Stabilization of cortical actin induces internalization of transient receptor potential 3 (Trp3)-associated caveolar Ca2+ signaling complex and loss of Ca2+ influx without disruption of Trp3-inositol trisphosphate receptor association
Stabilization of cortical actin induces internalization of transient receptor potential 3 (Trp3)-associated caveolar Ca2+ signaling complex and loss of Ca2+ influx without disruption of Trp3-inositol trisphosphate receptor association
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DOI：
10.1074/jbc.m106956200
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发表时间：
2001-11-09
影响因子：
4.8
通讯作者：
Ambudkar, IS
中科院分区：
文献类型：
--
作者：
Lockwich, T;Singh, BB;Ambudkar, IS
Ca ~（2+）通过质膜Trp ~ 3通道的内流被认为是通过与内质网中的三磷酸肌醇受体（IP，R）的可逆相互作用来调节的。皮质肌动蛋白层的缩合被认为是物理破坏这种相互作用，抑制Trp 3介导的Ca 2+内流。本研究探讨了细胞骨架重组对Trp 3和关键Ca 2+信号蛋白的定位和功能的影响。Calyculin-A处理导致在质膜处形成凝聚的肌动蛋白层; Trp 3、G α（q/11）、磷脂酶C β和小窝蛋白-1的内化;以及1-油酰基-2-乙酰基-sn-甘油-和ATP-刺激的Sr 2+内流的衰减。重要的是，Trp 3和IP 3R-3在细胞内保持共定位，并被免疫共沉淀。茉莉花激酶还诱导Trp 3和小窝蛋白-1的内化。用细胞松弛素D或星形孢菌素预处理细胞不影响Trp 3，但阻止了calyculin-A诱导的作用。基于这些数据，我们认为Trp 3与IP 3R，SERCA，G alpha（q/11），磷脂酶C β，小窝蛋白-1和ezrin组装在小窝Ca 2+信号复合物中。此外，我们的数据表明，条件下，稳定皮质肌动蛋白诱导Trp 3活性的损失，由于内化的Trp 3信号复合物，而不是IP 3R-Trp 3相互作用的中断。这表明Trp 3相关信号复合物的定位，而不是Trp 3-IP 3R偶联，取决于肌动蛋白细胞骨架的状态。
Ca2+ influx via plasma membrane Trp3 channels is proposed to be regulated by a reversible interaction with inositol trisphosphate receptor (IP,R) in the endoplasmic reticulum. Condensation of the cortical actin layer has been suggested to physically disrupt this interaction and inhibit Trp3-mediated Ca2+ influx. This study examines the effect of cytoskeletal reorganization on the localization and function of Trp3 and key Ca2+ signaling proteins. Calyculin-A treatment resulted in formation of condensed actin layer at the plasma membrane; internalization of Trp3, G alpha (q/11), phospholipase C beta, and caveolin-1; and attenuation of 1-oleoyl-2-acetyl-sn-glycerol- and ATP-stimulated Sr2+ influx. Importantly, Trp3 and IP3R-3 remained co-localized inside the cell and were co-immunoprecipitated. Jasplakinolide also induced internalization of Trp3 and caveolin-1. Pretreatment of cells with cytochalasin D or staurosporine did not affect Trp3 but prevented calyculin-A-induced effects. Based on these data, we suggest that Trp3 is assembled in a caveolar Ca2+ signaling complex with IP3R, SERCA, G alpha (q/11), phospholipase C beta, caveolin-1, and ezrin. Furthermore, our data demonstrate that conditions which stabilize cortical actin induce loss of Trp3 activity due to internalization of the Trp3-signaling complex, not disruption of IP3R-Trp3 interaction. This suggests that localization of the Trp3-associated signaling complex, rather than Trp3-IP3R coupling, depends on the status of the actin cytoskeleton.