Small molecules with big effects: Cyclic di-GMP-mediated stimulation of cellulose production by the amino acid ʟ-arginine.

In this issue of Science Signaling, Mills et al. show that the amino acid ʟ-arginine increases the concentration of the second messenger c-di-GMP in Salmonella enterica serovar Typhimurium through a specific diguanylate cyclase, leading to increased production of the exopolysaccharide cellulose, which is an extracellular matrix component of environmental and host-associated biofilms.