作者:Daisuke Kozai、Yoji Kabasawa、Maximilian Ebert、Shigeki Kiyonaka、Yuko Otani、Tomohiro Numata、Nobuaki Takahashi、Yasuo Mori、Tomohiko Ohwada
DOI:10.1124/mol.113.088864
日期:2014.1
S -Nitrosylation, the addition of a nitrosyl group to cysteine thiols, regulates various protein functions to mediate nitric oxide (NO) bioactivity. Recent studies have demonstrated that selectivity in protein S -nitrosylation signaling pathways is conferred through transnitrosylation, a transfer of the NO group, between proteins via interaction. We previously demonstrated that sensitivity to activation by synthetic NO-releasing agents via S -nitrosylation is a common feature of members of the transient receptor potential (TRP) family of Ca2+-permeable cation channels. However, strategies to confer subtype selectivity to nitrosylating agents targeted to TRP channels are yet to be developed. Here, we show selective activation of TRPA1 channels by novel NO donors derived from the ABBH (7-azabenzobicyclo[2.2.1]heptane) N -nitrosamines, which exhibit transnitrosylation reactivity to thiols without releasing NO. The NNO-ABBH1 ( N -nitroso-2-exo,3-exo-ditrifluoromethyl-7-azabenzobicyclo[2.2.1]heptane) elicits S -nitrosylation of TRPA1 proteins, and dose-dependently induces robust Ca2+ influx via both recombinant and native TRPA1 channels, but not via other NO-activated TRP channels. TRPA1 activation by NNO-ABBH1 is suppressed by specific cysteine mutations but not by NO scavenging, suggesting that cysteine transnitrosylation underlies the activation of TRPA1 by NNO-ABBH1. This is supported by the correlation of N–NO bond reactivity and TRPA1-activating potency in a congeneric series of ABBH N -nitrosamines. Interestingly, nonelectrophilic derivatives of ABBH also activate TRPA1 selectively, but less potently, compared with NNO-ABBH1. Thus, ABBH N -nitrosamines confer subtype selectivity on S -nitrosylation in TRP channels through synergetic effects of two chemical processes: cysteine transnitrosylation and molecular recognition of the nonelectrophilic moiety.
S-亚硝基化,即亚硝酰基团添加到半胱氨酸硫醇上,通过调节多种蛋白质功能来介导一氧化氮(NO)的生物活性。最近的研究表明,通过蛋白质间相互作用实现的NO基团转移,即转亚硝基化,赋予了蛋白质S-亚硝基化信号通路的选择性。我们之前证明,对合成NO释放剂通过S-亚硝基化激活的敏感性是瞬时受体电位(TRP)家族钙离子可通透阳离子通道成员的共同特征。然而,针对TRP通道的亚硝基化剂赋予亚型选择性的策略尚未开发。在这里,我们展示了由ABBH(7-氮杂苯并双环[2.2.1]庚烷)N-亚硝基胺衍生的新型NO供体对TRPA1通道的选择性激活,这些供体通过转亚硝基化对硫醇起反应而不释放NO。NNO-ABBH1(N-亚硝基-2-外端,3-外端-二三氟甲基-7-氮杂苯并双环[2.2.1]庚烷)诱发TRPA1蛋白的S-亚硝基化,并通过剂量依赖性地诱发重组和天然TRPA1通道的强烈钙内流,而不是通过其他NO激活的TRP通道。NNO-ABBH1对TRPA1的激活被特定半胱氨酸突变抑制,但不被NO清除剂抑制,表明半胱氨酸转亚硝基化是NNO-ABBH1激活TRPA1的基础。这一发现得到了ABBH N-亚硝基胺同源系列中N-NO键反应活性与TRPA1激活效能相关性的支持。有趣的是,ABBH的非亲电衍生物也能选择性地激活TRPA1,但相对于NNO-ABBH1,其效能较低。因此,ABBH N-亚硝基胺通过两种化学过程的协同效应,即半胱氨酸转亚硝基化和非亲电基团的分子识别,赋予TRP通道中S-亚硝基化的亚型选择性。