Blue light stimulates cyanobacterial motility via a cAMP signal transduction system.
The participation of cAMP in photosignal transduction in cyanobacteria was investigated. When cells of the cyanobacterium Synechocystis sp. PCC 6803 were exposed to light, cellular cAMP contents increased within a few minutes. Among incident monochromatic lights, blue light (450 nm) markedly increased cellular cAMP content, while red (630 nm) and far-red (720 nm) lights did not. Disruption of the cya1 gene encoding an adenylate cyclase caused the insensitivity of cellular cAMP level to blue light. Treatment of wild-type cells with the flavin antagonist phenylacetic acid inhibited this blue light effect. The motility of wild-type cells was enhanced by blue light, whereas that of cya1 mutant cells was not. Based on these results, we concluded that a blue light-cAMP signal transduction system stimulates the motility of Synechocystis sp. PCC 6803.
Terauchi
Kazuki
K
Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Komaba, Meguro, Tokyo 153-8902, Japan.
Ohmori
Masayuki
M
D000262:Adenylyl Cyclases / Q000235:genetics / Q000378:metabolism; D000963:Antimetabolites / Q000494:pharmacology; D000458:Cyanobacteria / Q000235:genetics / Q000502:physiology*; D000242:Cyclic AMP / Q000378:metabolism*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D008027:Light; D009068:Movement; D016254:Mutagenesis, Insertional; D010648:Phenylacetates / Q000494:pharmacology; D015398:Signal Transduction
D000963:Antimetabolites; D010648:Phenylacetates; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; D000262:Adenylyl Cyclases; C025136:phenylacetic acid