Lipids of Pavlova lutheri: Cellular site and metabolic role of DGCC

Pavlova lutheri contains triacylglycerols (TAG), monogalactosyldiacylglycerols (MGDG), galactosyldiacylglycerols (DGDG), sulfoquivonosyldiacylglycerols (SQDG), diacylglyceryl hydroxymethyl-N,N,N-trimethyl-β-alanine (DGTA), diacylglyceryl carboxyhydroxymethylcholine (DGCC) and diacylglyceryl glucuronide (DGGA) as major lipid components. Prominent fatty acids are 14:0, 16:0, 16:1, 18:4, 20:5, 22:5 and 22:6. In MGDG and DGDG, 18:4 and 20:5 predominate, while SQDG contains high proportions of 14:0 and 16:0. DGCC is enriched in 16:0 and 20:5, DGGA in 18:1, 22:5 and 22:6, and DGTA in 22:6. Analysis of subcellular membrane fractions demonstrated an accumulation of DGCC, DGTA and DGGA in non-plastid membranes. On incubation of cells with [1-14C] oleic acid, after 60 min of pulse, 30% of the incorporated label was found in TAG and 70% in polar lipids. DGCC (52%) and DGTA (12%) were the most strongly labelled polar lipids. Within 72 h of chase, in DGCC and in TAG the label rapidly decreased to 11 % and 17%, respectively, but in MGDG it increased in the same time up to 35% of the total. Only minor changes were observed in DGTA and no significant label was recorded in DAG during the chase-period. The shift of label from 18:1 to 18:4, 20:5 and 22:6 reflected further elongation and/or desaturation of the substrate. Very similar results obtained using [2-14C] acetate as precursor suggested that DGCC acts as a primary acceptor of de novo-formed or exogenous fatty acids which subsequently undergo processing and redistribution. It is suggested that C18 and C20 fatty acids are transferred individually from the cytoplasm to the chloroplast allowing the synthesis of eukaryotic MGDG without the import of DAG. © 1997 Elsevier Science Ltd. All rights reserved

[1]  M. Yamada,et al.  Positional distribution of fatty acids in galactolipids of algae , 1989 .

[2]  S. Miyachi,et al.  Polyunsaturated Fatty Acids and Betaine Lipids from Pavlova lutheri , 1995 .

[3]  Lin HeFang,et al.  Polar lipids and fatty acids of some marine macrophytes from the yellow sea , 1996 .

[4]  Fatty Acid Metabolism , 1988 .

[5]  P. Thompson,et al.  SELENIUM: AN ESSENTIAL ELEMENT FOR GROWTH OF THE COASTAL MARINE DIATOM THALASSIOSIRA PSEUDONANA (BACILLARIOPHYCEAE) 1, 2 , 1987 .

[6]  De Kok,et al.  Biochemsitry and Metabolism of Plant Lipids , 1982 .

[7]  P. Roughan,et al.  CELLULAR ORGANIZATION OF GLYCEROLIPID METABOLISM , 1982 .

[8]  A. Tietz,et al.  Octadecatetraenoate synthesis in the unicellular alga Isochrysis galbana: studies with intact and broken chloroplasts. , 1993, Biochimica et biophysica acta.

[9]  R. Appleby,et al.  The distribution and biosynthesis of arachidonic acid in algae , 1969 .

[10]  R. Borch.  Separation of long chain fatty acids as phenacyl esters by high pressure liquid chromatography. , 1975, Analytical chemistry.

[11]  J. Harwood,et al.  Lipid composition of the brown algae fucus vesiculosus and Ascophyllum nodosum , 1992 .

[12]  S. Araki,et al.  Betaine lipids and phospholipids in brown algae , 1993 .

[13]  E. Heinz,et al.  The suitability of lipase from Rhizopus arrhizus delemar for analysis of fatty acid distribution in dihexosyl diglycerides, phospholipids and plant sulfolipids. , 1973, Hoppe-Seyler's Zeitschrift fur physiologische Chemie.

[14]  H. Sano,et al.  Distribution of betaine lipids in marinealgae , 1995 .

[15]  P. Roessler,et al.  A mutant of Nannochloropsis deficient in eicosapentaenoic acid production , 1995 .

[16]  C. Giroud,et al.  Lipids of Chlamydomonas reinhardtii. Analysis of Molecular Species and Intracellular Site(s) of Biosynthesis , 1988 .

[17]  P. Roessler,et al.  RADIOLABELING STUDIES OF LIPIDS AND FATTY ACIDS IN NANNOCHLOROPSIS (EUSTIGMATOPHYCEAE), AN OLEAGINOUS MARINE ALGA 1 , 1994 .

[18]  W. Eichenberger,et al.  Diacylglyceryl-α-D-glucuronide from Ochromonas danica (Chrysophyceae)* , 1994 .

[19]  W. Eichenberger.  Betaine lipids in lower plant. Distribution of DGTS, DGTA and phospholipids, and the intracellular localization and site of biosynthesis of DGTS , 1993 .

[20]  R. J. Henderson,et al.  Gas chromatographic-mass spectrometric identification of betaine lipids in Chroomonas salina , 1996 .

[21]  E. Mackinlay,et al.  Radiolabelling studies of lipids in the marine cryptomonad Chroomonas salina in relation to fatty acid desaturation , 1992 .

[22]  Etsuko Takizawa,et al.  Changes in lipid and fatty acid composition of Pavlova lutheri , 1995 .

[23]  V. Dembitsky.  Betaine ether-linked glycerolipids: chemistry and biology. , 1996, Progress in lipid research.

[24]  W. Eichenberger.  Lipids of Chlamydomonas reinhardi under different growth conditions , 1976 .

[25]  N. Zhukova,et al.  Fatty acid composition of 15 species of marine microalgae , 1995 .

[26]  N. Murata,et al.  Positional Distribution of Fatty Acids in Glycerolipids of the Marine Red Alga, Porphyra yezoensis , 1987 .

[27]  J. Harwood,et al.  Lipid Metabolism in Algae , 1989 .

[28]  R. Hiller,et al.  The secondary structure content of pigment-protein complexes from the thylakoids of two Chromophyte algae , 1987 .

[29]  F. Schneider,et al.  Biosynthesis of very long chain fatty acids in higher plants. , 1994, Progress in lipid research.

[30]  S. Miyachi,et al.  A betaine lipid from Pavlova lutheri , 1994 .

[31]  G. Vogel,et al.  Betaine Lipids in Lower Plants. Biosynthesis of DGTS and DGTA in Ochromonas danica (Chrysophyceae) and the Possible Role of DGTS in Lipid Metabolism , 1992 .