Phosphotyrosyl protein phosphatases
نویسندگان
چکیده
منابع مشابه
Phosphotyrosyl protein phosphatases.
Enzyme-catalysed reversible protein phosphorylation is an important cellular regulatory mechanism (Nimmo & Cohen, 1977; Krebs & Beavo, 1979). Regulatory protein phosphorylation occurs most frequently on seryl and threonyl residues (Taborsky, 1974), and less frequently, on tyrosyl residues (Hunter, 1982). Protein phosphotyrosine [Tyr(P)] normally accounts for only 0.01-0.050o of the total protei...
متن کاملInsulin-receptor phosphotyrosyl-protein phosphatases.
Calmodulin-dependent protein phosphatase has been proposed to be an important phosphotyrosyl-protein phosphatase. The ability of the enzyme to attack autophosphorylated insulin receptor was examined and compared with the known ability of the enzyme to act on autophosphorylated epidermal-growth-factor (EGF) receptor. Purified calmodulin-dependent protein phosphatase was shown to catalyse the com...
متن کاملDephosphorylation of insulin-receptor autophosphorylation sites by particulate and soluble phosphotyrosyl-protein phosphatases.
Insulin stimulates autophosphorylation of the insulin receptor on multiple tyrosines in three domains: tyrosines 1316 and 1322 in the C-terminal tail, 1146, 1150 and 1151 in the tyrosine-1150 domain, and possibly 953, 960 or 972 in the juxtamembrane domain. In the present work the sequence of dephosphorylation of the various autophosphorylation sites by particulate and cytosolic preparations of...
متن کاملPhosphotyrosyl-protein phosphatases. I. Separation of multiple forms from bovine brain and purification of the major form to near homogeneity.
Seven Tyr-protein phosphatase activities were isolated from bovine brain using phosphotyrosyl-casein as a model substrate. The activities were resolved from the cytosolic fraction by a three-step procedure employing successive DEAE-cellulose, phosphocellulose, and gel permeation chromatography steps. The seven activities accounted for 70% of the Tyr-protein phosphatase activity in bovine brain ...
متن کاملSite-specific dephosphorylation and deactivation of the human insulin receptor tyrosine kinase by particulate and soluble phosphotyrosyl protein phosphatases.
Insulin receptor tyrosine kinase activation, induced by insulin-stimulated autophosphorylation, was measured using a synthetic peptide containing residues 1142-1153 of the insulin receptor and shown to be reversed by both particulate and soluble phosphotyrosyl protein phosphatases from rat liver. Deactivation of the tyrosine kinase was highly sensitive to phosphatase action and was correlated b...
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ژورنال
عنوان ژورنال: Biochemical Journal
سال: 1989
ISSN: 0264-6021,1470-8728
DOI: 10.1042/bj2570023