UNC-6/ネトリンとその受容体UNC-5は,局所的にデンドライトからのプレシナプス成分を除外します
Vivian Y Poon1, Matthew P Klassen, Kang Shen
1Neuroscience Program, Stanford University School of Medicine, 300 Pasteur Drive, California 94305, USA.
Nature
|September 9, 2008
まとめ
ネトリンやWntのような細胞外シグナルがニューロンの極性を誘導する. これらの信号は,プレシナプス成分がデンドライトに蓄積するのを防ぎ,適切なニューロン機能を保証します.
科学分野:
- 神経科学は神経科学である.
- 細胞生物学 細胞生物学
- 発達生物学 発達生物学について
背景:
- 機能に不可欠なニューロンの極性は,軸索とデンドライトの内在的な構造的差異によって決定されると考えられています.
- 細胞外シグナルの役割は,神経の極性 in vivo の確立と維持において,ほとんど未知のままである.
研究 の 目的:
- ニューロン内のシナプス前部構成要素の偏光化された局所化を指示する細胞外信号のインビボの役割を調査する.
- 軸索誘導シグナルが,シナプスタンパク質のデンドライトからの排除に影響するかどうかを判断する.
主な方法:
- Caenorhabditis elegansのモーターニューロン DA9をモデルシステムとして利用した.
- アクソン誘導シグナルUNC-6/ネトリンとその受容体UNC-5の機能を調査した.
- 分析された機能喪失変異体は,unc-6/netrinとunc-5.
- 子宮外のUNC-6/ネトリン発現の影響を調べました.
主要な成果:
- UNC-6/ネトリンとUNC-5は,DA9デンドライトからシナプスベジクルとアクティブゾーンタンパク質を積極的に排除します.
- UNC-6/ネトリンまたはUNC-5の喪失は,DA9デンドライトにプレシナプス成分の誤局につながります.
- エクトピックUNC-6/ネトリン発現は,アクソン内の特定のサブセルラー領域からのシナプスを除外します.
- ネトリンの抗シナプトジェニック活動は,異なる受容体にもかかわらず,LIN-44/Wntと互換性があります.
結論:
- ネトリンとWntを含む細胞外信号は,プレシナプス成分の偏光分布を調節する上で重要な役割を果たします.
- これらの信号は,軸索のナビゲーションを誘導するだけでなく,シナプス物質の局所的な排除を媒介することによって,神経の極性を確立します.
- ニューロンの極性は,内在的要因と外部シグナル伝達経路の組み合わせによって確立されます.
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