Molecular characterization of the human interferon-gamma receptor: analysis of polymorphism and glycosylation.
Different molecular masses have been assigned to the human interferon-gamma receptor (HuIFN-gamma-R) by several authors. After extensive purification from Raji cells, this receptor was shown in a previous work to consist of two major protein species with molecular masses of 92 kD and 50 kD, as revealed by SDS-PAGE. We show here that the 50-kD band is most probably a degradation product of the 92-kD band due to a trypsin-like protease active during the purification process. The native protein of Raji cells seems, therefore, to have a molecular mass of 92 kD. The same molecular mass was found with Colo 205 cells (derived from a colon carcinoma). However, in conditions where degradation does not occur, the HuIFN-gamma-R shows a certain polymorphism: in IM-9 cells, another B-cell line, two bands exist with molecular masses of 95 kD and 85 kD, and in Wish cells, an amnion-derived cell line, one (or two) band(s) can be detected around 87 kD. This polymorphism is due at least in part to a variable extent of N-glycosylation from line to line and also within the same line, since after tunicamycin treatment of the Raji, IM-9, and Wish cells, very similar bands are obtained with a molecular mass of 72 kD.
Mao
C
C
Unité 196 INSERM, Institut Curie, Paris, France.
Aguet
M
M
Merlin
G
G
D015153:Blotting, Western; D002460:Cell Line; D006031:Glycosylation; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism*; D008970:Molecular Weight; D011110:Polymorphism, Genetic; D011971:Receptors, Immunologic / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D017471:Receptors, Interferon; D014415:Tunicamycin / Q000494:pharmacology
D011971:Receptors, Immunologic; D017471:Receptors, Interferon; D014415:Tunicamycin; D007371:Interferon-gamma