GTPに結合したRan Ranによって誘発されたXenopus卵エキスにおけるマイクロチューブルアスターの自己組織化

T Ohba¹, M Nakamura, H Nishitani

¹Department of Molecular Biology, Graduate School of Medical Science, Kyushu University, Maidashi Higashi-ku, Fukuoka 812-8582, Japan.

Science (New York, N.Y.)

|May 21, 1999

まとめ

グアニンヌクレオチド交換因子RCC1は,マイクロチューブルアスター形成に不可欠である. RCC1によって調節されるRan GTPは,微小管の自己組織化を促し,ダイネインの活性を必要とします.

科学分野:

細胞生物学細胞生物学
分子生物学は分子生物学である.
バイオケミストリーバイオケミストリー

背景:

RCC1 (染色体凝縮の調節器1) は,Ran.の唯一のグアニンヌクレオチド交換因子である.
Ranは,Rasのような小さなGTPaseで,様々な細胞プロセスに不可欠です.
微小管アスターの形成は,細胞分裂と細胞内輸送に不可欠です.

研究の目的:

マイクロチューブルアスター形成におけるRCC1とその下流エフェクターRANの役割を調査する.
微小管の組織化を促進するRan (GTPまたはGDP) の特定のヌクレオチド結合状態を決定する.
Ran媒介による微小管の自己組織化におけるダイネインの関与を解明する.

主な方法:

使用済みのXenopus卵のエキス,ミオシスIIで停止した.
その必要性を評価するために,卵抽出物からRCC1を枯渇させた.
誘導された微小管アステル形成は,Ran GTPまたはRan GDPを使用して,RCC1-貧乏化された抽出物で.
観察された微小管組織におけるダイネイン活性に対する要求を評価した.

主要な成果:

RCC1の核酸交換活動は,マイクロチューブルのアスター形成に不可欠でした.
Ran GDPではなく,Ran GTPは,RCC1が欠乏した抽出物における自発的な微小管アスターの自己組織化を誘導した.
Ran-GTPが誘発した微小管の自己組織化プロセスは,ダイネイン活性を必要とした.

結論:

Ran GTPは,マイクロチューブルネットワーク形成の重要なレギュラーです.
Ranに対する核酸交換におけるRCC1の機能は,微小管の組織化を開始するために重要である.
ダイネインは,Ran媒介によるマイクロチューブルアスターの組み立てにおいて重要な役割を果たします.

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