Glucagon-induced phosphorylation of pyruvate kinase (type L) in rat liver slices
1977 (English)In: Biochemical and Biophysical Research Communications - BBRC, ISSN 0006-291X, E-ISSN 1090-2104, Vol. 78, no 4, 1147-1155 p.Article in journal (Refereed) Published
The effect of glucagon on the phosphorylation of pyruvate kinase in 32P-labelled slices from rat liver was investigated. Pyruvate kinase was isolated by immunoadsorbent chromatography. The enzyme was partially phosphorylated in the absence of added hormone (0.2 mol of phosphate/mol of enzyme subunit). Upon incubation with 10−7 M glucagon, the incorporation of [32P]phosphate was 0.6–0.7 mol/mol of enzyme subunit. Concomitantly, the concentration of intracellular cyclic 3′,5′-AMP increased from 0.3 to 3.2 μM. The phosphorylation inhibited the enzyme activity at low concentrations of phosphoenolpyruvate (60% at 0.5 mM). Almost maximal phosphorylation of the enzyme was reached within 2 min after the addition of glucagon. The concentration of hormone giving half maximal effect on the pyruvate kinase phosphorylation was about 7×10−9M. The inactivation of the enzyme paralleled the increase in phosphorylation. It is concluded that pyruvate kinase is phosphorylated in the intact liver cell.
Place, publisher, year, edition, pages
1977. Vol. 78, no 4, 1147-1155 p.
Other Basic Medicine
IdentifiersURN: urn:nbn:se:uu:diva-169191DOI: 10.1016/0006-291X(77)91413-9PubMedID: 200227OAI: oai:DiVA.org:uu-169191DiVA: diva2:505377