The Temporal Expression of Global Regulator Protein CsrA Is Dually Regulated by ClpP During the Biphasic Life Cycle of .

, an environmental bacterium that parasitizes protozoa, is the causative pathogen of Legionnaires' disease. adopts a distinct biphasic life cycle that allows it to adapt to environmental conditions for survival, replication, and transmission. This cycle consists of a non-virulent replicative phase (RP) and a virulent transmissive phase (TP).

The Legionella pneumophila effector WipA disrupts host F-actin polymerisation by hijacking phosphotyrosine signalling.

The major virulence determinant of Legionella pneumophila is the type IVB secretion system (T4BSS), which delivers approximately 330 effector proteins into the host cell to modulate various cellular processes. However, the functions of most effector proteins remain unclear. WipA, an effector, was the first phosphotyrosine phosphatase of Legionella with unknown function.