Morimoto Naoya, Nagata Takashi, Inoue Keiichi
The Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan.
Biochemistry. 2023 May 2;62(9):1429-1432. doi: 10.1021/acs.biochem.3c00084. Epub 2023 Apr 14.
Retinal G-protein-coupled receptor (RGR) plays a crucial role in the visual system of vertebrates as a retinal photoisomerase, which isomerizes all--retinal to 11--retinal to maintain the photosensitivity of visual rhodopsins. Despite the previous characterization of bovine RGR, little is known about the spectral properties of RGR from other species. In addition, photoreactivity of the 11--retinal-binding form remains unclear. In this study, we revealed that human and chicken RGRs form blue-absorbing pigments similar to bovine RGR. Furthermore, the spectroscopic and biochemical analyses revealed that bovine and chicken RGRs are bistable rhodopsins displaying a reversible photoreaction. These findings provide insight into the behavior of RGR as a retinal photoisomerase and aid in understanding its role in the visual system.
视网膜G蛋白偶联受体（RGR）作为一种视网膜光异构酶，在脊椎动物的视觉系统中起着至关重要的作用，它将全反式视黄醛异构化为11-顺式视黄醛，以维持视觉视紫红质的光敏性。尽管之前已经对牛RGR进行了表征，但对于其他物种RGR的光谱特性知之甚少。此外，11-顺式视黄醛结合形式的光反应性仍不清楚。在本研究中，我们发现人类和鸡的RGR形成了与牛RGR类似的吸收蓝光的色素。此外，光谱和生化分析表明，牛和鸡的RGR是双稳态视紫红质，表现出可逆的光反应。这些发现为RGR作为视网膜光异构酶的行为提供了见解，并有助于理解其在视觉系统中的作用。
