Niechi Ignacio, Silva Eduardo, Cabello Pablo, Huerta Hernan, Carrasco Valentina, Villar Paulina, Cataldo Luis Rodrigo, Marcelain Katherine, Armisen Ricardo, Varas-Godoy Manuel, Fernandez Cristina, Tapia Julio C
Cell Transformation Laboratory, Program of Cellular and Molecular Biology, ICBM, Faculty of Medicine, University of Chile, Santiago, Chile.
ICBM, Faculty of Medicine, University of Chile, Santiago, Chile.
Oncotarget. 2015 Dec 15;6(40):42749-60. doi: 10.18632/oncotarget.5722.
Endothelin-converting enzyme-1c (ECE-1c) is a membrane metalloprotease involved in endothelin-1 synthesis, which has been shown in vitro to have a role in breast, ovary and prostate cancer cell invasion. N-terminal end of ECE-1c displays three putative phosphorylation sites for the protein kinase CK2. We studied whether CK2 phosphorylates N-terminal end of ECE-1c as well as whether this has a role in migration and invasion of colon cancer cells. CK2 phosphorylated the N-terminal end of ECE-1c and this was precluded upon inhibition of CK2. Inhibition also led to diminished protein levels of both endogen ECE-1 or GFP-fused N-terminal end of ECE-1c in 293T embryonic and DLD-1 colon cancer cells, which highlighted the importance of this motif on UPS-dependent ECE-1c degradation. Full-length ECE-1c mutants designed either to mimic or abrogate CK2-phosphorylation displayed increased or decreased migration/invasion of colon cancer cells, respectively. Moreover, ECE-1c overexpression or its silencing with a siRNA led to increased or diminished cell migration/invasion, respectively. Altogether, these data show that CK2-increased ECE-1c protein stability is related to augmented migration and invasion of colon cancer cells, shedding light on a novel mechanism by which CK2 may promote malignant progression of this disease.
内皮素转化酶-1c（ECE-1c）是一种参与内皮素-1合成的膜金属蛋白酶，体外研究表明其在乳腺癌、卵巢癌和前列腺癌细胞侵袭中发挥作用。ECE-1c的N末端显示出蛋白激酶CK2的三个假定磷酸化位点。我们研究了CK2是否磷酸化ECE-1c的N末端，以及这是否在结肠癌细胞的迁移和侵袭中起作用。CK2磷酸化了ECE-1c的N末端，而抑制CK2则可阻止这种磷酸化。抑制作用还导致293T胚胎细胞和DLD-1结肠癌细胞中内源性ECE-1或ECE-1c的GFP融合N末端的蛋白水平降低，这突出了该基序在UPS依赖性ECE-1c降解中的重要性。设计用于模拟或消除CK2磷酸化的全长ECE-1c突变体分别显示结肠癌细胞的迁移/侵袭增加或减少。此外，ECE-1c的过表达或用siRNA使其沉默分别导致细胞迁移/侵袭增加或减少。总之，这些数据表明CK2增加的ECE-1c蛋白稳定性与结肠癌细胞迁移和侵袭的增强有关，揭示了CK2可能促进该疾病恶性进展的新机制。
