Identification and characterization of a protostome homologue of peropsin from a jumping spider
Identification and characterization of a protostome homologue of peropsin from a jumping spider
复制标题
DOI：
10.1007/s00359-009-0493-9
复制
发表时间：
2010-01-01
影响因子：
2.1
通讯作者：
Terakita, Akihisa
中科院分区：
文献类型：
--
作者：
Nagata, Takashi;Koyanagi, Mitsumasa;Terakita, Akihisa
Peropsin是视蛋白家族的一员，具有两种功能不同的视蛋白组的特征，即在视蛋白中保守的用于光传感的氨基酸残基和视醛光异构酶样分子性质。虽然这样的双边功能的peropsin似乎是重要的理解的多样性的视蛋白家族，以前的研究已限于高等后口，脊椎动物和文昌鱼peropsin。在这里，我们报告了一个原口类peropsin同系物从跳蜘蛛。我们发现了一种蜘蛛视蛋白，与已知的peropsins共享氨基酸同源性和保守的氨基酸残基。异源表达的蜘蛛视蛋白色素具有类似光异构酶的异构化特征和色素变性。根据其氨基酸同源性和光化学性质的特点，我们认为蜘蛛视蛋白是第一个原口动物视蛋白同源物。这些结果表明，peropsin存在于后口-原口分裂之前，就像视蛋白家族的其他成员一样。此外，蜘蛛peropsin定位于视网膜中的非视觉细胞，并且在peropsin定位的区域中也观察到来自还原的视网膜发色团的荧光。这些发现首次证明了peropsin可以在体内形成光敏色素，并成为非视觉功能的基础。
Peropsin, a member of the opsin family, has characteristics of two functionally distinct opsin-groups, that is, amino acid residues conserved among opsins for light-sensing and a retinal-photoisomerase-like molecular property. Although such a bilateral feature of peropsin seems to be important for understanding the diversity of the opsin family, previous studies have been limited to higher deuterostome, vertebrate and amphioxus peropsins. Here, we report a protostome peropsin homologue from a jumping spider. We found a spider opsin that shares amino acid homology and conserved amino acid residues with known peropsins. The spider opsin-based pigment heterologously expressed in cultured cells exhibited photoisomerase-like isomerization characteristics and a bistable nature. Based on the characteristics of both the amino acid homology and its photochemical properties, we concluded that the spider opsin is the first protostome peropsin homologue. These results show that peropsin existed before the deuterostome-protostome split like other members of the opsin family. In addition, the spider peropsin was localized to non-visual cells in the retina, and fluorescence from reduced retinal chromophore was also observed in the region where peropsin was localized. These findings provide the first demonstration that the peropsin can form a photosensitive pigment in vivo and underlie non-visual function.