MOLECULAR-CLONING OF A HUMAN BETA-3-ADRENERGIC RECEPTOR CDNA

We report the molecular cloning of a beta3-adrenergic receptor [beta3- AR] cDNA from human brown adipose tissue. The cDNA-encoded protein is identical to the previously cloned beta3-AR but with 6 additional amin o acids at the C-terminus. The C-terminus is shared by the beta3 recep tors expressed in human neuroblastoma cells [SK-N-MC] [Mol. Pharmacol. 42 (1992) 964 970]. Furthermore, using a polymerase chain reaction st rategy we have cloned and sequenced the beta3-AR introns. Sequence ana lysis demonstrates that the human beta3-AR gene comprises at least 3 e xons and 2 introns and that the most abundant beta3-AR transcripts enc ode a protein with an exon 3-derived C-terminus. Interestingly, althou gh a similar organization has been found in rodent genes, the rat beta 3-AR transcripts encode a receptor with an exon 2-derived C-terminus.