Identification of signaling states of a sensory receptor by modulation of lifetimes of stimulus-induced conformations: the case of sensory rhodopsin II.
Identification of signaling states of a sensory receptor by modulation of lifetimes of stimulus-induced conformations: the case of sensory rhodopsin II.
复制标题
通过调节刺激诱导构象的寿命来识别感觉受体的信号状态：以感觉视紫红质 II 为例。
DOI：
10.1021/bi00108a012
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发表时间：
1991
期刊：
影响因子：
2.9
通讯作者：
Spudich,JL
中科院分区：
文献类型：
--
作者：
Yan,B;Takahashi,T;Johnson,R;Spudich,JL
阿尔伯特·爱因斯坦医学院解剖学和结构生物学系，布朗克斯，纽约10461，哥伦比亚大学化学系，纽约，纽约10027，1991年3月21日接收;修订后的手稿，1991年8月20日接收摘要：刺激诱导的构象的趋光性受体感觉视紫红质II（SR-II）从盐生盐杆菌的寿命调制与7个受体类似物。通过监测体外受体动力学和体内细胞的生理反应，我们观察到受体信号传导效率随着受体循环频率（周转数）的降低而增加。结果表明，调制寿命的蛋白质构象在SR-II的光活化位点与发色团类似物改变的寿命的活性构象在信号传导位点。我们进一步探索光循环中间体和信号传导效率之间的关系，通过分析的时间平均浓度的两个长寿命的光谱中间体的SR-II光循环：S-II 350和S-II 530。结果与信号位点在S-II 350形成过程中被激活一致，但不是由S-II 350转变为S-II 530而重置的;相反，失活似乎需要S-II 530随后的衰变。结果表明，在S-II 350-*·S-II 530跃迁中光活化位点的结构变化不会重置信号位点。这里使用的程序，原则上适用于任何光活化或配体活化的受体，提供了一个初步的方法来确定关键的受体活化过程的结构改变。
Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York 10461, and Department of Chemistry, Columbia University, New York, New York 10027 Received March 21, 1991; Revised Manuscript Received August 20, 1991 abstract: Lifetimes of stimulus-induced conformations of the phototaxis receptor sensory rhodopsin II (SR-II) from Halobacterium halobium are modulated with seven receptor analogues. By monitoring the receptor dynamics in vitro and physiological responses of the cell in vivo, we observe receptor signaling efficiency increases with decreasing cycling frequency (turnover number) of the receptor. The results demonstrate that modulating lifetimes of protein conformations at the SR-II photoactivation site with chromophore analogues alters the lifetime of the active conformation at the signaling site. We further explore the relationship between photocycle intermediates and the signaling efficiency by analyzing the time-averaged concentrations of the two long-lived spectral intermediates of the SR-II photocycle: S-II350 and S-II530. The results are consistent with the signaling site being activated duringformation of S-II350, but not reset by the transition of S-II350 into S-II530; rather deactivation appears to require subsequent decay of S-II530. The results indicate the structural changes at the photoactivation site in the S-II350-*· S-II530 transition do not reset the signaling site. The procedure used here, applicable in principle to any photoactivated or ligand-activated receptor, provides an initial approach to identify structural alterations key to the receptor activation process.