Progress in Methodology Improved Reporter Gene Assays Used to Identify Ligands Acting on Orphan Seven-Transmembrane Receptors

Reverse pharmacology and the de-orphanization of 7TM receptors

Approximately 800 genes coding for seven-transmembrane, G-protein-coupled receptors have so far been recognized. In spite of this, many of these receptors are defined by their sequence only, and are therefore classified as orphan receptors. Without knowing what their endogenous ligands are, we lack the information needed to understand their physiological role and hence cannot make use of them as drug targets. In this communication, we discuss different strategies, as well as difficulties in the deorphanizing process.: