![[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}
|
|
|
|
|
||
z in the Recognition of
Gi-Coupled Receptors
Department of Biology (R.C.T., M.K.C.H., L.Y.Y., S.J., Y.H.W.) and
the
Biotechnology Research Institute (Y.H.W.), Hong Kong University of
Science and Technology, Clear Water Bay, Kowloon, Hong Kong
Many Gi-coupled receptors are known to interact with the
pertussis toxin (PTX)-insensitive Gz protein. Given that
the 
subunits of Gi and Gz share only 60%
identity in their amino acid sequences, their receptor-interacting
domains must be highly similar. By swapping the carboxyl termini of
i2 and z with each other or with those of t, 12, and 13,
we examined the relative contributions of the carboxyl-end 36 amino
acids of the chains toward receptor recognition. Chimeric chains lacking the site for PTX-catalyzed ADP-ribosylation were
coexpressed with the type II adenylyl cyclase (AC II) and one of
several Gi-coupled receptors (formyl peptide, dopamine
D2, and 
-opioid receptors) in human embryonic kidney 293 cells. The i2/z chimera was able to interact with both aminergic and peptidergic receptors, resulting in 
-mediated stimulation of
AC II in the presence of agonists and PTX. Functional and mutational analyses of i2/z revealed that this chimera can inhibit the endogenous ACs of 293 cells. Similarly, the z/i2 chimera seemed to retain the abilities to interact with receptors and inhibit cAMP
accumulation. Fusion of the carboxyl-terminal 36 amino acids of z to
a backbone of t1 produced a chimera, t1/z, that did not couple
to any of the Gi-coupled receptors tested. Interestingly, an 13/z chimera (with only the last five amino acids switched) displayed differential abilities to interact with receptors. Signals from aminergic, but not peptidergic, receptors were transduced by
13/z. A similar construct, 12/z, behaved just like
13/z. These results indicated that "i-like" or
"z-like" sequences at the carboxyl termini of subunits are
not always necessary or sufficient for specifying interaction with
Gi-coupled receptors.
This article has been cited by other articles:
|
|
 |
|
  P.-Y. Law, L. J. Erickson-Herbrandson, Q. Q. Zha, J. Solberg, J. Chu, A. Sarre, and H. H. Loh Heterodimerization of {micro}- and {delta}-Opioid Receptors Occurs at the Cell Surface Only and Requires Receptor-G Protein Interactions J. Biol. Chem., March 25, 2005; 280(12): 11152 - 11164. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Zheng, P. Yu, C. Zeng, Z. Wang, Z. Yang, P. M. Andrews, R. A. Felder, and P. A. Jose G{alpha}12- and G{alpha}13-Protein Subunit Linkage of D5 Dopamine Receptors in the Nephron Hypertension, March 1, 2003; 41(3): 604 - 610. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. M.F. Liu, M. K.C. Ho, C. S.S. Wong, J. H.P. Chan, A. H.M. Pau, and Y. H. Wong G{alpha}[16/z] Chimeras Efficiently Link a Wide Range of G Protein-coupled Receptors to Calcium Mobilization J Biomol Screen, February 1, 2003; 8(1): 39 - 49. [Abstract] [PDF]
|
|
|
|
 |
|
 M. K.C. Ho and Y. H. Wong The Amino Terminus of Galpha z is Required for Receptor Recognition, Whereas its alpha 4/beta 6 Loop Is Essential for Inhibition of Adenylyl Cyclase Mol. Pharmacol., November 1, 2000; 58(5): 993 - 1000. [Abstract] [Full Text]
|
|
|
|
|
|
J. L. Leaney, G. Milligan, and A. Tinker The G Protein alpha Subunit Has a Key Role in Determining the Specificity of Coupling to, but Not the Activation of, G Protein-gated Inwardly Rectifying K+ Channels J. Biol. Chem., January 14, 2000; 275(2): 921 - 929. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. M. Mody, M. K. C. Ho, S. A. Joshi, and Y. H. Wong Incorporation of Galpha z-Specific Sequence at the Carboxyl Terminus Increases the Promiscuity of Galpha 16 toward Gi-Coupled Receptors Mol. Pharmacol., January 1, 2000; 57(1): 13 - 23. [Abstract] [Full Text]
|
|
|
|
 |
|
 L. Y. Yung, S. A. Joshi, R. Y.K. Chan, J. S.C. Chan, G. Pei, and Y. H. Wong Galpha L1 (Galpha 14) Couples the Opioid Receptor-Like1 Receptor to Stimulation of Phospholipase C J. Pharmacol. Exp. Ther., January 1, 1999; 288(1): 232 - 238. [Abstract] [Full Text]
|
|
|
|
|
|
J. Blahos II, S. Mary, J. Perroy, C. de Colle, I. Brabet, J. Bockaert, and J.-P. Pin Extreme C Terminus of G Protein alpha -Subunits Contains a Site That Discriminates between Gi-coupled Metabotropic Glutamate Receptors J. Biol. Chem., October 2, 1998; 273(40): 25765 - 25769. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. W. Fong, D. S. Bahia, S. Rees, and G. Milligan Selective Activation of a Chimeric Gi1/Gs G Protein alpha Subunit by the Human IP Prostanoid Receptor: Analysis Using Agonist Stimulation of High Affinity GTPase Activity and [35S]Guanosine-5'-O-(3-thio)triphosphate Binding Mol. Pharmacol., August 1, 1998; 54(2): 249 - 257. [Abstract] [Full Text]
|
|
 |
 |
 |
|
 |
 |
 |
