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HOX Loci Focused CRISPR/sgRNA Library Screening Identifying Critical CTCF Boundaries
Published on: March 31, 2019
Cohesins functionally associate with CTCF on mammalian chromosome arms
Vania Parelho1, Suzana Hadjur, Mikhail Spivakov
1Lymphocyte Development Group, MRC Clinical Sciences Centre, Imperial College London, Du Cane Road, London W12 0NN, UK.
Cell
|February 2, 2008
Summary
Mammalian cohesins bind to DNA at specific sites, guided by CTCF protein. This binding explains cohesin’s role in gene regulation and integrates DNA sequence with epigenetic information.
Area of Science:
- Molecular Biology
- Genetics
- Epigenetics
Background:
- Cohesins are crucial for sister chromatid cohesion, vital for accurate chromosome segregation and DNA repair.
- Cohesins also influence gene expression and enhancer-promoter interactions, but the mechanisms were unclear.
- Understanding cohesin-binding sites and interactors in mammals was lacking.
Purpose of the Study:
- To identify cohesin-binding sites on mammalian chromosomes.
- To elucidate the functional interactors of cohesins in metazoans.
- To explain the noncanonical functions of cohesins in gene regulation.
Main Methods:
- Chromatin analysis to map cohesin distribution on mammalian chromosomes.
- Identification of sequence motifs at cohesin-binding sites.
- Investigating the role of CTCF in cohesin localization using genetic depletion.
Main Results:
- Cohesin distribution on mammalian chromosomes is independent of transcriptional activity.
- Mammalian cohesins preferentially bind to DNase I hypersensitive sites containing CTCF motifs.
- CTCF is essential for the localization of cohesins to these sites.
- Cohesin positioning is influenced by DNA sequence and epigenetic state via CTCF.
Conclusions:
- CTCF acts as a primary factor in recruiting cohesins to specific genomic locations in mammals.
- This CTCF-mediated recruitment provides a mechanistic explanation for cohesins' roles in gene regulation.
- Cohesin positioning integrates DNA sequence information with epigenetic modifications like DNA methylation.
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