In vitro protein kinase C phosphorylation sites of placental lipocortin.
Human placental lipocortin is a high-affinity substrate for rat brain protein kinase C in vitro with phosphorylation occurring on serine and threonine residues in a ratio of approximately 2 to 1. Comparison of the ability of various N-terminal-truncated derivatives of lipocortin to serve as phosphorylation substrates, and direct analysis of the N-terminal peptides cleaved from 32P-labeled lipocortin, indicated that threonine-24, serine-27, and serine-28 were the phosphorylation sites. The possibility is discussed that a lysine residue near the carboxy side of the phosphorylation site was involved in lipocortin interaction with the catalytic site of protein kinase C.
Schlaepfer
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DD
Department of Biological Chemistry, University of California, Irvine 92717.
Haigler
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HT
D000818:Animals; D017302:Annexins; D001665:Binding Sites; D005260:Female; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D010740:Phospholipases / Q000037:antagonists & inhibitors*; D010766:Phosphorylation; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D011493:Protein Kinase C / Q000378:metabolism*; D051381:Rats
D017302:Annexins; D006023:Glycoproteins; D011493:Protein Kinase C; D010740:Phospholipases