Protein kinase D2 contributes to either IL-2 promoter regulation or induction of cell death upon TCR stimulation depending on its activity in Jurkat cells
Protein kinase D2 contributes to either IL-2 promoter regulation or induction of cell death upon TCR stimulation depending on its activity in Jurkat cells
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DOI：
10.1093/intimm/dxl108
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发表时间：
2006-12-01
影响因子：
4.4
通讯作者：
Nishimura, Yasuharu
中科院分区：
文献类型：
--
作者：
Irie, Atsushi;Harada, Kumiko;Nishimura, Yasuharu
蛋白激酶D(PKD)家族成员丝氨酸/苏氨酸激酶(PKD1、PKD2和PKD3)在多种细胞中表达，调节包括免疫反应在内的多种细胞反应。我们之前已经证明，PKD参与了人类CD4(+)T细胞克隆在其同源抗原刺激下的信号通路。与上述文献相反，在人T细胞、Jurkat细胞、小鼠胸腺细胞和脾细胞中未检测到PKD1mRNA。相反，质谱学和逆转录-聚合酶链式反应分析显示，PKD2在T细胞中占主导地位。将野生型(WT)和结构性活性(CA)PKD2与IL-2启动子驱动的报告基因一起在Jurkat细胞中表达，以探讨PKD2的作用。在抗CD3单抗刺激下，WT-PKD2表达增强IL-2启动子活性，而CA-PKD2表达抑制IL-2启动子活性并诱导细胞死亡。尽管caspase抑制剂抑制了细胞死亡，但在TCR刺激下，表达CA-PKD2的细胞很少恢复IL-2启动子活性。WT-PKD2主要定位于TCR刺激后移位到胞核的胞浆，而CA-PKD2在刺激前后胞浆和胞核均有表达。蛋白质组学分析表明，CA-PKD2增加了Jurkat细胞中组蛋白乙酰化的组蛋白伴侣蛋白SET的磷酸化水平，并且重组的SET蛋白在体外被CA-PKD2磷酸化。这些数据提供了对T细胞中表达的PKD家族激酶亚群的新的见解，并表明PKD2参与了IL-2启动子的调节和细胞死亡，这取决于它在TCR刺激下的活性。
Members of protein kinase D (PKD) family serine/threonine kinases (PKD1, PKD2 and PKD3) are expressed in wide range of cells and regulate various cellular responses including immune responses. We have previously shown that PKD is involved in the signaling pathways of a human CD4(+) T cell clone stimulated with its cognate antigen. Contrary to foregoing publications, PKD1 mRNA was not detected in human T cells, Jurkat cells and mouse thymocytes and splenocytes. Instead, mass-spectrometric and reverse transcription-PCR analyses revealed that PKD2 was predominant in T cells. To investigate the roles of PKD2, wild-type (WT) and constitutively active (CA) PKD2 were expressed in Jurkat cells together with IL-2 promoter-driven reporter gene. Expression of WT-PKD2 enhanced IL-2 promoter activity upon stimulation with anti-CD3 mAb, while expression of CA-PKD2 inhibited IL-2 promoter activity and induced cell death. Although the cell death was suppressed by the treatment with caspase inhibitor, the IL-2 promoter activity was rarely recovered in CA-PKD2-expressing cells upon TCR stimulation. WT-PKD2 localized mainly in the cytoplasm translocated into the nucleus after TCR stimulation, while CA-PKD2 was present in both the cytoplasm and the nuclei before and after stimulation. Proteomic analyses revealed that CA-PKD2 enhanced the amount of phosphorylated SET protein, a histone chaperon that regulates histone acetylation, in Jurkat cells and the recombinant SET protein was phosphorylated by CA-PKD2 in vitro. The data provide a renewing insight into the subset of PKD family kinases expressed in T cells and suggest that PKD2 is involved in IL-2 promoter regulation and cell death depending on its activity upon TCR stimulation.