Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0023241 (Legionella)
 6,990 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chlamydia psittaci strain guinea-pig inclusion conjunctivitis (GPIC) produces a self-limiting ocular infection of guinea-pigs, and this condition is a representative animal model of ocular chlamydial disease. Convalescent guinea-pigs, which are resistant to reinfection, produce antibodies to several elementary-body proteins, including an uncharacterized antigen of 28 kDa. Convalescent guinea-pig sera were used to identify, from a lambda expression library, two overlapping GPIC genomic clones that produced the 28 kDa antigenic protein. Nucleotide sequence analysis revealed that the gene coding for the 28 kDa protein was similar to the mip (macrophage infectivity potentiator) genes from Legionella pneumophila and Chlamydia trachomatis. The GPIC gene and its product were accordingly designated mip and Mip, respectively. Analysis of the regions flanking mip identified three tightly linked open reading frames coding for predicted products with sequence similarity to asparagine tRNA ligase (AspS), rRNA methylase (SpoU), and thioredoxin (TrxA). The arrangement of these genes in GPIC was aspS-mip-spoU-trxA. Sequence analysis of PCR products produced using genomic DNA from an ovine abortion strain of C. psittaci and from C. trachomatis strain LGV-434 demonstrated that the arrangement of mip, spoU and trxA is common among these chlamydiae.
 ...
PMID:A 28 kDa major immunogen of Chlamydia psittaci shares identity with Mip proteins of Legionella spp. and Chlamydia trachomatis-cloning and characterization of the C. psittaci mip-like gene. 893 21

After uptake and intracellular multiplication of Legionella pneumophila in MRC-5 lung fibroblasts, important cytoskeletal filament structures, like actin, tubulin, or vimentin, and a cell membrane-associated fibronectin were rearranged during early infection, resulting in a loss of cell adhesion and collapse of the cytoskeleton. Dysregulation of the cellular phosphorylation and dephosphorylation cascade may contribute to the observed changes and may support intracellular survival and multiplication of L. pneumophila. We therefore studied expression of phosphoproteins during intracellular growth of L. pneumophila. By using an anti-tyrosine phosphoprotein antibody we showed that proteins phosphorylated on tyrosine residues accumulated progressively during late infection exclusively around or in phagosomes filled with bacteria. In contrast, expression of serine/threonine phosphoproteins did not change. To discern the origin of phosphorylated proteins, the host cells were treated with cycloheximide, an inhibitor of eukaryotic protein synthesis. The newly synthesized proteins were labeled metabolically with [(35)S]methionine-cysteine and immunoprecipitated with a phosphotyrosine-specific antibody. Sodium dodecyl sulfate gel electrophoresis gave evidence for synthesis of at least three protein clusters (160 to 200, 35 to 60, and 19 to 28 kDa) of Legionella origin that were phosphorylated on tyrosine residues 24 h after infection. Treatment of infected host cells with genistein, a tyrosine kinase inhibitor, revealed that tyrosine protein phosphorylation was not important for bacterial uptake but contributed to intracellular growth of L. pneumophila. Bacterial tyrosine phosphoproteins and the observed intracellular structural changes may be important to understanding the process involved in intracellular growth of L. pneumophila.
 ...
PMID:Legionella pneumophila invasion of MRC-5 cells induces tyrosine protein phosphorylation. 1045 91