玉米胚组蛋白乙酰转移酶B复合物的分析
Analysis of the histone acetyltransferase B complex of maize embryos.
作者信息
Lusser A, Eberharter A, Loidl A, Goralik-Schramel M, Horngacher M, Haas H, Loidl P
机构信息
Department of Microbiology, University of Innsbruck, Medical School, Fritz-Pregl-strasse 3, A-6020 Innsbruck, Austria.
出版信息
Nucleic Acids Res. 1999 Nov 15;27(22):4427-35. doi: 10.1093/nar/27.22.4427.
Purified histone acetyltransferase B (HAT-B) from maize consists of two subunits, p50 and p45. Cloning of the cDNA and genomic DNA encoding the catalytic subunit p50 revealed a consensus motif reminiscent of other acetyltransferases. Internal peptide sequences and immunological studies identified p45 as a protein related to the Retinoblastoma associated protein Rbap. Antibodies against recombinant p50 were able to immunoprecipitate the enzymatic activity of p50 as well as p45. Consistent with the idea that HAT-B is involved in acetylation of newly synthesized histone H4 during DNA replication, mRNA and protein levels are correlated with S-phases during embryo germination. Inhibition of histone deacetylases by HC toxin or Trichostatin A caused a decrease of the in vivo expression of HAT-B mRNA. Regardless of its predominant cytoplasmic localization, a significant proportion of HAT-B-p50 is present in nuclei, irrespective of the cell cycle stage, suggesting an additional nuclear function.
从玉米中纯化得到的组蛋白乙酰转移酶B（HAT-B）由两个亚基p50和p45组成。对编码催化亚基p50的cDNA和基因组DNA进行克隆，发现了一个与其他乙酰转移酶相似的共有基序。内部肽段序列和免疫研究确定p45是一种与视网膜母细胞瘤相关蛋白Rbap有关的蛋白质。针对重组p50的抗体能够免疫沉淀p50以及p45的酶活性。与HAT-B在DNA复制过程中参与新合成组蛋白H4的乙酰化这一观点一致，在胚胎萌发过程中，mRNA和蛋白质水平与S期相关。HC毒素或曲古抑菌素A对组蛋白脱乙酰酶的抑制导致HAT-B mRNA的体内表达下降。尽管HAT-B主要定位于细胞质，但无论细胞周期阶段如何，细胞核中都存在相当比例的HAT-B-p50，这表明它具有额外的核功能。
Zotero 插件