GRIP1 and 2 regulate activity-dependent AMPA receptor recycling via exocyst complex interactions
GRIP1 and 2 regulate activity-dependent AMPA receptor recycling via exocyst complex interactions
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DOI：
10.1073/pnas.1013494107
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发表时间：
2010-11-02
影响因子：
11.1
通讯作者：
Huganir, Richard L.
中科院分区：
文献类型：
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作者：
Mao, Lifang;Takamiya, Kogo;Huganir, Richard L.
PSD-95/SAP90/DLG/ZO-1 （PDZ）结构域介导的蛋白相互作用在调节AMPA受体转运和神经元可塑性中发挥重要作用。GRIP1和GRIP2是同源的多pdz结构域蛋白，与AMPA-R GluA2和GluA3亚基的c端结合。先前确定GRIP1和GRIP2在神经元中的细胞作用的尝试由于非特异性试剂和常规GRIP1 KO小鼠的胚胎致死性而变得复杂。为了避免这些问题，我们开发了一种条件靶向删除策略，以敲除来自GRIP2 KO小鼠的出生后神经元中的GRIP1。GRIP1和2的缺失不影响正常的AMPA-R稳态运输和内吞作用，但显著损害了活性依赖性AMPA-R的再循环。GRIP1的这种先前未被描述的作用似乎是通过胞囊蛋白复合物与细胞运输机制的新相互作用介导的。实际上，grip1 -外囊结合的破坏导致了AMPA-R循环中惊人相似的缺陷。综上所述，这些发现揭示了AMPA-R- grip1 -囊外蛋白复合物在活性依赖性AMPA-R转运中的作用。
PSD-95/SAP90/DLG/ZO-1 (PDZ) domain-mediated protein-protein interactions play important roles in regulating AMPA receptor trafficking and neuronal plasticity. GRIP1 and GRIP2 are homologous multi-PDZ domain-containing proteins that bind to the C-termini of AMPA-R GluA2 and GluA3 subunits. Previous attempts to determine the cellular roles of GRIP1 and GRIP2 in neurons have been complicated by nonspecific reagents, and by the embryonic lethality of conventional GRIP1 KO mice. To circumvent these issues we developed a conditional targeted deletion strategy to knock out GRIP1 in postnatal neurons derived from GRIP2 KO mice. Loss of GRIP1 and 2 did not affect normal AMPA-R steady-state trafficking and endocytosis, but strikingly impaired activity-dependent AMPA-R recycling. This previously uncharacterized role for GRIP1 appears to be mediated by novel interactions with the cellular trafficking machinery via the exocyst protein complex. Indeed, disruption of GRIP1-exocyst binding caused a strikingly similar deficit in AMPA-R recycling. Together these findings reveal a previously unidentified role for AMPA-R-GRIP1-exocyst protein complexes in activity-dependent AMPA-R trafficking.