Liu Lei, Leonard A Soren, Motto David G, Feller Margaret A, Price Margaret P, Johnson Wayne A, Welsh Michael J
Howard Hughes Medical Institute and Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City 52242, USA.
Neuron. 2003 Jul 3;39(1):133-46. doi: 10.1016/s0896-6273(03)00394-5.
The ability to detect salt is critical for the survival of terrestrial animals. Based on amiloride-dependent inhibition, the receptors that detect salt have been postulated to be DEG/ENaC channels. We found the Drosophila DEG/ENaC genes Pickpocket11 (ppk11) and Pickpocket19 (ppk19) expressed in the larval taste-sensing terminal organ and in adults on the taste bristles of the labelum, the legs, and the wing margins. When we disrupted PPK11 or PPK19 function, larvae lost their ability to discriminate low concentrations of Na(+) or K(+) from water, and the electrophysiologic responses to low salt concentrations were attenuated. In both larvae and adults, disrupting PPK11 or PPK19 affected the behavioral response to high salt concentrations. In contrast, the response of larvae to sucrose, pH 3, and several odors remained intact. These results indicate that the DEG/ENaC channels PPK11 and PPK19 play a key role in detecting Na(+) and K(+) salts.
检测盐分的能力对陆生动物的生存至关重要。基于amiloride依赖性抑制作用，人们推测检测盐分的受体是DEG/ENaC通道。我们发现果蝇的DEG/ENaC基因Pickpocket11（ppk11）和Pickpocket19（ppk19）在幼虫的味觉传感终端器官以及成虫的唇叶、腿部和翅缘的味觉刚毛中表达。当我们破坏PPK11或PPK19的功能时，幼虫失去了从水中辨别低浓度Na(+)或K(+)的能力，并且对低盐浓度的电生理反应减弱。在幼虫和成虫中，破坏PPK11或PPK19都会影响对高盐浓度的行为反应。相比之下，幼虫对蔗糖、pH 3以及几种气味的反应保持不变。这些结果表明，DEG/ENaC通道PPK11和PPK19在检测Na(+)和K(+)盐中起关键作用。
