Cc. Dirusso et T. Nystrom, THE FATS OF ESCHERICHIA-COLI DURING INFANCY AND OLD-AGE - REGULATION BY GLOBAL REGULATORS, ALARMONES AND LIPID INTERMEDIATES, Molecular microbiology, 27(1), 1998, pp. 1-8
The fluidity and phase state of bacterial lipid bilayers commonly chan
ge in response to ambient environmental conditions to maintain the cri
tical functions of the envelope as a semipermeable and selective bound
ary. A special, and intricate, set of alterations in membrane lipid me
tabolism is elicited by conditions causing growth arrest. Under such c
onditions, specific alterations in the membrane lipid-fatty acid compo
sition are required for survival of the cell and, concurrently, the me
mbrane lipids are suggested to serve as endogenous reserves providing
carbon/energy for maintenance requirements. It appears that the global
regulator FadR is required for both of these activities to be perform
ed properly and that the FadR regulon is interconnected to the univers
al stress response of Escherichia coli, FadR, in conjuction with long-
chain fatty acyl-CoA, long-chain acyl-ACP, ppGpp and cAMP, are key pla
yers in regulating the activities of enzymes and expression of genes i
nvolved in fatty acid and phospholipid metabolism in dividing and agei
ng E. coli cells.