Purpose: The aim of this study was to develop and test a cognitive dimension as a bolt-on for the German version of the EQ-5D-Y (Youth).
Methods: A literature review and six focus groups with children and adolescents were used to develop the cognitive dimension for the EQ-5D-Y. In a two-phase pretest, the acceptability, feasibility and performance of this dimension were assessed (phase 1: qualitative face-to-face interviews, phase 2: standard pretest in a clinical setting).
In a study to investigate the ability of chaperones to modulate src kinase activity, it was observed that BiP, a member of the HSP70 family found in the endoplasmic reticulum, is an excellent substrate for src kinase in vitro. The reaction requires polylysine and the results suggest that two tyrosine residues are phosphorylated. Although there is no evidence for this reaction in vivo, it does provide a very efficient method to label BiP.
View Article and Find Full Text PDFIt has been suggested that hyperphosphorylation of the tau protein in neurofibrillary tangles may be relevant to the etiology of Alzheimer's disease and that at least one of the hyperphosphorylated sites lies within a consensus sequence for the p34cdc2/cdc28 family of kinases. We describe a new method for large-scale purification of p34cdc28 kinase from Saccharomyces cerevisiae and show that the purified enzyme can phosphorylate bovine and human tau. Phosphorylation was greatly enhanced by the addition of basic and acidic substrate modulators.
View Article and Find Full Text PDFCurr Top Cell Regul
September 1992
We have described previously that in extracts of A431 cells epidermal growth factor (EGF) stimulates the phosphorylation of tyrosine as well as of threonine residues in the EGF receptor and in lipocortin 1. We now report that heparin at low concentrations also stimulates the autophosphorylation of the EGF receptor and of the recombinant 56-kDa domain of the EGF receptor that lacks the EGF binding site. To study the stimulations of phosphorylation of threonine residues, a fusion protein was prepared with glutathione S-transferase (GST) and an EGF receptor fragment, TK8 (residues 647-688), that contains the threonine phosphorylation site but no tyrosine.
View Article and Find Full Text PDFArch Biochem Biophys
May 1991
Fructose 2,6-bisphosphate (F-2,6-P2) stimulated glycolysis in cell-free extracts of both normal and ras-transfected rat-1 fibroblasts. The extract of the transformed cell glycolyzed more rapidly in both the absence and the presence of F-2,6-P2 than the extract of the parent fibroblast. Addition of mitochondrial ATPase (F1) or inorganic phosphate (Pi) further stimulated lactate production in both cell lines.
View Article and Find Full Text PDFExposure of rat-1 fibroblasts to cholera toxin increased aerobic lactate production 3- to 8-fold with maximal stimulation observed between 1 and 2 h at a concentration of 1-2 micrograms/ml. Concomitant with this change was a 10- to 40-fold elevation in the intracellular concentration of cAMP. The cell permeable cAMP analogue, N6,2'-O-dibutyryl cAMP and the cyclic nucleotide phosphodiesterase inhibitor RO-20-1724 also increased lactate production and intracellular cAMP levels, although less effectively.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
September 1990
The activities of src tyrosine kinases are greatly influenced by substrate modulators (chaperones). In the presence of bovine serum albumin, the phosphorylation of a random polymer of glutamic acid, alanine, and tyrosine (1:1:1) by src kinases is stimulated 20- to 100-fold, but there is little stimulation with a polymer of glutamic acid and tyrosine (4:1) as substrate. This suggests that serum albumin interacts with the substrates rather than with the enzyme.
View Article and Find Full Text PDFIn view of the possible effects of the sphingoid base on protein kinases, and the fact that the sphingoid bases used in previous studies were not chemically well-defined, we have studied the effects of chemically well-defined sphingosines and their derivatives on kinase activity. Both (4E)-D- and (4E)-L-erythro-sphingenine showed a weak inhibitory effect, and (4E)-L-threo-sphingenine had a moderate inhibitory effect. In contrast, (4E)-N,N-dimethyl-D-erythro-sphingenine and the sphingosine preparation from a commercial source showed a strong inhibitory effect on PK-C in A431 cells as well as on purified PK-C.
View Article and Find Full Text PDFIn this paper we show that epidermal growth factor (EGF) stimulates the phosphorylation of lipocortin 1, at threonine as well as at tyrosine residues, by a highly purified preparation of the EGF receptor. The phosphorylation of threonine residues is catalyzed by an enzyme that contaminates the receptor preparations, since crude extracts of A431 plasma membranes contain larger amounts of the threonine kinase than does the receptor preparation. Protein kinase P (2.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
May 1989
A 70-kDa protein is phosphorylated in cell-free preparations from rat or mouse fibroblasts by an endogenous protein kinase. This protein is immunologically related to a group of 68-kDa to 87-kDa proteins described in the literature as substrates for protein kinase C (PK-C). Although the phosphorylation of the 70-kDa protein by isolated plasma membranes takes place in the presence of EGTA, we conclude that the reaction is catalyzed by PK-C based on its inhibition by staurosporin.
View Article and Find Full Text PDFThe phosphorylation of histone by purified protein kinase C (PK-C) from rat brain is dependent on the presence of Ca2+ and lipids. Phosphorylation of a synthetic random polymer of arginine and serine (3:1) is only moderately enhanced by Ca2+ and lipids, but it is greatly enhanced in the absence of Ca2+ and lipids by a contaminant in crystalline bovine serum albumin or by heated cellular fractions. The phosphorylation ratio of histone to poly(arginine,serine) varies between different PK-C fractions from brains of rat, pig, or lamb.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
February 1989
Quiescent C3H-10T1/2 mouse fibroblasts that have not undergone any type of stress have a relatively low rate of 2-aminoisobutyrate (Aib) uptake by means of system A, which is primarily energized by the transmembrane Na+ chemical gradient potential. System A activity in these cells is not sensitive to ouabain or proton ionophores. In contrast, methylcholanthrene-transformed and confluent C3H-10T1/2 cells treated with 0.
View Article and Find Full Text PDFClathrin-coated vesicle acidification is mediated by an N-ethylmaleimide-sensitive, vanadate-resistant proton-translocating ATPase. This enzyme is a 530-kDa hetero-oligomer which catalyzes ATP-dependent proton pumping when reconstituted (Xie, X. S.
View Article and Find Full Text PDFArch Biochem Biophys
October 1988
Effects of various inhibitors on motility, heat, and lactate production of ejaculated bovine sperm were determined in the presence of antimycin A and rotenone. erythro-9-[3-(2-Hydroxynonyl)]adenine (EHNA) and polyvinylpyrrolidone (PVP-360) stopped motility and reduced heat or lactate production by 30-50%. Carbodiimides resulted in loss of motility and a reduction of metabolism by 60-75%.
View Article and Find Full Text PDFLiCl stimulated the formation of inositol monophosphate in PC12 cells that had been exposed to nerve growth factor (NGF) for 4-5 days. Half-maximal accumulation was observed at approximately 8 mM LiCl. Stimulation of formation of inositol bisphosphate plus inositol trisphosphate was half-maximal at approximately 1 mM LiCl.
View Article and Find Full Text PDFThe effects of bradykinin (BK) and lithium on the phosphatidylinositol cycle were examined in PC12 cells cultured for 20 h in the presence [PC12(+)] or in the absence [PC12(-)] of nerve growth factor (NGF). BK (1 microM) induced a small stimulation of the incorporation of myo-[2-3H]inositol into the lipids of PC12(-) cells and a three- to fourfold stimulation of such incorporation into the lipids of PC12 (+) cells. About 15 h of incubation with NGF and greater than 10 min of incubation with BK were needed for maximal stimulation of inositol incorporation by BK.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
August 1988
Five protein kinases are shown to serve as specific phosphatases in the absence of ADP. Although the rates of hydrolysis are very slow compared to the forward phosphorylation rates under optimal conditions, they are of the same order as the reverse reaction in the presence of ADP. Because cells contain approximately equal to 3 mM ATP, neither the reverse reaction nor the phosphatase is likely to play a physiological role.
View Article and Find Full Text PDFHuman erythrocyte ghosts catalyze a low rate of 32Pi uptake. A severalfold stimulation of 32Pi uptake was observed after exposure of the membranes to an erythrocyte lysate or to hemoglobin in the presence of Mg2+. Ghosts prepared from erythrocytes that had been exposed to 10 microM 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid showed a marked reduction in 32Pi uptake.
View Article and Find Full Text PDFRegulatory properties of a partially purified Ca2+ -channel preparation from isolated rabbit skeletal muscle triads were examined in proteoliposomes. These properties included (i) inhibition by phenylalkylamine antagonists, such as verapamil, (ii) inhibition by the GTP-binding protein Go in the presence of guanosine 5'-[gamma-thio]triphosphate, and (iii) regulation of phenylalkylamine inhibition as a result of phosphorylation by a polypeptide-dependent protein kinase (PK-P). By selective reconstitution of protein fractions obtained by wheat germ lectin and ion-exchange chromatography, a separation of Ca2+-channel activity (fraction C) from regulatory component(s) (fraction R) responsible for verapamil sensitivity was achieved.
View Article and Find Full Text PDFOuabain treatment (0.4 mM) of normal and transformed C3H-10T1/2 cells caused a progressive increase in 2-aminoisobutyrate (AIB) transport reaching a maximum after 16 to 18 h exposure. There was a virtually complete blockage of this stimulated rate when 3 microM cycloheximide (CHX) was added together with ouabain at T = 0.
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