has role has_role has role gene as virulence factor in pathogen gene mutant attenuated in host cell gene mutant attenuated in host has role has_role has role macrophage macrophage 巨噬细胞 Mus musculus Mus musculus 小家鼠 Brucella suis 1330 protein-coding gene of Brucella suis 1330 pcs 1165011 20140215 204722 BRA0572 Bin Zhao, Oliver He II NCBI-supplied PMID: 12271122 WEB: http://www.ncbi.nlm.nih.gov/gene phosphatidylcholine synthase protein-coding MUTATION: The role of Phosphatidylcholine (PC) in Brucella abortus was examined by generating mutants in pcs (BApcs) and pmtA (BApmtA), which encode key enzymes of the two bacterial PC biosynthetic routes, the choline and methyl-transferase pathways. In rich medium, BApcs and the double mutant BApcspmtA but not BApmtA displayed reduced growth, increased phosphatidylethanolamine and no PC, showing that Pcs is essential for PC synthesis under these conditions. In minimal medium, the parental strain, BApcs and BApmtA showed reduced but significant amounts of PC suggesting that PmtA may also be functional Probing with phage Tb, antibiotics, polycations and serum demonstrated that all mutants had altered envelopes. In macrophages, BApcs and BApcspmtA showed reduced ability to evade fusion with lysosomes and establish a replication niche. In mice, BApcs showed attenuation only at early times after infection, BApmtA at later stages and BApcspmtA throughout. The results suggest that Pcs and PmtA have complementary roles in vivo related to nutrient availability and that PC and the membrane properties that depend on this typical eukaryotic phospholipid are essential for Brucella virulence [PMID:16882035]. 995 virulence factor gene role