The B cell antigen receptor of class IgD can be expressed on the cell surface in two different forms.
Membrane-bound immunoglobulins of the IgM and IgD class are expressed on the B cell surface in association with a disulfide-linked heterodimer consisting of alpha and beta subunits. While the alpha component of the IgM antigen receptor (IgM-alpha, 34 kDa) is encoded by the B cell-specific gene mb-1, the gene coding for IgD-alpha (35 kDa) has not yet been identified. We show here that the alpha component of the IgD antigen receptor is also encoded by the mb-1 gene. The difference in molecular weight between IgM-alpha and IgD-alpha thus seems to be due to post-translational modifications of the mb-1 gene product. We also demonstrate that the previously described myeloma variant J558L delta m2.6 expresses an alternative form of the IgD antigen receptor, which does not contain an alpha/beta heterodimer.
Max-Planck-Institut für Immunbiologie, Freiburg, FRG.
J
J
Wienands
M
M
Reth
D000818:Animals; D016525:Antigenic Modulation; D001402:B-Lymphocytes / Q000737:chemistry*; D007072:Immunoglobulin D / Q000737:chemistry*; D007075:Immunoglobulin M / Q000737:chemistry; D066298:In Vitro Techniques; D046911:Macromolecular Substances; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000235:genetics; D051379:Mice; D008970:Molecular Weight; D011947:Receptors, Antigen, B-Cell / Q000737:chemistry*; D014162:Transfection
D007072:Immunoglobulin D; D007075:Immunoglobulin M; D046911:Macromolecular Substances; D008562:Membrane Glycoproteins; D011947:Receptors, Antigen, B-Cell