Novel complexes of guanylate cyclase with heat shock protein 90 and nitric oxide synthase

• Published in: American journal of physiology. Heart and circulatory physiology Vol. 285; no. 2; pp. H669 - H678
• Main Authors: Venema, Richard C, Venema, Virginia J, Ju, Hong, Harris, M. Brennan, Snead, Connie, Jilling, Tamas, Dimitropoulou, Christiana, Maragoudakis, Michael E, Catravas, John D
• Format: Journal Article
• Language: English
• Published: United States 01.08.2003
• Subjects: Animals; Aorta - cytology; Benzoquinones; Cattle; Cells, Cultured; Endothelium, Vascular - cytology; Endothelium, Vascular - enzymology; Enzyme Inhibitors - pharmacology; Guanylate Cyclase - metabolism; HSP90 Heat-Shock Proteins - metabolism; Lactams, Macrocyclic; Muscle, Smooth, Vascular - cytology; Muscle, Smooth, Vascular - enzymology; Nitric Oxide Donors - pharmacology; Nitric Oxide Synthase - metabolism; Nitric Oxide Synthase Type II; Nitric Oxide Synthase Type III; Nitroprusside - pharmacology; Quinones - pharmacology; Rats; Rats, Sprague-Dawley; Signal Transduction - drug effects; Signal Transduction - physiology
• ISSN: 0363-6135; 1522-1539
• DOI: 10.1152/ajpheart.01025.2002

1 Vascular Biology Center, 2 Department of Pediatrics, and 3 Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta, Georgia 30912-2500; and 4 Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611-3008 Submitted 2 December 2002 ; accepted in final form 1 April 2003 Soluble guanylate cyclase (sGC) is an important downstream intracellular target of nitric oxide (NO) that is produced by endothelial NO synthase (eNOS) and inducible NO synthase (iNOS). In this study, we demonstrate that sGC exists in a complex with eNOS and heat shock protein 90 (HSP90) in aortic endothelial cells. In addition, we show that in aortic smooth muscle cells, sGC forms a complex with HSP90. Formation of the sGC/eNOS/HSP90 complex is increased in response to eNOS-activating agonists in a manner that depends on HSP90 activity. In vitro binding assays with glutathione S -transferase fusion proteins that contain the - or -subunit of sGC show that the sGC -subunit interacts directly with HSP90 and indirectly with eNOS. Confocal immunofluorescent studies confirm the subcellular colocalization of sGC and HSP90 in both endothelial and smooth muscle cells. Complex formation of sGC with HSP90 facilitates responses to NO donors in cultured cells (cGMP accumulation) as well as in anesthetized rats (hypotension). These complexes likely function to stabilize sGC as well as to provide directed intracellular transfer of NO from NOS to sGC, thus preventing inactivation of NO by superoxide anion and formation of peroxynitrite, which is a toxic molecule that has been implicated in the pathology of several vascular diseases. smooth muscle cells; endothelium; vascular endothelial growth factor; bradykinin; cGMP accumulation Address for reprint requests and other correspondence: J. D. Catravas, Vascular Biology Center, Medical College of Georgia, Augusta, Georgia 30912-2500 (E-mail: jcatrava{at}mail.mcg.edu ).