Yip3は,内体内のRab-GDI複合体の解離を触媒として作用する

Ulf Sivars¹, Dikran Aivazian, Suzanne R Pfeffer

¹Department of Biochemistry, Stanford University School of Medicine, Stanford, California 94305-5307, USA.

Nature

|October 24, 2003

まとめ

統合膜タンパク質Yip3はGDI移位因子として作用し,膜標的化のためにGDIからRab GTPasesを放出します. この発見は,真核細胞におけるラブタンパク質の調節を理解するために極めて重要です.

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.
メンブラン取引メンブラン取引

背景:

Rab GTPasesは,細胞内膜の密輸の主要な調節体である.
プレニル化ラブタンパク質は,サイトゾール内の不活性なGDP結合状態 (GDIに結合) と,特定の膜区間の活性なGTP結合状態の間に循環する.
ラブタンパク質の適切な膜区間への正確な配送は,細胞機能にとって不可欠です.

研究の目的:

Rab-GDI複合体の解離に起因する因子を特定する.
特定の膜区間を標的とするラブタンパク質のメカニズムを解明する.
Rab GTPase 調節における Yip3 の役割を調査する.

主な方法:

GDI-異位活動の検査のための生化学的測定法.
Yip3を統合膜タンパク質として特徴づける.
Rab-GDI複合体の解離と膜配送のインビトロ再構成.

主要な成果:

統合膜タンパク質Yip3は,触媒的なGDI置換因子として特定されました.
Yip3は,グアニンヌクレオチド分裂阻害剤 (GDI) からプレニル化ラブタンパク質の解離を促進する.
Yip3は,Rabタンパク質がGDIから標的膜に伝達されるのを媒介する.

結論:

保存された Yip タンパク質は,GDI 置換因子として機能します.
Yipタンパク質は,Rab GTPasesの細胞膜への正確なターゲティングに不可欠です.
このメカニズムは,真核細胞におけるラブ媒介の膜密輸を調節するのに不可欠です.

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