Comparative study of phototactic and photophobic receptor chromophore properties in Chlamydomonas reinhardtii.
Comparative study of phototactic and photophobic receptor chromophore properties in Chlamydomonas reinhardtii.
复制标题
莱茵衣藻趋光和避光受体发色团特性的比较研究。
DOI：
10.1016/s0006-3495(93)81067-1
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发表时间：
1993
影响因子：
3.4
通讯作者：
Spudich,JL
中科院分区：
文献类型：
--
作者：
Zacks,DN;Derguini,F;Nakanishi,K;Spudich,JL
莱茵衣藻是一种单细胞真核生物，对光刺激具有两种不同的行为反应：趋光反应和憎光反应。两者都是由含视黄酸的受体介导的。本文着重于两种光响应的直接比较和它们的感光体的发色团的要求。使用计算机化的运动分析测定的趋光性和憎光反应由相同的细胞群体，我们测量了各种异构体和类似物的视网膜色素缺陷突变体FN 68中重建photobeavity的能力。结果表明，疏水性和趋光性反应各自需要具有全反式多烯链构型、平面紫罗酮环/多烯链构象以及在视网膜C13-C14双键周围异构化的能力的发色团。这两种行为之间的一个区别是，在趋光性反应没有变得脱敏的光刺激之后，畏光反应变得高度脱敏，这表明在畏光反应途径中存在至少一个不同的步骤。第二个区别是，视网膜再生的嫌光性反应，但不趋光性抑制的5元环13-trans-locked类似物。虽然这两种行为的发色团结构要求非常相似，但结果表明这两种反应在其感光蛋白水平和/或其转导过程中存在差异。
The motile, unicellular, eukaryotic alga Chlamydomonas reinhardtii exhibits two distinct behavioral reactions to light stimuli, phototaxis and the photophobic response. Both are mediated by retinal-containing receptors. This paper focuses on a direct comparison of the two photoresponses and the chromophore requirements for their photoreceptor(s). Using computerized motion analysis assays for phototaxis and photophobic responses by the same populations of cells, we measured the ability of various isomers and analogues of retinal to reconstitute photobehavior in the pigment-deficient mutant FN68. The results indicate that photophobic and phototaxis responses each require chromophores with an all-trans polyene chain configuration, planar ionone ring/polyene chain conformation, and the ability to isomerize around the retinal C13-C14 double bond. One difference between the two behaviors is that the photophobic response becomes highly desensitized after light stimuli to which the phototaxis response does not become desensitized, indicating the existence of at least one distinct step in the photophobic response pathway. A second difference is that the retinal regeneration of the photophobic response but not of phototaxis is inhibited by a 5-membered ring 13-trans-locked analogue. While showing close similarity in the chromophore structural requirements of the two behaviors, the results indicate that differences exist between the two responses at the level of their photoreceptor proteins and/or in their transduction processes.