Pin1 Prolyl isomerase regulates endothelial nitric oxide synthase

Ling Ruan, Christina M. Torres, Jin Qian, Feng Chen, James D. Mintz, David W. Stepp, David Fulton, Richard C. Venema

Research output: Contribution to journalArticlepeer-review

45 Scopus citations


Objective-: The Pin1 prolyl isomerase acts in concert with proline-directed protein kinases to regulate function of protein substrates through isomerization of peptide bonds that link phosphoserine or phosphothreonine to proline. We sought to determine whether Pin1 interacts with endothelial nitric oxide synthase (eNOS) in endothelial cells in a manner that depends on proline-directed phosphorylation of the eNOS enzyme and whether this interaction influences basal or agonist-stimulated eNOS activity. Methods and results-: Inhibitors of the extracellular-regulated kinase (ERK) 1/2 MAP kinases inhibit proline-directed phosphorylation of eNOS at serine 116 (Ser116) in bovine aortic endothelial cells (BAECs). Moreover, eNOS and Pin1 can be coimmunoprecipitated from BAECs only when Ser116 is phosphorylated. In addition, phosphomimetic Ser116Asp eNOS, but not wild-type eNOS, can be coimmunoprecipitated with Pin1 coexpressed in COS-7 cells. Inhibition of Pin1 in BAECs by juglone or by dominant negative Pin1 increases basal and agonist-stimulated NO release from the cells, whereas overexpression of wild-type Pin1 in BAECs suppresses basal and agonist-stimulated NO production. Overexpression of wild-type Pin1 in intact aortae also reduces agonist-induced relaxation of aortic rings. Conclusion-: Our results demonstrate a novel form of eNOS regulation in endothelial cells and blood vessels through Ser116 phosphorylation-dependent interaction of eNOS with Pin1.

Original languageEnglish (US)
Pages (from-to)392-398
Number of pages7
JournalArteriosclerosis, thrombosis, and vascular biology
Issue number2
StatePublished - Feb 2011


  • nitric oxide
  • nitric oxide synthase
  • signal transduction
  • vascular biology

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine


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