Cloning and Expression of the Histo-blood Group PkUDP-galactose:Galβ1–4Glcβ1-Cer α1,4-Galactosyltransferase: MOLECULAR GENETIC BASIS OF THE p PHENOTYPE *

摘要: The molecular genetic basis of the P histo-blood group system has eluded characterization despite extensive studies biosynthesis P1, P, and Pkglycolipids. main controversy been whether a single or two distinct UDP-Gal:Galβ1-R 4-α-galactosyltransferases catalyze syntheses structurally related P1 Pkantigens. polymorphism is linked to 22q11.3-ter. Data base searches with coding region an α4GlcNAc-transferase identified novel homologous gene at 22q13.2 designated α4Gal-T1. Expression full constructs α4Gal-T1 in insect cells revealed it encoded Pk but not synthase activity. Northern analysis showed expression transcript correlating activity antigen human B cell lines. Transfection Pk-negative Namalwa resulted strong expression. A homozygous missense mutation, M183K, was found six Swedish individuals rare p phenotype, confirming that represented Pkgene. Sequence P1+/− did reveal polymorphisms P1P2 typing.