Phase separation is required for PML nuclear body biogenesis and function
Phase separation is required for PML nuclear body biogenesis and function
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DOI：
10.1096/fj.202300216r
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发表时间：
2023-06-01
期刊：
影响因子：
4.8
通讯作者：
Meng，Guoyu
中科院分区：
文献类型：
--
作者：
Wu，Wenyu;Tan，Yangxia;Meng，Guoyu
PML核体（NB）故障常常导致急性白血病暴发和其他严重疾病。 PML NB 挽救是砷治疗急性早幼粒细胞白血病 (APL) 成功的分子基础。然而，目前尚不清楚 PML NB 是如何组装的。在这里，我们通过光漂白后的荧光恢复（FRAP）实验观察到NB形成中液-液相分离（LLPS）的存在。与野生型（WT）NB相比，源自耐砷白血病患者的PML A216V显着削弱了LLPS，但没有改变整体结构和PML RBCC寡聚化。与此同时，我们还报道了几个对 PML 卷曲螺旋结构域至关重要的 Leu 到 Pro 突变。 L268P 和 A216V 之间的 FRAP 表征和比较揭示了这些突变 NB 中明显不同的 LLPS 活性。对 LLPS 致残和未致残 NB 的透射电子显微镜 (TEM) 检查显示，A216V 和 WT/L268P NB 中分别存在聚集和环状 PML 堆积。更重要的是，正确的 LLPS 驱动的 NB 形成是伴侣招募、翻译后修饰 (PTM) 和 PML 驱动的细胞调节（例如 ROS 应激控制、线粒体产生和 PML-p53 介导的衰老和凋亡）的先决条件。总而言之，我们的结果有助于定义 PML NB 生物发生中的关键 LLPS 步骤。
PML nuclear body (NB) malfunction often leads to acute leukemia outbreaks and other severe diseases. PML NB rescue is the molecular basis of arsenic success in acute promyelocytic leukemia (APL) treatment. However, it is unclear how PML NBs are assembled. Here, we observed the presence of liquid–liquid phase separation (LLPS) in NB formation by fluorescence recovery after photobleaching (FRAP) experiment. Compared with the wild‐type (WT) NBs, PML A216V derived from arsenic‐resistant leukemia patients markedly crippled LLPS, but not altered the overall structure and PML RBCC oligomerization. In parallel, we also reported several Leu to Pro mutations that were critical to PML coiled‐coil domain. FRAP characterization and comparison between L268P and A216V revealed markedly different LLPS activities in these mutant NBs. Transmission electron microscopy (TEM) inspections of LLPS‐crippled and uncrippled NBs showed aggregation‐ and ring‐like PML packing in A216V and WT/L268P NBs, respectively. More importantly, the correct LLPS‐driven NB formation was the prerequisite for partner recruitment, post‐translational modifications (PTMs), and PML‐driven cellular regulations, such as ROS stress control, mitochondria production, and PML‐p53‐mediated senescence and apoptosis. Altogether, our results helped to define a critical LLPS step in PML NB biogenesis.