Savitskaya Ekaterina, Melnikova Larisa, Kostuchenko Margarita, Kravchenko Elena, Pomerantseva Ekaterina, Boikova Tatiana, Chetverina Darya, Parshikov Aleksander, Zobacheva Polyna, Gracheva Elena, Galkin Alexander, Georgiev Pavel
Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia.
Mol Cell Biol. 2006 Feb;26(3):754-61. doi: 10.1128/MCB.26.3.754-761.2006.
The Su(Hw) insulator found in the gypsy retrotransposon is the most potent enhancer blocker in Drosophila melanogaster. However, two such insulators in tandem do not prevent enhancer-promoter communication, apparently because of their pairing interaction that results in mutual neutralization. Furthering our studies of the role of insulators in the control of gene expression, here we present a functional analysis of a large set of transgenic constructs with various arrangements of regulatory elements, including two or three insulators. We demonstrate that their interplay can have quite different outcomes depending on the order of and distance between elements. Thus, insulators can interact with each other over considerable distances, across interposed enhancers or promoters and coding sequences, whereby enhancer blocking may be attenuated, cancelled, or restored. Some inferences concerning the possible modes of insulator action are made from collating the new data and the relevant literature, with tentative schemes illustrating the regulatory situations in particular model constructs.
在吉普赛逆转座子中发现的Su(Hw)绝缘子是黑腹果蝇中最有效的增强子阻断剂。然而，两个串联的此类绝缘子并不能阻止增强子与启动子的通讯，这显然是由于它们的配对相互作用导致了相互中和。为了进一步研究绝缘子在基因表达调控中的作用，我们在此展示了对大量具有各种调控元件排列（包括两个或三个绝缘子）的转基因构建体的功能分析。我们证明，它们的相互作用可能会根据元件的顺序和距离产生截然不同的结果。因此，绝缘子可以在相当远的距离上相互作用，跨越插入的增强子、启动子和编码序列，从而增强子阻断作用可能会减弱、消除或恢复。通过整理新数据和相关文献，我们对绝缘子可能的作用模式进行了一些推断，并给出了示意特定模型构建体中调控情况的初步方案。
