LTPとCaMKIIによってAMPA受容体をシナプスに誘導する:GluR1とPDZドメインの相互作用の要件
Y Hayashi1, S H Shi, J A Esteban
1Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.
まとめ
活動に依存したシナプス可塑性は,アルファ-アミノ-3-ヒドロキシ-5-メチル-4-イソクサゾールプロピオネート受容体 (AMPA-Rs) をシナプスに提供することを含む. このプロセスは,CaMKIIリン酸化ではなく,PDZドメインタンパク質と結合するGluR1サブユニットに依存しています.
科学分野:
- 神経科学は神経科学である.
- 分子生物学は分子生物学である.
- シナプスの可塑性
背景:
- シナプスの可塑性は,学習と記憶に不可欠です.
- アルファ-アミノ-3-ヒドロキシ-5-メチル-4-イソクサゾールプロピオネート受容体 (AMPA-Rs) は,刺激性シナプス伝送の主要な媒介体である.
- カルシウム/カルモジュリン依存タンパク質キナーゼII (CaMKII) はシナプス可塑性において重要な役割を果たします.
研究 の 目的:
- 活動に依存したシナプス可塑性の基礎となる分子メカニズムを調査する.
- シナプスへの受容体トラフィックにおけるCaMKIIと特定のAMPA受容体サブユニットの役割を決定する.
主な方法:
- ネズミの海馬の神経細胞におけるAMPA-Rsの電気生理学的タグ付け.
- 長期増強 (LTP) の誘導とCaMKII活動の操作.
- GluR1 AMPA-Rサブユニット (CaMKIIリン酸化部位とPDZドメインの相互作用部位) のサイト指向型変異.
主要な成果:
- LTPと増加したCaMKII活動は,タグされたAMPA-Rsのシナプスへの伝達を促進しました.
- GluR1のCaMKIIリン酸化部位の変異は,AMPA-Rの投与を防ぐことはできませんでした.
- GluR1の予測されたPDZドメインの相互作用部位を変異させることで,シナプスへのAMPA-Rの配送を阻害しました.
結論:
- 活動に依存するシナプス可塑性,特にLTPは,AMPA受容体のシナプスへの挿入を促します.
- この受容体密輸メカニズムは,GluR1サブユニットとPDZドメインを含むタンパク質の相互作用に依存しています.
- CaMKIIリン酸化ではなく,PDZタンパク質との関連は,AMPA-Rのシナプス伝達におけるこの側面において極めて重要です.
関連する概念動画
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Long-term potentiation, or LTP, is one of the ways by which synaptic plasticity—changes in the strength of chemical synapses—can occur in the brain. LTP is the process of synaptic strengthening that occurs over time between pre- and postsynaptic neuronal connections. The synaptic strengthening of LTP works in opposition to the synaptic weakening of long-term depression (LTD) and together are the main mechanisms that underlie learning and memory.
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