Differential localization of glutamate receptor subunits at the Drosophila neuromuscular junction
Differential localization of glutamate receptor subunits at the Drosophila neuromuscular junction
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DOI：
10.1523/jneurosci.1575-03.2004
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发表时间：
2004-02-11
影响因子：
5.3
通讯作者：
DiAntonio, A
中科院分区：
文献类型：
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作者：
Marrus, SB;Portman, SL;DiAntonio, A
突触后神经递质受体的亚基组成是突触生理学的关键决定因素。两种谷氨酸受体亚基，果蝇谷氨酸受体IIA（DGluRIIA）和DGluRIIB，在果蝇神经肌肉接头处表达，并且对于活力是多余的，但它们的生理特性不同。我们现在确定了第三个谷氨酸受体亚基在果蝇神经肌肉接头，DGluRIII，这是必不可少的生存能力。DGluRIII是DGluRIIA和DGluRIIB的突触定位以及突触传递所必需的。DGluRIII的突触定位需要DGluRIIA或DGluRIIB，但不是两者都需要。DGluRIIA和DGluRIIB相互竞争进入DGluRIII并随后定位于突触。这些结果与其中DGluRIII是必需组分的多聚体受体的模型一致。在接受来自多个运动神经元的神经支配的单个突触后细胞中，DGluRIII在所有突触处都是丰富的。然而，DGluRIIA和DGluRIIB差异定位在突触后密度相对不同的运动神经元。因此，支配运动神经元可以调节共享的突触后细胞内的受体场的亚基组成。突触前输入塑造突触后受体亚基组成的能力可能是突触特异性调节突触功能和可塑性的重要机制。
The subunit composition of postsynaptic neurotransmitter receptors is a key determinant of synaptic physiology. Two glutamate receptor subunits, Drosophila glutamate receptor IIA (DGluRIIA) and DGluRIIB, are expressed at the Drosophila neuromuscular junction and are redundant for viability, yet differ in their physiological properties. We now identify a third glutamate receptor subunit at the Drosophila neuromuscular junction, DGluRIII, which is essential for viability. DGluRIII is required for the synaptic localization of DGluRIIA and DGluRIIB and for synaptic transmission. Either DGluRIIA or DGluRIIB, but not both, is required for the synaptic localization of DGluRIII. DGluRIIA and DGluRIIB compete with each other for access to DGluRIII and subsequent localization to the synapse. These results are consistent with a model of a multimeric receptor in which DGluRIII is an essential component. At single postsynaptic cells that receive innervation from multiple motoneurons, DGluRIII is abundant at all synapses. However, DGluRIIA and DGluRIIB are differentially localized at the postsynaptic density opposite distinct motoneurons. Hence, innervating motoneurons may regulate the subunit composition of their receptor fields within a shared postsynaptic cell. The capacity of presynaptic inputs to shape the subunit composition of postsynaptic receptors could be an important mechanism for synapse-specific regulation of synaptic function and plasticity.