Recombinant Human Immunoglobulin mu Fc Receptor (IgM FcR) Fragment (aa 17-126) – a high-purity protein fragment encompassing the essential Ig-like domain, designed for investigating IgM binding, immune regulation, and signaling pathways in B cell development and mucosal immunity.

The full-length Immunoglobulin mu Fc receptor (IgM FcR), encoded by the FCMR gene, is a high-affinity Fc receptor for both secreted and membrane-bound immunoglobulin M (IgM). It plays a critical role in IgM transport and homeostasis, facilitating exocytosis and endocytosis of IgM complexes in lymphoid cells and mediating retrotranscytosis of antigen-IgM complexes across mucosal epithelium. This receptor triggers costimulatory signaling, supports B cell development, and regulates primary immune responses to infections by engaging non-canonical NF-kappa-B, MAP kinases, and calcium signaling pathways. It is primarily localized to the cell membrane, with dynamic recycling between cytoplasmic pools and the plasma membrane, and is