Integration of photo- and chemosensory signaling pathways in Chlamydomonas.
The behavior of Chlamydomonas reinhardtii Dangeard is regulated by both light and chemical stimuli. Generation of a transmembrane photoreceptor current is the earliest so far resolved event in phototaxis of green flagellates. Tryptone rapidly inhibits the photoreceptor current in gametes of C. reinhardtii and induces their accumulation. The time-course, concentration dependence and induction during gametogenesis of these two processes coincide. On the other hand, tryptone causes a weak stimulation of the photoreceptor current in the absence of any behavioral responses in vegetative cells. This shows that the tryptone-induced inhibition of the photoreceptor current in C. reinhardtii is due to activation of a gamete-specific chemosensory system, and that integration of the photo- and chemosensory signals already occurs at the initial steps of the signaling pathways.
Govorunova
Elena G
EG
Chair of Physico-Chemical Biology, Biology Department, Moscow State University, Vorobievy Gory, 119899 Moscow, Russia.
Sineshchekov
Oleg A
OA
D000818:Animals; D016825:Chlamydomonas reinhardtii / Q000187:drug effects / Q000254:growth & development* / Q000528:radiation effects; D005407:Flagella / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D008027:Light; D010461:Peptones / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects
D010461:Peptones; C001830:tryptones