cDNA cloning and sequence analysis of the human A3 adenosine receptor

We report the cloning of the cDNA encoding the homolog of the A3 adenosine receptor (A3AR) from a human heart library. The receptor shares a surprisingly low degree of sequence homology to the rat A3AR. Northern analysis of various human tissues showed the human A3AR gene to be expressed primarily in lung, liver, kidney and heart, with very little expression in the brain or in skeletal muscle.