High-Speed Atomic Force Microscopy Reveals Spatiotemporal Dynamics of Histone Protein H2A Involution by DNA Inchworming
High-Speed Atomic Force Microscopy Reveals Spatiotemporal Dynamics of Histone Protein H2A Involution by DNA Inchworming
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DOI：
10.1021/acs.jpclett.1c00697
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发表时间：
2021-04-14
影响因子：
5.7
通讯作者：
Wong, Richard W.
中科院分区：
文献类型：
--
作者：
Nishide, Goro;Lim, Keesiang;Wong, Richard W.
DNA与组蛋白的相互作用常常受到表观遗传调节因子的干扰而调控基因的表达。这种相互作用的直接形象化还有待实现。利用高速原子力显微镜（HS-AFM）观察了DNA与组蛋白H2 A的动态相互作用。HS-AFM电影显示了H2 A的球状核心和无序尾部。DNA-H2 A在多聚赖氨酸（PLL）和脂质底物上形成经典的“串珠状”构象。值得注意的是，一个短的线性化双链DNA（dsDNA），类似于尺蠖，包裹在一个单一的H2 A蛋白只观察到的脂质基板。对于质粒DNA或线性化的长dsDNA，在同一底物上不发生这种现象。PLL底物的强吸附导致DNA-H2 A的动态相互作用差。尽管如此，短线性化的dsDNA-H2 A在PLL基底上形成具有“钻石环”拓扑结构的稳定包裹。DNA-H2 A聚集体的可逆液-液相分离（LLPS）通过操纵盐浓度来可视化。总之，我们的研究表明，HS-AFM是可行的调查表观遗传修饰的DNA-组蛋白的相互作用。
DNA-histone interaction is always perturbed by epigenetic regulators to regulate gene expression. Direct visualization of this interaction is yet to be achieved. By using high-speed atomic force microscopy (HS-AFM), we have observed the dynamic DNA-histone H2A interaction. HS-AFM movies demonstrate the globular core and disordered tail of H2A. DNA-H2A formed the classic "beads-on-string" conformation on poly-L-lysine (PLL) and lipid substrates. Notably, a short-linearized double-stranded DNA (dsDNA), resembling an inchworm, wrapped around a single H2A protein only observed on the lipid substrate. Such a phenomenon does not occur for plasmid DNA or linearized long dsDNA on the same substrate. Strong adsorption of PLL substrate resulted in poor dynamic DNA-H2A interaction. Nonetheless, short-linearized dsDNA-H2A formed stable wrapping with a "diamond ring" topology on the PLL substrate. Reversible liquid-liquid phase separation (LLPS) of the DNA-H2A aggregate was visualized by manipulating salt concentrations. Collectively, our study suggest that HS-AFM is feasible for investigating epigenetically modified DNA-histone interactions.