Chauveau C, Pinaud E, Cogne M
Laboratoire d'Immunologie, CNRS EP118, Faculté de Médecine, Limoges, France.
Eur J Immunol. 1998 Oct;28(10):3048-56. doi: 10.1002/(SICI)1521-4141(199810)28:10<3048::AID-IMMU3048>3.0.CO;2-V.
Transcriptional enhancers of the IgH locus include E mu and four 3' elements (C alpha3', hs1-2, hs3 and hs4), some of which are by themselves weak. We show that these weak elements behave as strong "co-enhancers" when combined, and display a stage-dependent activity which differs from that obtained when they are alone. Combinations mimicking the palindromic structure of the 3' IgH region are particularly efficient. Noticeably in pre-B cells, hs4 is boosted by the addition of elements previously considered inactive at this stage, hs1-2 and hs3. Combinations of 3' elements also strongly boost E mu at all maturation stages, but inhibitory interactions occasionally occur between E mu and incomplete 3' combinations, indicating that full transcriptional activity is mainly achieved when all 5' and 3' partners play their respective roles.
免疫球蛋白重链（IgH）基因座的转录增强子包括Eμ和四个3'元件（Cα3'、hs1-2、hs3和hs4），其中一些本身作用较弱。我们发现，这些弱元件组合时表现为强“协同增强子”，并呈现出阶段依赖性活性，这与它们单独存在时不同。模拟3'Igh区域回文结构的组合特别有效。值得注意的是，在前B细胞中，添加此前认为在此阶段无活性的元件hs1-2和hs3可增强hs4。3'元件的组合在所有成熟阶段也能强烈增强Eμ，但Eμ与不完全的3'组合之间偶尔会发生抑制性相互作用，这表明只有当所有5'和3'元件发挥各自作用时，才能实现完全的转录活性。
