title: Association of SWAP-70 with the B cell antigen receptor complex.
abstract: 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.
authors.affiliation: Department of Microbiology, University of California, San Francisco, CA 94143, USA.
authors.forename: L
authors.initials: L
authors.lastname: Masat
authors.forename: J
authors.initials: J
authors.lastname: Caldwell
authors.forename: R
authors.initials: R
authors.lastname: Armstrong
authors.forename: H
authors.initials: H
authors.lastname: Khoshnevisan
authors.forename: R
authors.initials: R
authors.lastname: Jessberger
authors.forename: B
authors.initials: B
authors.lastname: Herndier
authors.forename: M
authors.initials: M
authors.lastname: Wabl
authors.forename: D
authors.initials: D
authors.lastname: Ferrick
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001692:Biological Transport; D019013:CD40 Antigens / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D020662:Guanine Nucleotide Exchange Factors; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D007075:Immunoglobulin M / Q000276:immunology; D015778:Minor Histocompatibility Antigens; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009687:Nuclear Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D011817:Rabbits; D011947:Receptors, Antigen, B-Cell / Q000378:metabolism*; D014018:Tissue Distribution; D014407:Tumor Cells, Cultured
chemical_list: D019013:CD40 Antigens; D004268:DNA-Binding Proteins; D020662:Guanine Nucleotide Exchange Factors; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D015778:Minor Histocompatibility Antigens; D009687:Nuclear Proteins; D011947:Receptors, Antigen, B-Cell; C491873:SWAP70 protein, human