热休克蛋白90与TAK1相互作用调节白介素-1β激活的信号转导

发布时间：2018-01-16 02:07

  本文关键词：热休克蛋白90与TAK1相互作用调节白介素-1β激活的信号转导　出处：《南京师范大学》2008年硕士论文　论文类型：学位论文

  更多相关文章： 热休克蛋白90 转化生长因子-β活化激酶1 格尔德霉素 白介素-1β 炎症 信号转导

【摘要】： 热休克蛋白90(Heat shock protein 90,Hsp90)是Hsp90家族成员,进化上高度保守,其结构主要由一个N端高度保守的ATPase结构域,一个中间结构域以及一个介导Hsp90二聚化的C端结构域三部分组成。Hsp90是胞内广泛存在的一个分子伴侣,其底物蛋白主要为一些在细胞内信号通路中起重要作用的类固醇激素受体、蛋白激酶、转录因子等。Hsp90特异性抑制剂GA或RAD,能够通过竞争的结合到Hsp90 N端的ATP/ADP结合位点阻断其分子伴侣功能,从而导致其底物蛋白通过蛋白酶体降解。因此,借助于Hsp90的抑制剂可以进一步扩大Hsp90的底物范围。IL-1是一种促炎细胞因子,主要由LPS刺激的单核/巨嗜细胞产生,在机体免疫反应和免疫缺陷性疾病如类风湿关节炎(rheumatoid arthritis,RA)中具有重要作用。TAK1作为MAPKKK参与IL-1β诱导的信号通路,并对下游MAPKs(JNK和p38)和NF-κ3的激活是必需的。蛋白质组学研究表明Hsp90能够与TAK1相互作用。 我们的研究发现并报道了Hsp90在IL-1β激活的信号级联中的新的调控作用。GA处理后抑制了IL-1β诱导的,TAK1-MAPKs和TAK1-NF-κ3通路的激活,从而导致炎症相关蛋白COX-2表达的减少。利用RNA干扰手段下调内源Hsp90的蛋白水平后,我们也得到了相同的结果。此外,T6RZC稳定表达细胞系可以通过Coumermycin A诱导T6RZC二聚化,从而模拟IL-1β激活的胞内信号级联,以避开Hsp90分子伴侣复合物对TAK1上游激酶IRAK-1的调节作用对MAPKs和NF-κB激活的影响。在T6RZC稳定表达细胞系中,GA明显抑制了JNK、p38 MAPKs的磷酸化和IκB的降解。免疫沉淀实验结果显示Hsp90能够在体内与TAK1发生相互作用,Hsp90的氨基端1-401位氨基酸介导了两者的结合。Hsp90的抑制剂能够在转录后水平下调内源TAK1的表达而不影响其mRNA水平,并且GA处理后TAK1蛋白的降解是通过蛋白酶体途径。这些结果表明Hsp90通过与TAK1发生蛋白间相互作用来调节IL-1β激活的MAPKs和NF-κB信号转导通路。 综上所述,本研究首次揭示了Hsp90通过调节TAK1蛋白的稳定性参与IL-1β激活的信号级联;提出了Hsp90在胞内调节MAPKs和NF-κB通路的新的作用机制。这些结果对于深入研究Hsp90在炎症相关信号通路中的调节作用具有重要的指导意义。
[Abstract]:Heat shock protein 90 (heat shock protein 90 Hsp90) is a member of the Hsp90 family and is highly conserved in evolution. Its structure is mainly composed of a highly conserved N-terminal ATPase domain. One intermediate domain and one C-terminal domain that mediates Hsp90 dimerization consist of three parts. Hsp90 is a ubiquitous molecular chaperone in the cell. Its substrate proteins are some steroid hormone receptors protein kinases transcription factors and other specific inhibitors GA or RAD which play an important role in intracellular signaling pathway. The molecular chaperone function can be blocked by competitive binding to the ATP/ADP binding site at the N-terminal of Hsp90, which leads to the degradation of its substrate protein through proteasome. The inhibitor of Hsp90 can further expand the range of substrates of Hsp90. IL-1 is a pro-inflammatory cytokine which is mainly produced by mononuclear / giant eosinophil stimulated by LPS. Rheumatoid arthritis in immune response and immunodeficient diseases such as rheumatoid arthritis. TAK1 plays an important role in IL-1 尾 -induced signaling pathway. TAK1 plays an important role in IL-1 尾 -induced signaling pathway. Activation of downstream MAPKs(JNK and p38) and NF- 魏 3 were necessary. Proteomic studies showed that Hsp90 could interact with TAK1. We found and reported the new regulation of Hsp90 in IL-1 尾 -activated signal cascades. Ga treatment inhibited IL-1 尾 -induced signaling. Activation of TAK1-MAPKs and TAK1-NF- 魏 3 pathway. This resulted in a decrease in the expression of inflammatory related protein COX-2. The same results were obtained after RNA interference was used to down-regulate the protein level of endogenous Hsp90. T6RZC stable expression cell line can induce T6RZC dimerization through Coumermycin A, thus mimicking the intracellular signal cascade activated by IL-1 尾. In order to avoid the effect of Hsp90 chaperone complex on the activation of MAPKs and NF- 魏 B in TAK1 upstream kinase IRAK-1, T6RZC stable expression cell line. Ga inhibited the phosphorylation of MAPKs and the degradation of I 魏 B. the immunoprecipitation results showed that Hsp90 could interact with TAK1 in vivo. The amino terminal 1-401 amino acids of Hsp90 mediate that the inhibitor of Hsp90 can down-regulate the expression of endogenous TAK1 at post-transcriptional level without affecting its mRNA level. The degradation of TAK1 protein after GA treatment was mediated by proteasome pathway. These results suggest that Hsp90 regulates the activation of IL-1 尾 -activated MAPKs by interacting with TAK1 proteins. NF- 魏 B signal transduction pathway. In conclusion, this study for the first time revealed that Hsp90 participates in the signal cascade of IL-1 尾 activation by regulating the stability of TAK1 protein. A new mechanism of intracellular regulation of MAPKs and NF- 魏 B pathway by Hsp90 was proposed. These results are important for further study of the regulatory role of Hsp90 in inflammatory signaling pathway. Guide meaning.
【学位授予单位】：南京师范大学
【学位级别】：硕士
【学位授予年份】：2008
【分类号】：R341

【引证文献】

相关硕士学位论文 前1条

1 李璐;应用抑制消减杂交技术（SSH）筛选癫痫的相关基因[D];山东大学;2012年

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