Researchers have identified properties in the protective structure of DNA that could transform the way scientists think about the human genome. Molecules involved in DNA’s supportive scaffolding go through dynamic and responsive changes to shield against mutations, recent research has shown. Experts say this finding is crucial to understanding DNA damage and genome organisation, and could impact current thinking on DNA-linked diseases, including cancers.
Researchers, led by the University of Edinburgh, showed that a chemical called scaffold attachment factor A (SAF-A) binds to specific molecules known as chromatin-associated RNAs (caRNAs) to form a protective chromatin mesh. For the first time, this mesh was shown to be dynamic, assembling and disassembling, and allowing the structure to be flexible and responsive to cell signals. In addition, loss of SAF-A was found to lead to abnormal folding of DNA, and to promote damage to the genome.
SAF-A has previously been shown in mouse studies to be essential to embryo development, and mutations of the SAF-A gene have been found in cancer gene screening studies. Scientists say the findings shed light on how chromatin protects DNA from high numbers of harmful mutations, a condition known as genetic instability.
The study, published in the journal Cell, was carried out in collaboration with Heriot Watt University. It was funded by the Medical Research Council (MRC).