第676回 生医研セミナー(多階層生体防御システム研究拠点)
下記のとおり、理化学研究所・統合生命医科学研究センターのJafar Sharif博士によるセミナーを開催致します。皆様のご来聴を心より歓迎いたします。
演題
Activation of repressed genes: A ménage à trois between hemimethylated DNA, Np95/Uhrf1 and ESET/Setdb1
（seminar in English）
演者
Dr. Jafar Sharif
理化学研究所・統合生命医科学研究センター
Developmental Genetics Laboratory, RIKEN Center for Integrative Medical Sciences
日時
2014年 7月4日（金） Jul. 4 (Fri), 2014
16：30～17：30
場所
九州大学 病院キャンパス内 生体防御医学研究所 本館1階 会議室
以下の地図の21番の建物になります。
（http://www.kyushu-u.ac.jp/access/map/hospital/hospital.html）
Seminar Room, Main Building 1F, Medical Institute of Bioregulation
No.21 on the following linked map.
（http://www.kyushu-u.ac.jp/access/map/hospital/hospital-e.html）
要旨
In the classical view for maintenance methylation, hemimethylated DNA (cytosine methylation in only one strand) is transiently generated at the replication foci, recognized by the SRA protein Np95 and converted into fully methylated ones by the activity of Dnmt1. Recent studies have challenged this model by showing that hemimethylated DNA persists in the genome, likely in a post-replicative manner, and may account for 5-10% of all methylated CpG dyads. However, the physiological roles of hemimethylated DNA remain obscure. In this talk, I am going to introduce some of our recent findings on elucidation of the function of hemimethylated DNA. In brief, we have found that Np95, a protein that is crucial for maintenance methylation, plays an unexpected role to induce robust transcription from hemimethylated loci. Intriguingly, this appears to be mediated by a previously unknown mechanism, namely, counter-silencing of the ESET/Setdb1-H3K9me3 repressive pathway by Np95 upon recognition of hemimethylated DNA. Finally, I will also discuss the physiological implications of such mechanisms by showing that the hemimethylated DNA and Np95 axis is essential for expressing endogenous retrotransposon derived sequences specifically in the trophoblast.
業績
Sharif J. et al., The SRA protein Np95 mediates epigenetic inheritance byrecruiting Dnmt1 to methylated DNA. Nature 450, 908-912 (2007)
連絡先
生体防御医学研究所 エピゲノム制御学分野 一柳 健司
Division of Epigenomics and Development, MIB, Kenji ICHIYANAGI
電話：092-642-6760