The regulatory role of dopamine receptor D1 on PP2A via SUMO-1 modification
The regulatory role of dopamine receptor D1 on PP2A via SUMO-1 modification
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SUMO-1修饰多巴胺受体D1对PP2A的调节作用
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
WP Luo
中科院分区：
文献类型：
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作者：
CQ Yu;LQ Yin;ZT Tu;DW Liu;WP Luo
目的：肾脏多巴胺受体D1在机体血压调节中起关键作用。在高血压状态下，D1受体过度磷酸化损害其功能。G蛋白激酶4（GRK 4）和蛋白磷酸酶2A（PP 2A）对D1受体起磷酸化和去磷酸化作用。目前的研究表明，GRK 4的抑制不能使D1受体的磷酸化水平正常化。同时，PP 2A在高血压时被激活，表明D1受体的去磷酸化功能异常，其原因尚不清楚。本研究旨在探讨SUMO-1修饰对多巴胺D1受体PP 2A的调控作用及其机制。材料与方法：利用生物信息学软件预测多巴胺D1受体的SUMO修饰位点。用肾多巴胺受体D1的突变体转染培养的CHO细胞。免疫共沉淀和Western blot检测过磷酸化的D1受体与PP 2A之间的相互作用。激光共聚焦显微镜检查它们的共定位。结果：生物信息学预测了多巴胺受体D1上的两个SUMO修饰位点K265和K402。免疫共沉淀实验显示PP 2A与磷酸化D1受体的相互作用减弱，从而阻碍了D1受体的去磷酸化和正常功能。结论：多巴胺D1受体存在两个SUMO修饰位点，SUMO修饰后D1受体的磷酸化可与PP 2A相互作用，从而抑制D1受体的去磷酸化，维持正常功能，为高血压的防治提供新的思路。
OBJECTIVE:.Renal dopamine receptor D1 played a critical role in the regulation of body blood pressure. Under hypertension, over-phosphorylation of D1 receptor impaired its function. G protein kinase 4 (GRK4) and protein phosphatase 2A (PP2A) exerted the effect to phosphorylate and de-phosphorylate D1 receptor. A current study revealed that the inhibition of GRK4 cannot normalize the phosphorylation level of D1 receptor. Meanwhile, the PP2A was activated under hypertension, indicating abnormal de-phosphorylation function of D1 receptor, the reason for which remains unknown. This study aimed to investigate the effect and mechanism of SUMO-1 modification on the regulation of dopamine receptor D1 to PP2A.MATERIALS AND METHODS:.Bioinformatics software predicted SUMO modification site in dopamine receptor D1. Cultured CHO cells were transfected with mutants of renal dopamine receptor D1. Co-immunoprecipitation and Western blot tested the interaction between over-phosphorylated D1 receptor and PP2A. Laser confocal microscopy examined their co-localization..RESULTS:.Bioinformatics predicted two SUMO modification sites K265 and K402 in dopamine receptor D1. Co-immunoprecipitation assay revealed weakened interaction between PP2A and phosphorylated D1 receptor, impeding the de-phosphorylation and normal function of D1 receptor..CONCLUSIONS:.Two SUMO modification sites existed in dopamine receptor D1, the phosphorylation of which, due to SUMO modification, can interact with PP2A, leading to the inhibition of D1 de-phosphorylation and normal function, thus providing new insights for treatment and prevention of hypertension.