BRCA1 function mediates a TRAP/DRIP complex through direct interaction with TRAP220 (Retracted article. See vol. 33, pg. 804, 2014)
BRCA1 function mediates a TRAP/DRIP complex through direct interaction with TRAP220 (Retracted article. See vol. 33, pg. 804, 2014)
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DOI：
10.1038/sj.onc.1207786
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发表时间：
2004-08-05
期刊：
影响因子：
8
通讯作者：
Kato, S
中科院分区：
文献类型：
--
作者：
Wada, O;Oishi, H;Kato, S
乳腺癌易感基因1（BRCA 1）是一种肿瘤抑制基因，在高比例的遗传性乳腺癌和卵巢癌中突变。多功能BRCA 1蛋白作用于细胞周期控制，通过不同的结构域发挥几个高度专业化的DNA修复过程。通过其C-末端结构域（BRCT）的基因调控是BRCA 1介导的肿瘤抑制必不可少的，这表明BRCT结构域与辅助调节复合物相互作用的可能性。使用HeLa S3细胞核提取物的生化方法，我们分离出BRCT相关复合物，并鉴定出其中一种纯化组分为TRAP 220。然后，我们进行了体内（免疫共沉淀）和体外（谷胱甘肽S-转移酶下拉试验）的相互作用研究，并表明BRCT直接与TRAP 220相互作用。这种体外相互作用被BRCT点突变完全消除，这些点突变是在缺乏反式激活功能的BRCA 1患者中发现的。BRCA 1反式激活功能依赖于瞬时表达试验中TRAP 220的表达水平。此外，细胞存活测定表明，反义TRAP 220表达破坏内源性TRAP 220表达显著降低了DNA损伤后BRCA 1增强的存活率。这些结果表明TRAP 220复合物作为推定的共激活物复合物在BRCA 1介导的肿瘤抑制中发挥重要作用。
Breast cancer susceptibility gene 1 (BRCA1) is a tumor suppressor gene mutated in a high percentage of hereditary breast and ovarian cancers. The multifunctional BRCA1 protein acts on cell cycle control, exerting several highly specialized DNA repair processes through diverse domains. Gene regulation through its C-terminal domain (BRCT) is indispensable for BRCA1-mediated tumor suppression, suggesting the possibility that the BRCT domain interacts with co-regulator complexes. Using a biochemical approach with HeLa S3 nuclear extracts, we isolated BRCT-associated complexes and identified one of the purified components as TRAP220. We then performed interaction studies in vivo (co-immunoprecipitation) and in vitro (glutathione S-transferase pull-down assays) and showed that BRCT directly interacted with TRAP220. This in vitro interaction was completely abolished by BRCT point mutations typical of those found in patients with BRCA1 that lack transactivation function. BRCA1 transactivation function was dependent on TRAP220 expression level in a transient expression assay. Moreover, a cell survival assay showed that antisense TRAP220 expression to disrupt endogenous TRAP220 expression significantly reduced the survival rate potentiated by BRCA1 after DNA damage. These results suggested that a TRAP220 complex play an important role as putative co-activator complexes in BRCA1-mediated tumor suppression.