PI3K class II α regulates δ-opioid receptor export from the trans-Golgi network.
PI3K class II α regulates δ-opioid receptor export from the trans-Golgi network.
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DOI：
10.1091/mbc.e17-01-0030
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发表时间：
2017-08-01
影响因子：
3.3
通讯作者：
Puthenveedu MA
中科院分区：
文献类型：
--
作者：
Shiwarski DJ;Darr M;Telmer CA;Bruchez MP;Puthenveedu MA
δ-阿片受体（δR）保留在神经元的细胞内结构中，但保留和调节输出的机制尚不清楚。非典型磷酸肌醇-3激酶C2 A是必需的，足以使NGF调节的δR从trans-Golgi网络输出和表面转运。信号传导和G蛋白偶联受体（GPCR）之间的相互作用主要集中在内吞运输。新合成的GPCR的表面递送是否以及如何受到细胞外信号的调节还不太清楚。在这里，我们定义了一个信号调节的检查点在trans-Golgi网络（TGN），控制δ阿片受体（δR）的表面交付。在PC 12细胞中，抑制磷脂酰肌醇-3激酶（PI 3 K）活性可阻断新合成的δR从高尔基体输出并递送至细胞表面，类似于神经生长因子（NGF）处理。II类磷脂酰肌醇-3激酶α（PI 3 K C2 A）的耗竭（而非I类PI 3 K的抑制）将δR输出阻断至相当水平，并减弱δ R介导的cAMP抑制。NGF处理将PI 3 K C2 A从高尔基体置换，并且将PI 3 K C2 A激酶结构域光遗传学募集到TGN诱导的NGF下游的δR输出。重要的是，PI 3 K C2 A表达促进了初级三叉神经节神经元中内源性δR的输出。综上所述，我们的结果确定PI 3 K C2 A是神经元细胞中δR输出和表面递送所必需的和足够的，并表明它可能是协调GPCR递送到表面的新型高尔基体输出检查点的关键调节剂。
The δ-opioid receptor (δR) is retained in intracellular structures in neurons, but the mechanisms of retention and regulated export are not known. The atypical phosphoinositide-3 kinase C2A is required and sufficient for NGF-regulated δR export from the trans-Golgi network and surface transport. The interplay between signaling and trafficking by G protein–coupled receptors (GPCRs) has focused mainly on endocytic trafficking. Whether and how surface delivery of newly synthesized GPCRs is regulated by extracellular signals is less understood. Here we define a signaling-regulated checkpoint at the trans-Golgi network (TGN) that controls the surface delivery of the delta opioid receptor (δR). In PC12 cells, inhibition of phosphoinositide-3 kinase (PI3K) activity blocked export of newly synthesized δR from the Golgi and delivery to the cell surface, similar to treatment with nerve growth factor (NGF). Depletion of class II phosphoinositide-3 kinase α (PI3K C2A), but not inhibition of class I PI3K, blocked δR export to comparable levels and attenuated δR-mediated cAMP inhibition. NGF treatment displaced PI3K C2A from the Golgi and optogenetic recruitment of the PI3K C2A kinase domain to the TGN-induced δR export downstream of NGF. Of importance, PI3K C2A expression promotes export of endogenous δR in primary trigeminal ganglion neurons. Taken together, our results identify PI3K C2A as being required and sufficient for δR export and surface delivery in neuronal cells and suggest that it could be a key modulator of a novel Golgi export checkpoint that coordinates GPCR delivery to the surface.