Cyclic di-nucleotides act as intracellular second messengers,modulating a variety of cellular activities including innate immune activation.Whereas phosphodiesterases (PDEs) hydrolyzing c-di-GMP and c-di-AMP have been identified,no PDEs for cGAMPs have been reported.Here we identified the first three cGAMP specific PDEs in V.cholerae (herein designated V-cGAP1/2/3 respectively),which degrade 33-cGAMP,but not other forms of cGAMP.