Identification of two distinct phosphoproteins as components of the human B cell antigen receptor complex.
In human B cells, the molecules that, upon receptor occupancy, couple membrane immunoglobulin to intracellular signal transduction pathways have never been identified. We here describe two phosphoproteins as integral parts of the B cell antigen receptor complex. Membrane IgM is non-covalently associated with a disulfide-linked heterodimer of glycoproteins. These molecules can be demonstrated on B cell lines and freshly isolated polyclonal B cell populations and are subject to phosphorylation at serine residues. Identification of these constituents of the B cell receptor complex opens up the opportunity to study coupling of the B cell antigen receptor to the intracellular signal transduction machinery at the molecular level.
Van Noesel
C J
CJ
Central Laboratory of the Netherlands Red Cross Blood Transfusion Service, Amsterdam.
Borst
J
J
De Vries
E F
EF
Van Lier
R A
RA
D001402:B-Lymphocytes / Q000502:physiology*; D002851:Chromatography, High Pressure Liquid; D004220:Disulfides; D006023:Glycoproteins / Q000502:physiology; D006801:Humans; D007075:Immunoglobulin M / Q000502:physiology; D046911:Macromolecular Substances; D008970:Molecular Weight; D010449:Peptide Mapping; D010750:Phosphoproteins / Q000737:chemistry / Q000502:physiology*; D010768:Phosphoserine / Q000378:metabolism; D011947:Receptors, Antigen, B-Cell / Q000737:chemistry* / Q000502:physiology
D004220:Disulfides; D006023:Glycoproteins; D007075:Immunoglobulin M; D046911:Macromolecular Substances; D010750:Phosphoproteins; D011947:Receptors, Antigen, B-Cell; D010768:Phosphoserine