A Possible Differential Role for Plant Acyl Carrier Protein Isoforms in Higher Plants
Acyl carrier protein (ACP) dependent fatty acid synthesis (FAS) in plant leaf tissues is exclusively localized in the chloroplast (1). Two forms of ACP have been purified from spinach and barley leaf, but, only one ACP isoform predominates in spinach seed tissue (2, 3). Oleic acid is the major product of fatty acid synthesis by isolated chloroplasts (4). The regulation of plant lipid metabolism is believed to involve the export of oleic acid from its site of synthesis (plastid) to sites of complex lipid metabolism (eg. ER). This pathway requires the initial release of oleic acid from ACP by oleoyl-ACP thioesterase (5). In addition, the oleoyl moiety may also enter glycerolipid synthesis within the plastid through the action of acyl-ACP acyl-transferase (6). The preferred substrate for both the thioesterase and glycerol-3-phosphate acyl transferase reactions is 18: 1-ACP (6, 7).
KeywordsOleic Acid Fatty Acid Synthesis Acyl Carrier Protein Acyl Transferase Barley Leaf
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- 4.P. K. Stumpf, D. N. Kuhn, D. J. Murphy, M. R. Pollard, T. McKeon, and J. MacCarthy, Oleic acid, the central substrate, in: “Biogenesis and Function of Plant Lipids” Mazliak P, Benviste P, Costes C., and Douce R, eds., pp 3-10, Elsevier/North-Holland (1980).Google Scholar
- 8.D. J. Guerra, J. B. Ohlrogge, and M. Frentzen, Activity of acyl carrier protein isoforms in reactions of plant fatty acid metabolism, Plant Physiol., In press (1986).Google Scholar