The deoxythymidylate phosphohydrolase (dTMPase) induced by Bacillus subtilis bacteriophage PBS2 (whose DNA contains uracil instead of thymine) has been partially purified and shown to possess deoxyuridylate phosphohydrolase (dUMPase) activity. The similarities of induction period, pH dependence, heat and trypsin inactivation, sulfhydryl reagent and fluoride inhibition, metal ion effects, kineti...

Lipid biosynthesis within the chloroplast, or more generally plastids, was conventionally called "prokaryotic pathway," which produces glycerolipids bearing C18 acids at the sn-1 position and C16 acids at the sn-2 position, as in cyanobacteria such as Anabaena and Synechocystis. This positional specificity is determined during the synthesis of phosphatidate, which is a precursor to diacylglycer...

An Arabidopsis thaliana gene (AtLPP1) was isolated on the basis that it was transiently induced by ionizing radiation. The putative AtLPP1 gene product showed homology to the yeast and mammalian lipid phosphate phosphatase enzymes and possessed a phosphatase signature sequence motif. Heterologous expression and biochemical characterization of the AtLPP1 gene in yeast showed that it encoded an e...

In the yeast Saccharomyces cerevisiae, the synthesis of phospholipids is coordinately regulated by mechanisms that control the homeostasis of the essential mineral zinc (Carman, G.M., and Han, G. S. (2007) Regulation of phospholipid synthesis in Saccharomyces cerevisiae by zinc depletion. Biochim. Biophys. Acta 1771, 322-330; Eide, D. J. (2009) Homeostatic and adaptive responses to zinc deficie...

In the yeast Saccharomyces cerevisiae, the DGK1-encoded diacylglycerol kinase catalyzes the CTP-dependent phosphorylation of diacylglycerol to form phosphatidate. This enzyme, in conjunction with PAH1-encoded phosphatidate phosphatase, controls the levels of phosphatidate and diacylglycerol for phospholipid synthesis, membrane growth, and lipid droplet formation. In this work, we showed that a ...

cell lines, whereas alkaline phosphohydrolase activity was 8 times greater in Sarcoma 180/TG. Alkaline phosphohydrolase activity was localized predominantly in particulate fractions from Sarcoma 180/TG, showed a pH optimum of 9.2, and hydrolyzed a wide variety of phosphate esters, including p-nitropheny (phosphate and 5'-nucleotides, such as 6-thioinosine 5'-phosphate. It is suggested that enha...

With isolated liver microsomes, both synthetic and hydrolytic activities of glucose-6-phosphatase (D-ghcase-6-phosphate phosphohydrolase, EC 3.1.3.9) are characterized by considerable latency (ie activity manifest only in the presence of detergent). Believing that latency may relate to the morphological state of the cellular structure to which the enzyme is bound, we have performed studies to d...