INVESTIGADORES
COMERCI Diego Jose
congresos y reuniones científicas
Título:
A Lov-domain histidine kinase is involved in Brucella abortus infection.
Autor/es:
PARIS G; SWARTZ TE; SPERA, J. M.; DIEGO JOSE COMERCI; BOGOMOLNI, R.; GOLDBAUM, F. A.
Lugar:
Rosario, Santa fe
Reunión:
Congreso; XLII Annual Meeting of the Argentine Society for Biochemistry and Molecular Biology Research(SAIB); 2006
Resumen:
Brucella abortus is a facultative intracellular pathogen that
causes brucellosis in domestic animals and and humans.
Brucella invade and replicates inside professional and nonprofessional
phagocytes. Two-component proteins are widely
recognized as environmental sensors in bacteria. Light, oxygen
or voltage (LOV) belongs to the PAS domain superfamily. LOV
domains bind a single molecule of FMN and undergo a selfcontained
photocycle that is dependent on the presence of a
highly conserved cysteine residue. We identified a gen coding for
a LOV domain protein in B.abortus (LOV-HPK). In addition to
LOV domain this gene also has a PAS domain and an histidine
kinase domains. The gene of LOV-HPK was cloned and
expressed in E.coli. Illumination of recombinant purified LOVHPK
protein in presence of ATP conduce to autophosphorylation
of kinase domain, showing that LOV-HPK is an active histidine
kinase. In order to investigate the in vivo function of LOV-HPK,
this gene was knocked-out and mutation was checked by PCR.
Cell infection assays in macrophages J774 shown that LOV-HPK
mutant bacterias has a attenuated phenotype as compared with
control. However, in HeLa cells, LOV-HPK mutant shown similar
infection as compared with control. Taking together these results
suggest that LOV-HPK protein from B.abortus is a virulence
factor involved in the defense against oxidative killing in
macrophages.