Biology Reference
In-Depth Information
CHAPTER
13
Christina Kuhn
*
and Wolfgang Meyerhof
{
*
Oligomerization of Sweet
and Bitter Taste Receptors
Axxam SpA, Bresso (Milan), Italy
{
Department of Molecular Genetics, German Institute of Human Nutrition Potsdam-Rehbruecke,
Nuthetal, Germany
CHAPTER OUTLINE
Introduction and Rationale....................................................................................... 230
13.1 Materials........................................................................................................232
13.2 Methods .........................................................................................................233
13.2.1 Generation of Expression Constructs ............................................ 233
13.2.2 Expression Analysis of Receptor Constructs .................................. 234
13.2.3 Coimmunoprecipitation............................................................... 235
13.2.4 Bioluminescence Resonance Energy Transfer................................ 237
13.3 Discussion......................................................................................................240
Summary ................................................................................................................ 241
Acknowledgments ................................................................................................... 241
References ............................................................................................................. 241
Abstract
The superfamily of G protein-coupled receptors (GPCRs) mediates numerous phys-
iological processes, including neurotransmission, cell differentiation and metabo-
lism, and sensory perception. In recent years, it became evident that these
receptors might function not only as monomeric receptors but also as homo- or het-
eromeric receptor complexes. The family of TAS1R taste receptors are prominent
examples of GPCR dimerization as they act as obligate functional heteromers:
TAS1R1 and TAS1R3 combine to form an umami taste receptor, while the combi-
nation of TAS1R2 and TAS1R3 is a sweet taste receptor. So far, TAS2Rs, a second
family of
25 taste receptors in humans that mediates responses to bitter com-
pounds, have been shown to function on their own, but if they do so as receptor
monomers or as homomeric receptors still remains unknown. Using two different
experimental approaches, we have recently shown that TAS2Rs can indeed form
