Among its diverse biological actions, the vasoactive peptide bradykinin (BK) induces the transcription factor AP-1 and proliferation of mesangial cells (S. S. El-Dahr, S. Dipp, I. V. Yosipiv, and W. H. Baricos. Kidney Int. 50: 1850-1855, 1996). In the present study, we examined the role of protein tyrosine phosphorylation and the mitogen-activated protein kinases, ERK1/2,in mediating BK-induced...

AIMS To study the regulation of type 1 insulin like growth factor receptor (IGF-1R) tyrosine kinase activity using the fission yeast Schizosaccharomyces pombe and a green fluorescent protein (GFP) tagged, full length IGF-1R. METHODS The beta chain of the IGF-1R (betawt) was expressed under inducible conditions in the fission yeast S. pombe. Western blot analysis with antiphosphotyrosine antib...

The rat alpha 1-1 glutathione S-transferase (GST) contains a single, non-essential tryptophan and only 8 tyrosines in each subunit. One of these tyrosines, Tyr-9, hydrogen bonds to the substrate glutathione and stabilizes the nucleophilic thiolate anion. Two mutant proteins that allow for the spectrocopic determination of the pKa of this catalytic residue have been constructed. The W21F mutant ...

The regulation of stable catalase from Aspergillus niger was investigated. The preincubation of catalase with peroxynitrite (PN) resulted in a significant decrease in the production of O2, while the subsequent incubation with reduced glutathione (GSH, 1mM) led to restoration of the enzymatic activity. Western blot analysis revealed not only the increased immunoreactivities of 3-nitrotyrosine an...

Objective(s) Motility plays a major role in pathogenicity of Helicobacter pylori, yet there is  scarce data regarding its chemotactic behaviour. The present study was designed to investigate the chemotactic responses of local isolates of H. pylori towards various sugars, amino acids, as well as some other chemical substances. Materials and Methods Chemotaxis was assayed by a modified Adler’s...

neuromelanin (nm) pigment accumulates with age in catecholaminergic neurons in man, and the ventral substantia nigra dopaminergic neurons that are the most vulnerable to degeneration in parkinson's disease (pd) contain the greatest amount of this pigment. in vitro data indicate that nm pigment is formed from the excess cytosolic catecholamine that is not accumulated into synaptic vesicles via t...

A hairy roots culture of Stephania suberosa was established using Agrobacterium rhizogenes ATCC15834. The production of dicentrine was found to be (8.92 +/- 0.07) mg/g dry wt on day 35 of culture. Effects of sucrose content, tyrosine, and medium strength on growth and dicentrine production of S. suberosa were investigated. 6% (w/v) sucrose was an optimum content for the growth and dicentrine ac...

Prohibitin (PHB or PHB1) is an evolutionarily conserved, multifunctional protein which is present in various cellular compartments including the plasma membrane. However, mechanisms involved in various functions of PHB are not fully explored yet. Here we report for the first time that PHB interacts with O-linked beta-N-acetylglucosamine transferase (O-GlcNAc transferase, OGT) and is O-GlcNAc mo...

Molecular interplay during snail-schistosome interactions is poorly understood and there is much to discover concerning the effect of snail host molecules on molecular processes in schistosomes. Using the Biomphalaria glabrata - Schistosoma mansoni host-parasite system, the effects of exposure to haemolymph, derived from schistosome-resistant and susceptible snail strains, on protein tyrosine p...

Contractile agonists may stimulate mitogenic responses in airway smooth muscle by mechanisms that involve tyrosine kinases. The role of contractile agonist-evoked activation of tyrosine kinases in contractile signaling is not clear. We addressed this issue using cultured rat airway smooth muscle cells. In these cells, serotonin (5-HT, 1 microM) caused contraction (quantitated by a decrease in c...