Transporteurs ABC chez Bacillus subtilis : fonctionnement et régulation
Mots clés : Bacillus subtilis, signal transduction, ABC-transporters, peptide antibiotic resistance, Ser/Thr signalling, Two-component systems.
Membrane bound transporter efflux of drugs or toxic compounds outside of the cell is one of the most effective strategy to escape the lethal effect of such compounds. We study the functioning and the regulation of the expression of these transporters, whether they are involved in MDR (Multi Drug Resistance) or in the resistance to antibiotics in Bacillus subtilis. The first project concerns the Mta regulator. In addition to its previously shown involvement in controlling two MDR transporter genes expression, it might be involved in a major physiological process at the intersection of three developmental programs : germination, biofilm formation and choice between cell chaining and motility. The second project concerns a new family of modules, only present in Firmicutes, comprising two component system and ABC transporter, modules probably all implicated in peptide antibiotic resistance. They showed particular structural characteristics and might all need a functional ABC transporter to be induced by the corresponding antibiotic, as for the B. subtilis BceRSAB module involved in bacitracin resistance. In both projects, a signal transduction mechanism is implicated and both are under study.