Systematic Proteomic Identification of the Heat Shock Proteins (Hsp) that Interact with Estrogen Receptor Alpha (ERα) and Biochemical Characterization of the ERα-Hsp70 Interaction.
Systematic Proteomic Identification of the Heat Shock Proteins (Hsp) that Interact with Estrogen Receptor Alpha (ERα) and Biochemical Characterization of the ERα-Hsp70 Interaction.
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DOI：
10.1371/journal.pone.0160312
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发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
Du Y
中科院分区：
文献类型：
--
作者：
Dhamad AE;Zhou Z;Zhou J;Du Y
热休克蛋白（Hsps）与雌激素受体（ER）结合，调节ER介导的细胞增殖。历史上，该领域的研究主要集中在Hsp 90上。然而，Hsp-ERα相互作用的一些关键方面仍不清楚。例如，我们不知道哪些Hsp是ERα的主要或次要相互作用物，以及不同的Hsp亚型是否与ERα同样相关。在本研究中，我们通过定量蛋白质组学方法发现，在含有细胞增殖所需元素的培养基中培养的人293 T细胞中，21种Hsp和3种Hsp辅伴侣蛋白与ERα相关。4种Hsp 70（Hsp 70 -1、Hsc 70、Grp 75和Grp 78）是与ERα相关的最丰富的Hsps，其次是2种Hsp 90（Hsp 90 α和Hsp 90 β）和3种Hsp 110（Hsp 105、HspA 4和HspA 4L）。发现在含ERα的复合物中，Hsp 90 α的丰度是Hsp 90 β的2-3倍。在已报道的热休克蛋白伴侣蛋白中，我们检测到前列腺素E合成酶3（p23），肽基脯氨酰顺反异构酶FKBP 5（FKBP 51）和E3泛素蛋白连接酶CHIP（CHIP）。以人乳腺癌MCF 7细胞为研究对象，对两种与ERα相关的Hsps Hsp 70 -1和Hsc 70进行了研究，结果表明，当细胞培养在含胎牛血清和酚红的培养基中时，这两种Hsps在细胞质和细胞核中都能与ERα相互作用。有趣的是，在激素饥饿条件下，ERα-Hsp 70 -1/Hsc 70相互作用仅在细胞质中检测到，而在细胞核中检测不到，并且用17β-雌二醇（E2）刺激饥饿的细胞并没有改变这种相互作用。另外，E2处理减弱了ERα-Hsc 70的相互作用，但对ERα-Hsp 70 -1的相互作用没有影响。进一步的研究表明，Hsp 70 -1和Hsc 70与转录活性染色质和非转录活性染色质相关，并且这两种Hsps在MCF 7细胞中与两种形式的染色质中的ERα相互作用。
Heat shock proteins (Hsps) are known to associate with estrogen receptors (ER) and regulate ER-mediated cell proliferation. Historically, the studies in this area have focused on Hsp90. However, some critical aspects of the Hsp-ERα interactions remain unclear. For example, we do not know which Hsps are the major or minor ERα interactants and whether or not different Hsp isoforms associate equally with ERα. In the present study, through a quantitative proteomic method we found that 21 Hsps and 3 Hsp cochaperones were associated with ERα in human 293T cells that were cultured in a medium containing necessary elements for cell proliferation. Four Hsp70s (Hsp70-1, Hsc70, Grp75, and Grp78) were the most abundant Hsps identified to associate with ERα, followed by two Hsp90s (Hsp90α and Hsp90β) and three Hsp110s (Hsp105, HspA4, and HspA4L). Hsp90α was found to be 2–3 times more abundant than Hsp90β in the ERα-containing complexes. Among the reported Hsp cochaperones, we detected prostaglandin E synthase 3 (p23), peptidyl-prolyl cis-trans isomerase FKBP5 (FKBP51), and E3 ubiquitin-protein ligase CHIP (CHIP). Studies with the two most abundant ERα-associated Hsps, Hsp70-1 and Hsc70, using human breast cancer MCF7 cells demonstrate that the two Hsps interacted with ERα in both the cytoplasm and nucleus when the cells were cultured in a medium supplemented with fetal bovine serum and phenol red. Interestingly, the ERα-Hsp70-1/Hsc70 interactions were detected only in the cytoplasm but not in the nucleus under hormone starvation conditions, and stimulation of the starved cells with 17β-estradiol (E2) did not change this. In addition, E2-treatment weakened the ERα-Hsc70 interaction but had no effect on the ERα-Hsp70-1 interaction. Further studies showed that significant portions of Hsp70-1 and Hsc70 were associated with transcriptionally active chromatin and inactive chromatin, and the two Hsps interacted with ERα in both forms of the chromatins in MCF7 cells.