Insulin and insulin antagonists evoke phosphorylation of P20 at serine 157 and serine 16 respectively in rat skeletal muscle

Yu Wang, Aimin Xu, Richard B. Pearson, Garth J.S. Cooper

Research output: Contribution to journalArticleResearchpeer-review

22 Citations (Scopus)


We show here that insulin and insulin antagonists differentially modify phosphorylation of three phospho-isoforms of P20 (termed S1, S2 and S3) in rat skeletal muscle. Precise phosphorylation sites of S1 and S2 were mapped to serine 157 and serine 16 respectively. Insulin evoked phosphorylation of P20 at serine 157 through the phosphatidylinositol (PI) 3-kinase pathway. Epinephrine and calcitonin gene-related peptide decreased phosphorylation at serine 157 and increased phosphorylation at serine 16 and other unidentified sites. These results demonstrate that the PI-3-kinase pathway of anabolic insulin and the cAMP pathway of catabolic hormones converge on P20 and suggest a potential role of this protein in regulating energy metabolism of skeletal muscle.

Original languageEnglish
Pages (from-to)25-30
Number of pages6
JournalFEBS Letters
Issue number1-2
Publication statusPublished - 26 Nov 1999
Externally publishedYes


  • Calcitonin gene-related peptide
  • Epinephrine
  • Insulin
  • P20
  • Phosphorylation
  • Signal transduction

Cite this