Gαq binds two effectors separately in cells:: Evidence for predetermined signaling pathways
Gαq binds two effectors separately in cells:: Evidence for predetermined signaling pathways
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DOI：
10.1529/biophysj.108.129353
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发表时间：
2008-09-01
影响因子：
3.4
通讯作者：
Scarlata, Suzanne
中科院分区：
文献类型：
--
作者：
Golebiewska, Urszula;Scarlata, Suzanne
G蛋白沿着沿着不同的途径传递信号，但参与途径选择的因素在很大程度上是未知的。在这里，我们研究了G α（q）在人胚肾293细胞中选择两种效应物-哺乳动物肌醇特异性磷脂酶C β（PLC β）和磷酸肌醇-3-激酶（PI 3 K）的能力。这些研究通过在基础状态和刺激期间使用福斯特共振能量转移测量eCFP-和eYFP-标记的蛋白质之间的相互作用来进行。我们发现G α（q）-PLC β和G α（q）-PI 3 K复合物在整个刺激周期中存在单独且稳定的池，而不是G α（q）通过扩散和交换与效应物缔合。这些单独的复合物存在，尽管G α（q）的能力，同时结合两个效应器，通过使用纯化的蛋白质在体外测量确定。预先形成的G蛋白/效应物复合物将限制给定信号将采取的途径的数量，这可以简化预测模型。
G-proteins transduce signals along diverse pathways, but the factors involved in pathway selection are largely unknown. Here, we have studied the ability of G alpha(q) to select between two effectors-mammalian inositide-specific phospholipase C beta(PLC beta) and phosphoinositide-3-kinase (PI3K)-in human embryonic kidney 293 cells. These studies were carried out by measuring interactions between eCFP- and eYFP-tagged proteins using Forster resonance energy transfer in the basal state and during stimulation. Instead of association of G alpha(q) with effectors through diffusion and exchange, we found separate and stable pools of G alpha(q)-PLC beta and G alpha(q)-PI3K complexes existing throughout the stimulation cycle. These separate complexes existed despite the ability of G alpha(q) to simultaneously bind both effectors as determined by in vitro measurements using purified proteins. Preformed G-protein/effector complexes will limit the number of pathways that a given signal will take, which may simplify predictive models.