The research described in this thesis has provided new insights in the activation mechanism of class A GPCRs and in particular of adenosine receptors. By a variety of mutagenesis approaches and the... Show moreThe research described in this thesis has provided new insights in the activation mechanism of class A GPCRs and in particular of adenosine receptors. By a variety of mutagenesis approaches and the use of a robust yeast reporter gene system, we identified several regions and amino acid positions that contribute to both agonist responses and constitutive activity of the human adenosine A1 receptor and the human adenosine A2B receptor. These results reveal new and surprising roles of the extracellular loops in the activation mechanism, greatly contributing to our notion of receptor activation. Show less
