The heterotrimeric G protein Go2 regulates catecholamine uptake by secretory vesicles
The heterotrimeric G protein Go2 regulates catecholamine uptake by secretory vesicles
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DOI：
10.1093/emboj/17.2.406
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发表时间：
1998-01-15
期刊：
影响因子：
11.4
通讯作者：
Jahn, R
中科院分区：
文献类型：
--
作者：
Ahnert-Hilger, G;Nürnberg, B;Jahn, R
分泌囊泡储存由胞吐作用释放的神经递质，它们的膜含有负责递质加载的转运蛋白，其由穿过囊泡膜的电化学质子梯度驱动。我们现在已经检查了去甲肾上腺素的摄取是否受异源三聚体G蛋白的调节。在链球菌溶血素O-透化的PC 12细胞中，GTP-类似物和AIF（4）（-）抑制去甲肾上腺素摄取，这种效应对百日咳毒素治疗敏感，G α o特异性抗体可阻止这种抑制作用，纯化的活化G α o可模拟这种抑制作用（2）。当检测G α o（2）以其非活性GDP结合形式或纯化的活化G α o（1）、G α i（1）和G α i（2）时，未观察到影响。当破伤风毒素轻链抑制胞吐作用时，摄取的下调保持不变，囊泡酸化不受影响，而GTP γ S和G α o（2）降低了[3 H]利血平的结合。这些数据表明，单胺转运蛋白而不是空泡ATP酶受到影响。我们得出结论，儿茶酚胺的摄取是由G α o控制的（2），这表明异源三聚体G蛋白在控制神经递质储存方面具有新的功能。
Secretory vesicles store neurotransmitters that are released by exocytosis, Their membrane contains transporters responsible for transmitter loading that are driven by an electrochemical proton gradient across the vesicle membrane, We have now examined whether uptake of noradrenaline is regulated by heterotrimeric G proteins, In streptolysin O-permeabilized PC 12 cells, GTP-analogues and AIF(4)(-) inhibited noradrenaline uptake, an effect that was sensitive to treatment with pertussis toxin, Inhibition of uptake was prevented by G alpha o-specific antibodies and mimicked by purified activated G alpha o(2). No effect was seen when G alpha o(2) in its inactive GDP-bound form or purified activated G alpha o(1), G alpha i(1) and G alpha i(2) were tested, Down-regulation of uptake remained unchanged when exocytosis was inhibited by the light chain of tetanus toxin, Vesicular acidification was not affected whereas binding of [3H]reserpine was reduced by GTP gamma S and G alpha o(2). These data suggest that the monoamine transporter rather than the vacuolar ATPase is affected, We conclude that catecholamine uptake is controlled by G alpha o(2), suggesting a novel function for heterotrimeric G proteins in the control of neurotransmitter storage.