HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

J. Biol. Chem., Vol. 282, Issue 44, 32453-32461, November 2, 2007

This Article Full Text Full Text (PDF) All Versions of this Article: 282/44/32453    most recent M706242200v1 Submit a Letter to Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Zhang, Y. Articles by Skidgel, R. A. Search for Related Content PubMed PubMed Citation Articles by Zhang, Y. Articles by Skidgel, R. A. Social Bookmarking                      What's this?

Dynamic Receptor-dependent Activation of Inducible Nitric-oxide Synthase by ERK-mediated Phosphorylation of Ser^745*

Yongkang Zhang, Viktor Brovkovych, Svitlana Brovkovych, Fulong Tan, Bao-Shiang Lee^¶, Tiffany Sharma, and Randal A. Skidgel¹

From the Departments of Pharmacology and Anesthesiology and the ^¶Protein Research Laboratory, University of Illinois at Chicago College of Medicine, Chicago, Illinois 60612

Nitric oxide (NO) is a pleiotropic regulator of vascular function, and its overproduction by inducible nitric-oxide synthase (iNOS) in inflammatory conditions plays an important role in the pathogenesis of vascular diseases. iNOS activity is thought to be regulated primarily at the level of expression to generate "high output" NO compared with constitutive NO synthases. Here we show iNOS activity is acutely up-regulated by activation of the B₁-kinin receptor (B₁R) in human endothelial cells or transfected HEK293 cells to generate 2.5-5-fold higher NO than that stimulated by Arg alone. Increased iNOS activity was dependent on B₁R activation of the MAPK ERK. In HEK293 cells transfected with human iNOS and B1R, ERK phosphorylated iNOS on Ser⁷⁴⁵ as determined by Western analysis using phospho-Ser antibody, in vitro kinase assays with activated ERK, and MALDI-TOF mass spectrometry. Mutation of Ser⁷⁴⁵ to Ala did not affect basal iNOS activity but eliminated iNOS phosphorylation and activation in response to B₁R agonist. Mutation of Ser⁷⁴⁵ to Asp resulted in a basally hyperactive iNOS whose activity was not further increased by B₁R agonist. ERK and phospho-ERK (after B₁R activation) were co-localized with iNOS as determined by confocal fluorescence microscopy. Furthermore, ERK co-immunoprecipitated with iNOS. The discovery that iNOS can be phosphorylated by ERK and acutely activated by receptor-mediated signaling reveals a new level of regulation for this isoform. These findings provide a novel therapeutic target to explore in the treatment of vascular inflammatory diseases.

Received for publication, July 30, 2007

^* This work was supported by National Institutes of Health Grant P01 HL 60678. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

¹ To whom correspondence should be addressed: Dept. of Pharmacology (m/c 868), Univ. of Illinois College of Medicine at Chicago, 835 S. Wolcott, Chicago, IL 60612. Tel.: 312-996-9179; Fax: 312-996-1648; E-mail: rskidgel{at}uic.edu.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				S. K. Gupta and N. E. Vlahakis Integrin {alpha}9{beta}1 mediates enhanced cell migration through nitric oxide synthase activity regulated by Src tyrosine kinase J. Cell Sci., June 15, 2009; 122(12): 2043 - 2054. [Abstract] [Full Text] [PDF]

				X. Zhang, F. Tan, Y. Zhang, and R. A. Skidgel Carboxypeptidase M and Kinin B1 Receptors Interact to Facilitate Efficient B1 Signaling from B2 Agonists J. Biol. Chem., March 21, 2008; 283(12): 7994 - 8004. [Abstract] [Full Text] [PDF]