Architects of the genome

Fitting two metres of DNA into a microscopic cell nucleus: that is the challenge that cohesin takes on, folding long chromosomes into many loops. CTCF, a nuclear protein, binds to DNA and acts as a barrier to cohesin, regulating its activity and restraining loop formation to specific areas of the genome. In a study published in Nature, IMP scientists and collaborators visualise CTCF in real time, showing that its role as a regulator of genome architecture is much more fine-tuned than expected.