近期研究表明丙酮酸激酶调控细胞衰老，但其中的分子生物学机制并不清楚。端粒在细胞衰老中起关键作用，研究表明端粒的异染色质沉默可调控细胞衰老。申请人前期利用蛋白质组学工具发现丙酮酸激酶Pyk1通过和其它代谢酶形成一个稳定的代谢酶复合体（SESAME）而被转运到细胞核中催化组蛋白H3苏氨酸11（H3T11）的磷酸化。进一步通过染色体免疫沉淀实验在端粒附近检测到SESAME和H3T11磷酸化，提示Pyk1可能通过端粒来调控衰老。本项目拟在上述发现的基础上开展如下研究：（1）利用端粒异染色质报告基因实验、RNA测序以及染色体免疫沉淀等技术分析SESAME对端粒异染色质基因沉默的影响及其机制；（2）分析SESAME及相关细胞代谢产物对细胞衰老的影响。上述研究的开展将有助于阐明丙酮酸激酶对端粒异染色质基因沉默及细胞衰老的调控与分子机制，为衰老防治提供新的理论依据。

Pyruvate kinase plays critical roles in cellular senescence but little is known about the underlying mechanism. Telomere especially telomere silencing has been reported to regulate senescence. Using proteomics tools, we found that Pyk1 forms a novel complex, called SESAME, with other metabolic enzymes. By forming this stable complex, Pyk1 can be translocated into nucleus, where it phosphorylates histone H3 at threonine 11 (H3T11). Using chromatin immunoprecipitation technique, we found that SESAME phosphorylates H3T11 near telomere, implying that Pyk1 might be invovled in telomere regulation. Based on these data, we plan to use telomere silencing reporter genes、RNA sequencing and chromatin immunoprecipitation to investigate how SESAME and H3T11 phosporylation regulate telomere strucutre from the perspective of telomere silencing. We will then analyze whether SESAME and metabolites regulate cellular senescence. Our project will elucidate how pyruvate kinase modulates telomere silencing and senescence and provide clues for anti-aging therapy.