Levy Dan, Adamovich Yaarit, Reuven Nina, Shaul Yosef
Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel.
Mol Cell. 2008 Feb 15;29(3):350-61. doi: 10.1016/j.molcel.2007.12.022.
Cells undergo apoptosis upon exposure to severe DNA damage stress. Under this condition, p73 is phosphorylated and activated by c-Abl. The transcription coactivator Yap1 binds p73 to generate a complex that escapes p73 proteasomal degradation and recruits p300 to support transcription of proapoptotic genes. However, the mechanism of selective activation of proapoptotic genes by Yap1 remained unclear. In this study, we show that c-Abl directly phosphorylates Yap1 at position Y357 in response to DNA damage. Tyrosine-phosphorylated Yap1 is a more stable protein that displays higher affinity to p73 and selectively coactivates p73 proapoptotic target genes. Furthermore, we show that Yap1 switches between p73-mediated proapoptotic and growth arrest target genes based on its phosphorylation state. Thus, our data demonstrate that modification of a transcription coactivator, namely the DNA damage-induced phosphorylation of Yap1 by c-Abl, influences the specificity of target gene activation.
细胞在受到严重DNA损伤应激时会发生凋亡。在这种情况下,p73会被c-Abl磷酸化并激活。转录共激活因子Yap1与p73结合形成一种复合物,该复合物可逃避p73的蛋白酶体降解,并募集p300以支持促凋亡基因的转录。然而,Yap1选择性激活促凋亡基因的机制仍不清楚。在本研究中,我们发现c-Abl会响应DNA损伤而直接在Y357位点磷酸化Yap1。酪氨酸磷酸化的Yap1是一种更稳定的蛋白质,对p73具有更高的亲和力,并选择性地共激活p73促凋亡靶基因。此外,我们还发现Yap1会根据其磷酸化状态在p73介导的促凋亡和生长停滞靶基因之间切换。因此,我们的数据表明,转录共激活因子的修饰,即c-Abl诱导的Yap1的DNA损伤依赖性磷酸化,会影响靶基因激活的特异性。