Kim Sung Oog, Merchant Kunal, Nudelman Raphael, Beyer Wayne F, Keng Teresa, DeAngelo Joseph, Hausladen Alfred, Stamler Jonathan S
Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA.
Cell. 2002 May 3;109(3):383-96. doi: 10.1016/s0092-8674(02)00723-7.
Redox regulation has been perceived as a simple on-off switch in proteins (corresponding to reduced and oxidized states). Using the transcription factor OxyR as a model, we have generated, in vitro, several stable, posttranslational modifications of the single regulatory thiol (SH), including S-NO, S-OH, and S-SG, and shown that each occurs in vivo. These modified forms of OxyR are transcriptionally active but differ in structure, cooperative properties, DNA binding affinity, and promoter activities. OxyR can thus process different redox-related signals into distinct transcriptional responses. More generally, our data suggest a code for redox control through which allosteric proteins can subserve either graded (cooperative) or maximal (noncooperative) responses, and through which differential responsivity to redox-related signals can be achieved.
氧化还原调节一直被视为蛋白质中的一种简单的开-关开关（对应于还原态和氧化态）。以转录因子OxyR为模型，我们在体外生成了单个调节性硫醇（SH）的几种稳定的翻译后修饰形式，包括S-NO、S-OH和S-SG，并证明每种修饰形式都存在于体内。这些OxyR的修饰形式具有转录活性，但在结构、协同特性、DNA结合亲和力和启动子活性方面存在差异。因此，OxyR可以将不同的氧化还原相关信号转化为不同的转录反应。更普遍地说，我们的数据表明存在一种氧化还原控制密码，通过该密码变构蛋白可以实现分级（协同）或最大（非协同）反应，并可以实现对氧化还原相关信号的不同反应性。
