Intramolecular Conformational Changes Optimize Protein Kinase C Signaling
Intramolecular Conformational Changes Optimize Protein Kinase C Signaling
复制标题
DOI：
10.1016/j.chembiol.2014.02.008
复制
发表时间：
2014-04-24
影响因子：
--
通讯作者：
Newton, Alexandra C.
中科院分区：
文献类型：
--
作者：
Antal, Corina E.;Violin, Jonathan D.;Newton, Alexandra C.
酶信号的最佳调谐对细胞内环境的稳定至关重要。我们在活细胞中使用荧光共振能量转移报告器来跟踪构象转变，从而调节多域信号转导蛋白激酶C(PKC)的亲和力，以实现对第二信使的最佳反应。这种酶由两个二酰甘油传感器组成，CM和ClB结构域对配体具有足够高的内在亲和力，因此如果没有掩盖其结构域的机制，酶将处于与配体结合的活性状态。我们发现两个二酰基甘油传感器都暴露在新合成的PKC中，启动磷酸化后的构象转变掩盖了结构域，因此低亲和力的传感器C1B结构域是二酰甘油的主要结合体。PKC的构象重排为多模块传感器如何优化其信号的动态范围提供了范例。
Optimal tuning of enzyme signaling is critical for cellular homeostasis. We use fluorescence resonance energy transfer reporters in live cells to follow conformational transitions that tune the affinity of a multidomain signal transducer, protein kinase C (PKC), for optimal response to second messengers. This enzyme comprises two diacylglycerol sensors, the CM and Cl B domains, that have a sufficiently high intrinsic affinity for ligand so that the enzyme would be in a ligand-engaged, active state if not for mechanisms that mask its domains. We show that both diacylglycerol sensors are exposed in newly synthesized PKC and that conformational transitions following priming phosphorylations mask the domains so that the lower affinity sensor, the C1B domain, is the primary diacylglycerol binder. The conformational rearrangements of PKC serve as a paradigm for how multimodule transducers optimize their dynamic range of signaling.