PB1 and UBA domains of p62 are essential for aggresome-like induced structure formation.
PB1 and UBA domains of p62 are essential for aggresome-like induced structure formation.
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DOI：
10.1016/j.bbrc.2018.06.153
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发表时间：
2018-09-18
影响因子：
3.1
通讯作者：
Bakowska JC
中科院分区：
文献类型：
--
作者：
Cabe M;Rademacher DJ;Karlsson AB;Cherukuri S;Bakowska JC
ALIS是大的、瞬时的、胞质聚集体，其充当泛素标记的缺陷核糖体产物的储存隔室。我们确定了p62蛋白在ALIS形成中的重要性，并证明了p62的两个结构域-PB1和UBA-是ALIS组装所必需的。p62的这两个主要结合结构域，也称为隔离体1，被证明在自噬体或细胞质聚集体的形成中起关键作用。具体地说，PB1结构域是自身寡聚化所必需的，而乌巴结构域允许p62与多聚泛素链或泛素化蛋白结合。用脂多糖刺激RAW 264.7巨噬细胞后，我们观察到ALIS细胞数量显著减少。重要的是，过表达PB1突变体或UBA缺失的p62构建体的细胞也表现出含有ALIS的细胞数量大幅减少。由于p62和泛素都在ALIS中发现，我们评估了ALIS中YFP标记的p62的动力学。与先前评估ALIS中GFP标记的泛素运动性的研究结果相反，我们确定YFP标记的p62具有非常有限的运动性。最后，我们确定GST标记的全长p62结合到赖氨酸-63连接的多聚泛素链，但不结合到赖氨酸-48连接的链。总之，我们的研究结果提供了对p62，特别是其PB1和乌巴结构域在ALIS形成中的重要作用的见解。
ALIS are large, transient, cytosolic aggregates that serve as storage compartments for ubiquitin-tagged defective ribosomal products. We determined the importance of the protein p62 in the formation of ALIS and demonstrated that two domains of p62—PB1 and UBA—are essential for ALIS assembly. Those two major binding domains of p62, also known as sequestosome 1, were shown to play a critical role in the formation of autophagosomes or cytoplasmic aggregates. Specifically, the PB1 domain is essential for self-oligomerization, and the UBA domain allows p62 to bind to polyubiquitin chains or ubiquitinated proteins. After stimulation of RAW 264.7 macrophages with lipopolysaccharide, we observed a significant decrease in the number of cells with ALIS. Importantly, cells overexpressing either a PB1 mutant or UBA-deleted p62 construct also exhibited a substantially diminished number of cells containing ALIS. Since both p62 and ubiquitin are found in ALIS, we evaluated the dynamics of YFP-tagged p62 in ALIS. In contrast to the findings of a previous study that evaluated GFP-tagged ubiquitin motility in ALIS, we determined that YFP-tagged p62 has very limited mobility. Lastly, we determined that GST–tagged full-length p62 binds to Lys-63-linked polyubiquitin chains but not to Lys-48-linked chains. Overall, our findings provide insight on the essential role that p62, particularly its PB1 and UBA domains, has in the formation of ALIS.
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影响因子：
4.8
作者：
Lamark, T;Perander, M;Johansen, T
通讯作者：
Johansen, T
影响因子：
3.5
作者：
Paine, MG;Babu, JR;Wooten, MW
通讯作者：
Wooten, MW
p62/SQSTM1形成自噬降解的蛋白质聚集体，并对亨廷顿蛋白诱导的细胞死亡具有保护作用。
影响因子：
7.8
作者：
Bjorkoy, Geir;Lamark, Trond;Brech, Andreas;Outzen, Heidi;Perander, Maria;Overvatn, Aud;Stenmark, Harald;Johansen, Terje
通讯作者：
Johansen, Terje
DOI：
10.1083/jcb.201009067
发表时间：
2011-01-10
期刊：
The Journal of cell biology
影响因子：
--
作者：
Itakura E;Mizushima N
通讯作者：
Mizushima N
影响因子：
64.8
作者：
Lelouard, H;Gatti, E;Pierre, P
通讯作者：
Pierre, P