Evidence for expression of the Joa blood group antigen on the Gya/Hy-active glycoprotein.
The phenotypic association between the non-assigned high-incidence antigen Joa and the Gya collection antigens Gya and Hy was investigated by haemagglutination studies, flow cytometric analysis, immune precipitation and immunoblotting experiments. In haemagglutination tests anti-Joa gave the same pattern of reactivity with erythrocytes pre-treated with pronase, trypsin, alpha-chymotrypsin and thiol reducing agents as did anti-Gya and anti-Hy. In addition, similar to that found for anti-Gya and anti-Hy, anti Joa also showed reduced binding, as determined by haemagglutination and flow cytometric analysis, to erythrocytes from patients with paroxysmal nocturnal haemoglobinuria. Immune precipitates prepared from radio-iodinated antigen-positive red cells with anti-Joa, anti-Gya and anti-Hy gave similar results--a major component of M(r) 49,000-60,000 (the Gya/Hy-active glycoprotein) and a second component of M(r) 85,000-92,000 (this may be a dimer of the Gya/Hy-active glycoprotein, or a coprecipitated protein). These immune precipitates, when probed with both anti-Gya and anti-Hy under non-reducing conditions, gave a positive immunoblotting reaction to both the M(r) 49,000-60,000 and the M(r) 85,000-92,000 components. These results strongly suggest that the Joa antigen is expressed on the same glycoprotein that carries the Gya and Hy antigens.
Spring
F A
FA
South Western Regional Transfusion Centre, Bristol, UK.
Reid
M E
ME
Nicholson
G
G
D001789:Blood Group Antigens / Q000096:biosynthesis*; D001788:Blood Grouping and Crossmatching / Q000379:methods; D004910:Erythrocyte Membrane / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D015151:Immunoblotting; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000276:immunology; D010641:Phenotype; D011233:Precipitin Tests; D012699:Serology
D001789:Blood Group Antigens; D008562:Membrane Glycoproteins