title: Endogenous expression of activation-induced cytidine deaminase in cell line WEHI-231.
abstract: Because of its susceptibility to apoptosis on Ag receptor cross-linking, cells of the mouse cell line WEHI-231 have been classified as immature B cells. Surprisingly, however, the cell line expresses activation-induced cytidine deaminase, the enzyme that mediates hypermutation and Ig class switch recombination in activated B cells. Although both cDNA sequence and protein expression of activation-induced cytidine deaminase appear normal, the cell line does not hypermutate an indicator plasmid. For the readout, the indicator plasmid depends on the removal of deoxyuridine after transition from C to U and, therefore, on functional expression of uracil N-glycosylase 2, which is normal in WEHI-231. At the endogenous Ig locus, however, WEHI-231 does undergo the canonical hypermutation of G. C to A. T base pairs to some extent. The cell line also expresses the germline transcripts of the Ig gamma 2b, epsilon, and alpha loci, but it does not switch its IgM surface Ig.
authors.affiliation: Department of Microbiology and Immunology, University of California, San Francisco, CA 94143, USA.
authors.forename: Freia J X
authors.initials: FJ
authors.lastname: Spillmann
authors.forename: Matthias
authors.initials: M
authors.lastname: Wabl
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D034961:Antigens, Nuclear / Q000096:biosynthesis / Q000235:genetics; D020029:Base Pairing; D001483:Base Sequence; D045744:Cell Line, Tumor / Q000201:enzymology; D003564:Cytidine Deaminase / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D045647:DNA Glycosylases / Q000235:genetics / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics; D004790:Enzyme Induction; D005803:Genes, Immunoglobulin; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins; D017578:Immunoglobulin Class Switching; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D007075:Immunoglobulin M / Q000235:genetics; D000072200:Ku Autoantigen; D008164:Luminescent Proteins / Q000235:genetics; D016393:Lymphoma, B-Cell / Q000201:enzymology* / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D008814:Mice, Inbred NZB; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics; D011947:Receptors, Antigen, B-Cell / Q000235:genetics; D016415:Sequence Alignment; D017385:Sequence Homology; D027041:Somatic Hypermutation, Immunoglobulin; D014162:Transfection; D051981:Uracil-DNA Glycosidase; D000098830:AICDA (Activation-Induced Cytidine Deaminase)
chemical_list: D034961:Antigens, Nuclear; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D007143:Immunoglobulin Heavy Chains; D007075:Immunoglobulin M; D008164:Luminescent Proteins; D011947:Receptors, Antigen, B-Cell; D049452:Green Fluorescent Proteins; D045647:DNA Glycosylases; D051981:Uracil-DNA Glycosidase; D000098830:AICDA (Activation-Induced Cytidine Deaminase); D003564:Cytidine Deaminase; C000606510:Xrcc6 protein, mouse; D000072200:Ku Autoantigen