DNA damage activates p53 through a phosphorylation-acetylation cascade
DNA damage activates p53 through a phosphorylation-acetylation cascade
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DOI：
10.1101/gad.12.18.2831
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发表时间：
1998-09-15
影响因子：
10.5
通讯作者：
Appella, E
中科院分区：
文献类型：
--
作者：
Sakaguchi, K;Herrera, JE;Appella, E
p53介导的转录激活是对DNA损伤的关键细胞反应。p53的稳定性和位点特异性DNA结合活性以及因此转录活性通过翻译后修饰（包括磷酸化和乙酰化）来调节。在这里，我们表明p53在体外被两种不同的组蛋白乙酰转移酶（HAT）（共激活因子p300和PCAF）在不同的位点乙酰化。p300乙酰化p53羧基末端区域的Lys-382，而PCAF乙酰化核定位信号中的Lys-320。在任一位点的乙酰化增强序列特异性DNA结合。使用多克隆抗血清特异性p53磷酸化或乙酰化的特定残基，我们表明，人p53的赖氨酸-382成为乙酰化和Ser-33和Ser-37成为磷酸化后，暴露于紫外线或电离辐射细胞在体内。在体外，氨基末端p53肽磷酸化在Ser-33和/或在Ser-37差异抑制p53乙酰化的每一个HAT。这些结果表明，DNA损伤增强p53作为转录因子的活性，部分通过羧基末端乙酰化，反过来，是由氨基末端磷酸化。
Activation of p53-mediated transcription is a critical cellular response to DNA damage. p53 stability and site-specific DNA-binding activity and, therefore, transcriptional activity, are modulated by post-translational modifications including phosphorylation and acetylation. Here we show that p53 is acetylated in vitro at separate sites by two different histone acetyltransferases (HATs), the coactivators p300 and PCAF. p300 acetylates Lys-382 in the carboxy-terminal region of p53, whereas PCAF acetylates Lys-320 in the nuclear localization signal. Acetylations at either site enhance sequence-specific DNA binding. Using a polyclonal antisera specific for p53 that is phosphorylated or acetylated at specific residues, we show that Lys-382 of human p53 becomes acetylated and Ser-33 and Ser-37 become phosphorylated in vivo after exposing cells to UV light or ionizing radiation. In vitro, amino-terminal p53 peptides phosphorylated at Ser-33 and/or at Ser-37 differentially inhibited p53 acetylation by each HAT. These results suggest that DNA damage enhances p53 activity as a transcription factor in part through carboxy-terminal acetylation that, in turn, is directed by amino-terminal phosphorylation.