TY - JOUR
T1 - An aspartic acid residue near the second transmembrane segment of ATP receptor/channel regulates agonist sensitivity
AU - Nakazawa, Ken
AU - Ohno, Yasuo
AU - Inoue, Kazuhide
N1 - Funding Information:
The authors are grateful to Dr. A. T. Brake for providing us the clone of P2X2 receptors. This work is supported in part by the grants from the Ministry of Health and Welfare, Japan, and the Ministry of Education, Science, and Culture, Japan, awarded to K.N.
PY - 1998/3/17
Y1 - 1998/3/17
N2 - Charged or polarized amino acid residues near or within the second transmembrane (M2) segment of neuronal ATP receptor/channels (P2X2 receptors) were neutralized by site-directed mutagenesis, and the properties of the mutants were electrophysiologically characterized using Xenopus oocytes. When Asp315 was substituted with Val (D315V), the sensitivity to ATP was reduced by about 60-fold. The sensitivity to ATP was not affected by the neutralization of Lys324, which is involved in a Walker type A ATP-binding sequence, Lys366, Tyr330, or Asn333. With D315V channels, the sensitivities to other agonists (ADP, ATPγS, and a-methylthio ATP) were also reduced. The sensitivities to antagonists (suramin and Cibacron Blue F3GA) were, however, not affected by this neutralization. The results suggest that Asp315, which is assumed to be present in the extracellular region near the M2 segment of P2X2 receptor/channels, serves to maintain agonist sensitivity.
AB - Charged or polarized amino acid residues near or within the second transmembrane (M2) segment of neuronal ATP receptor/channels (P2X2 receptors) were neutralized by site-directed mutagenesis, and the properties of the mutants were electrophysiologically characterized using Xenopus oocytes. When Asp315 was substituted with Val (D315V), the sensitivity to ATP was reduced by about 60-fold. The sensitivity to ATP was not affected by the neutralization of Lys324, which is involved in a Walker type A ATP-binding sequence, Lys366, Tyr330, or Asn333. With D315V channels, the sensitivities to other agonists (ADP, ATPγS, and a-methylthio ATP) were also reduced. The sensitivities to antagonists (suramin and Cibacron Blue F3GA) were, however, not affected by this neutralization. The results suggest that Asp315, which is assumed to be present in the extracellular region near the M2 segment of P2X2 receptor/channels, serves to maintain agonist sensitivity.
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U2 - 10.1006/bbrc.1998.8312
DO - 10.1006/bbrc.1998.8312
M3 - Article
C2 - 9514958
AN - SCOPUS:0032539778
SN - 0006-291X
VL - 244
SP - 599
EP - 603
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 2
ER -