Geldanamycin induces heat shock protein expression through activation of HSF1 in K562 erythroleukemic cells
Geldanamycin induces heat shock protein expression through activation of HSF1 in K562 erythroleukemic cells
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DOI：
10.1080/152165499306829
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发表时间：
1999-10-01
期刊：
影响因子：
4.6
通讯作者：
Kim, HD
中科院分区：
文献类型：
--
作者：
Kim, HR;Kang, HS;Kim, HD
热休克蛋白90是真核细胞中最丰富的热休克蛋白之一，与多种调节蛋白如激酶和转录因子形成复合物。格尔德霉素（GA）是一种苯醌安莎霉素，能特异性地与HSP90结合，破坏HSP90与靶蛋白的相互作用。因此，GA已被用作HSP90的特异性抑制剂。在这项研究中，我们研究是否GA可以影响蛋白质合成和基因表达的人红白血病细胞系K562。用GA处理，而不是除莠霉素A（另一种苯醌安莎霉素），高度诱导70 kDa的蛋白，这是揭示了与抗HSP 70抗体的免疫印迹和免疫沉淀HSP 70。此外，GA诱导热休克因子1（HSF 1）的激活，但不HSF 2，通过电迁移率变化和电迁移率超移测定确定。此外，与热休克处理相似，GA诱导了HSF 1的磷酸化。GA处理后3 h，HSP90的热休克元件结合活性和HSF1的磷酸化水平均降低。这些结果表明GA对HSP90的功能性失活可能通过激活HSF1来刺激热休克蛋白的表达。
HSP90 is one of the most abundant heat shock proteins (HSPs) in eukaryotic cells and is found in complex with several regulatory proteins such as kinases and transcription factors. Geldanamycin (GA), a benzoquinone ansamycin, specifically binds to HSP90 and disrupts the interaction of HSP90 and target proteins. Thus, GA has been used as a specific inhibitor of HSP90. In this study, we examined whether GA could affect protein synthesis and gene expression in the human erythroleukemic cell line K562. Treatment with GA, but not herbimycin A (another benzoquinone ansamycin), highly induced a 70-kDa protein, which was revealed to be HSP70 by immunoblotting and immunoprecipitation with anti-HSP70 antibody The expression of HSP28 was also enhanced by GA. Furthermore, GA induced the activation of heat shock factor 1 (HSF1), but not HSF2, as determined by electromobility shift and electromobility supershift assay. In addition, similar to heat shock treatment, GA inducted the phosphorylation of HSF1. Heat shock element-binding activity and phosphorylation of HSF1 were attenuated 3 h after GA treatment, These results indicate that the functional inactivation of HSP90 by GA potentially stimulates the expression of heat shock proteins through activation of HSF1.