Characterization of sites of serine phosphorylation in human placental insulin receptor copurified with insulin-stimulated serine kinase activity by two-dimensional thin-layer peptide mapping.
Insulin receptor was copurified from human placenta together with insulin-stimulated kinase activity that phosphorylates the insulin receptor on serine residues. Analysis of phosphorylated insulin receptor by two-dimensional tryptic peptide mapping showed that sites of insulin stimulated serine phosphorylation in the insulin receptor were recovered in the same peptides as those known to be phosphorylated on serine in vivo in response to insulin. This indicates that the serine kinase copurified with the insulin receptor represents a physiologically important enzyme involved in the insulin triggered serine phosphorylation of the insulin receptor in vivo.
Smith
D M
DM
Department of Biochemistry, School of Biochemical and Physiological Sciences, University of Southampton, England.
Sale
G J
GJ
D006801:Humans; D010449:Peptide Mapping; D010766:Phosphorylation; D010768:Phosphoserine / Q000378:metabolism*; D019000:Phosphotyrosine; D010920:Placenta / Q000378:metabolism; D011494:Protein Kinases / Q000302:isolation & purification / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases; D011972:Receptor, Insulin / Q000302:isolation & purification / Q000378:metabolism*; D012694:Serine / Q000031:analogs & derivatives*; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism
D010768:Phosphoserine; D019000:Phosphotyrosine; D014443:Tyrosine; D012694:Serine; D011494:Protein Kinases; D011972:Receptor, Insulin; D017346:Protein Serine-Threonine Kinases