Ubiquitin ligase TRIM65 promotes colorectal cancer metastasis by targeting ARHGAP35 for protein degradation
Ubiquitin ligase TRIM65 promotes colorectal cancer metastasis by targeting ARHGAP35 for protein degradation
复制标题
泛素连接酶 TRIM65 通过靶向 ARHGAP35 进行蛋白质降解促进结直肠癌转移
DOI：
10.1038/s41388-019-0891-6
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发表时间：
2019-09-12
期刊：
影响因子：
8
通讯作者：
Wang, Lei
中科院分区：
文献类型：
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作者：
Chen, Daici;Li, Yichen;Wang, Lei
TRIM 65是一种E3泛素连接酶，是多种细胞过程和肿瘤进展的关键调节因子。因此，必须在生理学或疾病背景下鉴定更多的底物。在这里，我们发现TRIM 65上调并与结直肠癌（CRC）的生存率低相关。更具体地，TRIM 65的高表达与CRC转移和复发相关。TRIM 65在CRC细胞系中的异位过表达增强了增殖、侵袭和迁移，而TRIM 65表达的敲低具有相反的效果。此外，我们确定了TRIM 65的一种新底物，即ARHGAP 35，一种参与极化细胞迁移的Rho GTP酶激活蛋白（GAP）。表型上，TRIM 65的强制表达诱导小鼠模型中迁移相关结构、局灶性粘连和/或丝状伪足的产生增加，并增强CRC向肝或肺的转移。机制研究表明，TRIM 65介导ARHGAP 35的泛素化，其降解导致Rho GT3活性升高。此外，我们还鉴定了TRIM 65上的几个磷酸化位点。总之，我们揭示了一种新的TRIM 65-GAP-Rho调节轴，其调节CRC细胞的肌动蛋白细胞骨架和迁移行为，并且TRIM 65-ARHGAP 35相互作用可能是CRC中有价值的治疗靶点。
Tripartite motif-containing protein 65 (TRIM65) is an E3 ubiquitin ligase and a critical regulator of a variety of cellular processes as well as tumor progression. Therefore, more substrates must be identified in the physiology or disease context. Here, we found that TRIM65 is upregulated and associated with poor survival in colorectal cancer (CRC). More specifically, high expression of TRIM65 is associated with CRC metastasis and recurrence. Ectopic overexpression of TRIM65 in CRC cell lines enhanced proliferation, invasion, and migration, while knockdown of TRIM65 expression had the opposite effects. Furthermore, we identified a new substrate of TRIM65, namely ARHGAP35, a Rho GTPase-activating protein (GAP) that is involved in polarized cell migration. Phenotypically, forced expression of TRIM65 induces increased production of migration-related structures, focal adhesions, and/or filopodia and enhances CRC metastasis to the liver or the lung in a mouse model. Mechanistic studies revealed that TRIM65 mediates ubiquitination of ARHGAP35, whose degradation leads to elevated Rho GTPase activity. In addition, we identified several phosphorylation sites on TRIM65. In sum, we reveal a novel TRIM65–GAP–Rho regulatory axis that modulates the actin cytoskeleton and the migration behavior of CRC cells, and the TRIM65–ARHGAP35 interaction might be a valuable therapeutic target in CRC.