In vivo and in vitro acylation of polypeptides in Vibrio harveyi: identification of proteins involved in aldehyde production for bioluminescence.
Incubation of soluble extracts from Vibrio harveyi with [3H]tetradecanoic acid (+ ATP) resulted in the acylation of several polypeptides, including proteins with molecular masses near 20 kilodaltons (kDa), and at least five polypeptides in the 30- to 60-kDa range. However, in growing cells pulse-labeled in vivo with [3H]tetradecanoic acid, only three of these polypeptides, with apparent molecular masses of 54, 42, and 32 kDa, were specifically labeled. When extracts were acylated with [3H] tetradecanoyl coenzyme A, on the other hand, only the 32-kDa polypeptide was labeled. When luciferase-containing dark mutants of V. harveyi were investigated, acylated 32-kDa polypeptide was not detected in a fatty acid-stimulated mutant, whereas the 42-kDa polypeptide appeared to be lacking in a mutant defective in aldehyde synthesis. Acylation of both of these polypeptides also increased specifically during induction of bioluminescence in V. harveyi. These results suggest that the role of the 32-kDa polypeptide is to supply free fatty acids, whereas the 42-kDa protein may be responsible for activation of fatty acids for their subsequent reduction to form the aldehyde substrates of the bioluminescent reaction.
D000215:Acylation; D000447:Aldehydes / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism*; D007700:Kinetics; D008163:Luminescent Measurements; D008970:Molecular Weight; D019814:Myristic Acid; D009227:Myristic Acids / Q000378:metabolism; D010455:Peptides / Q000302:isolation & purification / Q000378:metabolism*; D014316:Tritium; D014733:Vibrio / Q000378:metabolism*
D000447:Aldehydes; D001426:Bacterial Proteins; D009227:Myristic Acids; D010455:Peptides; D019814:Myristic Acid; D014316:Tritium