Cloning and characterization of two novel zebrafish P2X receptor subunits.
In this report we describe the cloning and characterization of two P2X receptor subunits cloned from the zebrafish (Danio rerio). Primary sequence analysis suggests that one cDNA encodes an ortholog of the mammalian P2X(4) subunit and the second cDNA encodes the ortholog of the mammalian P2X(5) subunit. The zP2X(4) subunit forms a homo-oligomeric receptor that displays a low affinity for ATP (EC(50)=274+/-48 microM) and very low affinity (EC(50)>500 microM) for other purinergic ligands such as alphabetameATP, suramin, and PPADS. As seen with the mammalian orthologs, the zP2X(5) subunit forms a homo-oligomeric receptor that yields very small whole-cell currents (<20pA), making determination of an EC(50) problematic. Both subunit genes were physically mapped onto the zebrafish genome using radiation hybrid analysis of the T51 panel, with the zp2x4 localized to LG21 and zp2x5 to LG5.
Diaz-Hernandez
Miguel
M
Department of Pharmacological and Physiological Sciences, Saint Louis University School of Medicine, 1402 S. Grand Blvd., St. Louis, MO 63104, USA.
Cox
Jane A
JA
Migita
Keisuke
K
Haines
William
W
Egan
Terrance M
TM
Voigt
Mark M
MM
D000255:Adenosine Triphosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004594:Electrophysiology; D006801:Humans; D008024:Ligands; D008969:Molecular Sequence Data; D020161:Physical Chromosome Mapping; D017434:Protein Structure, Tertiary; D018048:Receptors, Purinergic P2 / Q000737:chemistry* / Q000235:genetics*; D058848:Receptors, Purinergic P2X4; D058485:Receptors, Purinergic P2X5; D014162:Transfection; D015027:Zebrafish
D018076:DNA, Complementary; D008024:Ligands; C548226:P2RX4 protein, human; C546465:P2RX5 protein, human; D018048:Receptors, Purinergic P2; D058848:Receptors, Purinergic P2X4; D058485:Receptors, Purinergic P2X5; D000255:Adenosine Triphosphate