The calmodulin-dependent adenylate cyclase (Cya) domain of the cyclolysin toxin from Bordetella pertussis can be exploited as a reporter for translocation of effector proteins [PMID::10217833] [PMID::14702323]. Cya is not active in bacterial cytoplasm because bacteria do not possess calmodulin, and it is not naturally secreted or translocated by the type III secretion systems. However, when the N-terminal portion of an effector is fused to Cya, bacteria can deliver the resulting hybrid protein into the cytosol of host cells, where it can bind to calmodulin and produce cyclic AMP (cAMP) from ATP. Adenylate cyclase activity can also be assessed in vitro without translocation to a host.