Biosynthesis and Genetics of Ia Antigens and Their Associated Invariant Chain
Since the discovery of Ia antigens in 1974 a tremendous amount of information has been gathered on the structure, genetics and possible functions of these molecules. However, the finding in 1979 that Ia antigen immunopre- cipitates contain a third polypeptide chain, designated the Ia antigen-associated invariant chain (Ii) (1), raised new questions about the assembly, processing, and expression of Ia antigens. The Ii chain, a protein with a molecular weight of 31,000 and a pI greater than 8, is non- covalently-associated with both I-A and I-E subregioncontrolled Ia antigens (1). Recent studies have suggested that it has a rather unusual subcellular distribution. It appears to be associated with Ia chain complexes in the intracellular membranes but not in the plasma membrane (2,3) . Its carbohydrate side chains also differ from those of the α and β chains, containing mannose but not fucose (4) and lacking sialic acid (3), which suggests that the Li chain possesses only unprocessed high-mannose oligosaccharides.
KeywordsSialic Acid House Mouse Electrophoretic Variant Backcross Mouse Carbohydrate Side Chain
Unable to display preview. Download preview PDF.
- 3.Moosic, J.P., Sung, E., Nilson, A., Jones, P.P. & McKean, J. J. Biol. Chem. In press.Google Scholar
- 8.Frelinger, J.G., Hood, L. & Wettstein, P. (1981) Transplant. Proc. Vol. XIII, No. 2, 360–363.Google Scholar
- 9.Sung, E., Duncan, W.R., Streilein, J.W. & Jones, P.P. Immunogenetics. In press.Google Scholar
- 10.Jones, P.P. (1980) In: Selected Methods in Cellular Immunology, ed. Mishell, B.B. & Shiigi, S.M. (W.H. Freeman, NY), 398–440.Google Scholar
- 13.Marshall, J.T. (1981) In: The Mouse in Biomedical Research, Vol. I, ed. Foster, H.L., Small J.D. & Fox, J.G. (Academic Press, NY), 17–27.Google Scholar
- 14.Sage, R.D. (1981) In: The Mouse in Biomedical Research, Vol. I, ed. Foster, H.L., Small, J.D. & Fox, J.G. (Academic Press, NY), 27–90.Google Scholar
- 16.Wakeland, E.K. & Klein, J. (1981) In: Current Trends in Histocompatibility, Vol. I, ed. Reisfeld, R.A. & Ferrone, S. (Plenum Press, NY), pp. 289–306.Google Scholar