The roles of Conserved Domains in DEMETER-Mediated Active DNA Demethylation in planta

Full Title: The roles of Conserved Domains in DEMETER-Mediated Active DNA Demethylation in planta

Journal: bioRxiv

Year of Publication: 2017

PHHI Author(s): Tzung-Fu Hsieh Changqing Zhang
Publication Author(s): Changqing Zhang, Yu-Hung Hung, Xiang-Qian Zhang, Dapeng Zhang, Wenyan Xiao, Lakshminarayan M Iyer, L Aravind, Jin Hoe Huh, Tzung-Fu Hsieh

Abstract:

DNA methylation plays critical roles in maintaining genome stability, genomic imprinting, transposon silencing, and development. In Arabidopsis genomic imprinting is established in the central cell by DEMETER (DME)-mediated active DNA demethylation, and is essential for seed viability. DME is a large polypeptide with multiple poorly characterized conserved domains. Here we show that the C-terminal enzymatic core of DME is sufficient to complement dme associated developmental defects. When targeted by a native DME promoter, nuclear-localized DME C-terminal region rescues dme seed abortion and pollen germination defects, and ameliorates CG hypermethylation phenotype in dme-2 endosperm. Furthermore, targeted expression of the DME N-terminal region in wild-type central cell induces dme-like seed abortion phenotype. Our results support a bipartite organization for DME protein, and suggest that the N-terminal region might have regulatory function such as assisting in DNA binding and enhancing the processivity of active DNA demethylation in heterochromatin targets.

Link to Article: https://www.biorxiv.org/content/early/2017/08/10/175091