Specific binding of PCBP1 to heavily oxidized RNA to induce cell death
Specific binding of PCBP1 to heavily oxidized RNA to induce cell death
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DOI：
10.1073/pnas.1806912115
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发表时间：
2018-06-26
影响因子：
11.1
通讯作者：
Sekiguchi, Mutsuo
中科院分区：
文献类型：
--
作者：
Ishii, Takashi;Hayakawa, Hiroshi;Sekiguchi, Mutsuo
在需氧生长的细胞中，RNA 的鸟嘌呤碱基被氧化为 8-oxo-7,8-二氢鸟嘌呤 (8-oxoG)，从而诱导其基因表达的改变。我们之前证明，人 AUF1 蛋白与 RNA 中的 8-oxoG 结合，诱导氧化信使 RNA 的选择性降解。我们在此报道聚（C）结合蛋白 PCBP1 与更严重氧化的 RNA 结合以激活细胞凋亡相关反应。 AUF1 与携带单个 8-oxoG 的寡核糖核苷酸结合，而 PCBP1 不与此类寡核糖核苷酸结合，而是与两个 8-oxoG 残基位于附近的寡核糖核苷酸牢固结合。使用 CRISPR-Cas9 系统从人类 HeLa 53 细胞系构建的 PCBP1 缺陷细胞在应用小剂量过氧化氢时表现出比 HeLa 53 细胞更高的存活率。 PCBP1缺陷细胞中caspase-3激活和PARP-1裂解水平显着低于野生型细胞。 PCBP1的结构-功能关系是通过使用保守的KH结构域有缺陷的PCBP1突变蛋白建立的。人类细胞似乎拥有两种不同的机制，一种由 AUF1 控制，另一种由 PCBP1 控制，前者在信使 RNA 适度氧化时发挥作用，后者在 RNA 严重受损时发挥作用。
In aerobically growing cells, the guanine base of RNA is oxidized to 8-oxo-7,8-dihydroguanine (8-oxoG), which induces alteration in their gene expression. We previously demonstrated that the human AUF1 protein binds to 8-oxoG in RNA to induce the selective degradation of oxidized messenger RNA. We herein report that the poly(C)-binding protein PCBP1 binds to more severely oxidized RNA to activate apoptosis-related reactions. While AUF1 binds to oligoribonucleotides carrying a single 8oxoG, PCBP1 does not bind to such oligoribonucleotides but instead binds firmly to oligoribonucleotides in which two 8-oxoG residues are located nearby. PCBP1-deficient cells, constructed from the human HeLa 53 line using the CRISPR-Cas9 system, exhibited higher survival rates than HeLa 53 cells when small doses of hydrogen peroxide were applied. The levels of caspase-3 activation and PARP-1 cleavage in the PCBP1-deficient cells were significantly lower than those in wild-type cells. The structure-function relationship of PCBP1 was established with the use of PCBP1 mutant proteins in which the conserved KH domains were defective. Human cells appear to possess two distinct mechanisms, one controlled by AUF1 and the other by PCBP1, with the former functioning when messenger RNA is moderately oxidized and the latter operating when the RNA is more severely damaged.