Identification of a Developmental Chemoattractant in Myxococcus xanthus through Metabolic Engineering

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 98; no. 24; pp. 13990 - 13994
• Main Authors: Kearns, Daniel B., Venot, Andre, Bonner, Pamela J., Stevens, Brian, Boons, Geert-Jan, Shimkets, Lawrence J.
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 20-11-2001; National Acad Sciences; The National Academy of Sciences
• Subjects: Bacteria; Biological Sciences; Biosynthesis; Cell membranes; Cells; Chemotactic factors; Chemotactic Factors - metabolism; Fatty acids; Fatty Acids - metabolism; Fruiting bodies; Lipids; Metabolism; Morphogenesis; Myxococcus xanthus; Myxococcus xanthus - growth & development; Myxococcus xanthus - metabolism; phosphatidylethanolamine; Phosphatidylethanolamines - metabolism; Solar fibrils; Somatic cells; Starvation
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.251484598

Fruiting body formation of Myxococcus xanthus requires the ordered migration of tens of thousands of cells by using a form of surface motility known as gliding and chemical signal(s) that have yet to be elucidated. Directed movement is regulated by phosphatidylethanolamine (PE) purified from M. xanthus cell membranes. Because the purified PE preparation contains a remarkably diverse mixture of fatty acids, metabolic engineering was used to elucidate the biologically active fatty acid component. The mutational block in an esg mutant, which renders it defective in producing primers for branched-chain fatty acid biosynthesis, was bypassed with one of a series of primers that enriches for a particular family of branched-chain fatty acids. Each PE enrichment was observed for chemotactic activity by using an excitation assay and for fatty acid content. The excitation activity of a PE preparation was generally proportional with the concentration of the fatty acid 16:1ω5c. 1,2-O-Bis[11-(Z)-hexadecenoyl]-sn-glycero-3-phosphoethanolamine (PE-16: 1ω5c/16:1ω5c) was synthesized and elicited an excitation peak at 2 ng. This peak activity occurred at a 1,000-fold lower concentration than dilauroyl PE (PE- 12:0/12:0) and the peak magnitude was 2-fold higher. PE containing 16:1ω5c is likely to play a role in development because it is active at physiological concentrations and only under developmental conditions.