Discovery of new epigenetic modification by sugar linked to evolution of placental animals

September 12, 2016

Possibilities for elucidating/treating mammalian-specific diseases, nutritional science

Genomic DNA is wound around histone proteins in a nucleosome structure, with the structure determining how genes are used. Joint research work between the University of Tokyo, Waseda University and RIKEN CSRS has revealed a novel histone modification by N-acetylglucosamine. This sugar modification is generally known to have nutritional responsiveness and to exist in areas significantly influential to the nucleosome structures. Histones have various isoforms which are highly homologous and considered to have similar functions. However, this novel sugar modification is only bound to possible histone isoforms which are exclusive to placental animals, proving that isoforms have a distinct function. Diversity in organic evolution is difficult to explain solely through an increase in gene numbers. Around the period that viviparous animals first appeared, histone sugar modification became possible from a single amino acid change. If the resulting nucleosome diversity led to diversity in gene use, it could be that this development led to the appearance of epigenetic evolution in placental animals.

Monoclonal antibodies that specifically recognize the discovered sugar modification could serve as a powerful tool for elucidating biological functions–particularly for identifying the causes of/developing treatments for mammalian-specific diseases–or play an important role in the field of nutritional science.

 

Original article
Scientific Reports doi:10.1038/srep31785
M. Hirosawa, K. Hayakawa, C. Yoneda, D. Arai, H. Shiota, T. Suzuki, S. Tanaka, N. Dohmae, K. Shiota,
"Novel O-GlcNAcylation on Ser40 of canonical H2A isoforms specific to viviparity".

Contact
Naoshi Dohmae
Unit Leader
Biomolecular Characterization Unit