Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095-1662, USA.
Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095-1662, USA.
Gene Expr Patterns. 2020 Dec;38:119153. doi: 10.1016/j.gep.2020.119153. Epub 2020 Nov 10.
Dact/Dapper/Frodo members belong to an evolutionarily conserved family of Dishevelled-binding proteins present in mammals, birds, amphibians and fishes that are involved in the regulation of Wnt and TGF-β signaling. In addition to the three established genes (Dact1-3) that compose the Dact family, a fourth paralogue group of related proteins has been recently identified and named Dact-4. Interestingly, Dact-4 is the most rapidly evolving gene of the entire family, as it displays very low homology with other Dact proteins and has lost key conserved domains. Dact-4 is not present in mammals, but weakly conserved homologs were found in reptiles and fishes. Recent RNAseq from our group identified new genes specifically expressed in the Xenopus laevis Spemann organizer. Among these, LOC100170590 mRNA encoded a protein sharing weak homology with a coelacanth Dact-like protein member. Here, by analyzing protein phylogeny and synteny, we show that this organizer gene corresponds to Dact-4. We report that Dact-4 is expressed in the Xenopus blastula pre-organizer region in addition to the gastrula organizer, as well as in placodes, eyes, neural tube, presomitic mesoderm and pronephros. Dact-4-Flag microinjection experiments suggest it is a nucleocytoplasmic protein, as are the other Dact paralogues.
Dact/Dapper/Frodo 成员属于一个进化保守的 Dvl 结合蛋白家族，存在于哺乳动物、鸟类、两栖动物和鱼类中，参与 Wnt 和 TGF-β信号的调节。除了组成 Dact 家族的三个已建立的基因（Dact1-3）外，最近还鉴定出了第四个相关蛋白的 Dact 基因家族成员，称为 Dact-4。有趣的是，Dact-4 是整个家族中进化最快的基因，因为它与其他 Dact 蛋白的同源性很低，并且失去了关键的保守结构域。Dact-4 不存在于哺乳动物中，但在爬行动物和鱼类中发现了较弱的同源物。我们小组最近的 RNAseq 鉴定出了在非洲爪蟾 Spemann 组织者中特异性表达的新基因。其中，LOC100170590 mRNA 编码的蛋白与腔棘鱼 Dact 样蛋白成员具有较弱的同源性。在这里，通过分析蛋白质系统发育和基因同线性，我们表明该组织者基因对应于 Dact-4。我们报告 Dact-4 在非洲爪蟾囊胚前组织者区域以及原肠胚组织者、颅神经嵴、眼睛、神经管、体节前中胚层和前肾表达。Dact-4-Flag 微注射实验表明它是一种核质蛋白，与其他 Dact 基因家族成员一样。
