Phosphorylation of TOPK at Y74, Y272 by Src increases the stability of TOPK and promotes tumorigenesis of colon.
Phosphorylation of TOPK at Y74, Y272 by Src increases the stability of TOPK and promotes tumorigenesis of colon.
复制标题
Src磷酸化TOPK Y74、Y272位点，增加TOPK稳定性，促进结肠癌发生
DOI：
10.18632/oncotarget.8231
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发表时间：
2016-04-26
期刊：
影响因子：
--
通讯作者：
Zhu F
中科院分区：
文献类型：
--
作者：
Xiao J;Duan Q;Wang Z;Yan W;Sun H;Xue P;Fan X;Zeng X;Chen J;Shao C;Zhu F
T-LAK细胞源蛋白激酶（TOPK）是一种丝氨酸/苏氨酸蛋白激酶，在多种肿瘤中高度表达，并与人类恶性肿瘤的不良预后相关。然而，TOPK的激活机制尚不清楚。在此，我们首先发现Src在体外Y74和Y272位点直接结合并磷酸化TOPK。制备了抗磷酸化的Y74位点TOPK，在结肠癌细胞中检测到Y74位点TOPK的内源性磷酸化，在表达低水平Src的细胞中磷酸化被抑制。随后，我们将Y74和Y272双突变TOPK （TOPK- ff）稳定转染到JB6或SW480细胞中，观察到与野生型TOPK （TOPK- wt）相比，TOPK- ff细胞的非锚定生长能力和肿瘤发生能力均受到抑制。TOPK底物Histone H3 Ser10位点的磷酸化水平在体内和体外也显著降低。此外，我们发现Src可以抑制TOPK的泛素化。暂态表达的TOPK-WT比暂态表达的TOPK-FF更稳定。内源性TOPK在Src野生型（Src+/+） mef中比在Src敲除（Src−/−）mef中更稳定。综上所述，我们的研究结果表明Src是一种新的TOPK上游激酶。Src使TOPK在Y74和Y272位点磷酸化，增加了TOPK的稳定性和活性，促进了结肠癌的发生。这可能为结肠癌患者基于TOPK的预后和靶向治疗提供机会。
T-LAK cell-originated protein kinase (TOPK), a serine/threonine protein kinase, is highly expressed in a variety of tumors and associated with a poor prognosis of human malignancies. However, the activation mechanism of TOPK is still unrevealed. Herein, first we found that Src directly bound with and phosphorylated TOPK at Y74 and Y272 in vitro. Anti-phospho-TOPK at Y74 was prepared, the endogenous phosphorylation of TOPK at Y74 was detected in colon cancer cells, and the phosphorylation was inhibited in cells expressing low levels of Src. Subsequently, we stably transfected Y74 and Y272 double mutated TOPK (TOPK-FF) into JB6 or SW480 cells, and observed that both the anchorage-independent growth ability and tumorigenesis of TOPK-FF cells were suppressed compared with those of wild type TOPK (TOPK-WT) ex vivo and in vivo. The phosphorylation level of TOPK substrate, Histone H3 at Ser10 also decreased dramatically ex vivo or in vivo. Moreover, we showed that Src could inhibit the ubiquitination of TOPK. Transiently expressed TOPK-WT was more stable than TOPK-FF in pause and chase experiment. Endogenous TOPK was more stable in Src wild type (Src+/+) MEFs than in Src knockout (Src−/−). Taken together, our results indicate that Src is a novel upstream kinase of TOPK. The phosphorylation of TOPK at Y74 and Y272 by Src increases the stability and activity of TOPK, and promotes the tumorigenesis of colon cancer. It may provide opportunities for TOPK based prognosis and targeted therapy for colon cancer patients.
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影响因子：
11.2
作者：
Kim, Dong Joon;Li, Yan;Dong, Zigang
通讯作者：
Dong, Zigang
DOI：
10.1073/pnas.090102397
发表时间：
2000-05-09
影响因子：
11.1
作者：
Gaudet, S;Branton, D;Lue, RA
通讯作者：
Lue, RA
影响因子：
8
作者：
Hu, F.;Gartenhaus, R. B.;Rapoport, A. P.
通讯作者：
Rapoport, A. P.
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影响因子：
44.1
作者：
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影响因子：
--
作者：
Li Y;Yang Z;Li W;Xu S;Wang T;Wang T;Niu M;Zhang S;Jia L;Li S
通讯作者：
Li S