Witschas Katja, Jobin Marie-Lise, Korkut Dursun Nizam, Vladan Maria Magdalena, Salgado Gilmar, Lecomte Sophie, Vlachova Viktorie, Alves Isabel D
CBMN-UMR 5248 CNRS, University of Bordeaux, IPB, Allée Geoffroy St. Hilaire, 33600 Pessac, France; Department of Cellular Neurophysiology, Institute of Physiology, Academy of Sciences of the Czech Republic, Videnska 1083, 142 20 Prague 4, Czech Republic.
CBMN-UMR 5248 CNRS, University of Bordeaux, IPB, Allée Geoffroy St. Hilaire, 33600 Pessac, France.
Biochim Biophys Acta. 2015 May;1848(5):1147-56. doi: 10.1016/j.bbamem.2015.02.003. Epub 2015 Feb 14.
The transient receptor potential ankyrin 1 channel (TRPA1) belongs to the TRP cation channel superfamily that responds to a panoply of stimuli such as changes in temperature, calcium levels, reactive oxygen and nitrogen species and lipid mediators among others. The TRP superfamily has been implicated in diverse pathological states including neurodegenerative disorders, kidney diseases, inflammation, pain and cancer. The intracellular C-terminus is an important regulator of TRP channel activity. Studies with this and other TRP superfamily members have shown that the C-terminus association with lipid bilayer alters channel sensitivity and activation, especially interactions occurring through basic residues. Nevertheless, it is not yet clear how this process takes place and which regions in the C-terminus would be responsible for such membrane recognition. With that in mind, herein the first putative membrane interacting region of the C-terminus of human TRPA1, (corresponding to a 29 residue peptide, IAEVQKHASLKRIAMQVELHTSLEKKLPL) named H1 due to its potential helical character was chosen for studies of membrane interaction. The affinity of H1 to lipid membranes, H1 structural changes occurring upon this interaction as well as effects of this interaction in lipid organization and integrity were investigated using a biophysical approach. Lipid models systems composed of zwitterionic and anionic lipids, namely those present in the lipid membrane inner leaflet, where H1 is prone to interact, where used. The study reveals a strong interaction and affinity of H1 as well as peptide structuration especially with membranes containing anionic lipids. Moreover, the interactions and peptide structure adoption are headgroup specific.
瞬时受体电位锚蛋白1通道（TRPA1）属于TRP阳离子通道超家族，该家族可对一系列刺激做出反应，如温度变化、钙水平、活性氧和氮物种以及脂质介质等。TRP超家族与多种病理状态有关，包括神经退行性疾病、肾脏疾病、炎症、疼痛和癌症。细胞内C末端是TRP通道活性的重要调节因子。对该蛋白及其他TRP超家族成员的研究表明，C末端与脂质双层的结合会改变通道的敏感性和激活，尤其是通过碱性残基发生的相互作用。然而，目前尚不清楚这个过程是如何发生的，以及C末端的哪些区域负责这种膜识别。考虑到这一点，本文选择了人TRPA1 C末端的第一个假定膜相互作用区域（对应于一个29个残基的肽，IAEVQKHASLKRIAMQVELHTSLEKKLPL，因其潜在的螺旋特性而命名为H1）来研究膜相互作用。使用生物物理方法研究了H1与脂质膜的亲和力、这种相互作用发生时H1的结构变化以及这种相互作用对脂质组织和完整性的影响。使用了由两性离子和阴离子脂质组成的脂质模型系统，即H1易于相互作用的脂质膜内小叶中存在的那些脂质。研究揭示了H1的强烈相互作用和亲和力以及肽的结构化，特别是与含有阴离子脂质的膜的相互作用。此外，相互作用和肽结构的形成具有头基特异性。
