THE HUMAN P-2X1 RECEPTOR - MOLECULAR-CLONING, TISSUE DISTRIBUTION, AND LOCALIZATION TO CHROMOSOME-17

A human urinary bladder cDNA library was screened with a rat P-2X puri noceptor probe. A full-length cDNA was isolated, and like its rat homo logue, the deduced protein consists of 399 amino acids (M(r) = 44980 D a), contains two hydrophobic, putative transmembrane, domains flanking a large presumed extracellular loop, and represents the P-2X1 subtype of this multigene family (similar to 89% amino acid sequence identity to rat P-2X1, but only 40-50% identity to rat P-2X24). Expression of the P-2X1 gene in human bladder was confirmed by Northern analysis, wh ich demonstrated a major transcript of similar to 2.9 kb, Transcripts were also found in a variety of other tissues including adult peripher al leukocytes, pancreas, spleen, prostate, small intestine, colon, tes tis, acid ovary, and in fetal liver. The gene encoding the human P-2X1 receptor was localized to chromosome 17 by Southern analysis of DNAs isolated from a panel of somatic cell hybrids. The results support a r ole for P-2X purinoceptors in the regulation of human bladder function .