Random mutagenesis of the human adenosine A2B receptor followed by growth selection in yeast. Identification of constitutively active and gain of function mutations.

To gain insight in spontaneous as well as agonist-induced activation of the human adenosine A2B receptor, we applied a random mutagenesis approach in yeast to create a large number of receptor mutants and selected mutants of interest with a robust screening assay based on growth. The amino acid sequence of 14 mutated receptors was determined. All these mutated receptors displayed constitutive activity.