Involvement of distinct populations of phosphatidylglycerol and phosphatidylcholine molecules in photosynthetic electron-flow activities

Siegenthaler, Paul‐André; Smutny, Jana; Rawyler, André

doi:10.1016/0005-2728(87)90086-7

Cited by 38 publications

(32 citation statements)

References 26 publications

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“…This clearly demonstrated that h f 9 was impaired in desaturations from mono to diunsaturated fatty acids of these lipids, i.e. in desaturations from 16:1(7) to 16:2 (7,10) and from 18:1 (9) to 18:2 (9,12). Thus, we conclude that hf-9 was impaired in the desaturation activity as to the w6 position of fatty acids of chloroplasts.…”

Section: Fatty Acidmentioning

confidence: 79%

“…Table 2 shows the fatty acid compositions of the total lipids in the parent and hf-9. The major fatty acids were 16:0, 18:2 and 18:3 (9,12,15) in the parent, while lower contents of these fatty acids were observed, with increases in the 16:1(7) and 18:1(9) contents in hf-9.…”

Section: Defect In Squi-acy1gro Metabolism In Hf-2 C Reinhardtiimentioning

confidence: 92%

“…fatty acids, and plastoquinol-plastocyanin oxidoreductase activity of the cytochrome b,lf complex was restored by Gal,-acy1,-Gro, PtdGro and phosphatidylcholine (PtdCho) [7, 81. The electron transport activity of thylakoid membranes was modified on treatment with phospholipase A, [9]. These observations indicate that the lipid composition affects the functions of thylakoid membranes, either directly or indirectly.…”

mentioning

confidence: 86%

“…The electron transport activity of thylakoid membranes was modified on treatment with phospholipase A, [9]. These observations indicate that the lipid composition affects the functions of thylakoid membranes, either directly or indirectly.…”

mentioning

confidence: 86%

“…One of them was shown to be defective in chloroplast w6 desaturation: the contents of 16:1(7) andor 18:1 (9) were increased, with a concomitant decrease in major unsaturated fatty acids, 16:3 (7,10,13) andor 18:3 (9,12,15), in chloroplast lipids [34]. However, the mutation of chloroplast 0 6 desaturation caused little effect on chlorophyll fluorescence at room temperature in the A. thaliana mutant [35], as opposed to h f 9 which showed high chlorophyll fluorescence, possibly reflecting the lesion in photosynthesis (Table 4).…”

Section: Effects Of Lipid Mutations On Photosynthesismentioning

confidence: 99%

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Isolation and Characterization of Mutants Affected in Lipid Metabolism of Chlamydomonas Reinhardtii

Sato

Tsuzuki

Matsuda

et al. 1995

European Journal of Biochemistry

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Two mutants affected in lipid metabolism of Chlamydomonas reinhardtii were isolated by treating cells with ultraviolet light. Both mutants showed high chlorophyll fluorescent yields, as compared with parents, and were designated as hf-2 and hf9 (for high fluorescence). hf-2 was shown to be defective in the synthesis of a chloroplast-specific lipid, sulfoquinovosyl diacylglycerol. hf-9 was shown to be defective in desaturation at the 0 6 position of fatty acids of monogalactosyl diacylglycerol, digalactosyl diacylglycerol, sulfoquinovosyl diacylglycerol and phosphatidylglycerol. The mutants exhibited alterations in photosynthetic activity and chloroplast ultrastructure.Keywords. Chlamydomonas reinhardtii; chlorophyll fluorescence ; desaturation; sulfoquinovosyl diacylglycerol ; thylakoid membranes.Biomembranes are constructed from specific lipids and proteins which are responsible for their special functions. They facilitate partitioning, keeping materials at proper sites, transporting special substances or producing bioenergy. Chloroplasts contain three distinct membrane systems, i.e. thylakoid, inner envelope and outer envelope membranes. Thylakoid membranes convert light energy to ATP and NADPH, while the two types of envelope membranes are the sites of functions such as lipid biosynthesis [I].Major lipid constituents of thylakoid membranes are monogalactosyl diacylglycerol (Gal-acyl,Gro), digalactosyl diacylglycerol (Gal,-acyl,Gro), sulfoquinovosyl diacylglycerol (SQuiacyl,Gro), and phosphatidylglycerol (PtdGro). These lipids are ubiquitous in prokaryotic and eukaryotic oxygenic photosynthetic organisms [2-41. The former three lipids are specific to chloroplasts, and PtdGro of chloroplasts contains a unique monounsaturated fatty acid, 3-trans-hexadecenoic acid [16 : 1 (3t)l. In addition, Gal-acy1,Gro and Gal,-acy1,Gro contain substantial amounts of polyunsaturated fatty acids such as a-linolenic acid [I8 :3(9, 12, IS)]. Since thylakoid membranes possess photosynthetic electron transport and photophosphorylation activities, how these unique lipids contribute to the functions of thylakoid membranes is an intriguing question. Thylakoid membrane proteins such as the CF,-CF, and cytochrome b,lf complexes were co-purified with specific lipids [5, 61. It was demonstrated that ATPase activity of the CF,-CF, complex was stimulated by exogenously added Gal-acy1,Gro containing highly unsaturated Correspondence to A. Kawaguchi, Department of Biology, College of Arts and Sciences, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153, JapanAbbreviations. Gal,-acyl,Gro, digalactosyl diacylglycerol ; acy1,GroMe3Hse, diacylglyceryl trimethylhomoserine ; Gal-acyl,Gro, monogalactosyl diacylglycerol; SQui-acyl,Gro, sulfoquinovosyl diacylglycerol; fatty acyl groups are denoted by the numbers of carbon atoms and double bonds, e.g. 16:1(7) = palmitoleoyl. fatty acids, and plastoquinol-plastocyanin oxidoreductase activity of the cytochrome b,lf complex was restored by Gal,-acy1,-Gro, PtdGro and phosphatidylcholine (PtdCho) [7, 81....

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