Genetic diversity of Legionella pcs and pmtA genes and the effect of utilization of choline by Legionella spp. on induction of proinflammatory cytokines

• Published in: Pathogens and disease 2019-10, Vol.77 (7)
• Main Authors: Palusińska-Szysz, Marta, Szuster-Ciesielska, Agnieszka, Janczarek, Monika, Wdowiak-Wróbel, Sylwia, Schiller, Jürgen, Reszczyńska, Emilia, Gruszecki, Wiesław I, Fuchs, Beate
• Format: Article
• Language: English
• Subjects: Aminoacyltransferases - genetics; Bacterial Proteins - genetics; CDP-diacylglycerol; Cell surface; Choline; Choline - metabolism; Comparative analysis; Cytokines; Cytokines - metabolism; Diglycerides; Gene sequencing; Genes; Genes, Bacterial; Genetic diversity; Genetic Variation; Helices; Humans; Hydrophobicity; Inflammation; Inflammation Mediators - metabolism; Interleukin 6; Lecithin; Legionella; Legionella - chemistry; Legionella - classification; Legionella - genetics; Legionellosis - metabolism; Legionellosis - microbiology; Lipid Metabolism; Lipids; Lipids - chemistry; Magnetic Resonance Spectroscopy; Methylation; Methyltransferase; Methyltransferases - genetics; N-Methyltransferase; Nucleotides; Phosphatidylcholine; Phosphatidylethanolamine; Phosphatidylethanolamine N-methyltransferase; Phospholipids - chemistry; Phospholipids - metabolism; Phylogenetics; Phylogeny; PmtA gene; Proteins; Species; Spectroscopy, Fourier Transform Infrared; Surface properties; Tumor necrosis factor-α
• ISSN: 2049-632X; 2049-632X
• DOI: 10.1093/femspd/ftz065

ABSTRACT Legionella species synthesize phosphatidylcholine (PC) in two independent pathways: the three-step methylation of phosphatidylethanolamine PMT pathway and the one-step PCS pathway, in which the Pcs enzyme catalyzes the reaction between choline and CDP-diacylglycerol to form PC. Legionella pcs genes encode highly hydrophobic proteins with phosphatidylcholine synthase activity, which contain up to eight transmembrane helices with N- and C-termini located inside the bacterial cell. The comparative analysis of nucleotide sequences of pcs showed that these genes share high sequence identity among members of the Legionellaceae family. Legionella pmtA genes involved in the PMT pathway encoded small cytosolic proteins with putative phosphatidylethanolamine N-methyltransferase activity. The pmtA genes identified in Legionella species had lower sequence identity to each other than the pcs genes. The phylogenetic tree constructed based on the pcs and pmtA gene sequences showed phylogenetic relatedness between Legionella spp. and other bacteria. The utilization of extracellular choline by the four Legionella species leads to changes not only in the lipid components but also in proteins, and the interactions between these components lead to changes in cell surface properties, which result in a decline in induction of proinflammatory cytokines (TNF-α and IL-6). Utilization of exogenous choline by Legionella spp. affects the production of pro-inflammatory cytokines.