文章基本信息

标题：Ca-α1T, a fly T-type Ca2+ channel, negatively modulates sleep
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作者：Kyunghwa Jeong ; Soyoung Lee ; Haengsoo Seo 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2015
卷号：5
期号：1
DOI：10.1038/srep17893
语种：English
出版社：Springer Nature
摘要：Mammalian T-type Ca²⁺ channels are encoded by three separate genes (Ca_v3.1, 3.2, 3.3). These channels are reported to be sleep stabilizers important in the generation of the delta rhythms of deep sleep, but controversy remains. The identification of precise physiological functions for the T-type channels has been hindered, at least in part, by the potential for compensation between the products of these three genes and a lack of specific pharmacological inhibitors. Invertebrates have only one T-type channel gene, but its functions are even less well-studied. We cloned Ca- α 1T, the only Ca_v3 channel gene in Drosophila melanogaster , expressed it in Xenopus oocytes and HEK-293 cells, and confirmed it passes typical T-type currents. Voltage-clamp analysis revealed the biophysical properties of Ca- α 1T show mixed similarity, sometimes falling closer to Ca_v3.1, sometimes to Ca_v3.2, and sometimes to Ca_v3.3. We found Ca- α 1T is broadly expressed across the adult fly brain in a pattern vaguely reminiscent of mammalian T-type channels. In addition, flies lacking Ca- α 1T show an abnormal increase in sleep duration most pronounced during subjective day under continuous dark conditions despite normal oscillations of the circadian clock. Thus, our study suggests invertebrate T-type Ca²⁺ channels promote wakefulness rather than stabilizing sleep.