Molecular mechanisms of response of living body to environmental stress

1.研究了PP 2C ε在IL-1信号通路中的作用。PP 2C ε的异位表达可抑制IL-1和TAK 1诱导的丝裂原活化蛋白激酶激酶4（MKK 4）-c-Jun N-末端激酶或MKK 3-p38信号通路的激活。PP 2C ε在体外使TAK 1去磷酸化。免疫共沉淀实验表明，PP 2C ε与TAK 1稳定结合，并减弱TAK 1与MKK 4或MKK 6的结合。PP 2C ε的磷酸酶阴性突变体PP 2C ε（D/A）作为显性阴性形式的异位表达增强了TAK 1与MKK 4或MKK 6之间的关联以及TAK 1诱导的AP-1报告基因的激活。PP 2C ε和TAK 1之间的关联被IL-1处理的细胞暂时抑制。综上所述，这些结果表明，在缺乏IL-1诱导的信号的情况下，PP 2C ε通过与TAK 1结合和去磷酸化TAK 1，有助于保持TAK 1信号通路处于失活状态。 ...更多信息 在小鼠中使用基因敲除技术研究PP 2C β的生理功能。我们发现大多数PP 2C β^<Δ/Δ>胚胎在2 - 8细胞阶段死亡，而PP 2C β^<Δ/Δ> ES细胞是活的，这表明相对高的PP 2C β表达是植入前发育的早期阶段所必需的。使用ES细胞进行的PP 2C β敲低研究显示，血清诱导的p38激活，而非JNK、ERK或Akt，通过降低PP 2C β表达而进一步增强。由于p38参与了早期植入前胚胎有丝分裂的负调控，这些观察结果提出了一种可能性，即由于PP 2C β^<Δ/Δ>胚胎中p38的活性增强，早期卵裂阶段的细胞分裂可能受到严重干扰。3.我们已经表明，BMPRII，一种BMP II型受体，通过其独特的羧基末端区域与JNK结合，其含有推定的JNK结合结构域。BMPRII还能够结合MKK 4、MKK 7和ASK 1。BMP 2处理细胞诱导JNK向BMPRII的募集，并激活与BMPRII相关的ASK 1信号传导模块。这些结果表明，BMPRII作为细胞膜相关支架蛋白参与了ASK 1-JNK信号通路的空间调控。少

1.We investigated the role(s) of PP2Cε in the regulation of IL-1 signaling pathways. Ectopic expression of PP2Cε inhibited the IL-1-and TAK1-induced activation of mitogen-activated protein kinase kinase 4 (MKK4)-c-Jun N-terminal kinase or MKK3-p38 signaling pathway. PP2Cε dephosphorylated TAK1 in vitro. Co-immunoprecipitation experiments indicated that PP2Cε associates stably with TAK1 and attenuates the binding of TAK1 to MKK4 or MKK6. Ectopic expression of a phosphatase-negative mutant of PP2Cε, PP2Cε (D/A), which acted as a dominant negative form, enhanced both the association between TAK1 and MKK4 or MKK6 and the TAK1-induced activation of an AP-1 reporter gene. The association between PP2Cε and TAK1 was transiently suppressed by IL-1 treatment of the cells. Taken together, these results suggest that, in the absence of IL-1-induced signal, PP2Cε contributes to keeping the TAK1 signaling pathway in an inactive state by associating with and dephosphorylating TAK1.2.We investigated th … More e physiologic functions of PP2Cβ using a gene knockout technique in mice. We found that most PP2Cβ^<Δ/Δ> embryos die between the two-and eight-cell stages, whereas PP2Cβ^<Δ/Δ> ES cells are viable, suggesting that relatively high PP2Cβ expression is required for the early stages of pre-implantation development. PP2Cβ knockdown studies using ES cells revealed that serum-induced activation of p38, but not JNK, ERK, or Akt, was enhanced further by decreased PP2Cβ expression. Since p38 has been implicated in the negative regulation of mitosis in early pre-implantation embryos, these observations raise the possibility that cell division at early cleavage stages might be severely disturbed due to the enhanced activity of p38 in PP2Cβ^<Δ/Δ> embryos.3.We have shown that BMPRII, a BMP type II receptor, associates with JNK through its unique carboxyl-terminal region, which contains a putative JNK binding domain. BMPRII was also able to bind to MKK4, MKK7 and ASK1. BMP2 treatment of cells induced the recruitment of JNK to BMPRII and activated the ASK1 signaling module associated with BMPRII. These results suggest that BMPRII participates in the spatial regulation of the ASK1-JNK signaling pathway as a cell-membrane associated scaffolding protein. Less