Hsiang Y H, Goldman J P, Raulet D H
Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.
J Immunol. 1995 May 15;154(10):5195-204.
An enhancer has been localized 3 kb downstream of the C gamma 1 gene segment of the murine TCR-gamma locus. One element, the gamma 3 site, has been shown to be critical for its functional activity. Here we have determined that Myb-related transcription factors bind to the gamma 3 site and appear to be critical for the full activity of the TCR-gamma enhancer. c-myb products can transactivate the gamma 3 site in cell lines that do not ordinarily support enhancer activity of the gamma 3 site. Mutations in the myb site or an adjacent site for core-binding factor(s) prevent transactivation. c-myb expression in various cell lines is consistent with their capacity to activate the gamma 3 enhancer element using transient transfection assays. Therefore, c-Myb or a related factor appears to play an important role in regulating the murine TCR-gamma enhancer.
一个增强子定位于小鼠TCR-γ基因座Cγ1基因片段下游3 kb处。其中一个元件，即γ3位点，已被证明对其功能活性至关重要。在此，我们确定Myb相关转录因子与γ3位点结合，并且似乎对TCR-γ增强子的完全活性至关重要。c-myb产物可在通常不支持γ3位点增强子活性的细胞系中转激活γ3位点。Myb位点或核心结合因子的相邻位点发生突变会阻止转激活。通过瞬时转染试验，c-myb在各种细胞系中的表达与其激活γ3增强子元件的能力一致。因此，c-Myb或相关因子似乎在调节小鼠TCR-γ增强子中起重要作用。
