BACKGROUND Choline is obtained from the diet and from the biosynthesis of phosphatidylcholine. Phosphatidylcholine is catalyzed by the enzyme phosphatidylethanolamine-N-methyltransferase (PEMT), which is induced by estrogen. Because they have lower estrogen concentrations, postmenopausal women are more susceptible to the risk of organ dysfunction in response to a low-choline diet. A common gene...

Multiple mechanisms of regulation in the CDP-choline pathway for phosphatidylcholine (PC) synthesis were revealed by exploring the effects of choline and inositol on this pathway in Saccharomyces cerevisiae. At exogenous choline concentrations below 100 microM, phosphocholine cytidylyltransferase was rate-limiting; at higher choline concentrations the conversion of choline to phosphocholine by ...

Effects of different levels of choline and garlic powder on performance, liver health and immune response in broiler chickens were evaluated in this study. A factorial experiment with 2 dietary choline levels (the recommended level in Ross 308 broiler guidelines and 25 % less than the recommendation) and 3 dietary garlic powder levels (0, 5 or 10 g/kg diet) was conducted using Ross 308 broiler ...

Phosphatidylethanolamine synthesis by CDP-ethanolamine:1,2-diacylglycerol ethanolaminephosphotransferase (EC 2.7.8.1) from the endoplasmic reticulum of castor bean (Ricinus communis L. var. Hale) endosperm was characterized. The Michaelis-Menten constant of the enzyme for CDP-ethanolamine was approximately 8.0 micromolar. The pH optimum was 6.5 and a divalent cation was an absolute requirement ...

The Saccharomyces cerevisiae protein SEC14p is required for Golgi function and cell viability in vivo. This requirement is obviated by mutations that specifically inactivate the CDP-choline pathway for phosphatidylcholine biosynthesis. The biochemical basis for the in vivo relationship between SEC14p function and the CDP-choline pathway has remained obscure. We now report that SEC14p effects an...

The goal of this study was to assess the relative importance of the axonal synthesis of phosphatidylcholine for neurite growth using rat sympathetic neurons maintained in compartmented culture dishes. In a double-labeling experiment [14C]choline was added to compartments that contained only distal axons and [3H]choline was added to compartments that contained cell bodies and proximal axons. The...

The two recently characterized Streptococcus pneumoniae strains--R6Chi and R6Cho(-)--that have lost the unique auxotrophic requirement of this bacterial species for choline differ in their mechanisms of choline independence. In strain R6Chi the mechanism is caused by a point mutation in tacF, a gene that is part of the pneumococcal lic2 operon, which is essential for growth and survival of the ...

Lemna paucicostata Hegelm. 6746 possesses specific systems for uptake of choline and ethanolamine. Each is distinct from the six other systems for uptake of organic compounds so far identified in this plant. Both systems show biphasic kinetics, so that uptake by them can be described as the composite result of two Michaelis-Menten processes. Inhibitor studies are reported which indicate the ver...