CW198 acts as a genetic insulator to block enhancer-promoter interaction in plants
Insulators in vertebrates play a role in genome architecture and
orchestrate temporo-spatial enhancer-promoter interactions. In plants,
insulators and their associated binding factors have not been documented
as of yet, largely as a result of a lack of characterized insulators.
In this study, we took a comprehensive strategy to identify and validate
the enhancer-blocking insulator/CW198/. We show that a
1.08-kb/CW198/fragment from/Arabidopsis/can, when interposed between an
enhancer and a promoter, efficiently abrogate the activation function of
both constitutive and floral organ-specific enhancers in
transgenic/Arabidopsis/and tobacco plants.
In plants, both transcriptional crosstalk and spreading of histone
modifications were rarely detectable across/CW198/, which resembles the
insulation property observed across the CTCF insulator in the mammalian
genome. Taken together, our findings support that/CW198/acts as an
enhancer-blocking insulator in both/Arabidopsis/and tobacco.
The significance of the present findings and their relevance to the
mitigation of mutual interference between enhancers and promoters, as
well as multiple promoters in transgenes, is discussed.