The acetyltransferases CBP and p300 are multifunctional transcriptional co-activators. Here, we combined quantitative proteomics with CBP/p300-specific catalytic inhibitors, bromodomain inhibitor, ...and gene knockout to reveal a comprehensive map of regulated acetylation sites and their dynamic turnover rates. CBP/p300 acetylates thousands of sites, including signature histone sites and a multitude of sites on signaling effectors and enhancer-associated transcriptional regulators. Time-resolved acetylome analyses identified a subset of CBP/p300-regulated sites with very rapid (<30 min) 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 and for understanding the impact of small-molecule inhibitors targeting its catalytic and bromodomain activities.
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•Quantitative acetylomics reveals thousands of in vivo substrates of CBP/p300•CBP/p300-regulated sites display rapid deacetylation kinetics•Histone H2B is prominently acetylated by CBP/p300 at multiple sites•Rapid turnover of CBP/p300-catalyzed acetylation controls gene transcription
A comprehensive look at CBP/p300 acetylation reveals dynamic changes that shape the regulation of protein function and gene expression.
Breast cancer brain metastasis (BCBM) is a devastating disease. Radiation therapy remains the mainstay for treatment of this disease. Unfortunately, its efficacy is limited by the dose that can be ...safely applied. One promising approach to overcoming this limitation is to sensitize BCBMs to radiation by inhibiting their ability to repair DNA damage. Here, we report a DNA repair suppressor, leucine-rich repeat-containing protein 31 (LRRC31), that was identified through a genome-wide CRISPR screen. We found that overexpression of LRRC31 suppresses DNA repair and sensitizes BCBMs to radiation. Mechanistically, LRRC31 interacts with Ku70/Ku80 and the ataxia telangiectasia mutated and RAD3-related (ATR) at the protein level, resulting in inhibition of DNA-dependent protein kinase, catalytic subunit (DNA-PKcs) recruitment and activation, and disruption of the MutS homologue 2 (MSH2)-ATR module. We demonstrate that targeted delivery of the LRRC31 gene via nanoparticles improves the survival of tumour-bearing mice after irradiation. Collectively, our study suggests LRRC31 as a major DNA repair suppressor that can be targeted for cancer radiosensitizing therapy.
We report on a 69-year-old man suffering from chronic progressive oligoarthritis (localized in metacarpal and knee joints), which clinically was interpreted as steroid-sensitive seronegative chronic ...arthritis. The patient died from sudden death at the emergency department after a 4-week history of increasing cough and dyspnea (meanwhile obtaining negative testing results for SARS-CoV-2). During the autopsy, we found massive pancarditis affecting all cardiac compartments, in particular exhibiting constrictive pericarditis, myocarditis, and multivalvular endocarditis. Microscopically, interstitial myocarditis could be observed. Performing extensive molecular analyses, we detected Tropheryma whipplei in the tissue specimens of the heart, but not in various duodenal tissue probes or in the synovial membrane. Taken together, in the present case the cause of death was acute cardiac failure due to multivalvular pancarditis due to T. whipplei. Besides from classical symptoms and morphological signs, Whipple's disease may present with various features. Regarding the differential diagnosis of a chronic multisystem disorder with aspects of hitherto unknown arthralgia, Whipple's disease should be considered.
Objective MicroRNAs (miRNAs) are short noncoding RNAs capable of exerting dramatic effects by postranscriptionally regulating numerous messenger RNA targets. Toll-like receptor-4 (TLR-4) activation ...by lipopolysaccharide (LPS) induces the expression of three miRNAs in myeloid cells. The aim of this study was to investigate the in vivo consequences of expressing one of the LPS-induced miRNA, miR-146a, in bone marrow cells. Material and Methods The role of miR-146a in hematopoiesis was investigated by using retroviral infection and overexpression of miR-146a in mouse hematopoietic stem/progenitor cells, followed by bone marrow transplantations. Results miR-146a is mainly expressed in primitive hematopoietic stem cells and T lymphocytes. Overexpression of miR-146a in hematopoietic stem cells, followed by bone marrow transplantation, resulted in a transient myeloid expansion, decreased erythropoiesis, and impaired lymphopoiesis in select anatomical locations. Enforced expression of miR-146a also impaired bone marrow reconstitution in recipient mice and reduced survival of hematopoietic stem cells. Conclusions Our results indicate that miR-146a, an LPS-induced miRNA, regulates multiple aspects of hematopoietic differentiation and survival. Furthermore, the consequences of miR-146a expression in hematopoietic cells mimics some of the reported effects with acute LPS exposure.
Collectin 11 (CL-11), also referred to as collectin kidney 1 (CL-K1), is a pattern recognition molecule that belongs to the collectin group of proteins involved in innate immunity. It interacts with ...glycoconjugates on pathogen surfaces and has been found in complex with mannose-binding lectin-associated serine protease 1 (MASP-1) and/or MASP-3 in circulation. Mutation in the CL-11 gene was recently associated with the developmental syndrome 3MC. In the present study, we established and thoroughly validated a sandwich enzyme-linked immunosorbent assay (ELISA) based on two different monoclonal antibodies. The assay is highly sensitive, specific and shows excellent quantitative characteristics such as reproducibility, dilution linearity and recovery (97.7–104%). The working range is 0.15–34ng/ml. The CL-11 concentration in two CL-11-deficient individuals affected by the 3MC syndrome was determined to be below 2.1ng/ml. We measured the mean serum CL-11 concentration to 284ng/ml in 100 Danish blood donors, with a 95% confidence interval of 269–299ng/ml. There was no significant difference in the CL-11 concentration measured in matched serum and plasma samples. Storage of samples and repeated freezing and thawing to a certain extent did not influence the ELISA. This ELISA offers a convenient and reliable method for studying CL-11 levels in relation to a variety of human diseases and syndromes.
► The ELISA is based on monoclonal antibodies, highly sensitive and specific, and is the first of its kind. ► Validation shows excellent reproducibility, dilution linearity and recovery. ► We find that mean serum CL-11 concentration in 100 blood donors is 284ng/ml (95%CI=269–299ng/ml). ► The ELISA allows for direct comparison of plasma and serum samples. ► We measure the CL-11 concentration in persons with 3MC syndrome to be less than 2.1ng/ml.
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