Caveolin-1 interacts with 5-HT2A serotonin receptors and profoundly modulates the signaling of selected Gαq-coupled protein receptors
Caveolin-1 interacts with 5-HT2A serotonin receptors and profoundly modulates the signaling of selected Gαq-coupled protein receptors
复制标题
DOI：
10.1074/jbc.m404673200
复制
发表时间：
2004-08-13
影响因子：
4.8
通讯作者：
Roth, BL
中科院分区：
文献类型：
--
作者：
Bhatnagar, A;Sheffler, DJ;Roth, BL
5-羟色胺2A (5-HT2A) 5-羟色胺受体在血管平滑肌收缩、血小板聚集、感知、认知和情绪调节等多种功能中发挥重要作用。在寻找5-HT2A受体相互作用蛋白的过程中，我们发现小窝蛋白-1 (Cav-1)，一种富含小窝的支架蛋白，在许多细胞类型中与5-HT2A受体复合物，包括C6胶质瘤细胞、转染的HEK-293细胞和大鼠脑突触膜制剂。为了研究这种相互作用的功能意义，我们在C6胶质瘤细胞（一种内源性表达5-HT2A受体和Cav-1的细胞类型）中进行了RNA干扰介导的Cav-1敲低。通过钙通量测定，我们发现C6胶质瘤细胞中Cav-1的体外敲除几乎消除了5-HT2A受体介导的信号转导。RNA干扰介导的Cav-1的下调也大大减弱了内源性Galpha(q)偶联P2Y嘌呤能受体介导的信号传导，而不改变PAR-1凝血酶受体的信号传导。Cav-1似乎通过促进5-HT2A受体与Galpha的相互作用来调节5-HT2A信号传导(q)。这些研究提供了令人信服的证据，证明Cav-1不仅在调节5-HT2A 5-羟色胺受体的功能活性中起着重要作用，而且在调节选定的Galpha(q)偶联受体中也起着重要作用。
5-Hydroxytryptamine 2A (5-HT2A) serotonin receptors are important for a variety of functions including vascular smooth muscle contraction, platelet aggregation, and the modulation of perception, cognition, and emotion. In a search for 5-HT2A receptor-interacting proteins, we discovered that caveolin-1 (Cav-1), a scaffolding protein enriched in caveolae, complexes with 5-HT2A receptors in a number of cell types including C6 glioma cells, transfected HEK-293 cells, and rat brain synaptic membrane preparations. To address the functional significance of this interaction, we performed RNA interference-mediated knockdown of Cav-1 in C6 glioma cells, a cell type that endogenously expresses both 5-HT2A receptors and Cav-1. We discovered that the in vitro knockdown of Cav-1 in C6 glioma cells nearly abolished 5-HT2A receptor-mediated signal transduction as measured by calcium flux assays. RNA interference-mediated knockdown of Cav-1 also greatly attenuated endogenous Galpha(q)-coupled P2Y purinergic receptor-mediated signaling without altering the signaling of PAR-1 thrombin receptors. Cav-1 appeared to modulate 5-HT2A signaling by facilitating the interaction of 5-HT2A receptors with Galpha(q). These studies provide compelling evidence for a prominent role of Cav-1 in regulating the functional activity of not only 5-HT2A serotonin receptors but also selected Galpha(q)-coupled receptors.