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 locu s of approximately 40 kb. No significant similarities have been found between the genomic organisation of the mouse P2X(3) gene and genes en coding other ion channels. The encoded mouse P2X(3) protein consists o f 397 amino acids and shows 99% identity with rat P2X(3). IJsing RNase protection and primer extension assays, multiple transcription initia tion sites have been mapped in the mouse P2X(3) promoter to a region 1 62-168 bp upstream of the translation initiation codon. The P2X(3) gen e has been mapped to mouse chromosome 2p by fluorescence in situ hybri disation. The RAG locus-associated gene T160 is located 1.8 kb upstrea m of the transcription start site of mouse P2X(3) gene. The promoter r egion of the mouse P2X(3) gene lacks a conventional TATA and CCAAT con sensus sites, and initiator elements. P2X(3) is the first member of th e PZX gene family to be completely characterised. (C) 1997 Elsevier Sc ience B.V.