一个通过P2X2受体/通道调节电导的天冬酰胺残基。

An asparagine residue regulating conductance through P2X2 receptor/channels.

作者信息

Nakazawa K, Inoue K, Ohno Y

机构信息

Division of Pharmacology, National Institute of Health Science, Setagaya, Tokyo, Japan.

出版信息

Eur J Pharmacol. 1998 Apr 17;347(1):141-4. doi: 10.1016/s0014-2999(98)00207-6.

DOI:10.1016/s0014-2999(98)00207-6

PMID:9650860

Abstract

Single channel currents were recorded from Xenopus oocytes expressing wild-type and mutated P2X2 receptors. When 100 mM Na+ was used as the permeant cation, unitary currents of about 80 pS were recorded from the oocyte expressing the wild-type channels. The single channel conductance was roughly halved when Asn333 was replaced by Ile (N333I). A similar decrease in single channel currents was also observed when 100 mM Li+ or Cs+ was used as the permeant cation. With two other mutants, in which Asp315 was replaced by Val (D315V) or Tyr330 was replaced by lie (T333I), single channel conductance was almost the same as that of the wild-type channels. The results suggest that Asn333, which is believed to be involved in the channel pore, plays an essential role in ion transport through P2X2 receptor/channels.

摘要

从表达野生型和突变型P2X2受体的非洲爪蟾卵母细胞中记录单通道电流。当使用100 mM Na⁺作为通透阳离子时，从表达野生型通道的卵母细胞中记录到约80 pS的单位电流。当Asn333被Ile取代（N333I）时，单通道电导大致减半。当使用100 mM Li⁺或Cs⁺作为通透阳离子时，也观察到单通道电流有类似的下降。在另外两个突变体中，Asp315被Val取代（D315V）或Tyr330被Ile取代（T333I），单通道电导与野生型通道几乎相同。结果表明，被认为参与通道孔的Asn333在通过P2X2受体/通道的离子转运中起重要作用。