Melnikova Larisa, Kostyuchenko Margarita, Molodina Varvara, Parshikov Alexander, Georgiev Pavel, Golovnin Anton
Department of Drosophila Molecular Genetics, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St, Moscow, Russia, 119334.
Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St, Moscow, Russia, 119334.
Chromosoma. 2018 Mar;127(1):59-71. doi: 10.1007/s00412-017-0645-6. Epub 2017 Sep 22.
The best-studied Drosophila insulator complex consists of two BTB-containing proteins, the Mod(mdg4)-67.2 isoform and CP190, which are recruited cooperatively to chromatin through interactions with the DNA-binding architectural protein Su(Hw). While Mod(mdg4)-67.2 interacts only with Su(Hw), CP190 interacts with many other architectural proteins. In spite of the fact that CP190 is critical for the activity of Su(Hw) insulators, interaction between these proteins has not been studied yet. Therefore, we have performed a detailed analysis of domains involved in the interaction between the Su(Hw) and CP190. The results show that the BTB domain of CP190 interacts with two adjacent regions at the N-terminus of Su(Hw). Deletion of either region in Su(Hw) only weakly affected recruiting of CP190 to the Su(Hw) sites in the presence of Mod(mdg4)-67.2. Deletion of both regions in Su(Hw) prevents its interaction with CP190. Using mutations in vivo, we found that interactions with Su(Hw) and Mod(mdg4)-67.2 are essential for recruiting of CP190 to the Su(Hw) genomic sites.
研究最为深入的果蝇绝缘子复合体由两种含BTB结构域的蛋白质组成，即Mod(mdg4)-67.2亚型和CP190，它们通过与DNA结合结构蛋白Su(Hw)相互作用而协同募集到染色质上。虽然Mod(mdg4)-67.2仅与Su(Hw)相互作用，但CP190与许多其他结构蛋白相互作用。尽管CP190对Su(Hw)绝缘子的活性至关重要，但这些蛋白质之间的相互作用尚未得到研究。因此，我们对Su(Hw)与CP190之间相互作用所涉及的结构域进行了详细分析。结果表明，CP190的BTB结构域与Su(Hw) N端的两个相邻区域相互作用。在存在Mod(mdg4)-67.2的情况下，Su(Hw)中任一区域的缺失仅对CP190募集到Su(Hw)位点产生微弱影响。Su(Hw)中两个区域均缺失则会阻止其与CP190的相互作用。通过体内突变，我们发现与Su(Hw)和Mod(mdg4)-67.2的相互作用对于CP190募集到Su(Hw)基因组位点至关重要。
