Park Paul Shin-Hyun
Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, Ohio, USA.
Adv Pharmacol. 2014;70:1-36. doi: 10.1016/B978-0-12-417197-8.00001-8.
Rhodopsin is the light receptor in rod photoreceptor cells of the retina that initiates scotopic vision. In the dark, rhodopsin is bound to the chromophore 11-cis retinal, which locks the receptor in an inactive state. The maintenance of an inactive rhodopsin in the dark is critical for rod photoreceptor cells to remain highly sensitive. Perturbations by mutation or the absence of 11-cis retinal can cause rhodopsin to become constitutively active, which leads to the desensitization of photoreceptor cells and, in some instances, retinal degeneration. Constitutive activity can arise in rhodopsin by various mechanisms and can cause a variety of inherited retinal diseases including Leber congenital amaurosis, congenital night blindness, and retinitis pigmentosa. In this review, the molecular and structural properties of different constitutively active forms of rhodopsin are overviewed, and the possibility that constitutive activity can arise from different active-state conformations is discussed.
视紫红质是视网膜杆状光感受器细胞中的光受体，可启动暗视觉。在黑暗中，视紫红质与发色团11-顺式视黄醛结合，这会将受体锁定在非活性状态。在黑暗中维持非活性视紫红质对于杆状光感受器细胞保持高度敏感性至关重要。突变或缺乏11-顺式视黄醛引起的扰动可导致视紫红质持续激活，这会导致光感受器细胞脱敏，在某些情况下还会导致视网膜变性。视紫红质可通过多种机制产生持续活性，并可导致多种遗传性视网膜疾病，包括莱伯先天性黑蒙、先天性夜盲和色素性视网膜炎。在这篇综述中，概述了视紫红质不同持续活性形式的分子和结构特性，并讨论了持续活性可能源于不同活性状态构象的可能性。
