Molecular Structure and Expression of the Murine Lymphocyte Low-Affinity Receptor for IgE (FcεRII)

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 86; no. 19; pp. 7566 - 7570
• Main Authors: Bettler, Bernhard, Hofstetter, Hans, Rao, Mangala, Yokoyama, Wayne M., Kilchherr, Francois, Conrad, Daniel H.
• Format: Journal Article
• Language: English
• Published: Washington, DC National Academy of Sciences of the United States of America 01.10.1989; National Acad Sciences
• Subjects: Amino Acid Sequence; Amino acids; Animals; Antigens, Differentiation, B-Lymphocyte - genetics; B lymphocytes; B-Lymphocytes - immunology; Base Sequence; Biological and medical sciences; Cell Line; Cell lines; Cell receptors; Cell structures and functions; Cloning, Molecular; Complementary DNA; COS cells; DNA - genetics; Fundamental and applied biological sciences. Psychology; Gene Expression; Gene Library; Genes; Humans; Hybridomas; Immunoglobulin E - immunology; Messenger RNA; Mice; Miscellaneous; Molecular and cellular biology; Molecular Sequence Data; Receptors; Receptors, Fc - genetics; Receptors, IgE; Sequence Homology, Nucleic Acid; T lymphocytes; Transfection; Northern blotting; Vertebrata; Membrane receptor; Mammalia; Complementary DNA; Mouse; Nucleotide sequence; IgE; Rodentia; B-Lymphocyte; Gene expression; Aminoacid sequence
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.86.19.7566

The cDNA encoding the murine low-affinity receptor for IgE (FcεRII) has been isolated from a cDNA library prepared from B cells activated with lipopolysaccharide and interleukin 4. It encodes a 37-kDa protein of 331 amino acids with two potential N-linked glycosylation sites. Analogous to its human counterpart, there is no signal sequence and the putative transmembrane region is close to the amino terminus, indicating an inverse membrane orientation with the carboxyl terminus at the cell exterior. The predicted murine FcεRII amino acid sequence demonstrates a 57% identity with its human counterpart. The murine sequence has an additional internal repeat motif of 21 amino acids giving four repeats as compared to three in the human sequence. Furthermore, the murine FcεRII is truncated at the carboxyl terminus and the Arg-Gly-Asp sequence, a common recognition site of integrin receptors, which is found in the reverse configuration in human FcεRII, is missing. B cells activated with interleukin 4 and lipopolysaccharide have an increased amount of FcεRII mRNA as compared with resting or lipopolysaccharide-stimulated B cells. Con A-activated normal T cells, the TH-2 cell line D10, as well as the macrophage cell line J774 have no detectable FcεRII mRNA. Expression analysis using transiently transfected COS cells revealed that recombinant murine FcεRII binds anti-FcεRII as well as mouse and rat IgE but does not bind human IgE or mouse IgG. FcεRII expressed in COS cells has a molecular mass of 45 kDa whereas the FcεRII from B-cell lines is a 49-kDa protein.