Quintana, JuliaNovoa-Aponte, LorenaArgüello, José2023-12-122023-12-122017-07-31Quintana, J., Novoa-Aponte, L., and Argüello, J. M. M. (2017) Copper homeostasis networks in the bacterium Pseudomonas aeruginosa. The Journal of biological chemistry. 292, 15691–15704https://hdl.handle.net/10115/27130This work was supported by NIGMS, National Institutes of Health Grant R01 GM114949 (to J. M. A.).Bacterial copper (Cu⁺) homeostasis enables both precise metallation of diverse cuproproteins and control of variable metal levels. To this end, protein networks mobilize Cu⁺ to cellular targets with remarkable specificity. However, the understanding of these processes is rather fragmented. Here, we use genome-wide transcriptomic analysis by RNA-Seq to characterize the response of <i>Pseudomonas aeruginosa</i> to external 0.5 mm CuSO₄, a condition that did not generate pleiotropic effects. Pre-steady-state (5-min) and steady-state (2-h) Cu⁺ fluxes resulted in distinct transcriptome landscapes. Cells quickly responded to Cu²⁺ stress by slowing down metabolism. This was restored once steady state was reached. Specific Cu⁺ homeostasis genes were strongly regulated in both conditions. Our system-wide analysis revealed induction of three Cu⁺ efflux systems (a P_1B-ATPase, a porin, and a resistance-nodulation-division (RND) system) and of a putative Cu⁺-binding periplasmic chaperone and the unusual presence of two cytoplasmic CopZ proteins. Both CopZ chaperones could bind Cu⁺ with high affinity. Importantly, novel transmembrane transporters probably mediating Cu⁺ influx were among those largely repressed upon Cu⁺ stress. Compartmental Cu⁺ levels appear independently controlled; the cytoplasmic Cu⁺ sensor CueR controls cytoplasmic chaperones and plasma membrane transporters, whereas CopR/S responds to periplasmic Cu⁺ Analysis of &#x394;<i>copR</i> and &#x394;<i>cueR</i> mutant strains revealed a CopR regulon composed of genes involved in periplasmic Cu⁺ homeostasis and its putative DNA recognition sequence. In conclusion, our study establishes a system-wide model of a network of sensors/regulators, soluble chaperones, and influx/efflux transporters that control the Cu⁺ levels in <i>P. aeruginosa</i> compartments.engAttribution 4.0 Internacionalhttp://creativecommons.org/licenses/by/4.0/info:eu-repo/semantics/article10.1074/jbc.M117.804492info:eu-repo/semantics/openAccess