Search results for "acetylation"
showing 10 items of 140 documents
Mobility of Acetylated Histones in Sodium Dodecyl Sulfate–Polyacrylamide Gel Electrophoresis
1999
Abstract We describe an altered mobility for acetylated histone isoforms in sodium dodecyl sulfate–polyacrylamide gel electrophoresis. Isoforms of histones H3 and H4 with a higher acetylation degree have a slightly faster electrophoretic mobility. Since acetylation neutralizes the positive charge of the e-amino group of lysine, without significantly changing the molecular mass of the protein, the acetylation-dependent mobility shift could be explained by the increase of the net negative charge of the SDS–histone complexes. A possible consequence of this differential mobility for the acetylation site determination by protein microsequencing from SDS gels is discussed.
Site specificity of yeast histone acetyltransferase B complex in vivo
2008
Saccharomyces cerevisiae Hat1, together with Hat2 and Hif1, forms the histone acetyltransferase B (HAT-B) complex. Previous studies performed with synthetic N-terminal histone H4 peptides found that whereas the HAT-B complex acetylates only Lys12, recombinant Hat1 is able to modify Lys12 and Lys5. Here we demonstrate that both Lys12 and Lys5 of soluble, non-chromatin-bound histone H4 are in vivo targets of acetylation for the yeast HAT-B enzyme. Moreover, coimmunoprecipitation assays revealed that Lys12/Lys5-acetylated histone H4 is bound to the HAT-B complex in the soluble cell fraction. Both Hat1 and Hat2, but not Hif1, are required for the Lys12/Lys5-specific acetylation and for histone …
P/CAF-mediated spermidine acetylation regulates histone acetyltransferase activity
2016
Histones and polyamines are important determinants of the chromatin structure. Histones form the core of nucleosome particles and their modification by acetylation of N-terminal tails is involved in chromatin structural changes and transcriptional regulation. Polyamines, including spermidine, are also targets of both cytoplasmic and nuclear acetylation, which in turn alters their affinity for DNA and nucleosomes. Previous studies report the interplay between polyamines metabolism and levels of histone acetylation, but the molecular basis of this effect is still unclear. In this work, we have analyzed the in vitro effect of spermidine on histone H3 acetylation catalyzed by P/CAF, a highly co…
Caloric Restriction Mimetics Enhance Anticancer Immunosurveillance
2016
International audience; Caloric restriction mimetics (CRMs) mimic the biochemical effects of nutrient deprivation by reducing lysine acetylation of cellular proteins, thus triggering autophagy. Treatment with the CRM hydroxycitrate, an inhibitor of ATP citrate lyase, induced the depletion of regulatory T cells (which dampen anticancer immunity) from autophagy-competent, but not autophagy-deficient, mutant KRAS-induced lung cancers in mice, thereby improving anticancer immunosurveillance and reducing tumor mass. Short-term fasting or treatment with several chemically unrelated autophagy-inducing CRMs, including hydroxycitrate and spermidine, improved the inhibition of tumor growth by chemoth…
Epigenetic Alterations Upstream and Downstream of p53 Signaling in Colorectal Carcinoma
2021
Simple Summary Colorectal cancer (CRC) belongs to the most common cancer types. It is well known that half of all CRC possess missense mutations in the TP53 tumor suppressor gene. However, the entire signaling cascade upstream and downstream of the p53 protein may also contribute to CRC development, if relevant players in this signaling cascade lost their function. Besides p53 loss-of-function by mutations, epigenetic changes (DNA methylation, post translational modifications of histones, micro-RNAs) play a vital role in CRC development. In the present review, we concentrated on the epigenetic modifications related to the entire p53 signal transduction cascade upstream and downstream of p53…
Selective mono-de-O-acetylation of the per-O-acetylated brasilicardin carbohydrate side chain
2021
Abstract Methanol dried over powdered 4 A molecular sieves can be used for a selective mono-de-O-acetylation of the phenolic acetyl group of the per-O-acetyl protected brasilicardin A carbohydrate side chain. This reaction opens a practical procedure for a synthetic access to derivates of the immunosuppressive and cytotoxic natural product brasilicardin A.
Cyclic AMP-induced Chromatin Changes Support the NFATc-mediated Recruitment of GATA-3 to the Interleukin 5 Promoter
2008
Elevated intracellular cyclic AMP levels, which suppress the proliferation of naive T cells and type 1 T helper (Th1) cells are a property of T helper 2 (Th2) cells and regulatory T cells. While cyclic AMP signals interfere with the IL-2 promoter induction, they support the induction of Th2-type genes, in particular of il-5 gene. We show here that cyclic AMP signals support the generation of three inducible DNase I hypersensitive chromatin sites over the il-5 locus, including its promoter region. In addition, cyclic AMP signals enhance histone H3 acetylation at the IL-5 promoter and the concerted binding of GATA-3 and NFATc to the promoter. This is facilitated by direct protein-protein inte…
Alkali consumption of aliphatic carboxylic acids during alkaline pulping of wood and nonwood feedstocks
2013
Abstract The carbohydrate degradation products have been examined, which are formed during the conventional kraft pulping of a softwood, hardwoods, bamboo, and wheat straw as well as soda and soda-anthraquinone pulping of wheat straw. The focus was on “volatile” acids such as formic and acetic acids and “nonvolatile” hydroxy monocarboxylic and dicarboxylic acids. The different consumption profiles were obtained for the charged alkali required for the neutralization of these aliphatic acids depending on the feedstock and the cooking method. The relative composition of the acid fraction in the black liquors of softwood and hardwood and nonwood feedstocks showed characteristic variations. Howe…
Nuclear Pore Complex Acetylation Regulates mRNA Export and Cell Cycle Commitment in Budding Yeast
2021
AbstractNuclear pore complexes (NPCs) mediate communication between the nucleus and the cytoplasm and regulate gene expression by interacting with transcription and mRNA export factors. Lysine acetyl-transferases (KATs) promote transcription through acetylation of chromatin-associated proteins. We find that Esa1, the KAT subunit of the yeast NuA4 complex, also acetylates the nuclear pore basket component Nup60 to promote mRNA export. Acetylation of Nup60 recruits to the nuclear basket the mRNA export factor Sac3, the scaffolding subunit of the Transcription and Export 2 (TREX-2) complex. Esa1-dependent nuclear export of mRNAs promotes entry into S phase, and is inhibited by the Hos3 deacety…
Acetylation of 5-Amino-1H-[1,2,4]triazole Revisited
2002
The products of the acetylation reactions of the common herbicide 5-amino-1H-[1,2,4]triazole were investigated using HPLC, GC-MS, 1H NMR, and FTIR spectroscopy. The conventional annular monoacetylation procedures with acetyl chloride are not regioselective and furnish a mixture of isomers. Traditional diacetylation in neat acetic anhydride under reflux produces a mixture of di-, mono-, and triacetylated derivatives. By using equivalent amounts of acetic anhydride in a dimethylformamide solution, a rapid and selective annular monoacetylation of 5-amino-1H-[1,2,4]triazole was achieved. The monoacetylation proceeds via the formation of the intermediate, 1-acetyl-3-amino-1H-[1,2,4]triazole, whi…