Identification of the genes encoding the IgM-alpha and Ig-beta components of the IgM antigen receptor complex by amino-terminal sequencing.
Beside the immunoglobulin (Ig) heavy and light chains the murine B cell receptor of the IgM class contains a heterodimer of two transmembrane proteins (IgM-alpha and Ig-beta). By N-terminal sequencing of IgM-alpha and Ig-beta we have identified the genes encoding these proteins as mb-1 and B29, respectively. Both genes are B cell specific and have been previously cloned from B minus T cell subtractive cDNA libraries. We have constructed expression vectors of the two genes and demonstrate that expression of the mb-1 and B29 genes can influence the surface expression of IgM in micron-transfected myeloma cells. From the known sequences of the IgM-alpha and Ig-beta proteins and from the results of previous transfection experiments with various vectors expressing the mu chain we have developed a structural model of the B cell antigen receptor of class IgM which we compare with that of the T cell antigen receptor.
Hombach
J
J
Institut für Genetik, Universität zu Köln, FRG.
Lottspeich
F
F
Reth
M
M
D000595:Amino Acid Sequence; D000818:Animals; D015703:Antigens, CD; D001402:B-Lymphocytes / Q000502:physiology*; D051925:CD79 Antigens; D003001:Cloning, Molecular; D015870:Gene Expression; D005796:Genes; D007075:Immunoglobulin M / Q000737:chemistry*; D046911:Macromolecular Substances; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D011947:Receptors, Antigen, B-Cell / Q000737:chemistry* / Q000235:genetics
D015703:Antigens, CD; D051925:CD79 Antigens; C497882:Cd79a protein, mouse; D007075:Immunoglobulin M; D046911:Macromolecular Substances; D008562:Membrane Glycoproteins; D011947:Receptors, Antigen, B-Cell