Editing the fabric of life

Though humans have roughly the same number of protein-coding genes as worms and flies, our developmental pathways are much more complex. This is partly due to a mechanism known as ribonucleic acid (RNA) editing, where RNA molecules are processed as they carry genetic information from the genome to protein production machinery in the cytoplasm.

NTU researchers investigated a novel type of RNA editing called A-to-I editing, where the nucleic acid adenosine is exchanged with inosine. They compared the RNA profiles of over 8,500 human tissue samples with those from non-human primates and mice.

This schematic illustrates how RNA editing can increase the number of distinct biomolecules present in the cell beyond what is dictated by the genome. The distinct biomolecules can cause the cells to behave differently. Credit: Tan Meng How.

“We found that in humans the highest amount of editing occurs in the artery, and not in the brain as previously thought,” says team leader Assoc Prof Tan Meng How of NTU’s School of Chemical and Biomedical Engineering.

The team also discovered that RNA profiles are more similar between different tissues of the same organism (such as the human brain and lung) than between the same tissue of different organisms (such as the brains of humans, mice or chimpanzees).

The findings are described in “Dynamic landscape and regulation of RNA editing in mammals”, published in Nature (2017), DOI: 10.1038/nature24041.

This article appeared first in NTU’s research & innovation magazine Pushing Frontiers (issue #13, June 2018).