Scase T J, Heath M F, Allen J M, Sage S O, Evans R J
Centre for Veterinary Science, University of Cambridge, United Kingdom.
Biochem Biophys Res Commun. 1998 Jan 26;242(3):525-8. doi: 10.1006/bbrc.1997.8001.
It has been proposed that platelets possess a P2X1-purinoceptor-like ligand-gated cation channel, through which Ca2+ enters platelets from the extracellular medium upon ADP or ATP stimulation. In this paper we describe the cloning of human P2X1-specific cDNA from human platelets, K562 and human erythroleukaemic cell lines. Sequence analyses of these cDNAs show 100% nucleotide sequence identity with that of human P2X1 cloned from urinary bladder. Western blotting of platelet lysates separated by SDS-PAGE and probed with anti-P2X1 IgG shows the expected protein with a molecular mass of 60 kDa and a second protein of 45 kDa. These data confirm that platelets possess at least two distinct purinoceptors: a P2T purinoceptor which mediates platelet aggregation, inhibition of adenylate cyclase, and release of intracellular Ca2+ stores and a platelet P2X1 purinoceptor which upon ATP and ADP stimulation mediates the rapid entry of extracellular Ca2+ into platelets.
有人提出血小板拥有一种P2X1嘌呤受体样配体门控阳离子通道，在ADP或ATP刺激下，Ca2+通过该通道从细胞外介质进入血小板。在本文中，我们描述了从人血小板、K562和人红白血病细胞系中克隆人P2X1特异性cDNA的过程。对这些cDNA的序列分析表明，它们与从膀胱克隆的人P2X1具有100%的核苷酸序列同一性。用抗P2X1 IgG对经SDS-PAGE分离的血小板裂解物进行免疫印迹，显示出预期的分子量为60 kDa的蛋白质以及另一种分子量为45 kDa的蛋白质。这些数据证实血小板至少拥有两种不同的嘌呤受体：一种P2T嘌呤受体，它介导血小板聚集、抑制腺苷酸环化酶以及释放细胞内Ca2+储存；另一种血小板P2X1嘌呤受体，在ATP和ADP刺激下，介导细胞外Ca2+快速进入血小板。
