cis-unsaturated fatty acids specifically inhibit a signal-transducing protein kinase required for initiation of sporulation in Bacillus subtilis.
The initiation of sporulation in Bacillus subtilis is controlled by the Spo0A transcription factor which is activated by phosphorylation through a phosphorelay mechanism that is dependent upon the activity of one or more protein kinases. The enzymatic activity of one of these protein kinases, KinA, was found to be inhibited in vitro by certain fatty acids. The most potent inhibitors have at least one unsaturated double bond in the cis configuration and a chain length of 16-20 carbon atoms. Homologous isomers with a trans double bond are not inhibitory. Saturated straight- or branched-chain fatty acids are either much weaker inhibitors or have no effect. The inhibitors prevent autophosphorylation of KinA and are non-competitive with ATP. B. subtilis phospholipids were found to contain at least one as yet unidentified type of fatty acid that, when present in an unesterified form, inhibited KinA. The results suggest that the concentration of a specific unsaturated fatty acid may act as a signal linking the initiation of sporulation to the status of membrane synthesis and septation or some other specific membrane-associated activity.
Strauch
M A
MA
Department of Molecular and Experimental Medicine, Scripps Research Institute, La Jolla, California 92037.
de Mendoza
D
D
Hoch
J A
JA
D001412:Bacillus subtilis / Q000187:drug effects / Q000502:physiology*; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors*; D000431:Ethanol / Q000494:pharmacology; D005229:Fatty Acids, Monounsaturated / Q000494:pharmacology; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology*; D007536:Isomerism; D019301:Oleic Acid; D009829:Oleic Acids / Q000494:pharmacology; D010169:Palmitic Acids; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors; D011494:Protein Kinases / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*; D013171:Spores, Bacterial / Q000187:drug effects / Q000502:physiology*; D013329:Structure-Activity Relationship
D001426:Bacterial Proteins; D005229:Fatty Acids, Monounsaturated; D005231:Fatty Acids, Unsaturated; D009829:Oleic Acids; D010169:Palmitic Acids; D047428:Protein Kinase Inhibitors; C075521:kinA protein, Bacillus subtilis; C008757:palmitoleic acid; D019301:Oleic Acid; D000431:Ethanol; C065593:cis-vaccenic acid; D011494:Protein Kinases