Spontaneous human B2 bradykinin receptor activity determines the action of partial agonists as agonists or inverse agonists. Effect of basal desensitization
(1999) In Journal of Biological Chemistry 274(42). p.29603-29606- Abstract
In this report, we show that desensitization regulates ligand- independent, spontaneous activity of the human B2 bradykinin (BK) receptor, and the level of spontaneous receptor activity determines the action of the BK antagonists and partial receptor agonists NPC17731 and HOE140 as agonists or inverse agonists. Spontaneous receptor activity was monitored by measuring basal cellular phosphoinositide (PI) hydrolysis as a function of the density of the receptor in transiently transfected HEK293 cells. Minimal spontaneous activity of the wild-type B2 receptor was detected in these cells. Mutating a cluster of serines and threonines within the fourth intracellular domain of the receptor, which is critical for agonist-promoted... (More)
In this report, we show that desensitization regulates ligand- independent, spontaneous activity of the human B2 bradykinin (BK) receptor, and the level of spontaneous receptor activity determines the action of the BK antagonists and partial receptor agonists NPC17731 and HOE140 as agonists or inverse agonists. Spontaneous receptor activity was monitored by measuring basal cellular phosphoinositide (PI) hydrolysis as a function of the density of the receptor in transiently transfected HEK293 cells. Minimal spontaneous activity of the wild-type B2 receptor was detected in these cells. Mutating a cluster of serines and threonines within the fourth intracellular domain of the receptor, which is critical for agonist-promoted desensitization, significantly increased the spontaneous receptor activity. BK, the natural B2 receptor ligand and, consequently, a full agonist, stimulated PI hydrolysis at high and low levels of spontaneous receptor activity. On the other hand, the partial agonists NPC17731 and HOE140 were stimulatory, or agonists, at the lower level of receptor activity but inhibitory, or inverse agonists, at the higher level of activity. These results show that receptors are desensitized in response to their spontaneous activity. Furthermore, these results, which refute traditional theories, show that the capacity of a drug to modulate a receptor response is not intrinsic to the drug but is also dependent on the cellular environment in which the drug acts.
(Less)
- author
- Fathy, Dana B. ; Leeb, Tosso ; Mathis, Sandra A. and Leeb-Lundberg, L. M Fredrik LU
- publishing date
- 1999-10-15
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Journal of Biological Chemistry
- volume
- 274
- issue
- 42
- pages
- 29603 - 29606
- publisher
- American Society for Biochemistry and Molecular Biology
- external identifiers
-
- pmid:10514427
- scopus:0033569746
- ISSN
- 0021-9258
- DOI
- 10.1074/jbc.274.42.29603
- language
- English
- LU publication?
- no
- id
- bbce8a8b-241e-443b-86ec-7e7384761c17
- date added to LUP
- 2019-06-10 11:05:21
- date last changed
- 2024-01-16 01:00:45
@article{bbce8a8b-241e-443b-86ec-7e7384761c17, abstract = {{<p>In this report, we show that desensitization regulates ligand- independent, spontaneous activity of the human B2 bradykinin (BK) receptor, and the level of spontaneous receptor activity determines the action of the BK antagonists and partial receptor agonists NPC17731 and HOE140 as agonists or inverse agonists. Spontaneous receptor activity was monitored by measuring basal cellular phosphoinositide (PI) hydrolysis as a function of the density of the receptor in transiently transfected HEK293 cells. Minimal spontaneous activity of the wild-type B2 receptor was detected in these cells. Mutating a cluster of serines and threonines within the fourth intracellular domain of the receptor, which is critical for agonist-promoted desensitization, significantly increased the spontaneous receptor activity. BK, the natural B2 receptor ligand and, consequently, a full agonist, stimulated PI hydrolysis at high and low levels of spontaneous receptor activity. On the other hand, the partial agonists NPC17731 and HOE140 were stimulatory, or agonists, at the lower level of receptor activity but inhibitory, or inverse agonists, at the higher level of activity. These results show that receptors are desensitized in response to their spontaneous activity. Furthermore, these results, which refute traditional theories, show that the capacity of a drug to modulate a receptor response is not intrinsic to the drug but is also dependent on the cellular environment in which the drug acts.</p>}}, author = {{Fathy, Dana B. and Leeb, Tosso and Mathis, Sandra A. and Leeb-Lundberg, L. M Fredrik}}, issn = {{0021-9258}}, language = {{eng}}, month = {{10}}, number = {{42}}, pages = {{29603--29606}}, publisher = {{American Society for Biochemistry and Molecular Biology}}, series = {{Journal of Biological Chemistry}}, title = {{Spontaneous human B2 bradykinin receptor activity determines the action of partial agonists as agonists or inverse agonists. Effect of basal desensitization}}, url = {{http://dx.doi.org/10.1074/jbc.274.42.29603}}, doi = {{10.1074/jbc.274.42.29603}}, volume = {{274}}, year = {{1999}}, }