OCTAMER TRANSCRIPTION FACTORS AND THE CELL TYPE-SPECIFICITY OF IMMUNOGLOBULIN GENE-EXPRESSION

被引:84
作者
KEMLER, I
SCHAFFNER, W
机构
关键词
alternative splicing; immunoglobulin genes; octamer sequence; tissue-specific transcription; transcription factors;
D O I
10.1096/fasebj.4.5.2407588
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Antibodies are produced exclusively in B lymphocytes. The expression of the antibody-encoding genes, the immunoglobulin (Ig) genes, is also restricted to B cells. The octamer sequence ATGCAAAT is present in the promoter and the enhancer of Ig genes, and plays an important role in its tissue-specific expression. This sequence motif is a binding site for nuclear proteins, the so-called octamer transcription factors (Oct or OTF factors). The Oct-1 protein is present in all cell types analyzed so far, whereas Oct-2A and Oct-2B are found mainly in B lymphocytes. All three proteins show the same sequence specificity and binding affinity. It appears that the B cell-specific expression of Ig genes is mediated at least in part by cell type-specific Oct factors, and that there are both quantitative and qualitative differences between Oct-1 and Oct-2 factors. Recently, a number of other octamer factor variants were identified. Many of these may be created by alternative splicing of a primary transcript of one Oct factor gene and may serve a specific function in the fine tuning of gene expression.
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页码:1444 / 1449
页数:6
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