Survery Sabeen, Moparthi Lavanya, Kjellbom Per, Högestätt Edward D, Zygmunt Peter M, Johanson Urban
From the Department of Biochemistry and Structural Biology, Center for Molecular Protein Science, Lund University, SE-221 00 Lund, Sweden and.
the Clinical Chemistry and Pharmacology, Department of Laboratory Medicine, Lund University, SE-221 85 Lund, Sweden.
J Biol Chem. 2016 Dec 23;291(52):26899-26912. doi: 10.1074/jbc.M116.743443. Epub 2016 Nov 14.
Temperature sensors are crucial for animals to optimize living conditions. The temperature response of the ion channel transient receptor potential A1 (TRPA1) is intriguing; some orthologs have been reported to be activated by cold and others by heat, but the molecular mechanisms responsible for its activation remain elusive. Single-channel electrophysiological recordings of heterologously expressed and purified Anopheles gambiae TRPA1 (AgTRPA1), with and without the N-terminal ankyrin repeat domain, demonstrate that both proteins are functional because they responded to the electrophilic compounds allyl isothiocyanate and cinnamaldehyde as well as heat. The proteins' similar intrinsic fluorescence properties and corresponding quenching when activated by allyl isothiocyanate or heat suggest lipid bilayer-independent conformational changes outside the N-terminal domain. The results show that AgTRPA1 is an inherent thermo- and chemoreceptor, and analogous to what has been reported for the human TRPA1 ortholog, the N-terminal domain may tune the response but is not required for the activation by these stimuli.
温度传感器对于动物优化生存条件至关重要。离子通道瞬时受体电位A1（TRPA1）的温度反应很有趣；据报道，一些直系同源物可被寒冷激活，另一些则可被热激活，但其激活的分子机制仍然难以捉摸。对异源表达和纯化的冈比亚按蚊TRPA1（AgTRPA1）进行单通道电生理记录，有无N端锚蛋白重复结构域，结果表明这两种蛋白质都有功能，因为它们对亲电化合物异硫氰酸烯丙酯和肉桂醛以及热有反应。蛋白质相似的固有荧光特性以及在被异硫氰酸烯丙酯或热激活时相应的淬灭表明，在N端结构域之外存在与脂质双层无关的构象变化。结果表明，AgTRPA1是一种固有的热感受器和化学感受器，与人TRPA1直系同源物的报道类似，N端结构域可能会调节反应，但这些刺激的激活并不需要它。
