Regulators of cellular levels of histone acetylation in Saccharomyces cerevisiae
Regulators of cellular levels of histone acetylation in Saccharomyces cerevisiae
复制标题
DOI：
10.1534/genetics.107.085068
复制
发表时间：
2008-05-01
期刊：
影响因子：
3.3
通讯作者：
Kurdistani, Siavash K.
中科院分区：
文献类型：
--
作者：
Peng, Weimin;Togawa, Cynthia;Kurdistani, Siavash K.
组蛋白乙酰化水平通过组蛋白乙酰转移酶（HAT）和去乙酰化酶（HDAC）的相反活性来调节。虽然对组蛋白乙酰化的基因特异性控制了解很多，但对组蛋白乙酰化的总水平或细胞水平如何调节了解甚少。为了确定组蛋白乙酰化的细胞水平的调节剂，我们开发了一种基于免疫荧光的方法来筛选酿酒酵母的单基因缺失文库，以获得细胞组蛋白乙酰化水平显著降低的菌株。在筛选的4848个突变体中，我们确定了63个具有相当大的组蛋白H3和H4中N-末端赖氨酸的细胞低乙酰化的菌株。通过二次筛选（包括单个赖氨酸的质谱分析和特定基因组位点的染色质免疫沉淀）验证了所鉴定菌株亚组的细胞低乙酰化。在已鉴定的突变体中，有几个Ccr4-Not复合物、V型ATP酶和液泡蛋白分选复合物的成员，以及功能未知的基因。我们表明，GCN 5，一个主要的HAT在酵母中，减少组蛋白乙酰转移酶的活性，在特定的突变体，提供了一个合理的解释减少细胞乙酰化水平在体内。我们的研究结果揭示了组蛋白乙酰化，Gcn 5 HAT活性，和不同的过程，如转录，细胞离子稳态和蛋白质转运之间的意想不到的和新的联系。
Histone acetylation levels are regulated through the opposing activities of histone acetyltransferases (HATs) and deacetylases (HDACs). While much is known about gene-specific control of histone acetylation, little is understood about how total or cellular levels of histone acetylation are regulated. To identify regulators of cellular levels of histone acetylation, we developed an immunofluorescence-based approach to screen the single-gene deletion library of Saccharomyces cerevisiae for strains with significant reductions in cellular histone acetylation levels. Of the 4848 mutants screened, we identified 63 strains with considerable cellular hypoacetylation of N-terminal lysines in histones H3 and H4. The cellular hypoacetylation was validated for Subsets of the identified strains through secondary screens including mass spectrometric analysis of individual lysines and chromatin immunoprecipitation of specific genomic loci. Among the identified mutants were several members of the Ccr4-Not complex, V-type ATPases, and vacuolar protein-sorting complexes as well as genes with unknown functions. We show that Gcn5, a major HAT in yeast, has diminished histone acetyltransferase activity in particular mutants, providing a plausible explanation for reduction of cellular acetylation levels in vivo. Our findings have revealed unexpected and novel links between histone acetylation, Gcn5 HAT activity, and diverse processes such as transcription, cellular ion homeostasis, and protein transport.