Measuring Cyclic Diguanylate (c-di-GMP)-Specific Phosphodiesterase Activity Using the MANT-c-di-GMP Assay

: The second messenger, cyclic diguanylate (c-di-GMP), regulates a variety of bacterial cellular and social behaviors. A key determinant of c-di-GMP levels in cells is its degradation by c-di-GMP-specific phosphodiesterases (PDEs). Here, we describe an assay to determine c-di-GMP degradation rates in vitro using 2'-O-(N'-methylanthraniloyl)-cyclic diguanylate (MANT-c-di-GMP). Additionally, a protocol for the production and purification of recombinant Pseudomonas aeruginosa RocR, a c-di-GMP-specific PDE that may serve as a control in MANT-c-di-GMP assays, is provided. The use of the fluorescent MANT-c-di-GMP analogue can deliver fundamental information about PDE function, and is suitable for identifying and investigating c-di-GMP-specific PDE activators and inhibitors.