Cherayil B J, Pillai S
Molecular Immunology Laboratory, Cancer Center of Massachusetts General Hospital, Boston.
J Exp Med. 1991 Jan 1;173(1):111-6. doi: 10.1084/jem.173.1.111.
The membrane immunoglobulin heavy chain (micron) plays a feedback role during the pre-B stage of B lymphocyte differentiation. In pre-B cell lines, micron associates with two surrogate light chain proteins. The omega chain is disulfide linked to mu and was predicted to be the product of the lambda 5 gene. The iota chain is noncovalently associated with micron. We demonstrate that the omega protein is indeed the product of the lambda 5 gene and that mu, omega, and iota are coassociated in the same complex. Antibodies against the omega/lambda 5 protein demonstrate the existence of a subpopulation of "transitional" bone marrow B cells that express micron and omega on the cell surface. The majority of these cells also express surface kappa light chains, indicating that in B lymphoid ontogeny the lambda 5 gene is inactivated after the onset of kappa light chain expression.
膜免疫球蛋白重链（μ）在B淋巴细胞分化的前B阶段发挥反馈作用。在前B细胞系中，μ与两种替代轻链蛋白相关联。ω链通过二硫键与μ相连，预计是λ5基因的产物。ι链与μ非共价结合。我们证明ω蛋白确实是λ5基因的产物，并且μ、ω和ι在同一复合物中共存。针对ω/λ5蛋白的抗体表明存在一群“过渡性”骨髓B细胞亚群，它们在细胞表面表达μ和ω。这些细胞中的大多数也表达表面κ轻链，表明在B淋巴细胞个体发生中，λ5基因在κ轻链表达开始后失活。
