Permanent URL to this publication: http://dx.doi.org/10.5167/uzh-24591
Benke, D; Fakitsas, P; Roggenmoser, C; Michel, C; Rudolph, U; Mohler, H (2004). Analysis of the presence and abundance of GABAA receptors containing two different types of alpha subunits in murine brain using point-mutated alpha subunits. Journal of Biological Chemistry, 279(42):43654-43660.
Gamma-aminobutyric acid, type A (GABAA) receptors are pentameric proteins of which the majority is composed of two alpha subunits, two beta subunits and one gamma subunit. It is well documented that two different types of alpha subunits can exist in a singles GABAA receptor complex. However, information on the abundance of such GABAA receptors is rather limited. Here we tested whether mice containing the His to Arg point mutation in the alpha1, alpha2, or alpha3 subunit at positions 101, 101, and 126, respectively, which render the respective subunits insensitive to diazepam, would be suitable to analyze this issue. Immunodepletion studies indicated that the His to Arg point mutation solely rendered those GABAA receptors totally insensitive to diazepam binding that contain two mutated alpha subunits in the receptor complex, whereas receptors containing one mutated and one heterologous alpha subunit not carrying the mutation remained sensitive to diazepam binding. This feature permitted a quantitative analysis of native GABAA receptors containing heterologous alpha subunits by comparing the diazepam-insensitive binding sites in mutant mouse lines containing one mutated alpha subunit with those present in mouse lines containing two different mutated alpha subunits. The data indicate that the alpha1alpha1-containing receptors with 61% is the most abundant receptor subtype in brain, whereas the alpha1alpha2 (13%), alpha1alpha3 (15%), alpha2alpha2 (12%), alpha2alpha3 (2%), and alpha3alpha3 combinations (4%) are considerably less expressed. Only within the alpha1-containing receptor population does the combination of equal alpha subunits (84% alpha1alpha1, 7% alpha1alpha2, and 8% alpha1alpha3) prevail, whereas in the alpha2-containing receptor population (46% alpha2alpha2, 36% alpha2alpha1, and 19% alpha2alpha3) and particularly in the alpha3-containing receptor population (27% alpha3alpha3, 56% alpha3alpha1, and 19% alpha3alpha2), the receptors with two different types of alpha subunits predominate. This experimental approach provides the basis for a detailed analysis of the abundance of GABAA receptors containing heterologous alpha subunits on a brain regional level.
|Item Type:||Journal Article, refereed, original work|
|Communities & Collections:||04 Faculty of Medicine > Functional Genomics Center Zurich|
08 University Research Priority Programs > Systems Biology / Functional Genomics
|DDC:||570 Life sciences; biology|
610 Medicine & health
|Date:||15 October 2004|
|Deposited On:||18 Dec 2009 09:07|
|Last Modified:||23 Nov 2012 13:28|
|Publisher:||American Society for Biochemistry and Molecular Biology|
|Additional Information:||This research was originally published in Benke, D; Fakitsas, P; Roggenmoser, C; Michel, C; Rudolph, U; Mohler, H (2004). Analysis of the presence and abundance of GABAA receptors containing two different types of alpha subunits in murine brain using point-mutated alpha subunits. Journal of Biological Chemistry, 279(42):43654-43660. © the American Society for Biochemistry and Molecular Biology.|
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