Treier M, Bohmann D, Mlodzik M
Differentiation Programme, European Molecular Biology Laboratory, Heidelberg, Federal Republic of Germany.
Cell. 1995 Dec 1;83(5):753-60. doi: 10.1016/0092-8674(95)90188-4.
R7 photoreceptor fate in the Drosophila eye induced by the activation of the Sevenless receptor tyrosine kinase and the RAS/MAP kinase signal transduction pathway. We show that expression of a constitutively activated JUN isoform in ommatidial precursor cells is sufficient to induce R7 fate independent of upstream signals normally required for photoreceptor determination. We present evidence that JUN interacts with the ETS domain protein Pointed to promote R7 formation. This interaction is cooperative when both proteins are targeted to the same promoter and is antagonized by another ETS domain protein, YAN, a negative regulator of R7 development. Furthermore, phyllopod, a putative transcriptional target of RAS pathway activation during R7 induction, behaves as a suppressor of activated JUN. Taken together, these data suggest that JUN and Pointed act on common target genes to promote neuronal differentiation in the Drosophila eye, and that phyllopod might be such a common target.
果蝇眼中由Sevenless受体酪氨酸激酶和RAS/MAP激酶信号转导途径激活所诱导的R7光感受器命运。我们表明，在小眼体前体细胞中组成型激活的JUN亚型的表达足以独立于光感受器确定通常所需的上游信号来诱导R7命运。我们提供的证据表明，JUN与ETS结构域蛋白Pointed相互作用以促进R7形成。当这两种蛋白靶向同一启动子时，这种相互作用是协同的，并且被另一种ETS结构域蛋白YAN（R7发育的负调节因子）所拮抗。此外，phyllopod是R7诱导过程中RAS途径激活的一个假定转录靶点，其表现为激活的JUN的抑制因子。综上所述，这些数据表明JUN和Pointed作用于共同的靶基因以促进果蝇眼中的神经元分化，并且phyllopod可能就是这样一个共同的靶点。
