| First Author | Robinson WH | Year | 1992 |
| Journal | J Immunol | Volume | 149 |
| Issue | 3 | Pages | 880-6 |
| PubMed ID | 1634777 | Mgi Jnum | J:1507 |
| Mgi Id | MGI:50034 | Doi | 10.4049/jimmunol.149.3.880 |
| Citation | Robinson WH, et al. (1992) Extensive polymorphism in the extracellular domain of the mouse B cell differentiation antigen Lyb-2/CD72. J Immunol 149(3):880-6 |
| abstractText | Lyb-2/CD72 is a 45-kDa mouse B cell surface protein that binds CD5 and has been shown to play a role in B cell proliferation and differentiation. Using the polymerase chain reaction we have isolated and sequenced cDNA clones encoding the serologically defined mouse Lyb-2a, Lyb-2b, and Lyb-2c alleles. We confirmed that our full length cDNA clones encode the Lyb-2a, -2b, and -2c alleles, respectively, by transfecting the isolated Lyb-2/CD72 cDNA clones into L cells and demonstrating that the transfectants bind only the appropriate allele specific anti-Lyb-2/CD72 antibodies. Sequence comparisons demonstrate that the Lyb-2/CD72 allels are highly conserved in their cytoplasmic and transmembrane domains but exhibit a high degree of polymorphism in their extracellular domains. This polymorphism in the extracellular region involves amino acid substitutions at a minimum of 20 residues and is concentrated primarily in the membrane distal region. cDNA sequence comparisons also demonstrate two distinct seven amino acid insertion/deletions among these allelic variants. A form of Lyb-2b cDNA lacking the sequence encoding the transmembrane region was isolated from a C57B1/6 mouse and a CH12.LX subline. The Lyb-2/CD72 PCR products from mRNA of mice expressing Lyb-2a and Lyb-2c contain a DNA fragment that corresponds in size to the transmembraneless form, suggesting that these mouse strains also express this mRNA. |
