Cytoplasmic domain of human Fcalpha/mu receptor is required for ligand internalization

New B-cell CD molecules

“…The Ig-like domain is the binding site for polymeric IgM and IgA [16,17]. In terms of its expression, CD351 is abundantly found in kidney, small intestine, lymph node, intestinal lamina propria, and lymphoid follicles [17]. In the present study, we observe the faint expression of this molecule on monocytes, as well as on B and T cells.…”

“…CD351 contains a single Ig-like domain in its extracellular region, which is followed by a stalk region, a transmembrane domain, and a cytoplasmic tail. The Ig-like domain is the binding site for polymeric IgM and IgA [16,17]. In terms of its expression, CD351 is abundantly found in kidney, small intestine, lymph node, intestinal lamina propria, and lymphoid follicles [17].…”

Molecular characterization of the dimer formation of Fcα/μ receptor (CD351)

“…Fcα/μR is expressed not only on hematopoietic cells such as B cells and macrophages but also on follicular dendritic cells (FDCs) within follicles of lymphoid organs (Honda et al, 2009). Fcα/μR mediates endocytosis of the ligands IgA and IgM, for which the cytoplasmic portion of Fcα/μR is responsible (Shibuya et al, 2000;Yang et al, 2009). By using Fcα/μR-deficient mice, we reported that Fcα/μR negatively regulates T-independent antigens retention by FDCs, leading to suppression of humoral immune responses against T-independent antigens (Honda et al, 2009).…”