Histo-blood group p: biosynthesis of globoseries glycolipids in EBV-transformed B cell lines.
The genetic and biosynthetic basis of the histo-blood group P-system is not fully understood. Individuals with the rare p phenotype do not express the three glycolipid antigens (Pk, P and P1) of this system, probably because of deficiencies in glycosyltransferases involved in their biosynthesis. Iiuka et al. [Iiuka S, Chen SH, Yoshida A (1986) Biochem Biophys Res Commun 137: 1187-95], however, previously reported that detergent extracts from an EBV-transformed B cell line derived from a p individual did express the glycosyltransferase activity (Pk transferase) assumed to be missing in this blood group status. Here, we have reinvestigated the antigen expression and glycosyltransferase activities in two p individuals by analysing EBV-transformed cell lines as well as erythrocytes to confirm the blood group P status. The thin layer chromatography glycolipid profile of extracts from erythrocytes and EBV-transformed B cell lines showed characteristic accumulation of lactosylceramide and absence of Pk and P antigens. Glycosyltransferase activities of the B cell lines were analysed using glycolipid substrates and both extracts were found to contain lactosylceramide synthetase and P transferase activities but to be completely devoid of Pk transferase activity. The presented data indicate that p individuals, in contrast to previous reports, do not express a functional Pk glycosyltransferase.
Wiels
J
J
Laboratoire de Biologie des Tumeurs Humaines, CNRS URA 1156, Institut Gustave Roussy, Villejuif, France.
Taga
S
S
Tétaud
C
C
Cedergren
B
B
Nilsson
B
B
Clausen
H
H
D000954:Antigens, Surface / Q000378:metabolism; D001402:B-Lymphocytes / Q000201:enzymology / Q000378:metabolism*; D002461:Cell Line, Transformed; D006017:Glycolipids / Q000096:biosynthesis*; D016695:Glycosyltransferases / Q000378:metabolism; D004854:Herpesvirus 4, Human / Q000502:physiology*; D006801:Humans; D010127:P Blood-Group System
D000954:Antigens, Surface; D006017:Glycolipids; D010127:P Blood-Group System; D016695:Glycosyltransferases