京都大学 / 新制・課程博士 / 博士(生命科学) / 甲第25448号 / 生博第519号 / 京都大学大学院生命科学研究科統合生命科学専攻 / (主査)教授 河内 孝之, 教授 荒木 崇, 教授 中野 雄司 / 学位規則第4条第1項該当 / Doctor of Philosophy in Life Sciences / Kyoto University / DFAM

In many organisms, the most fundamental event during embryogenesis is differentiating between germline cells and specialized somatic cells. In C. elegans, PIE-1 functions to protect the germline from somatic differentiation and appears to do so by blocking transcription and by preventing chromatin remodeling in the germline during early embryogenesis. Yet the molecular mechanisms by which PIE-1 specifies germline remain poorly understood. Our work shows that SUMOylation facilitates PIE-1-dependent germline maintenance and specification. In vivo SUMO purification in various CRISPR strains revealed that PIE-1 is SUMOylated at lysine 68 in the germline and that this SUMOylation is essential for forming NuRD complex and preserving HDA-1 activity. Moreover, HDA-1 SUMOylation is dependent on PIE-1 and enhanced by PIE-1 SUMOylation, which is required for protecting germline integrity. Our results suggest the importance of SUMOylation in the germline maintenance and exemplify simultaneous SUMOylation of proteins in the same functional pathway.