Stabilization of the angiotensin-(1-7) receptor Mas through interaction with PSD95
Stabilization of the angiotensin-(1-7) receptor Mas through interaction with PSD95
复制标题
通过与 PSD95 相互作用稳定血管紧张素 (1-7) 受体 Mas
DOI：
10.1042/bj20121885
复制
发表时间：
2013-08-01
影响因子：
4.1
通讯作者：
He, Junqi
中科院分区：
文献类型：
--
作者：
Bian, Weihua;Sun, Licui;He, Junqi
已经对Ang-（1-7）[血管紧张素（1-7）]受体MAS的功能和信号传导机制进行了广泛的研究。但是，对MAS蛋白的细胞内调节的关注较少。在本研究中，鉴定出一种新型MAS受体的结合蛋白，PSD95（突触后密度95）被鉴定出来，并进一步表征了它们的关联。 MAS特异性与PDZ1-2相互作用，而不是通过MAS-CT（MAS C-terminus）和PSD95的PDZ3与PDZ3相互作用，而MAS-CT的最后四个氨基酸[ETVV（GLU-THR-VAL-VAL）]被确定为这种相互作用必不可少的，如GST duplown，Co-imunoprecimation和Conformations所必需。功能收益和功能丧失研究表明，PSD95通过增加受体的稳定来增强MAS蛋白的表达。蛋白酶体抑制剂MG132在时间和剂量依赖性的方式中强烈抑制MAS降解，而PSD95的表达受损的MAS泛素化受损，表明PSD95 MAS关联抑制了MAS受体受体通过泛素蛋白 - 磷酸化蛋白 - 蛋白质蛋白 - 蛋白质蛋白蛋白酶体蛋白质解释性pation pation。这些发现揭示了MAS受体调控的新机制，通过泛素化在翻译后水平上调节其表达，并阐明了PSD95的作用，PSD95的作用直接与MAS结合，阻断了受体的泛素化和随后通过泛素蛋白 - 蛋白酶体蛋白酶体蛋白质聚解体途径的降解。
The functions and signalling mechanisms of the Ang-(1-7) [angiotensin-(1-7)] receptor Mas have been studied extensively. However, less attention has been paid to the intracellular regulation of Mas protein. In the present study, PSD95 (postsynaptic density 95), a novel binding protein of Mas receptor, was identified, and their association was characterized further. Mas specifically interacts with PDZ1-2, but not the PDZ3, domain of PSD95 via Mas-CT (Mas C-terminus), and the last four amino acids [ETVV (Glu-Thr-Val-Val)] of Mas-CT were determined to be essential for this interaction, as shown by GST pull-down, co-immunoprecipitation and confocal co-localization experiments. Gain-of-function and loss-of-function studies indicated that PSD95 enhanced Mas protein expression by increasing the stabilization of the receptor. Mas degradation was robustly inhibited by the proteasome inhibitor MG132 in time- and dose-dependent manners, and the expression of PSD95 impaired Mas ubiquitination, indicating that the PSD95 Mas association inhibits Mas receptor degradation via the ubiquitin-proteasome proteolytic pathway. These findings reveal a novel mechanism of Mas receptor regulation by which its expression is modulated at the post-translational level by ubiquitination, and clarify the role of PSD95, which binds directly to Mas, blocking the ubiquitination and subsequent degradation of the receptor via the ubiquitin-proteasome proteolytic pathway.