Two rhodopsins mediate phototaxis to low- and high-intensity light in Chlamydomonas reinhardtii.

ABSTRACT: We demonstrate that two rhodopsins, identified from cDNA sequences, function as low- and high-light-intensity phototaxis receptors in the eukaryotic alga Chlamydomonas reinhardtii. Each of the receptors consists of an approximately 300-residue seven-transmembrane helix domain with a retinal-binding pocket homologous to that of archaeal rhodopsins, followed by approximately 400 residues of additional membrane-associated portion. The function of the two rhodopsins, Chlamydomonas sensory rhodopsins A and B (CSRA and CSRB), as phototaxis receptors is demonstrated by in vivo analysis of photoreceptor electrical currents and motility responses in transformants with RNA interference (RNAi) directed against each of the rhodopsin genes. The kinetics, fluence dependencies, and action spectra of the

SUBMITTER: Sineshchekov OA 

PROVIDER: S-EPMC124360 | biostudies-literature | 2002 Jun

REPOSITORIES: biostudies-literature