S. cerevisiaeのGタンパク質βサブユニットのフェロモン誘発のリン酸化は,フェロモンの交尾への適応反応と関連しています

G M Cole¹, S I Reed

¹Molecular Biology Department, Research Institute of Scripps Clinic, La Jolla, California 92037.

Cell

|February 22, 1991

まとめ

酵母では,Gタンパク質のリン酸化がペアリングフェロモンへの適応の鍵となる. 特定のGβ変異はフェロモンの感受性を高めますが,回復を阻害し,リン酸化を明らかにします.

科学分野:

細胞の信号伝達経路は,
分子生物学は分子生物学である.
イースト遺伝学イースト遺伝学

背景:

Saccharomyces cerevisiae (酵母) のペアリングフェロモン反応は,Gタンパク質媒介のシグナリングカスケードによって開始されます.
Gベータ・ガンマサブユニットは,この経路における主要な信号変換器として機能する.
外因的なフェロモンを加えると,Gベータは,タンパク質合成から独立した急速な,de novoタンパク質酸化を経験します.

研究の目的:

イーストのペアリングフェロモン反応におけるGベータリン酸化の役割を調査する.
Gβリン酸化が,他の既知の適応経路とは異なる適応的メカニズムであるかどうかを判断する.
信号誘発によるGベータリン酸化を防ぐ突然変異の効果を特徴付ける.

主な方法:

信号誘発型リン酸化部位が欠けているGβ変異体の構築と分析.
フェロモンに対する突然変異株の反応のフェノタイプ分析,感受性および回復を含む.
変異の存在下でGベータ・ガンマの信号伝送能力の評価.

主要な成果:

信号誘発のGベータリン酸化を排除する突然変異は,フェロモンに対する感受性の増加をもたらした.
Gベータリン酸化欠乏症の変異体は,フェロモンの暴露から回復が妨げられたことを示した.
この変異は,Gベータ・ガンマ複合体の交配信号を伝達する能力を損ねなかった.
Gβリン酸化はGαサブユニットによって促進されたが,フェロモン受容体C端とSST2遺伝子とは独立していた.

結論:

Gタンパク質のリン酸化,特にGベータサブユニットのリン酸化は,酵母におけるフェロモン誘発のシグナル伝達に対する適応反応を媒介する上で重要な役割を果たします.
このリン酸化イベントは,フェロモン受容体やSST2遺伝子を含むものとは別々の異なる適応メカニズムを表しています.
この発見は,酵母の交配行動とシグナル適応を制御する複雑な規制ネットワークを強調しています.

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