p27變構激活周期蛋白依賴性激酶4
作者:
小柯機器人發布時間:2019/12/13 18:34:04
近日,美國加州大學聖克魯斯分校Seth M. Rubin及其研究團隊發現p27能夠變構激活周期蛋白依賴性激酶4,並拮抗palbociclib抑制。相關論文發表在2019年12月13日出版的《科學》上。
研究人員發現,當p27被酪氨酸激酶磷酸化時,變構激活CDK4與細胞周期蛋白D1(CDK4-CycD1)形成複合物。結構和生化數據表明,磷酸化的p27(phosp27)與CDK4的結合改變了三磷酸腺苷激酶位點,從而促進了視網膜母細胞瘤抑癌蛋白(Rb)和其他底物的磷酸化。令人驚訝的是,純化的內源性phosp27-CDK4-CycD1複合物對靶向CDK4的藥物palbociclib不敏感。相反,palbociclib主要靶向乳腺腫瘤細胞中的單體CDK4和CDK6(CDK4/6)。這些數據將phosp27-CDK4-CycD1定義為一種活性Rb激酶,其對臨床相關的CDK4/6抑制劑具有耐藥性。
研究人員表示,p27蛋白是細胞增殖的典型負調節因子,主要通過抑制細胞周期蛋白依賴性激酶(CDK)發揮作用。在某些情況下,p27與活性CDK4相關,但尚未發現激活機制。
附:英文原文
Title: p27 allosterically activates cyclin-dependent kinase 4 and antagonizes palbociclib inhibition
Author: Keelan Z. Guiley, Jack W. Stevenson, Kevin Lou, Krister J. Barkovich, Vishnu Kumarasamy, Tilini U. Wijeratne, Katharine L. Bunch, Sarvind Tripathi, Erik S. Knudsen, Agnieszka K. Witkiewicz, Kevan M. Shokat, Seth M. Rubin
Issue&Volume: 2019/12/13
Abstract: The p27 protein is a canonical negative regulator of cell proliferation and acts primarily by inhibiting cyclin-dependent kinases (CDKs). Under some circumstances, p27 is associated with active CDK4, but no mechanism for activation has been described. We found that p27, when phosphorylated by tyrosine kinases, allosterically activated CDK4 in complex with cyclin D1 (CDK4-CycD1). Structural and biochemical data revealed that binding of phosphorylated p27 (phosp27) to CDK4 altered the kinase adenosine triphosphate site to promote phosphorylation of the retinoblastoma tumor suppressor protein (Rb) and other substrates. Surprisingly, purified and endogenous phosp27-CDK4-CycD1 complexes were insensitive to the CDK4-targeting drug palbociclib. Palbociclib instead primarily targeted monomeric CDK4 and CDK6 (CDK4/6) in breast tumor cells. Our data characterize phosp27-CDK4-CycD1 as an active Rb kinase that is refractory to clinically relevant CDK4/6 inhibitors.
DOI: 10.1126/science.aaw2106
Source: https://science.sciencemag.org/content/366/6471/eaaw2106
Science:《科學》,創刊於1880年。隸屬於美國科學促進會,最新IF:41.037