Diversion of the sign of phototaxis in a Chlamydomonas reinhardtii mutant incorporated with retinal and its analogs

FEBS Letters

Takahashi, Tetsuo²  Kubota, Mameru³  Yoshihara, Kazuo²  Derguini, Fadila¹  Nakanishi, Koji²  Watanabe, Masakatsu³ 

[1] Department of Chemistry, Columbia University, New York, NY 10027, USA;Suntory Institute for Bioorganic Research, Shimamoto-cho, Mishima-gun, Osaka, 618, Japan;National Institute for Basic Biology, Okazaki National Research Institutes, Myodaiji-cho, Okazaki, Aichi, 444, Japan

关键词: Rhodopsin;    Chlamydomonas reinhardtii;    Photoreceptor;    Retinal analog;    Phototaxis;    Eyespot;    C. reinhardtii;    Chlamydomonas reinhardtii;    OLS;    Okazaki Large Spectrograph;    NMM;    nitrogen-free minimal medium;    HPLC;    high performance liquid chromatography;    9;    11-dicis(7)-retinal;    9;    11-dicis retinal with fixed 11-ene by 7-membered ring;    11-trans(5)-retinal;    11-trans retinal with fixed 11-ene by 5-membered ring;    pentaenal retinal;    all-trans 3;    7;    11-trimethyl-10-Isopropyldodeca-2;    4;    6;    8;    10-pentaenal;   

DOI  :  10.1016/0014-5793(92)81488-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The blind mutant FN68 of the unicellular flagellate green alga Chlamydomonas reinhardtil is negatively phototactic in the presence of the native chromophore all-trans retinal. In contrast, analog chromophores such as a ring-acyclic retinal and those in which trans/cis isomerization about the C11–C12 double bond was blocked induced predominantly positive pho totaxis in the same strain under the same experimental conditions. These observations can be interpreted by assuming that the negative and the positive phototaxis is mediated distinctively by two rhodopsin species which differ in their affinities with the exogenous chromophores. However, a more reasonable explanation, which requires fewer assumptions, is that the sign of phototaxis depends on a delay in intracellular photosignal transduction. This novel view was deduced directly from the widely accepted Hypothesis [1980, Microbiol. Rev. 44, 572–630] on phototaxis mechanisms.

【 授权许可】

Unknown