HDL APOLIPOPROTEIN MEDIATED EXOCYTOSIS TO REMOVE EXCESS CELLULAR CHOLESTEROL

组蛋白乙酰化和去乙酰化似乎发挥了关键作用 染色质在调控转录激活中的作用 模板。来自酵母的研究表明，多个组蛋白 乙酰转移酶(HAT)和脱乙酰酶复合体与 能够修改特定的赖氨酸残基组合 组蛋白的尾巴。我们之前已经描述了四个天然核小体 具有不同目标特异性的HAT复合体，它产生 独特的乙酰化模式和体外刺激转录 来自染色质模板。发现酵母菌 转录适配蛋白Gcn5起催化作用 其中两个复合体中的亚基表明这些复合体可能是 通过与转录的相互作用针对特定的基因 各种因素。在这里，我们建议分析和识别 一种新型高分子量HAT络合物的组成，与 Ada和Saga Hat复合体显然也包含Gcn5 AS 催化亚基。该综合体目前高度提纯， 处于适合用质谱仪进行蛋白质分析的状态。这些 结果应该能进一步深入了解HAT复合体的作用 转录激活和它们的作用机制。

Histone acetylation and deacetylation appears to play a critical role in regulating transcriptional activation from chromatin templates. Studies from yeast have revealed that multiple histone acetyltransferases (HAT) and deacetylase complexes exist with the ability to modify specific combinations of lysine residues in the tails of histones.We have previously described four native nucleosomal HAT complexes with different target specificities, which generate unique patterns of acetylation and stimulate transcription invitro from chromatin templates. The discovery that the yeast transcriptional adaptor protein Gcn5 functions as the catalytic subunit in two of these complexes suggests that these complexes may be targetted to specific genes through interactions with transcription factors. Here we propose the analysis and identification of the components of a novel high molecular weight HAT complex, related to the Ada and SAGA HAT complexes which also apparently contains Gcn5 as the catalytic subunit. This complex is currently highly purified and in a state suitable for protein analysis by Mass spectrometry. These results should provide further insight into the role of HAT complexes in transcriptional activation and to the mechanism of their action.