Malonyl-coenzyme A (malonyl-CoA) is a critical precursor for the biosynthesis of a variety of biochemicals. It is synthesized by the catalysis of acetyl-CoA carboxylase (Acc1p), which was demonstrated to be deactivated by the phosphorylation of Snf1 protein kinase in yeast. In this study, we designed a synthetic malonyl-CoA biosensor and used it to screen phosphorylation site mutations of Acc1p...

We have investigated the extent to which membrane environment affects the catalytic properties of the malonyl-CoA-sensitive carnitine acyltransferase of liver microsomal membranes. Arrhenius-type plots of activity were linear in the absence and presence of malonyl-CoA (2.5 microM). Sensitivity to malonyl-CoA increased with decreasing assay temperature. Partly purified enzyme displayed an increa...

1. [14C]Malonyl-CoA bound to intact mitochondria isolated from rat liver and heart in a manner consistent with the presence of two independent classes of binding sites in each tissue. 2. The binding characteristics for mitochondria obtained from fed male rats were: for heart, KD(1) = 1 -l8 nM, KD(2) = 30uM, N1 = 7pmol/mg of protein, N2 = approx. 660pmol/mg of protein; for liver, KD(1) = 0.1 M, ...

Carnitine palmitoyltransferase (CPT) I, which catalyzes the conversion of palmitoyl-CoA to palmitoylcarnitine facilitating its transport through the mitochondrial membranes, is inhibited by malonyl-CoA. By using the SequenceSpace algorithm program to identify amino acids that participate in malonyl-CoA inhibition in all carnitine acyltransferases, we found 5 conserved amino acids (Thr(314), Asn...

Engineering metabolic biosynthetic pathways has enabled the microbial production of many useful chemicals. However, pathway productivities and yields are often limited by metabolic imbalances. Synthetic regulatory circuits have been shown to be able to balance engineered pathways, improving titers and productivities. Here we developed a negative feedback regulatory circuit based on a malonyl-Co...

Hypothalamic fatty acid metabolism is involved in central nervous system controls of feeding and energy balance. Malonyl-CoA, an intermediate of fatty acid biosynthesis, is emerging as a significant player in these processes. Notably, hypothalamic malonyl-CoA has been implicated in leptin's feeding effect. Leptin treatment increases malonyl-CoA level in the hypothalamic arcuate nucleus (Arc), a...

Participation of cytochrome b5 in the liver microsomal elongation of fatty acids in the rat is suggested by (a) an increase in the rate of reoxidation of liver microsomal cytochrome b5, following reduction by NADH, in the presence of both malonyl coenzyme A and ATP, and (b) a 60% inhibition of incorporation of malonyl-CoA into microsomal fatty acids in the presence of anti-cytochrome b6 IgG; co...

Autotrophic members of the Sulfolobales (Crenarchaeota) contain acetyl-coenzyme A (CoA)/propionyl-CoA carboxylase as the CO2 fixation enzyme and use a modified 3-hydroxypropionate cycle to assimilate CO2 into cell material. In this central metabolic pathway malonyl-CoA, the product of acetyl-CoA carboxylation, is further reduced to 3-hydroxypropionate. Extracts of Metallosphaera sedula containe...

There has been considerable interest in the observation that the overt form of carnitine palmitoyltransferase (CPT1) in liver mitochondria is potently inhibited by malonyl CoA [I ,2]. It has been suggested [2] that this is a competitive type of inhibition against long chain acyl CoA substrates. However, this is based upon measurements of ketogenesis [3-51 or indirect calculations of CPT, activi...

The hepatic carnitine palmitoyltransferase that is present on the outer surface of the mitochondrial inner membrane demonstrates hyperbolic substrate saturation curves with oleoyl-CoA in both fasted and fed rats. However, the addition of malonyl-CoA resulted in sigmoid substrate saturation curves, suggesting that malonyl-CoA induced the cooperative behavior. There was more of the outer carnitin...