Bedi Rajiv Kumar, Huang Danzhi, Li Yaozong, Caflisch Amedeo
Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, Zurich CH-8057, Switzerland.
ACS Bio Med Chem Au. 2023 Jun 14;3(4):359-370. doi: 10.1021/acsbiomedchemau.3c00023. eCollection 2023 Aug 16.
Methyltransferase-like 3 (METTL3) and METTL14 form a heterodimeric complex that catalyzes the most abundant internal mRNA modification, -methyladenosine (mA). METTL3 is the catalytic subunit that binds the co-substrate -adenosyl methionine (SAM), while METTL14 is involved in mRNA binding. The mA modification provides post-transcriptional level control over gene expression as it affects almost all stages of the mRNA life cycle, including splicing, nuclear export, translation, and decay. There is increasing evidence for an oncogenic role of METTL3 in acute myeloid leukemia. Here, we use structural and dynamic details of the catalytic subunit METTL3 for developing small-molecule inhibitors that compete with SAM. Starting from a hit identified by high-throughput docking, protein crystallography and molecular dynamics simulations were employed to guide the optimization of inhibitory activity. The potency was successfully improved by 8000-fold as measured by a homogeneous time-resolved fluorescence assay. The optimized compound is selective against the off-targets RNA methyltransferases METTL1 and METTL16.
甲基转移酶样3（METTL3）和METTL14形成一种异二聚体复合物，该复合物催化最丰富的内部mRNA修饰——N6-甲基腺苷（m6A）。METTL3是结合辅底物S-腺苷甲硫氨酸（SAM）的催化亚基，而METTL14参与mRNA结合。m6A修饰在转录后水平上控制基因表达，因为它几乎影响mRNA生命周期的所有阶段，包括剪接、核输出、翻译和降解。越来越多的证据表明METTL3在急性髓系白血病中具有致癌作用。在此，我们利用催化亚基METTL3的结构和动力学细节来开发与SAM竞争的小分子抑制剂。从高通量对接鉴定出的一个活性分子开始，采用蛋白质晶体学和分子动力学模拟来指导抑制活性的优化。通过均相时间分辨荧光测定法测得其效力成功提高了8000倍。优化后的化合物对脱靶RNA甲基转移酶METTL1和METTL16具有选择性。
