Guanine-quadruplexes and possible role in nutritional epigenetics and aging

Abstract

Guanine-quadruplexes are secondary DNA structures that have recently gained a lot of interest from the scientific community. These stable tetra-stranded DNA structures have been identified as mediators of DNA replication and regulators of gene expression and recombination. During DNA replication, these guaninequadruplex structures must be resolved by DNA helicases to prevent telomere dysfunction and DNA damage. Premature aging disorders exhibiting elevated DNA damage are characterized by mutation in DNA helicases involved in resolving guanine-quadruplexes. Epigenetic modification mechanisms such as DNA methylation as well as DNA base oxidation have been indicated to play a significant role regarding stability and occurrence of guanine-quadruplexes. Consequently, the stability and presence of guanine-quadruplexes in the genome may be affected by excess or insufficiencies in nutritional factors involved in DNA methylation and oxidation mechanisms. We also discuss the hypothesis that guanine- quadruplex structures may be associated with changes in genome integrity such as DNA damage. Guanine-quadruplexes have recently emerged as having important biological roles in both nutrition and aging, and they require further investigation as to their application in research for new biomarkers of disease.