Sun Yaning, An Shiheng, Henrich Vincent C, Sun Xiaoping, Song Qisheng
Division of Plant Sciences, 1-31 Agriculture Building, University of Missouri, Columbia, Missouri 65211, USA.
J Proteome Res. 2007 Nov;6(11):4478-88. doi: 10.1021/pr0705183. Epub 2007 Oct 9.
Ecdysone receptor (EcR) and its heterodimeric partner, ultraspiracle protein (USP), are nuclear receptors that mediate the action of the insect molting hormone 20-hydroxyecdysone (20E). There is evidence that the activity of both receptors is affected by phosphorylation. Using a proteomic approach, we have shown that protein kinase C (PKC) activity is necessary for mediating 20E-induced expression of 14 specific proteins, including three previously reported 20E responsive proteins, and is also responsible for the intracellular localization of EcR and USP in larval salivary glands of Drosophila melanogaster. The 20E-dependent expression of the proteins was verified using real-time PCR and/or Western blot analysis. For some genes, inhibition of PKC activity reduced 20E-dependent transcriptional activity rapidly, raising the possibility that these are direct gene targets of EcR and USP. The data further indicate that PKC-mediated phosphorylation is also required for genes regulated indirectly by 20E-induced changes in the larval salivary gland.
蜕皮激素受体(EcR)及其异源二聚体伴侣超气门蛋白(USP)是核受体,介导昆虫蜕皮激素20-羟基蜕皮酮(20E)的作用。有证据表明,这两种受体的活性都受磷酸化作用的影响。通过蛋白质组学方法,我们发现蛋白激酶C(PKC)活性对于介导20E诱导的14种特定蛋白质的表达是必需的,其中包括三种先前报道的20E反应蛋白,并且PKC还负责EcR和USP在黑腹果蝇幼虫唾液腺中的细胞内定位。使用实时PCR和/或蛋白质印迹分析验证了这些蛋白质的20E依赖性表达。对于某些基因,抑制PKC活性会迅速降低20E依赖性转录活性,这增加了这些基因是EcR和USP直接基因靶点的可能性。数据进一步表明,PKC介导的磷酸化对于由20E诱导的幼虫唾液腺变化间接调控的基因也是必需的。