Coordination of an array of signaling proteins through homo- and heteromeric interactions between PDZ domains and target proteins.
Coordination of an array of signaling proteins through homo- and heteromeric interactions between PDZ domains and target proteins.
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DOI：
10.1083/jcb.142.2.545
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发表时间：
1998-07-27
期刊：
影响因子：
--
通讯作者：
Montell C
中科院分区：
文献类型：
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作者：
Xu XZ;Choudhury A;Li X;Montell C
许多G蛋白信号级联的快速激活和反馈调节提高了关键信号蛋白可能紧密耦合的可能性。先前的研究表明，含有PDZ结构域的蛋白质INAD在果蝇视觉中起作用，通过直接结合光敏离子通道TRP和磷脂酶C（PLC）来协调信号复合物。INAD信号复合物还包括视紫红质、蛋白激酶C（PKC）和钙调蛋白，尽管不知道这些蛋白质是否与INAD结合。在目前的工作中，我们表明，视紫红质，钙调蛋白，PKC与信号复合物通过直接结合到INAD。我们还发现，第二个离子通道，TRPL，绑定到INAD。因此，大多数直接参与光转导的蛋白质似乎与INAD结合。此外，我们发现，INAD形成均聚物和均聚化发生通过两个PDZ域。因此，我们认为INAD超分子复合物是一个由INAD分子延伸网络组成的高阶信号网络，通过该网络连接G蛋白偶联级联反应。
The rapid activation and feedback regulation of many G protein signaling cascades raises the possibility that the critical signaling proteins may be tightly coupled. Previous studies show that the PDZ domain containing protein INAD, which functions in Drosophila vision, coordinates a signaling complex by binding directly to the light-sensitive ion channel, TRP, and to phospholipase C (PLC). The INAD signaling complex also includes rhodopsin, protein kinase C (PKC), and calmodulin, though it is not known whether these proteins bind to INAD. In the current work, we show that rhodopsin, calmodulin, and PKC associate with the signaling complex by direct binding to INAD. We also found that a second ion channel, TRPL, bound to INAD. Thus, most of the proteins involved directly in phototransduction appear to bind to INAD. Furthermore, we found that INAD formed homopolymers and the homomultimerization occurred through two PDZ domains. Thus, we propose that the INAD supramolecular complex is a higher order signaling web consisting of an extended network of INAD molecules through which a G protein–coupled cascade is tethered.