J. Biochem, 2004, Vol. 135, No. 5 605-613
© 2004 The Japanese Biochemical Society
CELL |
Stimulation of Increases in Intracellular Calcium and Prostaglandin E2 Generation in Chinese Hamster Ovary Cells Expressing Receptor-G
16 Fusion Proteins
,1,31 Department of Neurochemistry, Graduate School of Medicine, the University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033; 2 Department of Molecular Physiology, Institute for Molecular and Cellular Regulation, Gunma University, Showa-machi, Maebashi, Gunma 371-8512; 3 Institute for Biomolecular Science, Gakushuin University, Mejiro, Toshima-ku, Tokyo 171-8588; and 4 Department of Receptor Biology, Advanced Medical Research Center, Nihon University School of Medicine, Oyaguchi-kamimachi, Itabashi-ku, Tokyo 173-8610
We examined whether fusion proteins of G protein-coupled receptors with the
subunit of G16 (G
16) could activate downstream signals. We expressed fusion proteins of Gi-coupled receptors, i.e. CX3C chemokine receptor 1 (CX3CR1) and M2 receptor, in Chinese hamster ovary cells. An agonist for CX3CR1 induced greater increases in intracellular Ca2+ and prostaglandin E2 generation in cells expressing CX3CR1-G
16 fusion protein than in cells expressing CX3CR1 alone or both CX3CR1 and G
16 separately. Similarly, agonist-induced prostaglandin E2 generation was greater in cells expressing M2-G
16 fusion protein than ones expressing M2 alone or both M2 and G
16 separately. In cells expressing fusion proteins with G
16 of Gq-coupled receptors, i.e. urotensin II receptor and M1 receptor, the relevant agonists induced similar increases in intracellular Ca2+ and prostaglandin E2 generation as in ones expressing the receptor alone. In cells expressing urotensin II receptor-G
16 fusion protein, prostaglandin E2 generation exhibited a lower EC50 value than the intracellular Ca2+ increase. These results indicate that agonist-stimulated receptor-G
16 fusion proteins are coupled to downstream signaling pathways, and suggest that receptor-G
16 fusion proteins may be useful for screening for ligands of orphan G protein-coupled receptors and Gi-coupled receptors.
* To whom correspondence should be addressed. Department of Molecular Physiology, Institute for Molecular and Cellular Regulation, Gunma University, Tel: +81-27-220-8847, Fax: +81-27-220-8849, E-mail: hsuga{at}showa.gunma-u.ac.jp
Present address: Department of Nano-Material Systems, Graduate School of Engineering, Gunma University, Tenjin-cho, Kiryu, Gunma 376-8515.
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
Q. Zhang, M. Okamura, Z.-D. Guo, S. Niwa, and T. Haga Effects of Partial Agonists and Mg2+ Ions on the Interaction of M2 Muscarinic Acetylcholine Receptor and G Protein G{alpha}i1 Subunit in the M2-G{alpha}i1 Fusion Protein J. Biochem., May 1, 2004; 135(5): 589 - 596. [Abstract] [Full Text] [PDF] |
||||
