CDP-diacylglycerol synthase

Heacock, A.M., Uhler, M. D. and Agranoff, B. W. Cloning of CDP-diacylglycerol synthase from a human neuronal line. /. Neurochem. 67 2200-2203,1996. 

This enzyme [EC 2.7.7.41], also known as CTP phospha-tidate cytidylyltransferase and CDP-diacylglycerol synthase, catalyzes the reaction of CTP with phosphatidate to produce CDP-diacylglycerol and pyrophosphate. 

Shen, H., and Dowhan, W., 1996, Reducation of CDP-diacylglycerol synthase activity results in the excretion of inositol by Saccharomyces cerevisiae. J. Biol. Chem. 271 29043-29048. 

Martin, D., Gannoun-Zaki, L., Bonnefoy, S., Eldin, P., Wengelnik, K., and Vial, H. (2000). Characterization of Plasmodium falciparum CDP-diacylglycerol synthase, a proteolytically cleaved enzyme. Mol. Biochem. Parasitol. 110,93-105. 

PHOSPHATIDYLINOSITOL SYNTHASE CDP-Diacylglycerol L-serine O-phosphatidyl-transferase,... 

FIGURE 9.8 CTP synthase. CTP synthase catalyzes the transfer of an amino group to UTP, gCTierating CTP. Glutamine serves as the donor of the amino nitrogen. Folate is not involved in the synthesis of CTP. Cytidine 5 -diphosphate (CDP) is distinguished in that it is used in lipid metabolism, where it takes the forms of CDP-choline, CDP-ethanolamine, and CDP-diacylglycerol. 

Figure 1. Synthetic pathway for PS and PE in mammalian cells. The major steps occuring in the synthesis and interconversion of PS and PE are shown. The PS synthases condense serine with a phosphatidyl moiety derived from PC and PE. The nascent PS can be converted to PE by decarboxylation. PE can also be formed by transfer of a phosphoethanolamine moiety from CDP-ethanolamine to diacylglycerol via the Kennedy pathway. The abbreviations used are PC, phosphatidylcholine PS, phosphatidylserine PE, phosphatidylethanolamine DG, diacylglycerol PSD, phosphatidylserine decarboxylase PSS, PS synthase.

Fig. 7. Pathways for the biosynthesis of phosphatidylethanolamine (PE) and phosphatidylseiine (PS) in animals. The numbers indicate the enzymes. 1, ethanolamine kinase 2, CTP phosphoethanolamine cytidylyltransferase 3, CDP-ethanolamine l,2-diacylglycerol ethanolaminephosphotransferase 4, PS synthase-2 5, PS synthase-1 6, PS decarboxylase 7, acyl-CoA lyso-PE acyltransferase. PC, phosphatidylcholine.

Figure 5.1 Schematic iUuslTation of cardiolipin biosynthesis and remodeling pathways. Newly synthesized cardiolipin (CL) (immature or nascent CL) is formed by the condensation of phosphatidylglycerol (PG) and cytidine diphosphate-diacylglycerol (CDP-DAG) catalyzed by CL synthase. Immature CL is then deacylated to form monolysoCL and then reacylated using acyl chains from acyl CoA or Iransacylated from the sn-2 acyl chain of PC and PE species, leading to the formation of matured CL.

The enzyme responsible for the final step of de novo biosynthesis of phosphatidylinositol (PI) is an endoplasmic reticulum enzyme the cytidine diphosphate-diacylglycerol (CDP-DAG) my< -inositol transferase (EC 2.7.8.11), or briefly PI-synthase. This enzyme catalyses the formation of PI and cytidine monophosphate (CMP) from CDP-DAG and myo-inosiiol [1], In a previous work [2], we found that the PI-synthase displayed a strong selectivity among the endogenous CDP-DAG molecular species used as substrates, in the microsomes from several plant tissues 16 0/18 2 and 16 0/18.3-CDP-DAG were markedly more utilized than other molecular species. Here, we are interested in the Pl-synthase selectivity among CDP-DAG molecular species, both when the enzyme was left within microsomal membranes or when it was solubilized and pre-purified. As a continuation of our work upon the solubilization of the Pl-synthase [3], we used CHAPS to solubilize the microsomal membranes as previously described. 

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