Abstract
TALE-nuclease chimeras (TALENs) can bind to and cleave specific genomic loci and, are used to engineer gene knockouts and additions. Recently, instead of using the FokI domain, epigenetically active domains, such as TET1 and LSD1, have been combined with TAL effector domains to regulate targeted gene expression via DNA and histone demethylation. However, studies of histone methylation in the TALE system have not been performed. Therefore, in this study, we established a novel targeted regulation system with a TAL effector domain and a histone methylation domain. To construct a TALE-methylation fusion protein, we combined a TAL effector domain containing an E-Box region to act as a Snail binding site and the SET domain of EHMT 2 to allow for histone methylation. The constructed TALE-SET module (TSET) repressed the expression of E-cadherin via by increasing H3K9 dimethylation. Moreover, the cells that overexpressed TSET showed increased cell migration and invasion. This is the first phenotype-based study of targeted histone methylation by the TALE module, and this new system can be applied in new cancer therapies to reduce side effects.
Highlights
Transcription activator-like (TAL) effector nucleases (TALENs) can introduce genetic modifications such as gene knockouts and additions, by selective genomic cleavage [1, 2]
We found that expression of E-cadherin was repressed and cell migration and invasion were increased by TALE-SET module (TSET)
To establish a targeted histone methylation system with TAL effector repeat domains, we focused on E-cadherin regulation by the G9a-Snail complex
Summary
Transcription activator-like (TAL) effector nucleases (TALENs) can introduce genetic modifications such as gene knockouts and additions, by selective genomic cleavage [1, 2]. A TALEN-based knockout library for human microRNAs was constructed, and targeted gene knockout was performed in chickens, mice and zebrafish [3,4,5,6]. The TALEN system was applied for targeted regulation in cancer and for the pluripotent stem cell (iPS) cells [7, 8]. Several papers have reported that epigenetically active domains, such as TET1 and LSD1, combined with TAL effector domains can successfully regulate targeted gene expression. TALE-TET1 directly activated the expression of KLF4, RHOXF2 and HBB via targeted DNA demethylation. TALE-LSD1 was capable of demethylating enhancer-associated chromatin modifications [9, 10]. Studies of histone methylation in the TALE system have not been performed
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call