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Heat shock protein 90 mediates the balance of nitric oxide and superoxide anion from endothelial nitric-oxide synthase. J Biol Chem 2001 May 25;276(21):17621-4



Pubmed ID




Scopus ID

2-s2.0-0035947583   266 Citations


The balance of nitric oxide (.NO) and superoxide anion (O(2)) plays an important role in vascular biology. The association of heat shock protein 90 (Hsp90) with endothelial nitric-oxide synthase (eNOS) is a critical step in the mechanisms by which eNOS generates.NO. As eNOS is capable of generating both.NO and O(2), we hypothesized that Hsp90 might also mediate eNOS-dependent O(2) production. To test this hypothesis, bovine coronary endothelial cells (BCEC) were pretreated with geldanamycin (GA, 10 microg/ml; 17.8 microm) and then stimulated with the calcium ionophore, (5 microm). GA significantly decreased -stimulated eNOS-dependent nitrite production (p < 0.001, n = 4) and significantly increased -stimulated eNOS-dependent O(2) production (p < 0.001, n = 8). increased phospho-eNOS(Ser-1179) levels by >1.6-fold over vehicle (V)-treated levels. Pretreatment with GA by itself or with increased phospho-eNOS levels. In unstimulated V-treated BCEC cultures low amounts of Hsp90 were found to associate with eNOS. Pretreatment with GA and/or increased the association of Hsp90 with eNOS. These data show that Hsp90 is essential for eNOS-dependent.NO production and that inhibition of ATP-dependent conformational changes in Hsp90 uncouples eNOS activity and increases eNOS-dependent O(2) production.

Author List

Pritchard KA Jr, Ackerman AW, Gross ER, Stepp DW, Shi Y, Fontana JT, Baker JE, Sessa WC


John E. Baker PhD Professor in the Surgery department at Medical College of Wisconsin
Kirkwood A. Pritchard PhD Professor in the Surgery department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Cells, Cultured
Endothelium, Vascular
HSP90 Heat-Shock Proteins
Nitric Oxide
Nitric Oxide Synthase
Nitric Oxide Synthase Type III
jenkins-FCD Prod-482 91ad8a360b6da540234915ea01ff80e38bfdb40a