The DNA Replication Licensing Factor Miniature Chromosome Maintenance 7 Is Essential for RNA Splicing of Epidermal Growth Factor Receptor, c-Met, and Platelet-derived Growth Factor Receptor
The DNA Replication Licensing Factor Miniature Chromosome Maintenance 7 Is Essential for RNA Splicing of Epidermal Growth Factor Receptor, c-Met, and Platelet-derived Growth Factor Receptor
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DOI：
10.1074/jbc.m114.622761
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发表时间：
2015-01-16
影响因子：
4.8
通讯作者：
Luo, Jian-Hua
中科院分区：
文献类型：
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作者：
Chen, Zhang-Hui;Yu, Yan P.;Luo, Jian-Hua
微型染色体维护7（MCM7）是DNA复制许可复合物的重要组成部分。最近的研究表明，MCM7在多种人类恶性肿瘤中扩增和过表达。在这份报告中，我们表明，MCM7结合SF3B3。结合基序位于MCM7的N末端（氨基酸221 - 248）。MCM7或SF3B3的敲除显著增加了表皮生长因子受体、血小板衍生生长因子受体和c-Met的未剪接RNA。催产素外显子1-内含子-外显子2-EGFP构建体的报告基因表达的急剧下降也在SF3B3和MCM7敲减的PC3和DU145细胞中被鉴定。MCM7或SF3B3耗尽的细胞提取物在体外RNA剪接分析中未能剪接报告RNA。SF3B3和MCM7的敲低导致PC3和DU 145细胞的细胞死亡增加。这种细胞死亡诱导通过表达剪接的c-Met而部分挽救。据我们所知，这是第一份报告表明，MCM7是一个关键的RNA剪接因子，从而提供了显着的新见解，这种蛋白质的致癌活性。
Miniature chromosome maintenance 7 (MCM7) is an essential component of DNA replication licensing complex. Recent studies indicate that MCM7 is amplified and overexpressed in a variety of human malignancies. In this report, we show that MCM7 binds SF3B3. The binding motif is located in the N terminus (amino acids 221-248) of MCM7. Knockdown of MCM7 or SF3B3 significantly increased unspliced RNA of epidermal growth factor receptor, platelet-derived growth factor receptor, and c-Met. A dramatic drop of reporter gene expression of the oxytocin exon 1-intron-exon 2-EGFP construct was also identified in SF3B3 and MCM7 knockdown PC3 and DU145 cells. The MCM7 or SF3B3 depleted cell extract failed to splice reporter RNA in in vitro RNA splicing analyses. Knockdown of SF3B3 and MCM7 leads to an increase of cell death of both PC3 and DU145 cells. Such cell death induction is partially rescued by expressing spliced c-Met. To our knowledge, this is the first report suggesting that MCM7 is a critical RNA splicing factor, thus giving significant new insight into the oncogenic activity of this protein.