セミナー情報

In eukaryotic organisms, numerous transposons and other repetitive sequences are subjected to DNA methylation-mediated transcriptional silencing in order to maintain genome stability. On the other hand, some repetitive sequences including repetitive genes and genes containing repeat elements need to be protected from epigenetic silencing in order to be expressed. The ROS1 subfamily of 5-methylcytosine DNA glycosylases/lyases functions to prevent transcriptional gene silencing in Arabidopsis by active DNA demethylation. Our recent forward genetic screens have identified several proteins such as the histone acetyltransferase IDM1, the alpha-crystallin domain-containing proteins IDM2 and IDM3, and the methyl-DNA-binding protein MBD7, that are required for ROS1 to demethylate some genomic loci. Our results suggest that these proteins form a protein complex that helps to recognize ROS1 target loci and create a permissible chromatin environment for ROS1 to demethylate the target DNA.

References

Lang Z, Lei M, Wang X, Tang K, Miki D, Zhang H, Mangrauthia SK, Liu W, Nie W, Ma G, Yan J, Duan CG, Hsu CC, Wang C, Tao WA, Gong Z, Zhu JK. 2015. Demethylation to Limit DNA Hyper-Methylation and Transcriptional Gene Silencing. Mol Cell. 2015 Feb 11. pii: S1097-2765(15)00010-6. doi: 10.1016/j.molcel.2015.01.009. [Epub ahead of print] PMID: 25684209.

Lei M, La H, Lu K, Wang P, Miki D, Ren Z, Duan CG, Wang X, Tang K, Zeng L, Yang L, Zhang H, Nie W, Liu P, Zhou J, Liu R, Zhong Y, Liu D, Zhu JK. 2014. Arabidopsis EDM2 promotes IBM1 distal polyadenylation and regulates genome DNA methylation patterns. Proc Natl Acad Sci U S A. 111: 527-532.