Light-dependent cold-induced fatty acid unsaturation, changes in membrane fluidity, and alterations in gene expression in Synechocystis.
Cold stress causes unsaturation of the membrane lipids. This leads to adjustment of the membrane fluidity, which is necessary for cold acclimation of cells. Here we demonstrate that the cold-induced accumulation of PUFAs in the cyanobacterium Synechocystis is light-dependent. The desA(-)/desD(-) mutant, that lacks the genes for Δ12 and Δ6 desaturases, is still able to adjust the fluidity of its membranes in spite of its inability to synthesize PUFAs and modulate the fatty acid composition of the membrane lipids under cold stress. The expression of cold-induced genes, which are controlled by the cold sensor histidine kinase Hik33, depends on the fluidity of cell membranes and it is regulated by light, though it does not require the activity of the photosynthetic apparatus. The expression of cold-induced genes, which are not controlled by Hik33, does not depend on the membrane fluidity or light. Thus, membrane fluidity determines the temperature dependence of the expression of cold-induced genes that are under control of the Hik33, which might be the sensor of changes in the membrane fluidity. This article is part of a Special Issue entitled: Photosynthesis Research for Sustainability: from Natural to Artificial.
Russian Academy of Sciences, Moscow, Russia.
Kirill S
KS
Mironov
Roman A
RA
Sidorov
Marina S
MS
Trofimova
Vladimir S
VS
Bedbenov
Vladimir D
VD
Tsydendambaev
Suleyman I
SI
Allakhverdiev
Dmitry A
DA
Los
D003080:Cold Temperature; D044943:Fatty Acid Desaturases / Q000235:genetics*; D005227:Fatty Acids / Q000032:analysis; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D000071677:Histidine Kinase; D008027:Light; D008560:Membrane Fluidity; D008563:Membrane Lipids / Q000032:analysis; D011494:Protein Kinases / Q000502:physiology; D046939:Synechocystis / Q000378:metabolism*
D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; D008563:Membrane Lipids; D044943:Fatty Acid Desaturases; D011494:Protein Kinases; D000071677:Histidine Kinase