a new nuclear function of the entamoeba histolytica glycolytic enzyme enolase the metabolic regulation of cytosine-5 methyltransferase 2 (dnmt2) activity一个新的核函数的痢疾阿米巴糖酵解酶烯醇酶的代谢调节cytosine-5甲基转移酶2(dnmt2)活动.pdfVIP

A New Nuclear Function of the Entamoeba histolytica Glycolytic Enzyme Enolase: The Metabolic Regulation of Cytosine-5 Methyltransferase 2 (Dnmt2) Activity 1 1 2 2,3 1 Ayala Tovy , Rama Siman Tov , Ricarda Gaentzsch , Mark Helm , Serge Ankri * 1 Department of Molecular Microbiology, The Bruce Rappaport Faculty of Medicine, Technion, Haifa, Israel, 2 Department of Chemistry, The Pharmacy and Molecular Biotechnology Institute, Ruprecht-Karls University of Heidelberg, Heidelberg, Germany, 3 The Pharmacy and Biochemistry Institute, Johannes Gutenberg University, Mainz, Germany Abstract Cytosine-5 methyltransferases of the Dnmt2 family function as DNA and tRNA methyltransferases. Insight into the role and biological significance of Dnmt2 is greatly hampered by a lack of knowledge about its protein interactions. In this report, we address the subject of protein interaction by identifying enolase through a yeast two-hybrid screen as a Dnmt2-binding protein. Enolase, which is known to catalyze the conversion of 2-phosphoglycerate (2-PG) to phosphoenolpyruvate (PEP), was shown to have both a cytoplasmatic and a nuclear localization in the parasite Entamoeba histolytica. We discovered that enolase acts as a Dnmt2 inhibitor. This unexpected inhibitory activity was antagonized by 2-PG, which suggests that glucose metabolism controls the non-glycolytic function of enolase. Interestingly, glucose starvation drives enolase to accumulate within the nucleus, which in turn leads to the formation of additional enolase-E.histolytica DNMT2 homolog (Ehmeth) complex, and to a significant reduction of the tRNAAsp methylation in the parasite. The crucial role of enolase as a Dnmt2 inhibitor was also demonstrated in E.histolytica expressing