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Partial rescue of taste responses of alpha-gustducin null mice by transgenic expression of alpha-transducin.
- Source :
-
Chemical senses [Chem Senses] 2002 Oct; Vol. 27 (8), pp. 719-27. - Publication Year :
- 2002
-
Abstract
- The transduction of responses to bitter and sweet compounds utilizes guanine nucleotide binding proteins (G proteins) and their coupled receptors. Alpha-gustducin, a transducin-like G protein alpha-subunit, and rod alpha-transducin are expressed in taste receptor cells. Alpha-gustducin knockout mice have profoundly diminished behavioral and electrophysiological responses to many bitter and sweet compounds, although these mice retain residual responses to these compounds. Alpha-gustducin and rod alpha-transducin are biochemically indistinguishable in their in vitro interactions with retinal phosphodiesterase, rhodopsin and G protein betagamma-subunits. To determine if alpha-transducin can function in taste receptor cells and to compare the function of alpha-gustducin versus alpha-transducin in taste transduction in vivo, we generated transgenic mice that express alpha-transducin under the control of the alpha-gustducin promoter in the alpha-gustducin null background. Immunohistochemistry showed that the alpha-transducin transgene was expressed in about two-thirds of the alpha-gustducin lineage of taste receptor cells. Two-bottle preference tests showed that transgenic expression of rod alpha-transducin partly rescued responses to denatonium benzoate, sucrose and the artificial sweetener SC45647, but not to quinine sulfate. Gustatory nerve recordings showed a partial rescue by the transgene of the response to sucrose, SC45647 and quinine, but not to denatonium. These results demonstrate that alpha-transducin can function in taste receptor cells and transduce some taste cell responses. Our results also suggest that alpha-transducin and alpha-gustducin may differ, at least in part, in their function in these cells, although this conclusion must be qualified because of the limited fidelity of the transgene expression.
- Subjects :
- Analgesics, Non-Narcotic pharmacology
Animals
Dose-Response Relationship, Drug
Green Fluorescent Proteins
Guanidines pharmacology
Immunohistochemistry
Luminescent Proteins metabolism
Mice
Mice, Knockout
Mice, Transgenic
Microscopy, Fluorescence
Polymerase Chain Reaction
Promoter Regions, Genetic
Quaternary Ammonium Compounds pharmacology
Quinine pharmacology
Sucrose pharmacology
Sweetening Agents pharmacology
Taste genetics
Taste Buds physiology
Transducin genetics
Transgenes
Taste physiology
Transducin physiology
Subjects
Details
- Language :
- English
- ISSN :
- 0379-864X
- Volume :
- 27
- Issue :
- 8
- Database :
- MEDLINE
- Journal :
- Chemical senses
- Publication Type :
- Academic Journal
- Accession number :
- 12379596
- Full Text :
- https://doi.org/10.1093/chemse/27.8.719