Mirshahi M, Razaghi A, Mirshahi S S, Van Tuyen V, Faure J P
INSERM U 86, Paris, France.
Thromb Res. 1991 Dec 1;64(5):551-8.
S-antigen (also named arrestin or 48K protein) is a protein abundant in photoreceptor cells of vertebrates and invertebrates. The presently known function of this protein in retina is to arrest the enzymatic cascade of phototransduction in retinal rods, through its binding to photoactivated and phosphorylated rhodopsin. Proteins closely related to S-antigen were recently demonstrated in several non photosensitive cells. In this work, we demonstrated the presence of a protein similar to retinal S-antigen with regards to its immunoreactivity with a panel of monoclonal antibodies and its molecular weight in soluble extracts of human platelets. This protein was purified by immunoaffinity chromatography using a rabbit antibody to retinal S-antigen. This S-antigen-like protein could have a regulatory function in G-protein-mediated transduction of chemical signals in platelets, similar to arrestin function in phototransduction.
S抗原（也称为抑制蛋白或48K蛋白）是一种在脊椎动物和无脊椎动物的光感受器细胞中大量存在的蛋白质。目前已知该蛋白在视网膜中的功能是通过与光激活和磷酸化的视紫红质结合，终止视网膜视杆细胞中的光转导酶级联反应。最近在几种非感光细胞中发现了与S抗原密切相关的蛋白质。在这项研究中，我们在人血小板的可溶性提取物中证实了一种与视网膜S抗原相似的蛋白质的存在，该蛋白质与一组单克隆抗体的免疫反应性及其分子量与视网膜S抗原相似。使用抗视网膜S抗原的兔抗体通过免疫亲和层析法纯化了该蛋白。这种类S抗原蛋白可能在血小板中G蛋白介导的化学信号转导中具有调节功能，类似于其在光转导中的抑制蛋白功能。
