An aspartic acid residue near the second transmembrane segment of ATP receptor/channel regulates agonist sensitivity

Ken Nakazawa, Yasuo Ohno, Kazuhide Inoue

Research output: Contribution to journalArticle

15 Citations (Scopus)


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.

Original languageEnglish
Pages (from-to)599-603
Number of pages5
JournalBiochemical and Biophysical Research Communications
Issue number2
Publication statusPublished - Mar 17 1998
Externally publishedYes


All Science Journal Classification (ASJC) codes

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology

Cite this