Characterization of the enhancer region for germline transcription of the gamma 3 constant region gene of human immunoglobulin.
A constant region gene (C) of the immunoglobulin heavy chain can be transcribed as germline transcripts from a promoter located upstream of a switch region. We have studied the structure and function of the human C gamma 3 promoter region. When the human IgM-producing cell line SSK41 is stimulated with interleukin 4 (IL-4) in the presence of phorbol myristate acetate (PMA) or Staphylococcus aureus Cowan I, expression of germline C gamma 3 transcripts was specifically augmented within 4 h. Upstream DNA fragments flanking the I gamma 3 exon were fused with a reporter gene and tested for IL-4-induced promoter/enhancer activity by transfection of SSK41 cells. The DNA fragment between 450 and 250 bp upstream of the transcription initiation site of the C gamma 3 gene was shown to be required for transcriptional up-regulation by PMA and IL-4. The upstream 514 bp fragment of the I gamma 3 flanking region was shown to contain an enhancer activity in response to PMA and IL-4.
Kuze
K
K
Department of Medical Chemistry, Kyoto University Faculty of Medicine, Japan.
Shimizu
A
A
Honjo
T
T
D002460:Cell Line; D004742:Enhancer Elements, Genetic; D005091:Exons; D005803:Genes, Immunoglobulin; D006801:Humans; D007127:Immunoglobulin Constant Regions / Q000235:genetics; D007142:Immunoglobulin gamma-Chains / Q000235:genetics; D015847:Interleukin-4 / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014158:Transcription, Genetic
D007127:Immunoglobulin Constant Regions; D007142:Immunoglobulin gamma-Chains; D015847:Interleukin-4; D013755:Tetradecanoylphorbol Acetate