The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Science, Shandong University, Jinan 250100, China.
Endocrinology. 2014 May;155(5):1738-50. doi: 10.1210/en.2013-2020. Epub 2014 Feb 11.
The insect steroid hormone 20-hydroxyecdysone (20E) regulates gene transcription via a genomic pathway by forming a transcription complex that binds to DNA with the help of the chaperone proteins, heat shock proteins (Hsps) Hsc70 and Hsp90. However, the nongenomic mechanisms by which 20E regulates gene expression remain unclear. In this study, we found that 20E regulated the phosphorylation of serine/threonine protein kinase cyclin-dependent kinase 10 (CDK10) through a nongenomic pathway to mediate gene transcription in the lepidopteran Helicoverpa armigera. The down-regulation of CDK10 by RNA interference in larvae and the epidermal cell line delayed development and suppressed 20E-induced gene transcription. CDK10 was localized to the nucleus via its KKRR motif, and this nuclear localization and the ATPase motif were necessary for the efficient expression of the 20E-inducible gene. The rapid phosphorylation of CDK10 was induced by 20E, whereas it was repressed by the inhibitors of G-protein-coupled receptors, phospholipase C, and Ca²⁺ channels. Phosphorylated CDK10 exhibited increased interactions with Hsps Hsc70 and Hsp90 and then promoted the interactions between Hsps and ecdysone receptor EcRB1 and the binding of the Hsps-EcRB1 complex to the 20E response element for the regulation of gene transcription. CDK10 depletion suppressed the formation of the Hsps-EcRB1 complex at the hormone receptor 3 promoter. These results suggest that 20E induces CDK10 phosphorylation via a nongenomic pathway to regulate gene transcription in the nucleus.
昆虫类固醇激素 20-羟基蜕皮酮（20E）通过形成转录复合物与 DNA 结合，在伴侣蛋白热休克蛋白（Hsp）Hsc70 和 Hsp90 的帮助下，调节基因转录，从而通过基因组途径调节基因转录。然而，20E 调节基因表达的非基因组机制尚不清楚。在这项研究中，我们发现 20E 通过非基因组途径调节丝氨酸/苏氨酸蛋白激酶细胞周期蛋白依赖性激酶 10（CDK10）的磷酸化，以介导鳞翅目昆虫棉铃虫的基因转录。幼虫和表皮细胞系中 CDK10 的 RNA 干扰下调延迟了发育并抑制了 20E 诱导的基因转录。CDK10 通过其 KKRR 基序定位于细胞核，并且这种核定位和 ATP 酶基序对于 20E 诱导基因的有效表达是必要的。20E 迅速诱导 CDK10 的磷酸化，而 G 蛋白偶联受体、磷脂酶 C 和 Ca²⁺通道的抑制剂则抑制其磷酸化。磷酸化的 CDK10 与 Hsps Hsc70 和 Hsp90 的相互作用增加，然后促进 Hsps 与蜕皮激素受体 EcRB1 之间的相互作用以及 Hsps-EcRB1 复合物与 20E 反应元件的结合，从而调节基因转录。CDK10 耗竭抑制了激素受体 3 启动子处 Hsps-EcRB1 复合物的形成。这些结果表明，20E 通过非基因组途径诱导 CDK10 磷酸化，从而在细胞核中调节基因转录。
