The non-visual opsins expressed in deep brain neurons projecting to the retina in lampreys
The non-visual opsins expressed in deep brain neurons projecting to the retina in lampreys
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DOI：
10.1038/s41598-020-66679-2
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发表时间：
2020-06-15
影响因子：
4.6
通讯作者：
Terakita, Akihisa
中科院分区：
文献类型：
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作者：
Kawano-Yamashita, Emi;Koyanagi, Mitsumasa;Terakita, Akihisa
在低等脊椎动物中，大脑感光细胞表达脊椎动物特有的非视觉视蛋白。我们之前发现了一种与松果体相关的器官特异性视蛋白，副视蛋白，对紫外线敏感，并允许七鳃鳗和硬鱼的松果体波长识别。澳大利亚的七鳃鳗最近被报道有两个与旁平蛋白相关的基因。我们证明了来自日本河七鳃鳗的类旁视蛋白表现出与旁视蛋白不同的分子特性和分布。这种视蛋白在哺乳动物细胞培养实验中以光依赖的方式激活gi型G蛋白。异源作用光谱显示，视蛋白形成一种对紫到蓝敏感的色素。有趣的是，在河溪七鳃鳗中脑的Schober M5核（M5NS）细胞中，视蛋白与绿色敏感的p -视蛋白共定位。七鳃鳗的一些含视蛋白的细胞有纤毛，另一些细胞有突出到视网膜的轴突。七鳃鳗的视蛋白共同定位于向视网膜投射的离心神经元的纤毛中，这表明表达类旁视蛋白和p视蛋白的细胞对紫光和绿光敏感。此外，我们发现表达视蛋白的M5NS细胞与视网膜之间存在神经联系。这些发现表明视网膜活动可能是由大脑的光接受调节的。
In lower vertebrates, brain photoreceptor cells express vertebrate-specific non-visual opsins. We previously revealed that a pineal-related organ-specific opsin, parapinopsin, is UV-sensitive and allows pineal wavelength discrimination in lampreys and teleost. The Australian pouched lamprey was recently reported as having two parapinopsin-related genes. We demonstrate that a parapinopsin-like opsin from the Japanese river lamprey exhibits different molecular properties and distribution than parapinopsin. This opsin activates Gi-type G protein in a mammalian cell culture assay in a light-dependent manner. Heterologous action spectroscopy revealed that the opsin forms a violet to blue-sensitive pigment. Interestingly, the opsin is co-localised with green-sensitive P-opsin in the cells of the M5 nucleus of Schober (M5NS) in the mesencephalon of the river and brook lamprey. Some opsins-containing cells of the river lamprey have cilia and others an axon projecting to the retina. The opsins of the brook lamprey are co-localised in the cilia of centrifugal neurons projecting to the retina, suggesting that cells expressing the parapinopsin-like opsin and P-opsin are sensitive to violet to green light. Moreover, we found neural connections between M5NS cells expressing the opsins and the retina. These findings suggest that the retinal activity might be modulated by brain photoreception.