A Light Motif

Green algae move in response to light to find conditions that are optimal for photosynthetic growth, and this movement is mediated by photoreceptor currents. Nagel et al. have identified an opsin-related protein, channelopsin-1, in Chlamydomonas reinhardtii that is likely to be the photoreceptor involved in phototaxis. Expression of channelopsin-1 in the presence of all- trans retinal in Xenopus oocytes produced light-induced proton currents. Characteristics of the conductance suggest that channelopsin-1 forms a light-gated proton channel. G. Nagel, D. Ollig, M. Fuhrmann, S. Kateriya, A. M. Musti, E. Bamberg, P. Hegemann, Channelrhodopsin-1: A light-gated proton channel in green algae. Science 296 , 2395-2398 (2002). [Abstract] [Full Text]