Multiple motifs regulate the B-cell-specific promoter of the B29 gene.
The B-cell-specific B29 and mb1 genes code for covalently linked proteins (B29 or Ig beta and mb1 or Ig alpha, respectively) associated with membrane immunoglobulins in the antigen receptor complex on B cells. We have functionally analyzed the upstream region of the B29 gene and have identified a 164-bp region which comprises the minimal promoter responsible for B-cell-specific transcription. Linker scanning mutagenesis of this minimal promoter has established that both the previously identified octamer motif and a DNA motif that binds an unknown protein factor are critical for B29 gene expression in a pre-B-cell and B-cell line. Further mutations showed that binding motifs for Ets, microB/LyF1, and Sp1 also significantly contributed to the overall activity of the minimal B29 promoter. However, the relative contribution of certain motifs to promoter activity was different in a pre-B versus a B-cell line. The microB/LyF1 motif was necessary for full promoter activity in the pre-B cells but was not required in the B cells.
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Department of Microbiology and Immunology, School of Medicine, University of California, Los Angeles 90024.
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D000818:Animals; D015703:Antigens, CD; D001402:B-Lymphocytes / Q000378:metabolism*; D001483:Base Sequence; D051925:CD79 Antigens; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D015500:Chloramphenicol O-Acetyltransferase; D004268:DNA-Binding Proteins / Q000378:metabolism; D003850:Deoxyribonuclease I; D005786:Gene Expression Regulation; D008562:Membrane Glycoproteins / Q000096:biosynthesis*; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D010750:Phosphoproteins / Q000096:biosynthesis*; D011401:Promoter Regions, Genetic; D014158:Transcription, Genetic; D014162:Transfection
D015703:Antigens, CD; D051925:CD79 Antigens; D004268:DNA-Binding Proteins; D008562:Membrane Glycoproteins; D010750:Phosphoproteins; D015500:Chloramphenicol O-Acetyltransferase; D003850:Deoxyribonuclease I