MolPharm xPharm- The Comprehensive Pharmacology Reference

Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Submit a response
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
Services
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
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Stitham, J.
Right arrow Articles by Hwa, J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Stitham, J.
Right arrow Articles by Hwa, J.

Vol. 61, Issue 5, 1202-1210, May 2002

The Critical Role of Transmembrane Prolines in Human Prostacyclin Receptor Activation

Jeremiah Stitham, Kathleen A. Martin, and John Hwa

Department of Pharmacology & Toxicology, Dartmouth Medical School, Hanover, New Hampshire (J.S., K.A.M., J.H.); and Department of Surgery, Dartmouth Medical School, Lebanon, New Hampshire (K.A.M.)

The human prostacyclin receptor (hIP), a G protein-coupled receptor (GPCR), plays important roles in vascular smooth muscle relaxation as well as the prevention of platelet aggregation. It has been postulated that GPCR transmembrane (TM) prolines serve as molecular hinges or swivels and are necessary for proper binding and activation. By individually (as well as collectively) mutating these hIP prolines to alanine, the ability to form key structural and functional configurations was removed. Significant effects on both binding and activation were observed. Two highly conserved prolines across GPCRs, Pro-154, and Pro-254 (TMVI), showed the greatest effect on decreasing both binding and activation when changed to alanine. Along the extracellular boundary of the highly conserved transmembrane III domain, a proline-to-alanine mutation at position 89 (P89A) revealed normal binding affinity in comparison with the 1D4-epitope-tagged hIP (hIP1D4) wild-type control (Ki, iloprost = 3 ± 2 versus 7 ± 3 nM, respectively). In contrast, activation was markedly affected, with an EC50 of 12.0 ± 2.5 nM compared with that of 1.2 ± 0.3 nM (10-fold difference) for the hIP1D4. Movement within TMIII has been shown to be necessary for effective GPCR activation. Both the extracellular location (above the putative binding pocket) along with an exclusive effect upon activation suggest that this movement is facilitated by the presence of Pro-89 and independent from the actions of ligand binding. This finding strongly supports a model in which proline residues serve as molecular hinges or swivels, essential for coupling receptor binding to activation.

Copyright © 2002 by The American Society for Pharmacology and Experimental Therapeutics


This article has been cited by other articles:


Home page
 Circ. Res.Home page
E. Arehart, J. Stitham, F. W. Asselbergs, K. Douville, T. MacKenzie, K. M. Fetalvero, S. Gleim, Z. Kasza, Y. Rao, L. Martel, et al.
Acceleration of Cardiovascular Disease by a Dysfunctional Prostacyclin Receptor Mutation: Potential Implications for Cyclooxygenase-2 Inhibition
Circ. Res., April 25, 2008; 102(8): 986 - 993.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
J. Stitham, S. R. Gleim, K. Douville, E. Arehart, and J. Hwa
Versatility and Differential Roles of Cysteine Residues in Human Prostacyclin Receptor Structure and Function
J. Biol. Chem., December 1, 2006; 281(48): 37227 - 37236.
[Abstract] [Full Text] [PDF]

Home page
 Protein Eng Des SelHome page
T. Muramatsu and M. Suwa
Statistical analysis and prediction of functional residues effective for GPCR-G-protein coupling selectivity
Protein Eng. Des. Sel., June 1, 2006; 19(6): 277 - 283.
[Abstract] [Full Text] [PDF]

Home page
 Mol. Pharmacol.Home page
J. H. Li, H. Choe, A. F. Wang, K. Maiti, C. Wang, A. Salam, S. Y. Chun, W.-K. Lee, K. Kim, H. B. Kwon, et al.
Extracellular Loop 3 (EL3) and EL3-Proximal Transmembrane Helix 7 of the Mammalian Type I and Type II Gonadotropin-Releasing Hormone (GnRH) Receptors Determine Differential Ligand Selectivity to GnRH-I and GnRH-II
Mol. Pharmacol., April 1, 2005; 67(4): 1099 - 1110.
[Abstract] [Full Text] [PDF]

Home page
 Mol. Pharmacol.Home page
A. C. Conner, D. L. Hay, J. Simms, S. G. Howitt, M. Schindler, D. M. Smith, M. Wheatley, and D. R. Poyner
A Key Role for Transmembrane Prolines in Calcitonin Receptor-Like Receptor Agonist Binding and Signalling: Implications for Family B G-Protein-Coupled Receptors
Mol. Pharmacol., January 1, 2005; 67(1): 20 - 31.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
B. E. Knox, E. Salcedo, K. Mathiesz, J. Schaefer, W.-H. Chou, L. V. Chadwell, W. C. Smith, S. G. Britt, and R. B. Barlow
Heterologous Expression of Limulus Rhodopsin
J. Biol. Chem., October 17, 2003; 278(42): 40493 - 40502.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
J. Stitham, A. Stojanovic, B. L. Merenick, K. A. O'Hara, and J. Hwa
The Unique Ligand-binding Pocket for the Human Prostacyclin Receptor. SITE-DIRECTED MUTAGENESIS AND MOLECULAR MODELING
J. Biol. Chem., January 31, 2003; 278(6): 4250 - 4257.
[Abstract] [Full Text] [PDF]


Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
All ASPET Journals Molecular Pharmacology Pharmacological Reviews
Molecular Interventions Drug Metabolism and Disposition

Copyright © 2002 by the American Society for Pharmacology and Experimental Therapeutics