Role of acyl-CoAs and acyl-CoA-binding protein in regulation of carbon supply for fatty acid biosynthesis.
Acyl-CoA esters inhibit the plastidial glucose 6-phosphate (Glc-6-P) transporter and the adenylate transporter; the IC(50) values for the inhibition by oleoyl-CoA (18:1-CoA) are 200-400 nM and 1-2 microM respectively. The inhibition of either of these processes significantly reduces the flux of carbon from Glc-6-P or from acetate into long-chain fatty acids. The effect is dependent on the acyl chain length, e.g. lauryl-CoA is less inhibitory than oleoyl-CoA, causing 34 and 68% inhibition respectively of Glc-6-P uptake after 30 s. The inhibition of Glc-6-P and ATP transport is alleviated by addition of an equivalent concentration of acyl-CoA-binding protein (ACBP) or BSA. Acyl-CoAs do not inhibit pyruvate or glucose transporters. The endogenous concentrations of acyl-CoAs and ACBP are similar during embryo maturation.
Fox
S R
SR
John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
Rawsthorne
S
S
Hills
M J
MJ
D000214:Acyl Coenzyme A / Q000378:metabolism* / Q000494:pharmacology; D017920:Antiporters / Q000378:metabolism; D002250:Carbon Radioisotopes; D002352:Carrier Proteins / Q000378:metabolism*; D005227:Fatty Acids / Q000096:biosynthesis*; D019298:Glucose-6-Phosphate / Q000378:metabolism*; D006706:Homeostasis; D007700:Kinetics; D009004:Monosaccharide Transport Proteins / Q000378:metabolism; D010944:Plants / Q000378:metabolism*; D018087:Plastids / Q000187:drug effects / Q000378:metabolism*; D019289:Pyruvic Acid / Q000378:metabolism*
D000214:Acyl Coenzyme A; D017920:Antiporters; D002250:Carbon Radioisotopes; D002352:Carrier Proteins; D005227:Fatty Acids; D009004:Monosaccharide Transport Proteins; C111261:glucose 6-phosphate(transporter); C017585:oleoyl-coenzyme A; D019298:Glucose-6-Phosphate; D019289:Pyruvic Acid