Bitter taste receptors and their cells.

The molecular basis of human bitter taste perception is an area of intense research. Only 25 G protein-coupled receptors belonging to the hTAS2R gene family face the challenge to detect thousands of structurally different bitter compounds, most of which are plant metabolites. Since many natural bitter compounds are highly toxic, whereas others are part of our daily diets, bitter taste was crucial during evolution and still most likely affects our food selection.

Functions of human bitter taste receptors depend on N-glycosylation.

Human bitter taste receptors of the TAS2R gene family play a crucial role as warning sensors against the ingestion of toxic food compounds. Moreover, the genetically highly polymorphic hTAS2Rs recognize an enormous number of structurally diverse toxic and non-toxic bitter substances, and hence, may substantially influence our individual eating habits. Heterologous expression in mammalian cells is a useful tool to investigate interactions between these receptors and their agonists.

Members of RTP and REEP gene families influence functional bitter taste receptor expression.

Functional characterization of chemosensory receptors is usually achieved by heterologous expression in mammalian cell lines. However, many chemoreceptor genes, including bitter taste receptors (TAS2Rs), show only marginal cell surface expression. Usually, these problems are circumvented by using chimeric receptors consisting of "export tags" and the receptor sequence itself.