Abstract
Signaling pathways involving second messenger c-di-GMP regulate various aspects of bacterial physiology and behavior. We describe the use of a red light-activated diguanylate cyclase (c-di-GMP synthase) and a blue light-activated c-di-GMP phosphodiesterase (hydrolase) for manipulating intracellular c-di-GMP levels in bacterial cells. We illustrate the application of these enzymes in regulating several c-di-GMP-dependent phenotypes, i.e., motility and biofilm phenotypes in E. coli and chemotactic behavior in the alphaproteobacterium Azospirillum brasilense. We expect these light-activated enzymes to be also useful in regulating c-di-GMP-dependent processes occurring at the fast timescale, for spatial control of bacterial populations, as well as for analyzing c-di-GMP-dependent phenomena at the single-cell level.