Qa-region class I gene expression: identification of a second class I gene, Q9, encoding a Qa-2 polypeptide
A feature of the expression of the tissue-specific class I antigen Qa-2 is the quantitative variation among mouse strains. Recently, the class I gene Q7 has been shown to encode a protein product that is biochemically indistinguishable from the lymphocyte-bound Qa-2 molecule. Utilizing gene transfection, we have identified a second Qa-2 subregion class I gene (Q9), in H-2b mice, which encodes a polypeptide biochemically similar to the Q7 and the Qa-2 polypeptides. Furthermore, we have observed that cell lines transfected with the allelic forms of the Q7 gene from C57BL/10 (Qa-2hi) or BALB/C (Qa-2low) display quantitative differences in cell-surface expression. Based on these studies, we suggest that gene dosage and allele-specific variation in cell-surface expression contribute to the strain-specific variation in the levels of Qa-2 antigen expression.
© 1988 by the National Academy of Sciences. Communicated by Kimishige Ishizaka, December 23, 1987. We thank Dr. Martin Low for his kind gift of purified phospholipase. The assistance of Mrs. Seema Thakur, Mrs. Dawn Schott, and Mrs. Andrea Lulkowski during the preparation of this manuscript is gratefully acknowledged. We are indebted to the technical assistance of Alan Lattimore and K. Blackburn. This work was supported by National Institutes of Health Grant AI 20922 and American Cancer Society Grant I-378 to M.S. and National Institutes of Health Grant AI 19624 to L.H. The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact.
Published - SOLpnas88.pdf