[A feedback between membrane fluidity and transcription of the desB gene for the omega3 fatty acid desaturase in the cyanobacterium Synechocystis].
Prokaryotic cells, including cyanobacteria, respond to a decrease in ambient temperature by activation of numerous cold shock genes. Low temperatures cause a decrease in membrane fluidity, which is maintained at some optimal level mainly by fatty acid (FA) desaturases. Here, temperature-dependent expression of the desB gene for the omega3-desaturase in Synechocystis, which synthesized polyunsaturated FAs, and in its mutant, desA-/desD-, which is defective in genes for delta12- and delta6-desaturases and is capable of synthesizing only monounsaturated FAs was studied. Low temperatures caused the increase in the amount of the desB mRNA in the wild-type cells with the maximum observed at 24 degrees C. In the double mutant desA-/desD- cells, the maximum amount of this mRNA was accumulated at 28-30 degrees C. Thus, our studies of the desB gene for the omega3-desaturase demonstrated that temperature-dependent expression of genes, which are responsible for the maintenance of the optimal membrane fluidity, depends on physical state of these membranes and is regulated by a feedback mode.
K S
KS
Mironov
E G
EG
Maksimov
G V
GV
Maksimov
D A
DA
Los'
D000458:Cyanobacteria / Q000235:genetics* / Q000378:metabolism* / Q000502:physiology; D044943:Fatty Acid Desaturases / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D015525:Fatty Acids, Omega-3 / Q000096:biosynthesis / Q000235:genetics; D025461:Feedback, Physiological; D005786:Gene Expression Regulation / Q000502:physiology; D008560:Membrane Fluidity / Q000235:genetics / Q000502:physiology; D009154:Mutation; D013696:Temperature
D015525:Fatty Acids, Omega-3; D044943:Fatty Acid Desaturases