Wnt生長因子是決定細胞命運的基本調節(jié)因子，但是Wnt信號是如何在生物反應中轉錄翻譯的目前還了解不太*。近日來自意大利帕多瓦大學醫(yī)學院的科研人員報導了作為下游元件的信號/β-連環(huán)蛋白級聯(lián)中一個強大的生物轉錄激活TAZ，這擴寬了人們對Wnt信號通路的認識，相關論文發(fā)表在2012年12月13日的Cell雜志上。

TAZ基因編碼的蛋白質在心臟和骨骼肌中表達水平很高，這個基因的突變已與一些臨床疾病存在關聯(lián)。在本次研究中，研究人員發(fā)現(xiàn)TAZ在Hippo信號通路中充分發(fā)揮了介質作用，在沒有Wnt 信號的條件下，作為β-catenin的復合體組成部分的APC, Axin, 和 GSK3保持較低水平，TAZ降解取決于磷酸化β-連環(huán)（TAZ及其泛素連接酶β- trcp）。

在Wnt 信號中，β-catenin復合體的破壞導致TAZ降解。全基因組水平上，很大一部分的Wnt 基因轉錄的反應由TAZ.介導。TAZ.的激活是Wnt信號和相關生物效應中的普遍特征。

原文摘要：

Role of TAZ as Mediator of Wnt Signaling

Wnt growth factors are fundamental regulators of cell fate, but how the Wnt signal is translated into biological responses is incompley understood. Here, we report that TAZ, a biologically potent transcriptional coactivator, serves as a downstream element of the Wnt/β-catenin cascade. This function of TAZ is independent from its well-established role as mediator of Hippo signaling. In the absence of Wnt activity, the components of the β-catenin destruction complex—APC, Axin, and GSK3—are also required to keep TAZ at low levels. TAZ degradation depends on phosphorylated β-catenin that bridges TAZ to its ubiquitin ligase β-TrCP. Upon Wnt signaling, escape of β-catenin from the destruction complex impairs TAZ degradation and leads to concomitant accumulation of β-catenin and TAZ. At the genome-wide level, a substantial portion of Wnt transcriptional responses is mediated by TAZ. TAZ activation is a general feature of Wnt signaling and is functionally relevant to mediate Wnt biological effects.