Phosphorylation of type‐L pyruvate kinase in intact hepatocytes Localisation of the phosphorylation site in response to both glucagon and the Ca2+‐linked agonist phenylephrine

[摘要]

Pyruvate kinase is one of the enzymes which can be phosphorylated by stimulation of the cell with either glucagon or Ca²⁺-linked hormones. Whether these two classes of hormones phosphorylate the same site on the enzyme is unclear. Our results demonstrate that isolation of [³²P]phosphorylated type-L pyruvate kinase from glucagon-treated hepatocytes followed by aspartyl-prolyl cleavage yields a [³²P]phosphorylated peptide of M _r 17000. This fragment is also phosphorylated in response to the Ca²⁺-mediated agonist phenylephrine.

[学科分类] 生物化学/生物物理

[关键词] Pyruvate kinase;Phosphorylation;Glucagon;Phenylephrine;Phosphorylation site;Aspartyl-prolyl deavage