Wang Na, Cai Xin-Yu, Gao Wei, Shen Ying
School of Medicine, Zhejiang University City College.
Department of Neurobiology, Zhejiang University School of Medicine, Hangzhou, Zhejiang, People's Republic of China.
Neuroreport. 2018 Aug 1;29(11):902-906. doi: 10.1097/WNR.0000000000001051.
The protein Numb localizes to clathrin-coated vesicles and participates in the trafficking of transmembrane receptors. We previous reported that Numb promotes the presence of metabotropic glutamate receptor 1 (mGlu1) on neuronal membrane, and Numb deficiency impairs synaptic expression of mGlu1. However, the actions of different Numb isoforms on mGlu1 trafficking are unknown. Here, we found that Numb-p72 and Numb-p65 are distinctly expressed in HEK293T cells. Interestingly, Numb-p72, but not Numb-p65, binds to mGlu1α and promotes the membrane expression of mGlu1α by antagonizing its internalization. We hypothesize that the incomplete structure of Numb-p65 does not act in the same way as Numb-p72 on mGlu1 trafficking.
蛋白质Numb定位于网格蛋白包被的小泡，并参与跨膜受体的运输。我们之前报道过，Numb促进代谢型谷氨酸受体1（mGlu1）在神经元膜上的存在，而Numb缺乏会损害mGlu1的突触表达。然而，不同Numb异构体对mGlu1运输的作用尚不清楚。在这里，我们发现Numb-p72和Numb-p65在HEK293T细胞中表达明显不同。有趣的是，Numb-p72而非Numb-p65与mGlu1α结合，并通过拮抗其内化来促进mGlu1α的膜表达。我们推测，Numb-p65的不完整结构在mGlu1运输上的作用方式与Numb-p72不同。
