报告人：Min-Hao Kuo， Associate Professor，Department of Biochemistry and Molecular Biology, Michigan State University
报告题目：Chromatin control of mitotic segregation & Longevity promotion by intracellular triacylglycerol
报告时间： 2016年7月18日 上午10:00
报告地点： 图书馆报告厅
主持人： 骆健俊 博士
报告摘要：
Prof. Kuo will present two stories on the regulation of mitosis and of lifespan. In the first,“Chromatin control of mitotic segregation”, evidence will be shown for the existence of the tension sensing motif of histone H3 that plays a critical role in the establishment of biorientation of mitotic chromosomes. This novel motif of H3 functions by retaining the conserved Shugoshin protein, Sgo1p, at the pericentromeres. Intriguingly, loss-of-function mutations of the tension sensing motif are suppressed by deleting a histone acetyltransferase or mutations in the N’tail domain, but phenotypically augmented by deleting a histone deacetylases. ChIP-Seq further demonstrates a unique tension sensing motif-dependent Sgo1p localization pattern in each chromosome. Their data suggest an intricate network of histone, chromatin modifying enzymes, and Sgo1p in establishing biorientation that is essential for successful segregation during cell division.
The second story regards the novel pro-longevity function of cellular triacylglycerol (TAG) in yeast. TAG is a ubiquitous fat best known for its high-density energy storage. However, in many species, TAG accumulation is triggered by stresses, not excessive nutrients. Prof. Kuo and his colleagues discovered that yeast cells, which synthesize TAG in the stationary phase, with more TAG, by natural variation or by genetic manipulation, live much longer than normal or lean cells. Importantly, TAG promotes longevity via an energy-independent manner that is distinct from several conserved longevity factors, including dietary restriction and the Target of Rapamycin (TOR) pathway. They suspect that TAG is part of a stress response that protects aging cells from damages derived from metabolism. A“Radicals Sink”model will be discussed.
