TY - JOUR T1 - Transnitrosylation Directs TRPA1 Selectivity in <em>N</em>-Nitrosamine Activators JF - Molecular Pharmacology JO - Mol Pharmacol SP - 175 LP - 185 DO - 10.1124/mol.113.088864 VL - 85 IS - 1 AU - Daisuke Kozai AU - Yoji Kabasawa AU - Maximilian Ebert AU - Shigeki Kiyonaka AU - Firman AU - Yuko Otani AU - Tomohiro Numata AU - Nobuaki Takahashi AU - Yasuo Mori AU - Tomohiko Ohwada Y1 - 2014/01/01 UR - http://molpharm.aspetjournals.org/content/85/1/175.abstract N2 - 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. ER -