![[Feedback]](/icons/banner/feedbackACT.gif){kind=icon}
![[For Subscribers]](/icons/banner/subscriberACT.gif){kind=icon}
![[Archive]](/icons/banner/archiveACT.gif){kind=icon}
![[Search]](/icons/banner/searchACT.gif){kind=icon}
![[Contents]](/icons/banner/tocACT.gif){kind=icon}
|
|
|
|
|
||
DH Wolsing and JS Rosenbaum
Procter and Gamble Company, Corporate Research Division, Miami Valley Laboratories, Cincinnati, Ohio.
[3H]Bradykinin (BDK) binds to two distinct binding sites (P less than .01, N = 12) in NG108-15 cell membranes; (site 1: Kd1 = 3.09 x 10(-10) M, Bmax1 = 242 +/- 24 fmol/mg protein) and (site 2: Kd2 = 1.94 x 10(-8) M, Bmax2 = 491 +/- 75 fmol/mg protein). Although site 1 comprises only 33 +/- 4% (N = 12) of the total binding site population, comparison of the binding affinity and functional potency for BDK agonist analogs exhibiting differential selectivity for the two sites reveals that this high affinity site is the receptor mediating inositol monophosphate (IP) production in this cell line. BDK-stimulated IP production undergoes a very rapid (5 min) desensitization that is characterized by both a loss in agonist potency (EC50 = 3.57 x 10(-9) M vs. 1.94 x 10(- 10) M in controls; P less than .001, N = 12) and a decrease in amplitude of response (fold stimulation = 1.45 +/- 0.06 vs. 1.80 +/- 0.09 in controls; P less than .01, N = 12). Only the decrease in response amplitude is attenuated by down-regulation of protein kinase C by prior long term treatment of the cells with 12-O- tetradecanoylphorbol 13-acetate (TPA), indicating an involvement of protein kinase C activation in the desensitization process. Desensitization is accompanied by down-regulation of site 1 only (Bmax1 = 71 +/- 8 fmol/mg (N = 10; P less than .001 vs. controls)); Bmax2 and the Kd for BDK at both sites remain unchanged, further supporting the contention that site 1 is the functionally relevant receptor. In contrast to the functional data, long term TPA treatment does not attenuate the receptor down-regulation, indicating that the rapid desensitization involves both receptor-related and postreceptor mechanisms. The implications of this property of the BDK receptor for analog design and receptor classification are discussed.
This article has been cited by other articles:
|
|
 |
|
  L. M. F. Leeb-Lundberg, F. Marceau, W. Muller-Esterl, D. J. Pettibone, and B. L. Zuraw International Union of Pharmacology. XLV. Classification of the Kinin Receptor Family: from Molecular Mechanisms to Pathophysiological Consequences Pharmacol. Rev., March 1, 2005; 57(1): 27 - 77. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Pizard, A. Blaukat, W. Muller-Esterl, F. Alhenc-Gelas, and R. M. Rajerison Bradykinin-induced Internalization of the Human B2 Receptor Requires Phosphorylation of Three Serine and Two Threonine Residues at Its Carboxyl Tail J. Biol. Chem., April 30, 1999; 274(18): 12738 - 12747. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Pizard, J. Marchetti, J. Allegrini, F. Alhenc-Gelas, and R. M. Rajerison Negative Cooperativity in the Human Bradykinin B2 Receptor J. Biol. Chem., January 16, 1998; 273(3): 1309 - 1315. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Blaukat, S. A. Alla, M. J. Lohse, and W. Muller-Esterl Ligand-induced Phosphorylation/Dephosphorylation of the Endogenous Bradykinin B2 Receptor from Human Fibroblasts J. Biol. Chem., December 13, 1996; 271(50): 32366 - 32374. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
I. R. Coe, L. Yao, I. Diamond, and A. S. Gordon The Role of Protein Kinase C in Cellular Tolerance to Ethanol J. Biol. Chem., November 15, 1996; 271(46): 29468 - 29472. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Blaukat, A. Pizard, A. Breit, C. Wernstedt, F. Alhenc-Gelas, W. Muller-Esterl, and I. Dikic Determination of Bradykinin B2 Receptor in Vivo Phosphorylation Sites and Their Role in Receptor Function J. Biol. Chem., October 26, 2001; 276(44): 40431 - 40440. [Abstract] [Full Text] [PDF]
|
|
 |
 |
 |
|
 |
 |
 |
