Reiner A P, Aramaki K M, Teramura G, Gaur L
Puget Sound Blood Center and Department of Medicine, Universisty of Washington, Seattle 98104-1256, USA.
Thromb Haemost. 1998 Sep;80(3):449-56.
Glycoprotein Ia (alpha2 integrin) is a subunit of the heterodimeric membrane complex (GPIa/IIa) that mediates platelet adhesion to collagen. Several nucleotide sequence variations of GPIa have been described. A nucleotide 1648 G/A dimorphism that leads to a Glu/Lys substitution at amino acid 505 is responsible for the human platelet antigen system, HPA-5. Recently, two other linked GPIa nucleotide dimorphisms involving codons Phe224 and Thr246 were identified: a C/T substitution at nucleotide 807 and a G/A substitution at nucleotide 873(1). Using restriction enzyme digestion of amplified GPIa genomic DNA fragments (PCR-RFLP) to distinguish genotypes, we have determined the allele frequencies of the GPIa 807C/T and Glu/Lys505 dimorphisms in three North American populations, and a panel of non-human primates. Our results indicate a genetic relationship between the 807C/T and Glu/Lys505 dimorphisms that leads to an evolutionary model of GPIa isoforms.
糖蛋白Ia（α2整合素）是异二聚体膜复合物（GPIa/IIa）的一个亚基，介导血小板与胶原蛋白的黏附。已描述了GPIa的几种核苷酸序列变异。导致第505位氨基酸发生Glu/Lys替换的1648位核苷酸G/A二态性是人类血小板抗原系统HPA-5的原因。最近，还鉴定出另外两个与GPIa相关的核苷酸二态性，涉及密码子Phe224和Thr246：第807位核苷酸的C/T替换和第873位核苷酸的G/A替换(1)。我们使用扩增的GPIa基因组DNA片段的限制性酶切（PCR-RFLP）来区分基因型，确定了三个北美人群以及一组非人类灵长类动物中GPIa 807C/T和Glu/Lys505二态性的等位基因频率。我们的结果表明807C/T和Glu/Lys505二态性之间存在遗传关系，这导致了GPIa亚型的进化模型。
