Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2008-5-13
pubmed:abstractText
Legionella pneumophila is a ubiquitous organism in the aquatic environment where it is capable of invasion and intracellular proliferation within various protozoan species and is also capable of causing pneumonia in humans. In silico analysis showed that the three sequenced L. pneumophila genomes each contained a common multigene family of 11 ankyrin (ank) genes encoding proteins with approximately 30-35 amino acid tandem Ankyrin repeats that are involved in protein-protein interactions in eukaryotic cells. To examine whether the ank genes are involved in tropism of protozoan hosts, we have constructed isogenic mutants of L. pneumophila in ten of the ank genes. Among the mutants, the DeltaankH and DeltaankJ mutants exhibit significant defects in robust intracellular replication within A. polyphaga, Hartmanella vermiformis and Tetrahymena pyriformis. A similar defect is also exhibited in human macrophages. Most of the ank genes are upregulated by L. pneumophila upon growth transition into the post-exponential phase in vitro and within Acanthamoeba polyphaga, and this upregulation is mediated, at least in part, by RpoS. Single-cell analyses have shown that upon co-infection of the wild-type strain with the ankH or ankJ mutant, the replication defect of the mutant is rescued within communal phagosomes harbouring the wild-type strain, similar to dot/icm mutants. Therefore, at least two of the L. pneumophila eukaryotic-like Ank proteins play a role in intracellular replication of L. pneumophila within amoeba, ciliated protozoa and human macrophages. The Ank proteins may not be involved in host tropism in the aquatic environment. Many of the L. pneumophila eukaryotic-like ank genes are triggered upon growth transition into post-exponential phase in vitro as well as within A. polyphaga. Our data suggest a role for AnkH and AnkJ in modulation of phagosome biogenesis by L. pneumophila independent of evasion of lysosomal fusion and recruitment of the rough endoplasmic reticulum.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
1462-2920
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
10
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1460-74
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:18279343-Animals, pubmed-meshheading:18279343-Ankyrins, pubmed-meshheading:18279343-Bacterial Proteins, pubmed-meshheading:18279343-Cell Line, pubmed-meshheading:18279343-Cells, Cultured, pubmed-meshheading:18279343-Colony Count, Microbial, pubmed-meshheading:18279343-Eukaryota, pubmed-meshheading:18279343-Gene Deletion, pubmed-meshheading:18279343-Gene Expression Profiling, pubmed-meshheading:18279343-Gene Expression Regulation, Bacterial, pubmed-meshheading:18279343-Gene Order, pubmed-meshheading:18279343-Genes, Bacterial, pubmed-meshheading:18279343-Humans, pubmed-meshheading:18279343-Legionella pneumophila, pubmed-meshheading:18279343-Macrophages, pubmed-meshheading:18279343-Repetitive Sequences, Amino Acid, pubmed-meshheading:18279343-Sigma Factor, pubmed-meshheading:18279343-Virulence, pubmed-meshheading:18279343-Virulence Factors
pubmed:year
2008
pubmed:articleTitle
Role for the Ankyrin eukaryotic-like genes of Legionella pneumophila in parasitism of protozoan hosts and human macrophages.
pubmed:affiliation
Department of Microbiology and Immunology, Room MS-410, College of Medicine, University of Louisville, Louisville, KY 40292, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural