Tang Z, Kadesch T
Department of Genetics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6145, USA.
Nucleic Acids Res. 2001 Jun 1;29(11):2284-91. doi: 10.1093/nar/29.11.2284.
CSL is the primary target of the Notch signaling pathway in mammalian cells. It is a DNA binding protein that generally represses transcription in the absence of Notch signaling and activates transcription upon formation of a ternary complex with NICD, the protease-generated intracellular domain of NOTCH: Previous mapping experiments identified the central third of CSL as both necessary and sufficient for DNA binding and activation by NOTCH: Here we show that CSL promotes transcription in 293T cells in the absence of added NICD and that this activity requires both the central domain plus the C-terminal third of the protein. Evidence is presented that argues against a contribution of endogenous NICD and instead supports the possibility that distinct coactivators may directly stimulate the activity of CSL in a cell type-specific manner. This conclusion supports a recent finding that Drosophila CSL (Suppressor of Hairless) can also mediate transcriptional activation in the absence of NOTCH:
CSL是哺乳动物细胞中Notch信号通路的主要靶点。它是一种DNA结合蛋白，在没有Notch信号时通常抑制转录，而在与NICD（NOTCH蛋白酶产生的细胞内结构域）形成三元复合物后激活转录：先前的定位实验确定CSL的中间三分之一对于DNA结合和Notch激活是必要且充分的：在这里我们表明，在没有添加NICD的情况下，CSL在293T细胞中促进转录，并且这种活性需要蛋白质的中央结构域加上C端的三分之一。有证据表明内源性NICD没有作用，而是支持不同的共激活因子可能以细胞类型特异性方式直接刺激CSL活性的可能性。这一结论支持了最近的一项发现，即果蝇CSL（无翅抑制因子）在没有Notch的情况下也能介导转录激活。
