All-trans/13-cis isomerization of retinal is required for phototaxis signaling by sensory rhodopsins in Halobacterium halobium.
All-trans/13-cis isomerization of retinal is required for phototaxis signaling by sensory rhodopsins in Halobacterium halobium.
复制标题
卤杆菌中感觉视紫红质的趋光信号需要视网膜的全反式/13-顺式异构化。
DOI：
10.1016/s0006-3495(90)82600-x
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发表时间：
1990
影响因子：
3.4
通讯作者：
Spudich,JL
中科院分区：
文献类型：
--
作者：
Yan,B;Takahashi,T;Johnson,R;Derguini,F;Nakanishi,K;Spudich,JL
一种全反式视网膜的类似物，其中全反式/13-顺式异构化被从C12到C14的碳桥阻断，被纳入视网膜缺陷盐菌膜中感觉视紫红质I （SR-I）和感觉视紫红质II （SR-II，也称为光视紫红质）的载蛋白中。“全反式锁定”视网膜类似物形成与天然色素吸收光谱相似的SR-I和SR-II类似色素。阻断异构化可阻止sr - 1光循环（S373）和SR-II光循环（S-II360和S-II530）的长寿命中间体的形成。计算机细胞跟踪和运动分析系统能够检测2%的天然色素活性，用于评估运动行为。在体内将锁定的类似物引入sr - 1或SR-II载子蛋白中，不会通过三种已知的光感系统（sr - 1引诱剂、sr - 1驱避剂或SR-II驱避剂）中的任何一种恢复光致反应。我们得出的结论是，与衣藻reinhardtii的趋光性受体不同，衣藻的趋光性受体介导的生理反应没有特异性的双键异构化（Foster et al., 1989），全反式/13-顺式异构化对于SR-I和SR-II趋光性信号至关重要。
An analogue of all-trans retinal in which all-trans/13-cis isomerization is blocked by a carbon bridge from C12 to C14 was incorporated into the apoproteins of sensory rhodopsin I (SR-I) and sensory rhodopsin II (SR-II, also called phoborhodopsin) in retinal-deficient Halobacterium halobium membranes. The "all-trans-locked" retinal analogue forms SR-I and SR-II analogue pigments with similar absorption spectra as the native pigments. Blocking isomerization prevents the formation of the long-lived intermediate of the SR-I photocycle (S373) and those of the SR-II photocycle (S-II360 and S-II530). A computerized cell tracking and motion analysis system capable of detecting 2% of native pigment activity was used for assessing motility behavior. Introduction of the locked analogue into SR-I or SR-II apoprotein in vivo did not restore phototactic responses through any of the three known photosensory systems (SR-I attractant, SR-I repellent, or SR-II repellent). We conclude that unlike the phototaxis receptor of Chlamydomonas reinhardtii, which has been reported to mediate physiological responses without specific double-bond isomerization of its retinal chromophore (Foster et al., 1989), all-trans/13-cis isomerization is essential for SR-I and SR-II phototaxis signaling.