The human platelet alloantigens, HPA-5(a+, b-) and HPA-5(a-, b+), are associated with a Glu505/Lys505 polymorphism of glycoprotein Ia (the alpha 2 subunit of VLA-2).
GP Ia/IIa (also called VLA-2 or alpha 2 beta 1) is the primary receptor for collagen on platelets. The human platelet alloantigens HPA-5a(Brb) and HPA-5b(Bra) have been found to reside on the platelet GP Ia/IIa complex. In order to establish the molecular basis of the HPA-5 system, platelet RNA was isolated form HPA-5 (a+, b-) and HPA-5(a-, b+) individuals. After reverse transcription, cDNA coding for glycoprotein Ia (GP Ia) was amplified by the polymerase chain reaction (PCR). Nucleotide sequence analysis of the PCR products revealed an A-->G polymorphism at base pair 1648 of the coding region of the mature protein, resulting in a substitution of lysine (AAG) in HPA-5b(Bra) by glutamic acid (GAG) in HPA-5a(Brb) at amino acid 505. Subsequent PCR-ASRA (allele-specific restriction enzyme analysis) with Mnl I using cDNA derived from three HPA-5 (a+, b-), one HPA-5 (a+, b+) individuals demonstrated that HPA-5a and -5b alleles are distinguishable by DNA typing. In addition to the A-->G substitution at base pair 1648, three silent mutations were identified, G-->C (195 bp), C-->T (837 bp), G-->A (1041 bp).
Simsek
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Department of Immunological Haematology, Central Laboratory of the Netherlands Red Cross Blood Transfusion Service, Amsterdam.
Gallardo
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D
Ribera
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von dem Borne
A E
AE
D016824:Antigens, Human Platelet / Q000235:genetics*; D001483:Base Sequence; D001792:Blood Platelets / Q000276:immunology*; D005971:Glutamates / Q000235:genetics*; D018698:Glutamic Acid; D006801:Humans; D039661:Integrin beta3; D008239:Lysine / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation; D015345:Oligonucleotide Probes / Q000737:chemistry; D010980:Platelet Membrane Glycoproteins / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic
D016824:Antigens, Human Platelet; D005971:Glutamates; C061248:ITGB3 protein, human; D039661:Integrin beta3; D015345:Oligonucleotide Probes; D010980:Platelet Membrane Glycoproteins; D018698:Glutamic Acid; D008239:Lysine