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Opening and closing of a CFTR Cl(-) channel is controlled by PKA-mediated phosphorylation of its cytoplasmic regulatory (R) domain and by ATP binding, and likely hydrolysis, at its two nucleotide binding domains. Functional interactions between the R domain and the two nucleotide binding domains were probed by characterizing the gating of severed CFTR(More)
The plasma membrane H(+)-ATPase of Saccharomyces cerevisiae is an essential protein that is required to establish cellular membrane potential and maintain a normal internal pH. An Asp-378 to Asn substitution at the residue phosphorylated during catalysis is dominant lethal when the pma1-D378N mutation is expressed along with a wild-type plasma membrane(More)
CFTR (cystic fibrosis transmembrane conductance regulator), the protein whose dysfunction causes cystic fibrosis, is a chloride ion channel whose gating is controlled by interactions of MgATP with CFTR's two cytoplasmic nucleotide binding domains, but only after several serines in CFTR's regulatory (R) domain have been phosphorylated by cAMP-dependent(More)
Vitamin D Receptor (VDR) is expressed in both animal and human ovarian tissue, however, the role of vitamin D in human ovarian steroidogenesis is unknown. Cultured human ovarian cells were incubated in tissue culture medium supplemented with appropriate substrates, with or without 50 pM-150 pM or 50 nM-150 nM of 1,25-(OH)2D3, and in the presence or absence(More)
The cystic fibrosis transmembrane conductance regulator is a Cl(-) channel that belongs to the family of ATP-binding cassette proteins. The CFTR polypeptide comprises two transmembrane domains, two nucleotide binding domains (NBD1 and NBD2), and a regulatory (R) domain. Gating of the channel is controlled by kinase-mediated phosphorylation of the R domain(More)
The fungal plasma membrane H(+)-ATPase possesses important attributes that make it desirable as a target for antifungal drug discovery. First, the enzyme is essential to fungal cell physiology, being required for the formation of a large electrochemical proton gradient and the maintenance of intracellular pH. While complete inhibition of the proton pump(More)
The effects of rosiglitazone or pioglitazone (thiazolidinediones, TZDs) on estrogen production and aromatase activity in human ovarian cells were examined. Human granulosa cells were incubated in the tissue culture medium supplemented with androstenedione or testosterone, with or without insulin, TZDs, or type 1 17β-hydroxysteroid-dehydrogenase (17β-HSD)(More)
A molecular model for transmembrane segments 1 and 2 from the fungal proton pumping ATPase has been developed, and this structure is predicted to form a helical hairpin loop structure in the membrane. This region was selected because it is highly conformationally active and is believed to be an important site of action for clinically important therapeutics(More)
The membrane lipids from two obligately and two facultatively alkalophilic strains of Bacillus spp. were characterized in a comparative study that included B. subtilis. Preparations of membrane lipids were made from pH 10.5-grown cells of all of the alkalophiles and from pH 7.5- or 7.0-grown cells of the two facultative strains and B. subtilis. The two(More)
The yeast plasma membrane proton pumping ATPase (H(+)-ATPase) was investigated as a potential molecular target for antifungal drug therapy by examining the inhibitory effects of the sulfhydryl-reactive reagent omeprazole on cell growth, glucose-induced medium acidification and H(+)-ATPase activity. Omeprazole inhibits the growth of Saccharomyces cerevisiae(More)