"Heat shock lipid" in cyanobacteria during heat/light-acclimation.
Parallel with the heat/light-induced thylakoid microdomain reorganization and thermal stabilization of photosynthesis we observed an increase in the level of the highly saturated monoglucosyldiacylglycerol (MGlcDG) in Synechocystis cells. The unusually high microviscosity obtained in thylakoid MGlcDG liposomes by monitoring DPH anisotropy was in good agreement with its exceptionally high acyl chain saturation. The MGlcDG membranes remained stable even at extreme high temperatures. Strikingly, in monolayer experiments, out of the five thylakoid polar lipids tested, MGlcDG expressed the strongest interaction with the thylakoid-stabilizing small Hsp from Synechocystis, Hsp17. The preferential interaction of Hsp17 with non-bilayer phase forming lipids supports our notion that sHsps counteract the formation of thermally induced local non-bilayer structures [Proc. Natl. Acad. Sci. USA 99 (2002) 13504] and thus implicated in microdomain organization and in the preservation of functional integrity of thylakoid membranes challenged by heat stress in the light. We also suggest that the highly saturated MGlcDG functions as a "heat shock lipid" and is of potential importance in the development of acquired thermotolerance of heat/light-primed cyanobacterial thylakoids.
Balogi
Zsolt
Z
Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, H-6701 Szeged, Hungary.
Török
Zsolt
Z
Balogh
Gábor
G
Jósvay
Katalin
K
Shigapova
Natalia
N
Vierling
Elizabeth
E
Vígh
László
L
Horváth
Ibolya
I
D016880:Anisotropy; D002462:Cell Membrane / Q000378:metabolism; D002853:Chromatography, Liquid; D000458:Cyanobacteria / Q000378:metabolism*; D005227:Fatty Acids / Q000737:chemistry; D006360:Heat-Shock Proteins / Q000737:chemistry / Q000378:metabolism; D006358:Hot Temperature; D008027:Light; D008051:Lipid Bilayers / Q000737:chemistry; D008055:Lipids / Q000737:chemistry; D008081:Liposomes / Q000378:metabolism; D013058:Mass Spectrometry; D008956:Models, Chemical; D018832:Molecular Chaperones / Q000378:metabolism; D010788:Photosynthesis; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D046939:Synechocystis; D013696:Temperature; D020524:Thylakoids / Q000378:metabolism; D013997:Time Factors
D005227:Fatty Acids; D006360:Heat-Shock Proteins; D008051:Lipid Bilayers; D008055:Lipids; D008081:Liposomes; D018832:Molecular Chaperones