A multifunctional, ubiquitous molecule, adenosine acts at cell-surface G protein-coupled receptors, as well numerous enzymes, including protein kinases and adenylyl cyclase. Extracellular is thought to be produced either by export or metabolism, predominantly through ecto-5’-nucleotidase activity (also producing inorganic phosphate). It inactivated extracellular metabolism via deaminase ammonia...

It is thought that free oligosaccharides in the cytosol are an outcome of quality control of glycoproteins by endoplasmic reticulum-associated degradation (ERAD). Although considerable amounts of free oligosaccharides accumulate in the cytosol, where they presumably have some function, detailed analyses of their structures have not yet been carried out. We isolated 21 oligosaccharides from the ...

Recent studies have demonstrated the existence of a novel family of calcium-independent plasmalogen-selective phospholipases A2 in canine myocardium that have been implicated as enzymic mediators of ischemic membrane damage. We now report that human myocardium contains two functionally distinct isoforms of cytosolic calcium-independent phospholipase A2. The major cytosolic phospholipase A2 isof...

Estrogen increases baseline transepithelial permeability across CaSki cultures and augments the increase in permeability in response to hypertonic gradients. In estrogen-treated cells, lowering cytosolic calcium abrogated the hypertonicity-induced augmented increase in permeability and decreased baseline permeability to a greater degree than in estrogen-deprived cells. Steady-state levels of cy...

Large-conductance Ca2+- and voltage-regulated K+ channels (Slo1 BK-type) are controlled by two physiological stimuli, membrane voltage and cytosolic Ca2+. Regulation by voltage is similar to that in voltage-dependent K+ channels, arising from positively charged amino acids primarily within the S4 transmembrane helices. The basis for regulation by Ca2+ remains controversial. One viewpoint sugges...

Cytosolic calcium increases were analyzed in guard cells of the Arabidopsis farnesyltransferase deletion mutant era1-2 (enhanced response to abscisic acid). At low abscisic acid (ABA) concentrations (0.1 microM), increases of guard cell cytosolic calcium and stomatal closure were activated to a greater extent in the era1-2 mutant compared with the wild type. Patch clamping of era1-2 guard cells...

Trop2 is a transmembrane signaling glycoprotein upregulated in stem and carcinoma cells. Proliferation-enhancing signaling involves regulated intramembrane proteolytic release of a short cytoplasmic fragment, which is later engaged in a cytosolic signaling complex. We propose that Trop2 function is modulated by phosphorylation of a specific serine residue within this cytosolic region (Ser303), ...

Voltage-gated changes in cytosolic free calcium ion concentration were measured in single, differentiated cells of mouse neuroblastoma clone N1E-115 using the calcium-sensitive dye arsenazo III (AIII). In cells bathed in normal medium containing 10 mM calcium, the changes in AIII absorbance during a single action potential indicated an increase of 1.4 nM in cytosolic calcium. When 10 mM tetraet...

Proteins and other macromolecules that cross biological membranes have great potential as tools for research and next-generation therapeutics. Here, we describe two assays that effectively quantify the cytosolic localization of a number of previously reported peptides and protein domains. One assay, which we call GIGI (glucocorticoid-induced eGFP induction), is an amplified assay that informs o...

Thyrotropin causes a time- and concentration-dependent increase in cytosolic Ca2+ in FRTL-5 rat thyroid cells as measured by Quin2 fluorescence; the half-maximal response occurs in response to 1 X 10(-7) M thyrotropin. The effect of added thyrotropin is the same whether cells have been previously and chronically exposed to thyrotropin or whether they have been thyrotropin "starved" for several ...