BACKGROUND Vascular endothelial growth factor receptor-2 (VEGFR-2, KDR), a receptor tyrosine kinase, regulates mitogenic, chemotactic, hyperpermeability, and survival signals in vascular endothelial cells in response to its ligand vascular permeability factor/ vascular endothelial growth factor (VPF/VEGF). SHP-1 is a protein tyrosine phosphatase known to negatively regulate signaling from recep...

objective(s):higher cellular reactive oxygen species (ros) levels is important in reducing cellular energy charge (ec) by increasing the levels of key metabolic protein, and nitrosative modifications, and have been shown to damage the cardiac tissue of diabetic mice. however, the relation between energy production and heart function is unclear. materials and methods:streptozotocin (stz, 150 mg/...

Webb, Rachel J., Jacob D. Judah, Lee-Chiang Lo, and Geraint M. H. Thomas. Constitutive secretion of serum albumin requires reversible protein tyrosine phosphorylation events in trans-Golgi. Am J Physiol Cell Physiol 289: C748–C756, 2005. First published April 20, 2005; doi:10.1152/ajpcell.00019.2005.—Serum albumin secretion from rat hepatocytes proceeds via the constitutive pathway. Although mu...

Concomitant tumor resistance (CR) is a phenomenon in which a tumor-bearing host is resistant to the growth of secondary tumor implants and metastasis. Although previous studies indicated that T-cell-dependent processes mediate CR in hosts bearing immunogenic small tumors, manifestations of CR induced by immunogenic and nonimmunogenic large tumors have been associated with an elusive serum facto...

The glycosyl-phosphatidylinositol (GPI)-anchored F3 molecule, a member of the Ig superfamily made up of Ig and FNIII-like domains, is involved in cell-cell adhesion, neuronal pathfinding and fasciculation. Little is known about the mechanism(s) that governs the F3-mediated cell-cell recognition. In particular, it is not known whether F3 transduces signals across the membrane. Here we show that ...

The genome of the protozoan parasite Toxoplasma gondii was found to contain two genes encoding tyrosine hydroxylase; that produces L-DOPA. The encoded enzymes metabolize phenylalanine as well as tyrosine with substrate preference for tyrosine. Thus the enzymes catabolize phenylalanine to tyrosine and tyrosine to L-DOPA. The catalytic domain descriptive of this class of enzymes is conserved with...

Earlier we reported the tendency of ferrocenylmethyl substituted amino acids to organize around Cu(ii) in a C(2) symmetry. In this paper we have utilized this property to form a chiral cavity using a l-tyrosine derivative. Structural characterization of [Cu(II)(S-fTyr)(2)(MeCN)(2)] (), where S-fTyr(1-) is ferrocenylmethyl-l-tyrosinate, showed that the alignment of two tyrosine aromatic rings ar...

Signaling through the B cell antigen receptor (BCR) results in rapid increases in tyrosine phosphorylation on a number of proteins. The BCR associates with two classes of tyrosine kinase: Src-family kinase (Src-protein-tyrosine kinase [PTK]; Lyn, Fyn, Blk, or Lck) and Syk kinase. We have investigated the interaction between the Src-PTK and the Syk kinase in the BCR signaling. In contrast to wil...

Methionine and tyrosine are competing targets of oxidizing free radicals in peptides or proteins. The first step is the addition of OH radicals either on the sulphur atom of methionine, followed by OH elimination, or on the aromatic cycle of tyrosine. The next step can be stabilization of methionine radical cation by a two centre-three electron bond, or intramolecular electron transfer from tyr...

A population of polysomes isolated from frogskinis capable of supporting protein synthesis in a cell-free system containing an energy generating system,' soluble components', and amino acids. These polysomes catalyse the oxidation of DOPA after gentle trypsinization, and they also have antigenic determinants attributable to tyrosine oxidase. Skin polysomes sedimented in 10-30 % sucrose gradient...