Yassin L, Gillo B, Kahan T, Halevi S, Eshel M, Treinin M
Department of Physiology, Hadassah Medical School, Jerusalem, 91120, Israel.
Mol Cell Neurosci. 2001 Mar;17(3):589-99. doi: 10.1006/mcne.2000.0944.
The nicotinic acetylcholine receptor family (nAChR) is a large family of acetylcholine-gated cation channels. Here we characterize the Caenorhabditis elegans DEG-3/DES-2 nAChR, a receptor identified due to its involvement in neuronal degeneration. Pharmacological analysis of a DEG-3/DES-2 receptor expressed in Xenopus oocytes shows that this receptor is preferentially activated by choline. This choline sensitivity of the DEG-3/DES-2 channel can explain its role in neuronal degeneration, as shown by the toxic effects of choline on oocytes expressing the mutant DEG-3/DES-2 channel. We also show that in C. elegans the DEG-3/DES-2 receptor is localized to nonsynaptic regions, including the sensory endings of chemosensory neurons. This localization is in agreement with a role for this receptor in chemosensation of choline, as inferred from a defect in chemotaxis for choline seen in deg-3 mutants. Thus, this work also provides evidence for the diversity of nonsynaptic activities associated with nAChRs.
烟碱型乙酰胆碱受体家族（nAChR）是一个由乙酰胆碱门控阳离子通道组成的大家族。在此，我们对秀丽隐杆线虫的DEG-3/DES-2 nAChR进行了表征，该受体因其与神经元变性有关而被鉴定出来。对非洲爪蟾卵母细胞中表达的DEG-3/DES-2受体进行的药理学分析表明，该受体优先被胆碱激活。DEG-3/DES-2通道对胆碱的敏感性可以解释其在神经元变性中的作用，胆碱对表达突变型DEG-3/DES-2通道的卵母细胞的毒性作用就证明了这一点。我们还表明，在秀丽隐杆线虫中，DEG-3/DES-2受体定位于非突触区域，包括化学感受神经元的感觉末梢。这种定位与该受体在胆碱化学感受中的作用一致，这是从deg-3突变体中观察到的对胆碱趋化性缺陷推断出来的。因此，这项工作也为与nAChRs相关的非突触活动的多样性提供了证据。
