Characterization of the ligand binding site of the bovine IgA Fc receptor (bFc alpha R).
Recently, we identified a bovine IgA Fc receptor (bFc alpha R), which shows high homology to the human myeloid Fc alpha R, CD89. IgA binding has previously been shown to depend on several specific residues located in the B-C and F-G loops of the membrane-distal extracellular domain 1 of CD89. To compare the ligand binding properties of these two Fc alpha Rs, we have mapped the IgA binding site of bFc alpha R. We show that, in common with CD89, Tyr-35 in the B-C loop is essential for IgA binding. However, in contrast to earlier observations on CD89, mutation of residues in the F-G loop did not significantly inhibit IgA binding.
Laboratory for Immunohistochemistry and Immunopathology, Institute of Pathology, University of Oslo, Rikshospitalet, N-0027 Oslo, Norway. h.c.morton@medisin.uio.no
H Craig
HC
Morton
Richard J
RJ
Pleass
Jenny M
JM
Woof
Per
P
Brandtzaeg
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D015703:Antigens, CD / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D001665:Binding Sites; D019556:COS Cells; D002417:Cattle; D002462:Cell Membrane / Q000737:chemistry; D015870:Gene Expression; D006801:Humans; D007070:Immunoglobulin A / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015394:Molecular Structure; D016296:Mutagenesis; D011961:Receptors, Fc / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D012397:Rosette Formation; D017385:Sequence Homology; D014162:Transfection; D014443:Tyrosine / Q000378:metabolism
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; C036832:Fc(alpha) receptor; D007070:Immunoglobulin A; D011961:Receptors, Fc; D014443:Tyrosine