CLONING AND CHROMOSOMAL LOCALIZATION OF THE HUMAN A(2B) ADENOSINE RECEPTOR GENE (ADORA2B) AND ITS PSEUDOGENE

To determine the chromosomal localization of the human A(2b) adenosine receptor, the corresponding genomic clone was isolated and used as a probe for fluorescence in situ hybridization to metaphase chromesomes. Partial sequence analysis of the A(2b) gene (ADORA2B) revealed an intron that interrupted the coding region corresponding to the second intracellular loop similar to that reported for A(1) and A(2a) adenosine receptor genes. A pseudogene for the A(2b) receptor was also identified; it exhibited 79% identity to the A(2b) adenosine receptor cDNA coding sequence and contained multiple deletions, point mutations, and frame shifts and two in-frame stops. These changes would result in the inability to encode a functional receptor. The genomic clones were utilized to localize the A(2b) receptor to chromosome 17p12 and the A(2b) pseudogene to chromosome 1q32. (C) 1995 Academic Press, Inc.