Project description:The CH1 protein interaction domain of the transcriptional coactivators p300 and CBP is thought to interact with HIF-1alpha and this interaction is thought to be critical to the expression of HIF-1alpha target genes in response to hypoxia. To test the requirement of the CH1 domain for gene expression in response to hypoxia, rimary mouse embryonic fibroblasts (MEFs) were generated from C57Bl/6x129/Sv F2 e14.5 embryos that contain a deletion in the CH1 domain of three of four alleles of CBP and p300. The remaining allele of p300 or CBP was a conditional knock out allele. Control MEFs with only a single conditional knockout allele of p300 or CBP were also generated. At passage 3 MEFs were infected with Cre Adenovirus and grown until they had expanded at least 100 fold. Subconfluent MEFs were treated with 21% oxygen (normoxia) or 0.1% oxygen (hypoxia) with 5% carbon dioxide at 37 C in a humid chamber for 6hrs. At the start of treatment, medium was removed and replaced with medium (DMEM+10% FBS+pen-strep+ l-glu) that had been preequilibrated overnight in normoxia or hypoxia as appropriate. Immediately after treatment, cells were lysed in Trizol for RNA extraction. 12 samples; 4 genotypes [CBP+/flox (flox1), p300 +/flox (flox2), CBP CH1/flox;p300 CH1/CH1 (triCH1flox1),CBP CH1/CH1;p300 CH1/flox (triCH1flox2)] , 2 treatments (normoxia and hypoxia).
Project description:The C-terminal activation domain (C-TAD) of the hypoxia-inducible transcription factors HIF-1? and HIF-2? binds the CH1 domains of the related transcriptional coactivators CREB-binding protein (CBP) and p300, an oxygen-regulated interaction thought to be highly essential for hypoxia-responsive transcription. The role of the CH1 domain in vivo is unknown, however. We created mutant mice bearing deletions in the CH1 domains (?CH1) of CBP and p300 that abrogate their interactions with the C-TAD, revealing that the CH1 domains of CBP and p300 are genetically non-redundant and indispensable for C-TAD transactivation function. Surprisingly, the CH1 domain was only required for an average of ~35-50% of global HIF-1?-responsive gene expression, whereas another HIF-transactivation mechanism that is sensitive to the histone deacetylase inhibitor trichostatin A (TSAS) accounts for ~70%. Both pathways are required for greater than 90% of the response for some target genes. Our findings suggest that a novel functional interaction between the protein acetylases CBP and p300, and deacetylases, is essential for nearly all HIF-responsive transcription. Keywords: genetic modification, dose response
Project description:The C-terminal activation domain (C-TAD) of the hypoxia-inducible transcription factors HIF-1? and HIF-2? binds the CH1 domains of the related transcriptional coactivators CREB-binding protein (CBP) and p300, an oxygen-regulated interaction thought to be highly essential for hypoxia-responsive transcription. The role of the CH1 domain in vivo is unknown, however. We created mutant mice bearing deletions in the CH1 domains (?CH1) of CBP and p300 that abrogate their interactions with the C-TAD, revealing that the CH1 domains of CBP and p300 are genetically non-redundant and indispensable for C-TAD transactivation function. Surprisingly, the CH1 domain was only required for an average of ~35-50% of global HIF-1?-responsive gene expression, whereas another HIF-transactivation mechanism that is sensitive to the histone deacetylase inhibitor trichostatin A (TSAS) accounts for ~70%. Both pathways are required for greater than 90% of the response for some target genes. Our findings suggest that a novel functional interaction between the protein acetylases CBP and p300, and deacetylases, is essential for nearly all HIF-responsive transcription. Experiment Overall Design: Three separate affymetrix experiments using mouse embryonic fibroblasts derived from embryos bearing the ?CH1 mutation in p300 and/or CBP and treated with hypoxia or combinations of dipyridyl (a hypoxia mimetic) and trichostatin A (a histone deacetylase inhibitor) are described (GSE3195, GSE3196 and GSE3296). Samples are not directly comparable between experiments because of differences in experiment design and Affymetrix chips used.
Project description:The CH1 (TAZ) domain of the transcriptional coactivators p300 and CBP has been reported to interact with the transcription factor HIF-1alpha and this interaction is thought to be critical for HIF-1alpha target gene expression in response to hypoxia. To determine the requirement for the CH1 domain in hypoxia-responsive gene expression, primary mouse embryonic fibroblasts (MEFs) were generated from e14.5 C57B/6x129/Sv F2 embryos that were either wildtype or bore deletion mutations in the CH1 protein binding domains of both alleles of p300 and one allele of CBP (tri_CH1). Subconfluent MEFs were treated with 21% oxygen (normoxia) or 0.1% oxygen (hypoxia) with 5% carbon dioxide at 37 C in a humid chamber for 6hrs. At the start of treatment, medium was removed and replaced with medium (DMEM+10% FBS+pen-strep+ l-glu) that had been preequilibrated overnight in normoxia or hypoxia as appropriate. Immediately after treatment, cells were lysed in Trizol for RNA extraction. Keywords: genetic modification, dose response
Project description:The CH1 protein interaction domain of the transcriptional coactivators p300 and CBP is thought to interact with HIF-1alpha and this interaction is thought to be critical to the expression of HIF-1alpha target genes in response to hypoxia. Trichostatin A (TSA), an inhibitor of histone deacetylases, has been reported to repress the expression of HIF-1alpha target genes. To test the requirement of the CH1 domain and TSA for gene expression in response to dipyridyl (a hypoxia mimetic), primary mouse embryonic fibroblasts (MEFs) were generated from C57Bl/6x129/Sv F2 e14.5 embryos that contain a deletion in the CH1 domain of three of four alleles of CBP and p300. The remaining allele of p300 or CBP was a conditional knock out allele. Control MEFs with only a single conditional knockout allele of p300 or CBP were also generated. At passage 3 MEFs were infected with Cre Adenovirus and grown until they had expanded at least 100 fold. Subconfluent MEFs were treated with ethanol vehicle or 100ng/ml TSA with 5% carbon dioxide at 37 C in a humid chamber for 30 min., followed by ethanol vehicle or 100 umdipyridyl (DP) for an additional 3hrs. Immediately after treatment, cells were lysed in Trizol for RNA extraction. Keywords: genetic modification, dose response
Project description:The CH1 protein interaction domain of the transcriptional coactivators p300 and CBP is thought to interact with HIF-1alpha and this interaction is thought to be critical to the expression of HIF-1alpha target genes in response to hypoxia. To test the requirement of the CH1 domain for gene expression in response to hypoxia, rimary mouse embryonic fibroblasts (MEFs) were generated from C57Bl/6x129/Sv F2 e14.5 embryos that contain a deletion in the CH1 domain of three of four alleles of CBP and p300. The remaining allele of p300 or CBP was a conditional knock out allele. Control MEFs with only a single conditional knockout allele of p300 or CBP were also generated. At passage 3 MEFs were infected with Cre Adenovirus and grown until they had expanded at least 100 fold. Subconfluent MEFs were treated with 21% oxygen (normoxia) or 0.1% oxygen (hypoxia) with 5% carbon dioxide at 37 C in a humid chamber for 6hrs. At the start of treatment, medium was removed and replaced with medium (DMEM+10% FBS+pen-strep+ l-glu) that had been preequilibrated overnight in normoxia or hypoxia as appropriate. Immediately after treatment, cells were lysed in Trizol for RNA extraction. Keywords: genetic modification, dose response
Project description:The CH1 protein interaction domain of the transcriptional coactivators p300 and CBP is thought to interact with HIF-1alpha and this interaction is thought to be critical to the expression of HIF-1alpha target genes in response to hypoxia. Trichostatin A (TSA), an inhibitor of histone deacetylases, has been reported to repress the expression of HIF-1alpha target genes. To test the requirement of the CH1 domain and TSA for gene expression in response to dipyridyl (a hypoxia mimetic), primary mouse embryonic fibroblasts (MEFs) were generated from C57Bl/6x129/Sv F2 e14.5 embryos that contain a deletion in the CH1 domain of three of four alleles of CBP and p300. The remaining allele of p300 or CBP was a conditional knock out allele. Control MEFs with only a single conditional knockout allele of p300 or CBP were also generated. At passage 3 MEFs were infected with Cre Adenovirus and grown until they had expanded at least 100 fold. Subconfluent MEFs were treated with ethanol vehicle or 100ng/ml TSA with 5% carbon dioxide at 37 C in a humid chamber for 30 min., followed by ethanol vehicle or 100 umdipyridyl (DP) for an additional 3hrs. Immediately after treatment, cells were lysed in Trizol for RNA extraction.
Project description:The CH1 (TAZ) domain of the transcriptional coactivators p300 and CBP has been reported to interact with the transcription factor HIF-1alpha and this interaction is thought to be critical for HIF-1alpha target gene expression in response to hypoxia. To determine the requirement for the CH1 domain in hypoxia-responsive gene expression, primary mouse embryonic fibroblasts (MEFs) were generated from e14.5 C57B/6x129/Sv F2 embryos that were either wildtype or bore deletion mutations in the CH1 protein binding domains of both alleles of p300 and one allele of CBP (tri_CH1). Subconfluent MEFs were treated with 21% oxygen (normoxia) or 0.1% oxygen (hypoxia) with 5% carbon dioxide at 37 C in a humid chamber for 6hrs. At the start of treatment, medium was removed and replaced with medium (DMEM+10% FBS+pen-strep+ l-glu) that had been preequilibrated overnight in normoxia or hypoxia as appropriate. Immediately after treatment, cells were lysed in Trizol for RNA extraction. Experiment Overall Design: 4 samples: two genotypes (1 control, 1 mutant); two treatments (normoxia, hypoxia).
Project description:Organisms respond to mitochondrial stress by activating multiple defense pathways including the mitochondrial unfolded protein response (UPRmt). However, how different layers of UPRmt regulators are orchestrated to transcriptionally activate the stress responses remains largely unknown. Here we identified CBP-1, the worm ortholog of the mammalian acetyltransferases CBP/p300, as an essential regulator for UPRmt activation, as well as for mitochondrial stress-induced immune response, amyloid-β aggregation reduction and lifespan extension in Caenorhabditis elegans. Mechanistically, CBP-1 acts downstream of histone demethylases, JMJD-1.2/JMJD-3.1, and upstream of UPRmt transcription factors including ATFS-1, to systematically induce a broad spectrum of UPRmt genes and execute multiple beneficial functions. In mouse and human populations, transcript levels of CBP/p300 positively correlate with UPRmt transcripts and longevity. Furthermore, CBP/p300 inhibition disrupts, while forced expression of p300 is sufficient to activate, the UPRmt in mammalian cells. These results highlight an evolutionarily conserved mechanism that determines mitochondrial stress response, and promotes health and longevity through CBP/p300.