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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Identification and functional characterization of K+ transporters encoded by Legionella pneumophila kup genes

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Hori, Juliana I. [1] ; Pereira, Marcelo S. F. [1] ; Roy, Craig R. [2] ; Nagai, Hiroki [3] ; Zamboni, Dario S. [1]
Total Authors: 5
[1] Univ Sao Paulo, Dept Biol Celular Mol & Bioagentes Patogen, FMRP, BR-14049900 Ribeirao Preto, SP - Brazil
[2] Yale Univ, Sch Med, Sect Microbial Pathogenesis, New Haven, CT 06511 - USA
[3] Osaka Univ, Microbial Dis Res Inst, Int Res Ctr Infect Dis, Suita, Osaka 5650871 - Japan
Total Affiliations: 3
Document type: Journal article
Source: Cellular Microbiology; v. 15, n. 12, p. 2006-2019, DEC 2013.
Web of Science Citations: 3

Legionnaires' disease is an emerging, severe, pneumonia-like illness caused by the Gram-negative intracellular bacteria Legionella pneumophila, which are able to infect and replicate intracellularly in macrophages. Little is known regarding the mechanisms used by intracellular L.pneumophila for the acquisition of specific nutrients that are essential for bacterial replication. Here, we investigate three L.pneumophila genes with high similarity to the Escherichia coliK(+) transporters. These three genes were expressed by L.pneumophila and have been designated kupA, kupB and kupC. Investigation using the L.pneumophilakup mutants revealed that kupA is involved in K+ acquisition during axenic growth. The kupA mutants replicated efficiently in rich axenic media, but poorly in a chemically defined medium. The kupA mutants were defective in the recruitment of polyubiquitinated proteins to the Legionella-containing vacuole that is formed in macrophages and displayed an intracellular multiplication defect during the replication in Acanthamoeba castellanii and in mouse macrophages. We found that bafilomycin treatment of macrophages was able to rescue the growth defects of kupA mutants, but itdid not influence the replication of wild-type bacteria. The defects identified in kupA mutants of L.pneumophila were complemented by the expression E.colitrkD/Kup gene in trans, a bona fide K+ transporter encoded by E.coli. Collectively, our data indicate that KupA is a functional K+ transporter expressed by L.pneumophila that facilitates the bacterial replication intracellularly and in nutrient-limited conditions. (AU)

FAPESP's process: 11/22617-4 - Determination of the functional mechanisms that operate in the signaling pathway flagellin- NLRC4-dependent/caspase1-independent for restriction of L. pneumophila infection and determination of the mechanisms that operate in a flagellin-independent manner
Grantee:Marcelo de Souza Fernandes Pereira
Support Opportunities: Scholarships in Brazil - Post-Doctoral
FAPESP's process: 12/09363-6 - Molecular pathogenesis and subversion of host responses in infections with Legionella spp.
Grantee:Dario Simões Zamboni
Support Opportunities: Regular Research Grants
FAPESP's process: 11/51023-5 - Role of bacterial potassium transporters in inflammatory activation process and in macrophages response to infection by Legionella pneumophila
Grantee:Juliana Issa Hori
Support Opportunities: Scholarships in Brazil - Post-Doctoral