视蛋白

Progress in the studies on opsins

视蛋白是一种膜蛋白,属于G蛋白偶联受体超家族。根据分子系统学分析和功能不同,视蛋白可分为7个亚家族,它们分布于视网膜、脑、睾丸、皮肤等组织,具有视觉感光功能和一些非视觉功能,如调节生物昼夜节律、参与瞳孔对光反射、作为一种视黄醛光异构酶等,此外,有一些视蛋白功能未知,有待于进一步的研究。

Opsins, which are membrane proteins, are G-protein-coupled receptors （GPCRs）, and they have a seven- transmembrane structure similar to that of other GPCRs. Detailed molecular phylogenetic analyses showed that the opsin family is divided into seven subfamilies, which corresponds well to functional classification of opsins. The opsin genes are expressed in retina, brain, testes, skin and so on. The most extensively studied function of opsin based on photopigments is their role in vision, whereas accumulated evidence suggests that a few opsins are involved in circadian rhythm, pupillary light reflex and serve as retinal photoisomerases. In addition, some opsins have unknown functions.