SIAH ubiquitin ligases target the nonreceptor tyrosine kinase ACK1 for ubiquitinylation and proteasomal degradation.
SIAH ubiquitin ligases target the nonreceptor tyrosine kinase ACK1 for ubiquitinylation and proteasomal degradation.
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DOI：
10.1038/onc.2012.515
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发表时间：
2013-10-10
期刊：
影响因子：
8
通讯作者：
Kraemer, O. H.
中科院分区：
文献类型：
--
作者：
Buchwald, M.;Pietschmann, K.;Brand, P.;Guenther, A.;Mahajan, N. P.;Heinzel, T.;Kraemer, O. H.
活化的Cdc 42相关激酶1（ACK 1）是一种与细胞转化相关的非受体酪氨酸激酶。ACK 1的异常调节促进肿瘤进展和转移。因此，ACK 1被认为是癌症治疗的有效靶点。七种缺席同源物（SIAH）泛素连接酶促进底物泛素化，将蛋白质靶向蛋白酶体降解途径。在这里，我们报告，从智人的ACK 1和SIAH 1在酵母双杂交筛选中相互作用。蛋白质-蛋白质相互作用的研究和蛋白质降解分析，使用删除和点突变体的ACK 1验证SIAH 1和相关的SIAH 2与ACK 1相互作用。SIAH和ACK 1之间的关联依赖于位于ACK 1远端C末端的高度保守的SIAH结合基序的完整性。此外，我们证明了ACK 1与SIAH 1的相互作用和SIAH 1对ACK 1的蛋白酶体降解的诱导是独立于ACK 1的激酶活性的。阻断蛋白酶体活性的化学抑制剂证实SIAH 1和SIAH 2通过诱导其蛋白酶体周转而使ACK 1蛋白不稳定。这种机制明显不同于在用表皮生长因子刺激后靶向ACK 1的溶酶体途径。我们的数据还表明，ACK 1，但不是ACK 1突变体缺乏SIAH结合基序，有一个明显的负面影响SIAH水平。此外，靶向SIAH 2 mRNA的敲除方法特别发现，通过激素诱导的雌激素受体（ER）激活来诱导SIAH 2表达，可以降低人乳腺癌细胞中ACK 1的水平。总的来说，我们的数据提供了新的见解的分子机制，调节ACK 1和他们的位置SIAH泛素连接酶作为ACK 1在转化细胞中的负调节。
Activated Cdc42-associated kinase 1 (ACK1) is a nonreceptor tyrosine kinase linked to cellular transformation. The aberrant regulation of ACK1 promotes tumor progression and metastasis. Therefore, ACK1 is regarded as a valid target in cancer therapy. Seven in absentia homolog (SIAH) ubiquitin ligases facilitate substrate ubiquitinylation that targets proteins to the proteasomal degradation pathway. Here we report that ACK1 and SIAH1 from Homo sapiens interact in a yeast two-hybrid screen. Protein–protein interaction studies and protein degradation analyses using deletion and point mutants of ACK1 verify that SIAH1 and the related SIAH2 interact with ACK1. The association between SIAHs and ACK1 depends on the integrity of a highly conserved SIAH-binding motif located in the far C-terminus of ACK1. Furthermore, we demonstrate that the interaction of ACK1 with SIAH1 and the induction of proteasomal degradation of ACK1 by SIAH1 are independent of ACK1’s kinase activity. Chemical inhibitors blocking proteasomal activity corroborate that SIAH1 and SIAH2 destabilize the ACK1 protein by inducing its proteasomal turnover. This mechanism apparently differs from the lysosomal pathway targeting ACK1 after stimulation with the epidermal growth factor. Our data also show that ACK1, but not ACK1 mutants lacking the SIAH binding motif, has a discernable negative effect on SIAH levels. Additionally, knockdown approaches targeting the SIAH2 mRNA uncover specifically that the induction of SIAH2 expression, by hormonally-induced estrogen receptor (ER) activation, decreases the levels of ACK1 in luminal human breast cancer cells. Collectively, our data provide novel insights into the molecular mechanisms modulating ACK1 and they position SIAH ubiquitin ligases as negative regulators of ACK1 in transformed cells.
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影响因子：
11.4
作者：
Buchwald, M.;Pietschmann, K.;Kraemer, O. H.
通讯作者：
Kraemer, O. H.
DOI：
10.1073/pnas.0700420104
发表时间：
2007-05-15
影响因子：
11.1
作者：
Mahajan, Nupam P.;Liu, Yuanbo;Whang, Young E.
通讯作者：
Whang, Young E.
影响因子：
21.3
作者：
Calzado, Marco A.;de la Vega, Laureano;Schmitz, M. Lienhard
通讯作者：
Schmitz, M. Lienhard
影响因子：
2.8
作者：
Mahajan, Kiran;Challa, Sridevi;Coppola, Domenico;Lawrence, Harshani;Luo, Yunting;Gevariya, Harsukh;Zhu, Weiwei;Chen, Y. Ann;Lawrence, Nicholas J.;Mahajan, Nupam P.
通讯作者：
Mahajan, Nupam P.
影响因子：
3.8
作者：
Jansen, Maurice P. H. M.;Ruigrok-Ritstier, Kirsten;Berns, Els M. J. J.
通讯作者：
Berns, Els M. J. J.