Novel iso-branched ether lipids as specific markers of developmental sporulation in the myxobacterium Myxococcus xanthus.
Iso-fatty acids (FAs) are the dominant FA family in all myxobacteria analyzed. Furthermore, it was postulated that iso-FAs or compounds derived thereof are involved in fruiting body formation in Myxococcus xanthus, since mutants with a reduced level of iso-FA due to a reduced level of the precursor isovaleryl-CoA, are delayed in aggregation and produce only few myxospores. To elucidate the function of iso-FAs and their corresponding lipids we have analyzed the developmental phenotype of mutants having different levels of iso-FAs resulting in a clear correlation between the amount of iso-FAs and the delay of aggregation and reduction in spore yield. Addition of either isovalerate or 13-methyltetradecanoic acid resulted in restoration of the wild-type FA profile and normal development. Detailed analysis of the fatty acid (FA) profile during fruiting body formation in Myxococcus xanthus wild-type revealed the specific accumulation of 13-methyltetradecanal and 1-O-13-methyltetradecylglycerol which were produced specifically in the myxospores and which are derived from 1-O-(13-methyl-1-Z-tetradecenyl)-2-O-(13-methyltetradecanoyl)-glycero-3-phosphatidylethanolamine (VEPE) and 1,2-di-(13-methyltetradecanoyl)-3-(13-methyltetradecyl)glycerol (TG-1), respectively. The structures of these unusual ether lipids have been determined by spectrometric methods and synthesis (for TG-1). Analysis of several mutants blocked at different stages of development indicated that the biosynthesis of TG-1 is developmentally regulated and that VEPE might be an intermediate in the TG-1 biosynthesis. Finally, addition of TG-1 to mutants blocked in the biosynthesis of isovaleryl-CoA could restore aggregation and sporulation emphasizing the important role of iso-branched lipids for myxobacterial development.
Ring
Michael W
MW
Institut für Pharmazeutische Biotechnologie, Universität des Saarlandes, 66041 Saarbrücken, Germany.
Schwär
Gertrud
G
Thiel
Verena
V
Dickschat
Jeroen S
JS
Kroppenstedt
Reiner M
RM
Schulz
Stefan
S
Bode
Helge B
HB
D002851:Chromatography, High Pressure Liquid; D004987:Ethers / Q000737:chemistry; D005227:Fatty Acids / Q000737:chemistry; D015964:Gene Expression Regulation, Bacterial; D045782:Hemiterpenes; D008055:Lipids / Q000737:chemistry*; D008956:Models, Chemical; D009154:Mutation; D009227:Myristic Acids / Q000737:chemistry; D016941:Myxococcus xanthus / Q000737:chemistry* / Q000502:physiology*; D010421:Pentanoic Acids / Q000494:pharmacology; D010446:Peptide Fragments / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization; D013171:Spores, Bacterial / Q000502:physiology*; D013997:Time Factors; D014280:Triglycerides / Q000737:chemistry
D004987:Ethers; D005227:Fatty Acids; D045782:Hemiterpenes; D008055:Lipids; D009227:Myristic Acids; D010421:Pentanoic Acids; D010446:Peptide Fragments; C107162:TG-1 peptide; D014280:Triglycerides; C008216:isovaleric acid; C027332:13-methyltetradecanoin tri-(13-methyltetradecanoyl)glycerol; C027331:13-methyltetradecanoic acid