A genetical screening of a protein trap library for active chromatin-binding factors on polytene chromosome in Drosophila

显然，基因调控与染色质重组是耦合的，但参与这一过程的因素和分子基础仍有待确定。在本研究中，通过建立EGFP蛋白陷阱方法，对果蝇蜕皮激素诱导的羽毛形成的相关因素进行了遗传筛选。在候选中，果蝇CG11138/Ringfect被发现是蜕皮激素受体(ECR)的共同激活剂。通过生化鉴定，Ringfect可以作为组蛋白的伴侣。我们描述了通过筛选蛋白陷阱转基因果蝇文库来鉴定新的泡芙定位因子。果蝇CG11138/Ringfect和烯醇化酶在遗传学上被认为是一种喷雾定位因子和共激活因子，并与S2细胞中的ECR相互作用。因此，本研究认为Ringfect和Enolase被归类为一类新的核受体共激活剂。

It is evident that gene regulation is coupled with chromatin reorganaization, but factors and molecular basis involving in this process remain to be identified. In the present study, factors responsible for ecdysone-induced puff formation were genetically screened in Drosophila fly by establishing an EGFP protein-trap approach. Among the candidates, Drosophila CG11138/Ringfect was found as a co-activator for ecdysone receptor (EcR). Through biochemical characterization, Ringfect could be shown to serve as a histone chaperon. We describe the identification of novel puff-localized factors by screening the protein trap transgenic fly library. Drosophila CG11138/Ringfect and enolase were genetically identified as a puff-localized factor and a co-activator, and interacted with EcR in S2 cell. Thus, the present study suggests that Ringfect and enolase are categorized as a novel class of nuclear receptor co-activators.