CDNA encodes Xenopus P2Y1 nucleotide receptor:: expression at the neuromuscular junctions

A cDNA encoding Xenopus P2Y(1) receptor was isolated by cross-hybridization with chicken homolog. The deduced amino acid sequence of Xenopus P2Y(1) receptor with 361 amino residues is 80-85% identical to human, rodent and avian homologs. When the cDNA was expressed in mammalian cells, the activation of Xenopus P2Y(1) receptor by adenine nucleotides stimulated the accumulation of inositol phosphate, and adenosine 3',5'-bismonophosphate (A3P5P) or other antagonists blocked its action; these pharmacological properties showed resemblance of P2Y(1) receptor family in higher vertebrate. A transcript encoding Xenopus P2Y(1) receptor at similar to 3.2 kb was revealed in the brain, spinal cord and muscle of adult Xenopus, and it is strongly expressed in developing brain, spinal cord and myotomal muscles of the embryos by in situ hybridization. P2Y(1) receptor was shown to be restricted to the neuromuscular junctions and co-localized with AChRs in adult muscle. These results support the notion that ATP and its P2Y(1) receptor subtype are effectors in organizing the post-synaptic apparatus.