COMMON FEATURES OF THE QUORUM SENSING SYSTEMS IN VIBRIO SPECIES

摘要

In V. harveyi, the model for the regulation of luminescence includes sensors 1 and 2, LuxN and LuxQ, that autophosphorylate within the sensor recognition kinase domain, then transphosphorylate to the downstream receiver domain. Phosphorelay to the hpt (histidine-containing phosphate transfer) domain in LuxU followed by transfer to the response domain of the regulator, LuxO, then ensues. LuxO is a σ~(54)-binding activator whose phosphorylated form at low cell densities represses luminescence. As autoinducers (AI) accumulate, AI-1 interacts with LuxN, and AI-2, the luxS product, associates with a periplasmic protein LuxP to interact with LuxQ. The sensors switch from kinase to phosphatase activity causing inactivation of LuxO. With the recent discovery that luxS is present in many bacteria and appears to have similar interspecies functions, it is of interest to see whether the signal transduction pathway to LuxO is also widely distributed.