The amidation of a synthetic peptide D-Tyr-Pro-Gly-Gly by sheep hypothalamic and pituitary preparations was measured. This substrate was designed as a glycine-extended C-terminal peptide analogue of gonadotropin-releasing hormone (GnRH) to test the ability of these tissues to convert the product produced by cleavage of the GnRH prohormone into the active amidated decapeptide. An alpha-amidating...

Three allatostatins have been isolated from the mosquito Aedes aegypti. These peptides have the following structures: Ser-Pro-Lys-Tyr-Asn-Phc-Gly-Leu-amide, Leu-Pro-His-Tyr-Asn-Phe-Gly-Leu-amide, and Arg-Val-Tyr-Asp-Phe-Gly-Leu-amide. A cDNA encoding these peptides was isolated from an abdominal ganglia cDNA library and sequenced. It was found to encode two additional allatostatins: Ala-Ser-Ala...

Background: Activation loop Y807F or juxtamembrane domain Y559F mutations compromise CSF-1 receptor-mediated macrophage proliferation. Results: Tyr-559 suppresses constitutive proliferative activity of Tyr-807; ligand-induced Tyr559 phosphorylation relieves this inhibition and activates pathways. Conclusion: Tyr-807 drives proliferation. Tyr-559 confers ligand dependence. Significance: How indi...

DTD (D-Tyr-tRNA(Tyr) deacylase) is known to be able to deacylate D-aminoacyl-tRNAs into free D-amino acids and tRNAs and therefore contributes to cellular resistance against D-amino acids in Escherichia coli and yeast. We have found that h-DTD (human DTD) is enriched in the nuclear envelope region of mammalian cells. Treatment of HeLa cells with D-Tyr resulted in nuclear accumulation of tRNA(Ty...

G protein-coupled receptor kinase-interactor 1 (Git1) is involved in cell motility control by serving as an adaptor that links signaling proteins such as Pix and PAK to focal adhesion proteins. We previously demonstrated that Git1 was a multiply tyrosine-phosphorylated protein, its primary phosphorylation site was Tyr-554 in the vicinity of the focal adhesion targeting-homology (FAH) domain, an...

Dictyostelium actin was shown to become phosphorylated on Tyr-53 late in the developmental cycle and when cells in the amoeboid stage are subjected to stress but the phosphorylated actin had not been purified and characterized. We have separated phosphorylated and unphosphorylated actin and shown that Tyr-53 phosphorylation substantially reduces actin's ability to inactivate DNase I, increases ...

Repetitive deformation due to villous motility or peristalsis may support the intestinal mucosa, stimulating intestinal epithelial proliferation under normal circumstances and restitution in injured and inflamed mucosa rich in tissue fibronectin. Cyclic strain enhances Caco-2 and IEC-6 intestinal epithelial cell migration across fibronectin via ERK. However, the upstream mediators of ERK activa...

Tyrosines 292 and 293 in the mammalian glucose transporter GLUT1 have been substituted by either isoleucine or phenylalanine. Chinese hamster ovary clones that were transfected with Tyr-292-->Ile, Tyr-292-->Phe, Tyr-293-->Ile, and Tyr-293-->Phe constructs of GLUT1 were shown, by Western blotting and cell surface carbohydrate labeling, to have expression levels that were comparable with the wild...

We explored the mechanism(s) of increased aromatic amino acids concentrations in liver cirrhosis using phenylalanine (Phe) and tyrosine (Tyr) isotope infusions in male patients with compensated cirrhosis (five in Child Class A, three in B) and in eight matched healthy controls, in both postabsorptive and fed states. After a baseline period, a standard liquid mixed meal was fed continuously over...