Mysterious DNA Modification Seen in Stress Response
Source: Emory University
Summary: In a recent study researchers have found that modification of DNA appears more in the brain under stress conditions.
The research advancement in Genomics is leading to the discovery of additional components of the DNA alphabet in animals. Are these unusual chemical modifications of DNA have a valid reason or just the cellular machines making some mistakes? A team of Geneticists led by Peng Jin at Emory University School of Medicine have been studying a modification of DNA – methylation of the DNA letter A (adenine) which is not well understood in animals. They have found that modification of DNA appears more in the brain under stress conditions which may have a role in neuropsychiatric disorders. The results were published in the journal Nature Communications.
Methylation is the addition of a methyl group (-CH3) to the Cytosine and Adenine residues of the DNA and leads to the epigenetic modification of DNA. Generally, methylation on cytosine shuts genes off where the DNA code is read without altering the DNA letters themselves. Methylation of Adenine was previously observed in bacteria and the same modification was recently identified in the DNA of insects and mammals. Yao, Jin and colleagues, observed the brain’s prefrontal cortex region of the mice that were subjected to stress and found that there is an increase the amount N6-methyl adenine in the brain cells rose to four-fold. The researchers speculated that these changes could contribute to the neuropsychiatric diseases by recruiting DNA binding proteins ectopically.
Vice-chair of research, Jin said, “We found that 6-methyl A is dynamic, which could suggest a functional role”, “That said, the enzymes that recognize, add and erase this type of DNA methylation are still mysterious” and further added “It does appear that the enzymes that add methyl groups to A when it is part of RNA are not involved.”
More Information: Bing Yao et al, “DNA N6-methyladenine is dynamically regulated in the mouse brain following environmental stress”, Nature Communications (2017). DOI: 10.1038/s41467-017-01195-y