Advertisement
JBC

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Originally published In Press as doi:10.1074/jbc.M204259200 on June 21, 2002

J. Biol. Chem., Vol. 277, Issue 37, 34434-34442, September 13, 2002
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
277/37/34434    most recent
M204259200v1
Right arrow Submit a Letter to Editor
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowRequest Permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Gille, A.
Right arrow Articles by Seifert, R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Gille, A.
Right arrow Articles by Seifert, R.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?

Distinct Interactions of GTP, UTP, and CTP with Gs Proteins*

Andreas GilleDagger , Hui-Yu LiuDagger §, Stephen R. Sprang, and Roland SeifertDagger ||

From the Dagger  Department of Pharmacology and Toxicology, the University of Kansas, Lawrence, Kansas 66045-7582, and the  Howard Hughes Medical Institute and Department of Biochemistry, the University of Texas Southwestern Medical Center, Dallas, Texas 75390-9050

Early studies showed that in addition to GTP, the pyrimidine nucleotides UTP and CTP support activation of the adenylyl cyclase (AC)-stimulating Gs protein. The aim of this study was to elucidate the mechanism by which UTP and CTP support Gs activation. As models, we used S49 wild-type lymphoma cells, representing a physiologically relevant system in which the beta 2-adrenoreceptor (beta 2AR) couples to Gs, and Sf9 insect cell membranes expressing beta 2AR-Galpha s fusion proteins. Fusion proteins provide a higher sensitivity for the analysis of beta 2AR-Gs coupling than native systems. Nucleoside 5'-triphosphates (NTPs) supported agonist-stimulated AC activity in the two systems and basal AC activity in membranes from cholera toxin-treated S49 cells in the order of efficacy GTP >=  UTP > CTP > ATP (ineffective). NTPs disrupted high affinity agonist binding in beta 2AR-Galpha s in the order of efficacy GTP > UTP > CTP > ATP (ineffective). In contrast, the order of efficacy of NTPs as substrates for nucleoside diphosphokinase, catalyzing the formation of GTP from GDP and NTP was ATP >=  UTP >=  CTP >=  GTP. NTPs inhibited beta 2AR-Galpha s-catalyzed [gamma -32P]GTP hydrolysis in the order of potency GTP > UTP > CTP. Molecular dynamics simulations revealed that UTP is accommodated more easily within the binding pocket of Galpha s than CTP. Collectively, our data indicate that GTP, UTP, and CTP interact differentially with Gs proteins and that transphosphorylation of GDP to GTP is not involved in this G protein activation. In certain cell systems, intracellular UTP and CTP concentrations reach ~10 nmol/mg of protein and are higher than intracellular GTP concentrations, indicating that G protein activation by UTP and CTP can occur physiologically. G protein activation by UTP and CTP could be of particular importance in pathological conditions such as cholera and Lesch-Nyhan syndrome.

* This work was supported Grant 0051404Z from the Heartland Affiliate of the American Heart Association (to R. S.), the J. R. and Inez Jay biomedical research award from the University of Kansas (to R. S.), a new faculty award from the University of Kansas (to R. S.), and a predoctoral fellowship from the Studienstiftung des Deutschen Volkes (to A. G.).The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

We dedicate this paper to G. Schultz on the occasion of his 65th birthday.

§ Present address: Laboratory of Neural Signaling, Cell Biology Group, The John P. Robarts Research Institute, 100 Perth Dr., London, Ontario N6A 5K8, Canada.

|| To whom correspondence should be addressed: Dept. of Pharmacology and Toxicology, the University of Kansas, Malott Hall, Rm. 5064, 1251 Wescoe Hall Dr., Lawrence, KS 66045-7582. Tel.: 785-864-3525; Fax: 785-864-5219; E-mail: rseifert@ku.edu.

Copyright © 2002 by The American Society for Biochemistry and Molecular Biology, Inc.
Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati    What's this?


This article has been cited by other articles:


Home page
 J. Biol. Chem.Home page
A. Gille, G. H. Lushington, T.-C. Mou, M. B. Doughty, R. A. Johnson, and R. Seifert
Differential Inhibition of Adenylyl Cyclase Isoforms and Soluble Guanylyl Cyclase by Purine and Pyrimidine Nucleotides
J. Biol. Chem., May 7, 2004; 279(19): 19955 - 19969.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
A. Gille and R. Seifert
2'(3')-O-(N-Methylanthraniloyl)-substituted GTP Analogs: A Novel Class of Potent Competitive Adenylyl Cyclase Inhibitors
J. Biol. Chem., April 4, 2003; 278(15): 12672 - 12679.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
A. Gille, K. Wenzel-Seifert, M. B. Doughty, and R. Seifert
GDP Affinity and Order State of the Catalytic Site Are Critical for Function of Xanthine Nucleotide-selective Galpha s Proteins
J. Biol. Chem., February 28, 2003; 278(10): 7822 - 7828.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
 All ASBMB Journals   Molecular and Cellular Proteomics 
 Journal of Lipid Research   ASBMB Today 
Copyright © 2002 by the American Society for Biochemistry and Molecular Biology.
Advertisement
spacer
Advertisement
Advertisement