INVESTIGADORES
RAIMUNDA daniel Cesar
artículos
Título:
Periplasmic response upon disruption of transmembrane Cu transport in Pseudomonas aeruginosa
Autor/es:
RAIMUNDA, DANIEL; PADILLA-BENAVIDES, TERESITA; VOGT, STEFAN; TOMKINSON, KALEIGH; BOUTIGNY, SYLVAIN; FINNEY, LYDIA; ARGUEELLO, JOSE M
Revista:
METALLOMICS
Editorial:
ROYAL SOC CHEMISTRY
Referencias:
Lugar: CAMBRIDGE; Año: 2013 vol. 5 p. 144 - 151
ISSN:
1756-5901
Resumen:
Pseudomonas
aeruginosa, an opportunistic pathogen, has two transmembrane Cu+ transport
ATPases, CopA1 and CopA2. Both proteins export cytoplasmic Cu+ into the
periplasm and mutation of either gene leads to attenuation of virulence. CopA1
is required for maintaining cytoplasmic copper levels, while CopA2 provides
copper for cytochrome c oxidase assembly. We hypothesized that transported Cu+
ions would be directed to their destination via specific periplasmic partners
and disruption of transport should affect the periplasmic copper homeostasis.
Supporting this, mutation of either ATPase gene led to large increments in
periplasmic cuproprotein levels. Toward identifying the proteins participating
in this cellular response the periplasmic metalloproteome was resolved in
non-denaturing bidimensional gel electrophoresis, followed by X-ray
fluorescence visualization and identification by mass-spectrometry. A single
spot containing the electron shuttle protein azurin was responsible for the observed
increments in cuproprotein contents. In agreement, lack of either Cu+-ATPase
induced an increase in azu transcription. This is associated with an increase
in the expression of anr and rpoS oxidative stress response regulators, rather
than cueR, a copper sensing regulator. We propose that azurin overexpression
and accumulation in the periplasm is part of the cellular response to
cytoplasmic oxidative stress in P. aeruginosa.