Insulin-stimulated serine/threonine phosphorylation of the insulin receptor: paucity of threonine 1348 phosphorylation in vitro indicates the involvement of more than one serine/threonine kinase in vivo.

Source:http://linkedlifedata.com/resource/pubmed/id/1654905

Biochem. Biophys. Res. Commun. 1991 Sep 16 179 2 962-71

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General Info

Authors

Siddle K, Pillay TS

Affiliation

Department of Clinical Biochemistry, University of Cambridge, Addenbrooke's Hospital, UK.

Abstract

Immunoaffinity-purified insulin receptors were used to analyse and compare the serine/threonine sites phosphorylated on the insulin receptor in vitro (isolated receptor) with the insulin-stimulated phosphorylation in vivo (intact cells in culture). In vivo, insulin-stimulation resulted in the appearance of three phosphoserine-containing phosphopeptides and a distinct phosphothreonine peptide (threonine 1348). In vitro, similar phosphoserine peptides were observed but the phosphothreonine peptide was absent. These results indicate that multiple serine sites are phosphorylated in vivo and in vitro and that an additional protein kinase mediates insulin-stimulated insulin receptor threonine phosphorylation in vivo.

PMID
1654905

Publication types

Comparative Study; Research Support, Non-U.S. Gov't