background. 4 mice of each genotype were used to extract RNA from the tibialis anterior muscle.
2014-01-01 | E-GEOD-52424 | biostudies-arrayexpress
Project description:Mechanosignaling, initiated by the extracellular physical forces and propagated through the intracellular cytoskeletal network, triggers signaling cascades leading to processes such as embryogenesis, tissue maintenance and disease development. While signal transduction by transcription factors occurs downstream of cellular mechanosensing, nothing is known about the cell intrinsic mechanisms that can regulate mechanosignaling. Here we show that transcription factor PREP1 (PKNOX1) regulates the expression of LINC complex proteins and mechanotransduction of YAP-TAZ. PREP1 depletion upsets the nuclear membrane protein stoichiometry rendering nuclei soft. However, reduced nuclear tension is not conveyed to the cytoplasm, since these cells display fortified actomyosin network with bigger focal adhesion complexes resulting in greater traction forces at the substratum. Intriguingly, YAP-TAZ remains localized to the cytoplasm irrespective of the substrate rigidity indicating disrupted mechanotransduction. Our data demonstrate a hitherto unknown transcriptional mechanism which regulate mechanosignaling upstream of YAP-TAZ transduction.
2022-03-14 | GSE160286 | GEO
Project description:Down-regulation (DR) of PREP1 (aka PKNOX1) tumor suppressor induces H2Ax foci in human fibroblasts. Here we have analyzed the effect of PREP1 DR on DNA replication using cell cycle analysis, Repliseq, DNA combing, ChIP-seq, RNA-seq and immunofluorescence (IF). In human cells, PREP1 DR similarly affects both the rate of DNA replication and the progression of cells through the S phase. Genome wide, PREP1 DR induces late to early DNA replication shifts in normally late-replicated genomic regions amounting to 25% of the genome, in addition to unscheduled origins firing. A concomitant strong increase of unidirectional replication forks explains the appearance of DNA damage foci. The DNA target of PREP1 DR is the Lamin Associated DNA, in agreement with the simultaneous decrease of Lamin B1. Therefore PREP1 is a novel regulator of replication timing and Lamin B1 level, which ChIP-seq and RNA-seq data indicate as independent from its transcriptional activity. This activity must constitute the basis for its tumor suppression function.
2018-02-28 | GSE101775 | GEO
Project description:Down-regulation (DR) of PREP1 (aka PKNOX1) tumor suppressor induces H2Ax foci in human fibroblasts. Here we have analyzed the effect of PREP1 DR on DNA replication using cell cycle analysis, Repliseq, DNA combing, ChIP-seq, RNA-seq and immunofluorescence (IF). In human cells, PREP1 DR similarly affects both the rate of DNA replication and the progression of cells through the S phase. Genome wide, PREP1 DR induces late to early DNA replication shifts in normally late-replicated genomic regions amounting to 25% of the genome, in addition to unscheduled origins firing. A concomitant strong increase of unidirectional replication forks explains the appearance of DNA damage foci. The DNA target of PREP1 DR is the Lamin Associated DNA, in agreement with the simultaneous decrease of Lamin B1. Therefore PREP1 is a novel regulator of replication timing and Lamin B1 level, which ChIP-seq and RNA-seq data indicate as independent from its transcriptional activity. This activity must constitute the basis for its tumor suppression function.
2018-02-28 | GSE101774 | GEO
Project description:Down-regulation (DR) of PREP1 (aka PKNOX1) tumor suppressor induces H2Ax foci in human fibroblasts. Here we have analyzed the effect of PREP1 DR on DNA replication using cell cycle analysis, Repliseq, DNA combing, ChIP-seq, RNA-seq and immunofluorescence (IF). In human cells, PREP1 DR similarly affects both the rate of DNA replication and the progression of cells through the S phase. Genome wide, PREP1 DR induces late to early DNA replication shifts in normally late-replicated genomic regions amounting to 25% of the genome, in addition to unscheduled origins firing. A concomitant strong increase of unidirectional replication forks explains the appearance of DNA damage foci. The DNA target of PREP1 DR is the Lamin Associated DNA, in agreement with the simultaneous decrease of Lamin B1. Therefore PREP1 is a novel regulator of replication timing and Lamin B1 level, which ChIP-seq and RNA-seq data indicate as independent from its transcriptional activity. This activity must constitute the basis for its tumor suppression function.
2018-02-28 | GSE101773 | GEO
Project description:Prep1 is a tumor-suppressor, whereas Meis1 is an oncogene. We show that to perform these activities in MEFs both proteins competitively hetero-dimerize with Pbx1. Meis1 alone transforms Prep1-deficient fibroblasts while Prep1 overexpression inhibits Meis1 tumorigenicity. Pbx1 can therefore alternatively act as oncogene or tumor-suppressor. Prep1 post-translationally controls the level of Meis1 decreasing its stability by sequestering Pbx1. The different levels of Meis1 and the presence of Prep1 are followed at the transcriptional level by the induction of specific transcriptional signatures. The decrease of Meis1 prevents Meis1 interaction with Ddx3x and Ddx5, which are essential for Meis1 tumorigenesis, and modifies the growth promoting DNA binding landscape of Meis1 to the growth controlling landscape of Prep1. Hence the key feature of Prep1 tumor inhibiting activity is the control of Meis1 stability.
2016-06-01 | GSE58802 | GEO
Project description:Prep1 is a tumor-suppressor, whereas Meis1 is an oncogene. We show that to perform these activities in MEFs both proteins competitively hetero-dimerize with Pbx1. Meis1 alone transforms Prep1-deficient fibroblasts while Prep1 overexpression inhibits Meis1 tumorigenicity. Pbx1 can therefore alternatively act as oncogene or tumor-suppressor. Prep1 post-translationally controls the level of Meis1 decreasing its stability by sequestering Pbx1. The different levels of Meis1 and the presence of Prep1 are followed at the transcriptional level by the induction of specific transcriptional signatures. The decrease of Meis1 prevents Meis1 interaction with Ddx3x and Ddx5, which are essential for Meis1 tumorigenesis, and modifies the growth promoting DNA binding landscape of Meis1 to the growth controlling landscape of Prep1. Hence the key feature of Prep1 tumor inhibiting activity is the control of Meis1 stability.
2014-03-05 | GSE54221 | GEO
Project description:Transcriptional regulators are crucial in adipocyte differentiation. We now show that the homeodomain-containing transcription factor Prep1 is a repressor of adipogenic differentiation since its down-regulation (DR) in both ex vivo bone marrow-derived mesenchymal stromal cells (MSC) and in vitro 3T3-L1 pre-adipocytes significantly increases their adipogenic differentiation ability. Prep1 acts at a stage preceding the activation of the differentiation machinery because its DR makes cells more prone to adipogenic differentiation even in the absence of the adipogenic inducers. Prep1 DR expands the DNA binding landscape of C/EBP(CAAT enhancer binding protein ) without affecting its expression or activation. The data indicate that Prep1 normally acts by restricting DNA binding of transcription factors to adipogenic enhancers, in particular C/EBP.
2017-12-06 | GSE100056 | GEO
Project description:Transcriptional regulators are crucial in adipocyte differentiation. We now show that the homeodomain-containing transcription factor Prep1 is a repressor of adipogenic differentiation since its down-regulation (DR) in both ex vivo bone marrow-derived mesenchymal stromal cells (MSC) and in vitro 3T3-L1 pre-adipocytes significantly increases their adipogenic differentiation ability. Prep1 acts at a stage preceding the activation of the differentiation machinery because its DR makes cells more prone to adipogenic differentiation even in the absence of the adipogenic inducers. Prep1 DR expands the DNA binding landscape of C/EBPß(CAAT enhancer binding protein ß) without affecting its expression or activation. The data indicate that Prep1 normally acts by restricting DNA binding of transcription factors to adipogenic enhancers, in particular C/EBPß.
2017-12-06 | GSE100055 | GEO