Talic Emily S, Wooten Ashley, Zeczycki Tonya N, Mansfield Kyle D
Biochemistry and Molecular Biology Department, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA.
Mass Spectrometry Core Facility, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA.
Curr Issues Mol Biol. 2023 Jun 29;45(7):5460-5480. doi: 10.3390/cimb45070346.
METTL16, a human m6A RNA methyltransferase, is currently known for its modification of U6 and MAT2A RNAs. Several studies have identified additional RNAs to which METTL16 binds, however whether METTL16 modifies these RNAs is still in question. Moreover, a recent study determined that METTL16 contains more than one RNA-binding domain, leaving the importance of each individual RNA-binding domain unknown. Here we examined the effects of mutating the METTL16 protein in certain domains on overall cell processes. We chose to mutate the N-terminal RNA-binding domain, the methyltransferase domain, and the C-terminal RNA-binding domain. With these mutants, we identified changes in RNA-binding ability, protein and RNA expression, cell cycle phase occupancy, and proliferation. From the resulting changes in RNA and protein expression, we saw effects on cell cycle, metabolism, intracellular transport, and RNA processing pathways, which varied between the METTL16 mutant lines. We also saw significant effects on the G1 and S phase occupancy times and proliferative ability with some but not all the mutants. We have therefore concluded that while METTL16 may or may not m6A-modify all RNAs it binds, its binding (or lack of) has a significant outcome on a variety of cell processes.
METTL16是一种人类m6A RNA甲基转移酶，目前因其对U6和MAT2A RNA的修饰作用而为人所知。多项研究已鉴定出METTL16结合的其他RNA，然而METTL16是否修饰这些RNA仍存在疑问。此外，最近一项研究确定METTL16含有不止一个RNA结合结构域，每个单独的RNA结合结构域的重要性尚不清楚。在此，我们研究了METTL16蛋白某些结构域发生突变对整体细胞过程的影响。我们选择对N端RNA结合结构域、甲基转移酶结构域和C端RNA结合结构域进行突变。利用这些突变体，我们鉴定了RNA结合能力、蛋白质和RNA表达、细胞周期阶段占据情况以及增殖方面的变化。从RNA和蛋白质表达的结果变化中，我们观察到对细胞周期、代谢、细胞内运输和RNA加工途径的影响，这些影响在METTL16突变体系之间存在差异。我们还观察到一些（但并非全部）突变体对G1期和S期占据时间以及增殖能力有显著影响。因此，我们得出结论，虽然METTL16可能会也可能不会对其结合的所有RNA进行m6A修饰，但其结合（或未结合）对多种细胞过程具有重大影响。
