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Updated: May 11, 2026

Exploring Sequence Space to Identify Binding Sites for Regulatory RNA-Binding Proteins
Published on: August 9, 2019
CCCTC-binding factor controls its own nuclear transport via regulating the expression of importin 13
Rong Wang1, Jingjing Shen, Peitang Huang
1Laboratory of Protein Engineering, Beijing Institute of Biotechnology, Beijing, China.
Abstract:
CCCTC-binding factor (CTCF), a multivalent zinc-finger protein, is involved in different aspects of regulation including promoter activation or repression, gene silencing, chromatin insulation, gene imprinting, X-chromosome inactivation, cell growth or differentiation and tumor genesis. However, the molecular mechanisms of CTCF nuclear import remains unclear. In this study, we showed that the expression of CTCF influenced the intracellular distribution of itself, which might go through transport receptor - import 13 (IPO13). We further confirmed that there is a CTCF target site in ipo13 -774∼-573 bp promoter region and CTCF regulates the expression of IPO13. Besides, GST pull-down and Co-IP experiments demonstrated that CTCF interacts with IPO13. Immunofluorescence staining showed that IPO13 influenced intracellular distribution of CTCF. In all, we conclude that CTCF regulates the expression of IPO13, which, in turn, mediates the nuclear import of CTCF.
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