title: Molecular characterization of the dimer formation of Fcα/μ receptor (CD351).
abstract: Fcα/μR (CD351) is an Fc receptor for both IgA and IgM and forms an atypical dimer that is resistant to reduction by 2-mercaptoethanol or boiling. We previously demonstrated that the cytoplasmic portion of Fcα/μR is required for dimer formation and for its efficient cell-surface expression. However, the biochemical nature of these phenomena has not been determined. By using a BW5147 mouse cell line expressing deletion mutants of the cytoplasmic region of Fcα/μR, we found that the region spanning amino acids 504-523 was required for efficient cell-surface expression, whereas the region spanning amino acids 481-490 was required for dimmer formation. Immunoblotting analyses of transfectants simultaneously expressing Flag-tagged Fcα/μR and hemagglutinin-tagged Fcα/μR suggested that Fcα/μR does not form homodimers. Instead, our data suggest that Fcα/μR forms heterodimers with an as-yet-unknown molecule with a molecular weight of 60-70 kDa.
authors.affiliation: Department of Immunology, Institute of Basic Medical Sciences, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Kana
authors.initials: K
authors.lastname: Takagaki
authors.forename: Kazuki
authors.initials: K
authors.lastname: Satoh
authors.forename: Shin-ichiro
authors.initials: S
authors.lastname: Honda
authors.forename: Akira
authors.initials: A
authors.lastname: Shibuya
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D045744:Cell Line, Tumor; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D011485:Protein Binding; D055503:Protein Multimerization; D011961:Receptors, Fc / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D014162:Transfection
chemical_list: C526791:Fcalpha-mu protein, mouse; D011961:Receptors, Fc; D049452:Green Fluorescent Proteins