A novel HECT-type E3 ubiquitin protein ligase NEDL1 enhances the p53-mediated apoptotic cell death in its catalytic activity-independent manner
A novel HECT-type E3 ubiquitin protein ligase NEDL1 enhances the p53-mediated apoptotic cell death in its catalytic activity-independent manner
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DOI：
10.1038/sj.onc.1211032
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发表时间：
2008-06-01
期刊：
影响因子：
8
通讯作者：
Nakagawara, A.
中科院分区：
文献类型：
--
作者：
Li, Y.;Ozaki, T.;Nakagawara, A.
NEDL 1（NEDD 4-like ubiquitin protein ligase-1）是一种新发现的HECT型E3泛素蛋白连接酶，在神经母细胞瘤中高表达。在本研究中，我们发现NEDL 1与p53协同诱导细胞凋亡。在顺铂（CDDP）介导的神经母细胞瘤SH-SY 5 Y细胞凋亡过程中，诱导p53积累与NEDL 1表达水平的增加有关。NEDL 1的增强表达导致携带野生型p53的SH-SY 5 Y和U2 OS细胞中G418抗性集落的数量减少，而NEDL 1对p53缺陷的H1299和SAOS-2细胞没有检测到影响。类似地，NEDL 1的强制表达增加了具有亚G1 DNA含量的U2 OS细胞的数量。免疫共沉淀和体外结合试验表明，NEDL 1结合的COOH末端区域的p53。荧光素酶报告基因检测显示NEDL 1具有增强p53转录活性的能力。小干扰RNA介导的内源性NEDL 1的敲低赋予U2 OS细胞对阿霉素的抗性。值得注意的是，NEDL 1以其催化活性非依赖性方式增强p53的促凋亡活性。总之，我们目前的研究结果表明，NEDL 1与p53的功能相互作用可能有助于诱导携带野生型p53的癌细胞的凋亡。
NEDL1 (NEDD4-like ubiquitin protein ligase-1) is a newly identified HECT-type E3 ubiquitin protein ligase highly expressed in favorable neuroblastomas as compared with unfavorable ones. In this study, we found that NEDL1 cooperates with p53 to induce apoptosis. During cisplatin (CDDP)-mediated apoptosis in neuroblastoma SH-SY5Y cells, p53 was induced to accumulate in association with an increase in expression levels of NEDL1. Enforced expression of NEDL1 resulted in a decrease in number of G418-resistant colonies in SH-SY5Y and U2OS cells bearing wild-type p53, whereas NEDL1 had undetectable effect on p53-deficient H1299 and SAOS-2 cells. Similarly, enforced expression of NEDL1 increased number of U2OS cells with sub-G1 DNA content. Co-immunoprecipitation and in vitro binding assays revealed that NEDL1 binds to the COOH-terminal region of p53. Luciferase reporter assay showed that NEDL1 has an ability to enhance the transcriptional activity of p53. Small interfering RNA-mediated knockdown of the endogenous NEDL1 conferred the resistance of U2OS cells to adriamycin. It is noteworthy that NEDL1 enhanced pro-apoptotic activity of p53 in its catalytic activity-independent manner. Taken together, our present findings suggest that functional interaction of NEDL1 with p53 might contribute to the induction of apoptosis in cancerous cells bearing wild-type p53.