Parietal-eye phototransduction components and their potential evolutionary implications
Parietal-eye phototransduction components and their potential evolutionary implications
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DOI：
10.1126/science.1123802
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发表时间：
2006-03-17
期刊：
影响因子：
56.9
通讯作者：
Yau, KW
中科院分区：
文献类型：
--
作者：
Su, CY;Luo, DG;Yau, KW
顶眼感光器是独一无二的，因为它在同一细胞中有两条相互拮抗的光信号通路-对蓝光最敏感的超极化通路和对绿光最敏感的去极化通路。在这里，我们报告了这两个途径的分子组成。我们在同一个细胞中发现了两种视蛋白：对蓝色敏感的视黄素和以前未知的对绿色敏感的视蛋白，我们将其命名为顶叶视黄素。信号成分包括Gustducin-α和Gα(O)，但不包括视杆或视锥转导蛋白-α。单细胞记录表明，G(O)介导了去极化反应。Gustducin-α在功能上类似于转导蛋白-α，可能介导超极化反应。顶叶胡萝卜素-G(O)信号对为视杆细胞和视锥细胞的光转导如何进化提供了线索。
The parietal-eye photoreceptor is unique because it has two antagonistic light signaling pathways in the same cell - a hyperpolarizing pathway maximally sensitive to blue light and a depolarizing pathway maximally sensitive to green light. Here, we report the molecular components of these two pathways. We found two opsins in the same cell: the blue-sensitive pinopsin and a previously unidentified green-sensitive opsin, which we name parietopsin. Signaling components included gustducin-alpha and G alpha(o), but not rod or cone transducin-alpha. Single-cell recordings demonstrated that G(o) mediates the depolarizing response. Gustducin-alpha resembles transducin-alpha functionally and likely mediates the hyperpolarizing response. The parietopsin-G(o) signaling pair provides clues about how rod and cone phototransduction might have evolved.