RECOVERIN IN PINEAL ORGANS AND RETINAE OF VARIOUS VERTEBRATE SPECIES INCLUDING MAN
RECOVERIN IN PINEAL ORGANS AND RETINAE OF VARIOUS VERTEBRATE SPECIES INCLUDING MAN
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DOI：
10.1016/0006-8993(92)91452-k
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发表时间：
1992-11-06
期刊：
影响因子：
2.9
通讯作者：
KLEIN, DC
中科院分区：
文献类型：
--
作者：
KORF, HW;WHITE, BH;KLEIN, DC
Recoverin是最近发现的一种26 kDa的钙结合蛋白，当细胞内游离钙浓度在光刺激下下降时，它会激活视网膜光感受器中的鸟苷环化酶。本研究用免疫细胞化学方法研究了非洲爪哇幼虫、1日龄鸡、成年鸽子、白化大鼠、绵羊和人视网膜和松果体器官中恢复素的分布。除鸡外，在所有被调查的物种中均发现Recoverin免疫反应。在视网膜，恢复素免疫反应仅限于光感受器；所有其他类型的细胞均为免疫阴性。在松果体，恢复素免疫反应被标记为感觉线松果体细胞，即非洲爪哇幼虫的经典松果体光感受器、改良的鸽子松果体光感受器和哺乳动物的松果体细胞。不同哺乳动物松果体细胞的数量有很大差异：大鼠松果体细胞很少，而兔、羊和人的松果体细胞大量恢复素免疫反应。重组蛋白预吸收复苏素抗体后，未见免疫细胞化学染色。免疫印迹实验表明，免疫反应是由于视网膜和松果体组织中都有一种26 kDa的蛋白质引起的。因此，恢复素似乎属于在视网膜和松果体器官中都表达的蛋白质家族，并且在系统发育过程中高度保守。Recoverin可能参与了变温脊椎动物和鸟类对光敏感的松果体器官的光转导。然而，恢复素在哺乳动物松果体器官中的功能作用仍不清楚，因为它不是光敏的。
Recoverin is a recently discovered 26 kDa calcium-binding protein, which activates guanylate cyclase in retinal photoreceptors when the intracellular concentration of free calcium drops upon photoexcitation. In this study we examined the distribution of recoverin in retinae and pineal organs of Xenopus laevis larvae, 1-day-old chicken, adult pigeon, albino rat, sheep and man by means of immunocytochemistry. Recoverin immunoreaction was found in all species investigated except for the chicken. In the retina, recoverin immunoreaction was restricted to photoreceptors; all other cell types were immunonegative. In the pineal organ, the recoverin immunoreaction labeled 'pinealocytes of the sensory line', i.e. classical pineal photoreceptors of Xenopus laevis larvae, modified pineal photoreceptors of pigeon, and pinealocytes of mammals. The number of recoverin immunoreactive pinealocytes varied considerably among species of mammals: very few cells were stained in the rat pineal organ, whereas in rabbit, sheep and man, numerous pinealocytes were found to be recoverin-immunoreactive. No immunocytochemical staining was observed after preabsorption of the recoverin antibody with the recombinant protein. Immunoblotting experiments showed that the immunoreaction is due to a protein of 26 kDa in both retina and pineal tissue. Thus, recoverin appears to belong to the family of proteins which are expressed in both retina and pineal organ and are highly conserved in the course of phylogeny. Recoverin may be involved in phototransduction in the directly light-sensitive pineal organs of poikilothermic vertebrates and birds. However, the functional role of recoverin in the mammalian pineal organ, which is not photosensitive, remains unknown.