Identification of ALDH4 as a p53-inducible gene and its protective role in cellular stresses
Identification of ALDH4 as a p53-inducible gene and its protective role in cellular stresses
复制标题
DOI：
10.1007/s10038-003-0122-3
复制
发表时间：
2004-03-01
影响因子：
3.5
通讯作者：
Arakawa, H
中科院分区：
文献类型：
--
作者：
Yoon, KA;Nakamura, Y;Arakawa, H
为了确定p53的其他靶点，我们使用cDNA微阵列系统来检查基因表达模式，以响应p53缺陷癌细胞中外源性p53的强制表达，并确定醛脱氢酶4（ALDH 4）基因作为p53的直接靶点。ALDH 4是一种细胞基质NAD（+）依赖性酶，催化脯氨酸降解途径的第二步。在HCT 116细胞中，阿霉素处理引起的DNA损伤以p53依赖的方式诱导ALDH 4 mRNA的表达。ALDH 4基因内含子1中含有p53结合序列，EMSA和ChIP分析显示p53与该位点相互作用。我们证实了p53依赖的转录活性的结合位点的报告分析的手段。反义寡核苷酸抑制ALDH 4表达能够增强Ad-p53感染诱导的细胞死亡。转化为过表达ALDH 4的H1299细胞在用过氧化氢或UV处理后显示出比亲本或对照细胞显著更低的细胞内活性氧（ROS）水平。这些细胞也能抵抗过氧化氢造成的细胞损伤。这些结果表明，p53可能通过转录激活ALDH 4对细胞内ROS的产生诱导的细胞损伤发挥保护作用。
To identify additional targets of p53, we used a cDNA microarray system to examine gene-expression patterns in response to enforced expression of exogenous p53 in p53-deficient cancer cells, and identified the aldehyde dehydrogenase 4 (ALDH4) gene as a direct target of p53. ALDH4 is a mitochondrial-matrix NAD(+)-dependent enzyme catalyzing the second step of the proline degradation pathway. Expression of ALDH4 mRNA was induced in HCT116 cells in response to DNA damage caused by adriamycin treatment, in a p53-dependent manner. ALDH4 contains a potential p53 binding sequence in intron1 and the interaction of p53 with the site was shown by EMSA and ChIP assays. We confirmed p53-dependent transcriptional activity of the binding site by means of a reporter assay. Inhibition of ALDH4 expression by antisense oligonucleotides was able to enhance cell death induced by infection with Ad-p53. H1299 cells transformed to over-express ALDH4 showed significantly lower intracellular reactive oxygen species (ROS) levels than parental or control cells after treatment with hydrogen peroxide or UV. Those cells were also resistant to cell damage caused by hydrogen peroxide. These results suggest that p53 might play a protective role against cell damage induced by generation of intracellular ROS, through transcriptional activation of ALDH4.