Chen X, Rubock M J, Whitman M
Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA.
Nature. 1996 Oct 24;383(6602):691-6. doi: 10.1038/383691a0.
The transforming-growth-factor-beta (TGF-beta) superfamily is critical for establishing mesoderm during early embryogenesis in Xenopus. The transcriptional activation of Mix.2, an immediate-early response gene specific to activin-like members of the TGF-beta superfamily, is associated with the rapid appearance of a site-specific DNA-binding activity that recognizes a fifty-base-pair regulatory element known as ARE in the Mix.2 promoter. Cloning of the site-specific DNA-binding component of this activity revealed it to be a new winged-helix transcription factor and a direct target for signalling by the TGF-beta superfamily. XMAD2, a recently identified TGF-beta signal transducer, forms a complex with the transcription factor in an activin-dependent fashion to generate an activated ARE-binding complex. A model is proposed to explain how TGF-beta superfamily signals might regulate the expression of specific genes in the early embryo.
转化生长因子β（TGF-β）超家族对于非洲爪蟾早期胚胎发育过程中中胚层的形成至关重要。Mix.2是TGF-β超家族中激活素样成员特有的即时早期反应基因，其转录激活与一种位点特异性DNA结合活性的快速出现相关，该活性识别Mix.2启动子中一个被称为ARE的50个碱基对的调控元件。对该活性的位点特异性DNA结合成分进行克隆后发现，它是一种新的翼状螺旋转录因子，也是TGF-β超家族信号传导的直接靶点。XMAD2是最近鉴定出的一种TGF-β信号转导分子，它以激活素依赖的方式与转录因子形成复合物，从而产生一种活化的ARE结合复合物。本文提出了一个模型来解释TGF-β超家族信号如何调控早期胚胎中特定基因的表达。
