Association of SWAP-70 with the B Cell Antigen Receptor Complex

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 97; no. 5; pp. 2180 - 2184
• Main Authors: Masat, L., Caldwell, J., Armstrong, R., Khoshnevisan, H., Jessberger, R., Herndier, B., Wabl, M., Ferrick, D.
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences of the United States of America 29-02-2000; National Acad Sciences; National Academy of Sciences; The National Academy of Sciences
• Subjects: AB-cell receptor; Amino Acid Sequence; Amino acids; Animals; Antibodies; B lymphocytes; Biological Sciences; Biological Transport; CD40 Antigens - metabolism; Cell lines; Cell membranes; Cell nucleus; DNA-Binding Proteins - genetics; DNA-Binding Proteins - immunology; DNA-Binding Proteins - metabolism; Enzymes; Guanine Nucleotide Exchange Factors; Humans; Immunoglobulin G - immunology; Immunoglobulin M - immunology; Immunology; Minor Histocompatibility Antigens; Molecular Sequence Data; Mutagenesis; Nuclear membrane; Nuclear Proteins - genetics; Nuclear Proteins - immunology; Nuclear Proteins - metabolism; Plasma cells; Proteins; Rabbits; Receptors, Antigen, B-Cell - metabolism; Spleen cells; SWAP-70 protein; T lymphocytes; Tissue Distribution; Tumor Cells, Cultured
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.040374497

SWAP-70 is a component of an enzyme complex that recombines Ig switch regions in vitro. We report here the cloning of the human cDNA and its B lymphocyte-specific expression. Although its sequence contains three nuclear localization signals, in small resting B cells, SWAP-70 is mainly found in the cytoplasm. On stimulation, SWAP-70 translocates to the nucleus. In activated, class-switching B cell cultures, it is associated with membrane IgG, but not IgM. The membrane Ig association requires a functional pleckstrin homology domain and is controlled by the C terminus. We suggest that SWAP-70 is involved not only in nuclear events but also in signaling in B cell activation.