Growth Regulation by Recombinant Muscarinic Acetylcholine Receptors Expressed in Chinese Hamster Ovary Cells

2000 ◽  
Vol 28 (5) ◽  
pp. A426-A426
Author(s):  
D. Burdon ◽  
R. Patel ◽  
R. A. J. Challiss ◽  
J. L. Blank
Keyword(s):  
Chinese Hamster Ovary ◽  
Acetylcholine Receptors ◽  
Growth Regulation ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Muscarinic Acetylcholine Receptors ◽  
Ovary Cells ◽  
Muscarinic Acetylcholine

Down-regulation of the G-proteins Gqα and G11α by transfected human M3 muscarinic acetylcholine receptors in Chinese hamster ovary cells is independent of receptor down-regulation

1995 ◽  
Vol 310 (2) ◽  
pp. 559-563 ◽  
Author(s):  
E van de Westerlo ◽  
J Yang ◽  
C Logsdon ◽  
J A Williams
Keyword(s):  
G Proteins ◽  
Chinese Hamster Ovary ◽  
Acetylcholine Receptors ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Muscarinic Acetylcholine Receptors ◽  
Phosphoinositide Hydrolysis ◽  
Down Regulation ◽  
Ovary Cells ◽  
Muscarinic Acetylcholine

Chinese hamster ovary cells stably transfected with human M3 muscarinic acetylcholine receptors show a 40-50% reduction in the immunoreactive G-proteins Gq alpha and G11 alpha when stimulated with the cholinergic agonist carbachol. This effect is seen after 9 h, is maximal after 24 h, and occurs over a range of carbachol concentrations that activate phosphoinositide hydrolysis in these cells. The effect is specific for Gq alpha family proteins as Gs alpha was slightly increased after carbachol treatment and G13 alpha was unchanged. Using a urea gel system, we were able to resolve Gq alpha and G11 alpha, both of which were down-regulated by carbachol. An M3 receptor mutant, with C-terminal threonines changed to alanines as described previously, binds ligand and activates phosphoinositide hydrolysis normally but is not down-regulated in response to carbachol. This receptor, however, induces Gq alpha/G11 alpha down-regulation similarly to wild-type M3 receptors, indicating that G-protein down-regulation is not directly coupled to receptor down-regulation. Thus down-regulation of Gq alpha and G11 alpha may contribute to heterologous desensitization particularly at longer times of agonist exposure.

Sign in / Sign up

Export Citation Format

Share Document