Type 3 Inositol 1,4,5-Trisphosphate Receptor is a Crucial Regulator of Calcium Dynamics Mediated by Endoplasmic Reticulum in HEK Cells
Type 3 Inositol 1,4,5-Trisphosphate Receptor is a Crucial Regulator of Calcium Dynamics Mediated by Endoplasmic Reticulum in HEK Cells
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3 型肌醇 1,4,5-三磷酸受体是 HEK 细胞内质网介导的钙动态的重要调节剂。
DOI：
10.3390/cells9020275
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发表时间：
2020-02-01
期刊：
影响因子：
6
通讯作者：
Wang, Youjun
中科院分区：
文献类型：
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作者：
Yue, Lili;Wang, Liuqing;Wang, Youjun
作为哺乳动物细胞中最大的钙库，内质网（ER）介导的Ca 2+信号通常涉及通过肌醇1，4，5-三磷酸受体（IP 3R）释放Ca 2+和通过质膜（PM）上的Ca 2+释放激活的Ca 2+（CRAC）通道的钙库操纵的Ca 2+内流（SOCE）。IP（3）Rs在功能上与CRAC通道和其他Ca 2+处理蛋白偶联。然而，IP（3）Rs是否能够独立于其Ca ~（2+）释放能力调节ER介导的Ca ~（2+）信号，目前还没有很好的定义。为了解决这个问题，我们产生了IP（3）Rs三重和双敲除人胚肾（HEK）细胞系（IP（3）Rs-TKO、IP（3）Rs-DKO），并系统地检查了这些细胞中的ER Ca 2+动力学和CRAC通道活性。结果显示，IP（3）Rs-TKO细胞内质网Ca ~（2+）漏出率、再充盈率及SOCE均明显降低。这些TKO效应可以通过IP（3）R3的过表达来挽救。此外，结果表明，SOCE的减少是由NEDD 4L介导的Orai 1蛋白的泛素化引起的。总之，我们的研究结果表明，IP（3）R3是协调ER介导的Ca 2+信号传导的关键参与者。
Being the largest the Ca2+ store in mammalian cells, endoplasmic reticulum (ER)-mediated Ca2+ signalling often involves both Ca2+ release via inositol 1, 4, 5-trisphosphate receptors (IP3R) and store operated Ca2+ entries (SOCE) through Ca2+ release activated Ca2+ (CRAC) channels on plasma membrane (PM). IP(3)Rs are functionally coupled with CRAC channels and other Ca2+ handling proteins. However, it still remains less well defined as to whether IP(3)Rs could regulate ER-mediated Ca2+ signals independent of their Ca2+ releasing ability. To address this, we generated IP(3)Rs triple and double knockout human embryonic kidney (HEK) cell lines (IP(3)Rs-TKO, IP(3)Rs-DKO), and systemically examined ER Ca2+ dynamics and CRAC channel activity in these cells. The results showed that the rate of ER Ca2+ leakage and refilling, as well as SOCE were all significantly reduced in IP(3)Rs-TKO cells. And these TKO effects could be rescued by over-expression of IP(3)R3. Further, results showed that the diminished SOCE was caused by NEDD4L-mediated ubiquitination of Orai1 protein. Together, our findings indicate that IP(3)R3 is one crucial player in coordinating ER-mediated Ca2+ signalling.