Photophobic responses and phototaxis in Chlamydomonas are triggered by a single rhodopsin photoreceptor

FEBS Letters

Hegemann, Peter¹  Kröger, Petra¹ 

[1] Institut für Biochemie, Universität Regensburg, 93040 Regenburg, Germany

关键词: Rhodopsin;    Phototaxis;    Blue light receptor;    Chlamydomonas reinhardtii;   

DOI  :  10.1016/0014-5793(94)80229-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The rhodopsin nature of the photoreceptor for the behavioural light responses in Chlamydomonas has originally been revealed by action spectroscopy. Meanwhile most physiological experiments and the identification of all-trans-retinal in cell extracts favour that this chlamyrhodopsin contains an all-trans-type retinal chromophore with strong similarity to the light sensors SR I and SRII from Halobacteria. Reconstitution of retinal-deficient cells with [³H]retinal identified a single retinal protein with a MW of 30,000. Chlamyrhodopsin triggers a photoreceptor current in the eyespot region resulting in direction changes or phototaxis. Furthermore, when the light stimulus oversteps a critical level, two flagellar currents appear, which are the basis for photophobic responses. The physiological, electrophysiological and biochemical experiments suggest that all behavioural responses are triggered by a single rhodopsin-type receptor.

【 授权许可】

Unknown