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bioRxiv · 10.1101/175091

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

Zhang, C.·Hung, Y.-H.·Zhang, X.-Q.·Zhang, D.·Xiao, W.·Iyer, L. M.·Aravind, L.·Huh, J. H.·Hsieh, T.-F.
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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.

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Zhang, C., Hung, Y.-H., Zhang, X.-Q., Zhang, D., Xiao, W., Iyer, L. M., Aravind, L., Huh, J. H., Hsieh, T.-F.. 2017-08-10. The roles of Conserved Domains in DEMETER-Mediated Active DNA Demethylation in planta. https://doi.org/10.1101/175091

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