Structure and chromosomal mapping of the mouse P2X(3) gene

P2X(3) is one of seven cloned ATP-gated non-selective cation channels. We :have isolated a full-length mouse P2X(3) gene from a phage lambda-129/Sv genomic library. The gene consists of 12 exons spanning a locus of approximately 40 kb. No significant similarities have been found between the genomic organisation of the mouse P2X(3) gene and genes encoding other ion channels. The encoded mouse P2X(3) protein consists of 397 amino acids and shows 99% identity with rat P2X(3). IJsing RNase protection and primer extension assays, multiple transcription initiation sites have been mapped in the mouse P2X(3) promoter to a region 162-168 bp upstream of the translation initiation codon. The P2X(3) gene has been mapped to mouse chromosome 2p by fluorescence in situ hybridisation. The RAG locus-associated gene T160 is located 1.8 kb upstream of the transcription start site of mouse P2X(3) gene. The promoter region of the mouse P2X(3) gene lacks a conventional TATA and CCAAT consensus sites, and initiator elements. P2X(3) is the first member of the PZX gene family to be completely characterised. (C) 1997 Elsevier Science B.V.