![[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}
|
|
|
|
|
||
Vol. 57, Issue 5, 932-939, May 2000
2 Subunit of the -Aminobutyric AcidA Receptor
Department of Physiology, University of Wisconsin-Madison, Madison,
Wisconsin
-Aminobutyric acidA receptor -subunits are important
for benzodiazepine (BZD) binding and modulation of the -aminobutyric acid-mediated Cl
current. Previously, by using 2/
1
chimeric subunits, we identified two domains of the 2-subunit,
Lys-41-Trp-82 and Arg-114-Asp-161, that are, in conjunction,
necessary and sufficient for high-affinity BZD binding. In this study,
we generated additional 2/1 chimeric subunits and 2 point
mutants to identify specific residues within the 2 Lys-41-Trp-82
region that contribute to BZD binding. Mutant 2 and 2/1
chimeric subunits were expressed with wild-type 1 and 
2 subunits
in HEK 293 cells, and the binding of several BZDs was measured. We
present evidence that the 2 region Met-57-Ile-62 is important for
flunitrazepam binding and that, in particular, 2 Met-57 and 2
Tyr-58 are essential determinants for conferring high-affinity binding.
Furthermore, we identify an additional residue, 2 Ala-79, that not
only is important for high-affinity binding by flunitrazepam (a strong
positive modulator) but also plays a crucial role in the binding of the
imidazobenzodiazepines Ro15-1788 (a zero modulator) and Ro15-4513 (a
weak negative modulator) in the BZD binding pocket. Results from
site-directed mutagenesis of 2 Ala-79 suggest that this residue may
be part of a microdomain within the BZD binding site that is important
for binding imidazobenzodiazepines. This separation of drug-specific
microdomains for competitive BZD ligands lends insight into the
structural determinants governing the divergent effects of these compounds.
This article has been cited by other articles:
|
|
 |
|
  L. M. Sharkey and C. Czajkowski Individually Monitoring Ligand-Induced Changes in the Structure of the GABAA Receptor at Benzodiazepine Binding Site and Non-Binding-Site Interfaces Mol. Pharmacol., July 1, 2008; 74(1): 203 - 212. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. Hsiao, K. B. Mihalak, K. L. Magleby, and C. W. Luetje Zinc Potentiates Neuronal Nicotinic Receptors by Increasing Burst Duration J Neurophysiol, February 1, 2008; 99(2): 999 - 1007. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. H. Kloda and C. Czajkowski Agonist-, Antagonist-, and Benzodiazepine-Induced Structural Changes in the {alpha}1 Met113-Leu132 Region of the GABAA Receptor Mol. Pharmacol., February 1, 2007; 71(2): 483 - 493. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. M. C. Lema and A. Auerbach Modes and models of GABAA receptor gating J. Physiol., April 1, 2006; 572(1): 183 - 200. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. Hsiao, K. B. Mihalak, S. E. Repicky, D. Everhart, A. H. Mederos, A. Malhotra, and C. W. Luetje Determinants of Zinc Potentiation on the {alpha}4 Subunit of Neuronal Nicotinic Receptors Mol. Pharmacol., January 1, 2006; 69(1): 27 - 36. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. M. Jones-Davis, L. Song, M. J. Gallagher, and R. L. Macdonald Structural Determinants of Benzodiazepine Allosteric Regulation of GABAA Receptor Currents J. Neurosci., August 31, 2005; 25(35): 8056 - 8065. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. G. Newell, R. A. McDevitt, and C. Czajkowski Mutation of Glutamate 155 of the GABAA Receptor {beta}2 Subunit Produces a Spontaneously Open Channel: A Trigger for Channel Activation J. Neurosci., December 15, 2004; 24(50): 11226 - 11235. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. G. Newell and C. Czajkowski The GABAA Receptor alpha 1 Subunit Pro174-Asp191 Segment Is Involved in GABA Binding and Channel Gating J. Biol. Chem., April 4, 2003; 278(15): 13166 - 13172. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. M. Kucken, J. A. Teissere, J. Seffinga-Clark, D. A. Wagner, and C. Czajkowski Structural Requirements for Imidazobenzodiazepine Binding to GABAA Receptors Mol. Pharmacol., February 1, 2003; 63(2): 289 - 296. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. W. Sawyer, D. C. Chiara, R. W. Olsen, and J. B. Cohen Identification of the Bovine gamma -Aminobutyric Acid Type A Receptor alpha Subunit Residues Photolabeled by the Imidazobenzodiazepine [3H]Ro15-4513 J. Biol. Chem., December 13, 2002; 277(51): 50036 - 50045. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. H. Holden and C. Czajkowski Different Residues in the GABAA Receptor alpha 1T60-alpha 1K70 Region Mediate GABA and SR-95531 Actions J. Biol. Chem., May 17, 2002; 277(21): 18785 - 18792. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. A. Teissere and C. Czajkowski A {beta}-Strand in the {gamma}2 Subunit Lines the Benzodiazepine Binding Site of the GABAA Receptor: Structural Rearrangements Detected during Channel Gating J. Neurosci., July 15, 2001; 21(14): 4977 - 4986. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. A. Wagner and C. Czajkowski Structure and Dynamics of the GABA Binding Pocket: A Narrowing Cleft that Constricts during Activation J. Neurosci., January 1, 2001; 21(1): 67 - 74. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. J. Boileau, J. G. Newell, and C. Czajkowski GABAA Receptor beta 2 Tyr97 and Leu99 Line the GABA-binding Site. INSIGHTS INTO MECHANISMS OF AGONIST AND ANTAGONIST ACTIONS J. Biol. Chem., January 18, 2002; 277(4): 2931 - 2937. [Abstract] [Full Text] [PDF]
|
|
 |
 |
 |
|
 |
 |
 |
