The CKI1-encoded choline kinase (ATP:choline phosphotransferase, EC 2.7.1.32) from Saccharomyces cerevisiae was phosphorylated in vivo on multiple serine residues. Activation of protein kinase A activity in vivo resulted in a transient increase in the phosphorylation of choline kinase. This phosphorylation was accompanied by a stimulation in choline kinase activity. In vitro, protein kinase A p...

Recent developments in nutrition have established that choline is an essential nutrient for mammals when a sufficient supply in methionine and folates are not available in the diet. Vitamin B12 is also involved in this process. The dynamic interactions between these components introduced the concept of choline as vitamin-like compound. Two types of choline functions are known: as choline per se...

When type II pneumonocytes from adult rats were maintained in a medium that lacked choline, the incorporation of ['4C]glycerol into phosphatidylcholine was not greatly diminished during the period that the cells displayed characteristics of type II pneumonocytes. Cells that were maintained in choline-free medium that contained choline oxidase and catalase, however, became depleted of choline an...

Choline is required to make essential membrane phospholipids. It is a precursor for the biosynthesis of the neurotransmitter acetylcholine and also is an important source of labile methyl groups. Mammals fed a choline-deficient diet develop liver dysfunction; however, choline is not considered an essential nutrient in humans. Healthy male volunteers were hospitalized and fed a semisynthetic die...

Activation of nerve elements in uivo and in vitro is associated with an increased rate of choline uptake by a Na+-dependent high affinity transport system. Following the methodology of BARKER (1976), rat cortical synaptosomes were depolarized (37"C, 10 min) by 25 mM-KCI in the presence of CaClz (I mM) or other divalent cations. After reisolation by centrifugation, the rate of 3H-choline uptake ...

accurate protein function prediction is an important subject in bioinformatics, especially wheresequentially and structurally similar proteins have different functions. malate dehydrogenaseand l-lactate dehydrogenase are two evolutionary related enzymes, which exist in a widevariety of organisms. these enzymes are sequentially and structurally similar and sharecommon active site residues, spati...

Choline has critical roles during periods of rapid growth and development, such as infancy. In human milk, choline is mostly present in water-soluble forms (free choline, phosphocholine, and glycerophosphocholine). It is thought that milk choline concentration is influenced by maternal choline intake, and the richest food sources for choline are of animal origin. Scarce information exists on mi...

The conversion of W-labeled fatty acylsphingosine and phosphatidyl[14C]choline to sphingomyelin could be demonstrated in lyophilized microsomes from mouse liver. Radioactive CDP-choline did not act as a choline donor. No cofactors were needed, although CDP-choline and P-choline exerted some stimulatory action. The unnatural ceramide, acetyl threo-sphingosine, could be converted to the correspon...