Binding of Free Immunoglobulin Light Chains to VpreB3 Inhibits Their Maturation and Secretion in Chicken B Cells

The VpreB3 gene product was first characterized as an immunoglobulin (Ig) μ heavy chain-binding protein in mouse precursor B (pre-B) cells. Although its function is unknown, it has been proposed to participate in the assembly and transport of the pre-B cell receptor. We have identified a VpreB3 orthologous gene in chicken that is located close to the immunoglobulin light chain (LC) gene cluster and specifically expressed in the bursa of...