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.
Project description:The acetyltransferases CBP and p300 are multifunctional transcriptional co-activators; however, their acetylation targets, site-specific acetylation kinetics, and function in proteome regulation are incompletely understood. We combined quantitative proteomics with novel CBP/p300-specific catalytic inhibitors, bromodomain inhibitor, and gene knockout to show that CBP/p300 acetylates thousands of sites, including signature histone sites, as well as a multitude of sites on signaling effectors and enhancer-associated transcriptional regulators. Kinetic analysis identified a subset of CBP/p300-regulated sites with very rapid (<30min) acetylation turnover, revealing a dynamic balance between acetylation and deacetylation. Quantification of acetylation, mRNA, and protein abundance after CBP/p300 inhibition reveals a kinetically competent network of gene expression that strictly depends on CBP/p300-catalyzed rapid acetylation. Collectively, our in-depth acetylome analyses reveal systems attributes of CBP/p300 targets, and the resource dataset provides a framework for investigating CBP/p300 functions, as well as for understanding the impact of small molecule inhibitors targeting its catalytic and bromodomain activities.
Project description:The acetyltransferases CBP and p300 are multifunctional transcriptional co-activators; however, their acetylation targets, site-specific acetylation kinetics, and function in proteome regulation are incompletely understood. We combined quantitative proteomics with novel CBP/p300-specific catalytic inhibitors, bromodomain inhibitor, and gene knockout to show that CBP/p300 acetylates thousands of sites, including signature histone sites, as well as a multitude of sites on signaling effectors and enhancer-associated transcriptional regulators. Kinetic analysis identified a subset of CBP/p300-regulated sites with very rapid (<30min) acetylation turnover, revealing a dynamic balance between acetylation and deacetylation. Quantification of acetylation, mRNA, and protein abundance after CBP/p300 inhibition reveals a kinetically competent network of gene expression that strictly depends on CBP/p300-catalyzed rapid acetylation. Collectively, our in-depth acetylome analyses reveal systems attributes of CBP/p300 targets, and the resource dataset provides a framework for investigating CBP/p300 functions, as well as for understanding the impact of small molecule inhibitors targeting its catalytic and bromodomain activities.