Regulation of SV40 large T-antigen stability by reversible acetylation
Regulation of SV40 large T-antigen stability by reversible acetylation
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DOI：
10.1038/sj.onc.1209731
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发表时间：
2006-11-01
期刊：
影响因子：
8
通讯作者：
Yoshida, M.
中科院分区：
文献类型：
--
作者：
Shimazu, T.;Komatsu, Y.;Yoshida, M.
蛋白质赖氨酸残基上的可逆乙酰化已显示调节核蛋白如组蛋白和p53以及细胞质蛋白如α-微管蛋白的功能。为了鉴定新的乙酰化蛋白质，我们通过对来自用曲马斯他汀A（TSA）处理的细胞的抗乙酰化赖氨酸抗体的亲和力纯化了几种蛋白质。在鉴定的蛋白质中，在这里我们报告SV 40大T抗原（T-Ag）的乙酰化。乙酰化位点被确定为赖氨酸-697，其位于邻近C-末端Cdc 4磷酸降解决定子（CPD）。CBP乙酰转移酶的过表达乙酰化T-Ag，而HDAC 1，HDAC 3和SIRT 1结合和脱乙酰化T-Ag。乙酰化和脱乙酰化独立于p53（T-Ag的结合伴侣）发生，但乙酰化在p53存在下增强。TSA和NA或乙酰化模拟突变体（K697 Q）处理的细胞中的T-Ag在COS-7细胞中变得不稳定，表明乙酰化调节T-Ag的稳定性。事实上，稳定表达K697 Q的NIH 3 T3细胞与表达野生型或K697 R突变体的NIH 3 T3细胞相比，显示出锚定非依赖性生长降低。这些结果表明乙酰化使T-Ag不稳定并调节NIH 3 T3细胞中T-Ag的转化活性。
Reversible acetylation on protein lysine residues has been shown to regulate the function of both nuclear proteins such as histones and p53 and cytoplasmic proteins such as alpha-tubulin. To identify novel acetylated proteins, we purified several proteins by the affinity to an anti-acetylated-lysine antibody from cells treated with trichostatin A (TSA). Among the proteins identified, here we report acetylation of the SV40 large T antigen (T-Ag). The acetylation site was determined to be lysine-697, which is located adjacent to the C-terminal Cdc4 phosphodegron (CPD). Overexpression of the CBP acetyltransferase acetylated T-Ag, whereas HDAC1, HDAC3 and SIRT1 bound and deacetylated T-Ag. The acetylation and deacetylation occurred independently of p53, a binding partner of T-Ag, but the acetylation was enhanced in the presence of p53. T-Ag in the cells treated with TSA and NA or the acetylation mimic mutant (K697Q) became unstable in COS-7 cells, suggesting that acetylation regulates stability of T-Ag. Indeed, NIH3T3 cells stably expressing K697Q showed decreased anchorage-independent growth compared with those expressing wild type or the K697R mutant. These results demonstrate that acetylation destabilizes T-Ag and regulates the transforming activity of T-Ag in NIH3T3 cells.