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：
10.1080/713803536
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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
HSP90是真核细胞中最丰富的热休克蛋白（HSPs）之一，与激酶和转录因子等多种调节蛋白复合物存在。格尔达霉素（GA）是一种苯醌类ansamycin，特异性结合HSP90并破坏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，我们检测了GA是否会影响人红白血病细胞系K562的蛋白质合成和基因表达。用GA而不是herbimycin A（另一种苯醌类ansamycin）处理，高诱导了一个70 kda的蛋白，通过免疫印迹和抗HSP70抗体的免疫沉淀显示该蛋白为HSP70， HSP28的表达也被GA增强。此外，通过电移动性转移和电移动性超转移实验确定，GA诱导热休克因子1 （HSF1）的激活，但不诱导HSF2的激活。此外，与热休克处理类似，GA诱导HSF1磷酸化。GA处理3 h后，热休克元件结合活性和HSF1磷酸化减弱，说明GA对HSP90的功能失活可能通过激活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.