Competitive regulation of E-cadherin juxtamembrane domain degradation by p120-catenin binding and Hakai-mediated ubiquitination.
Competitive regulation of E-cadherin juxtamembrane domain degradation by p120-catenin binding and Hakai-mediated ubiquitination.
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DOI：
10.1371/journal.pone.0037476
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发表时间：
2012
期刊：
影响因子：
3.7
通讯作者：
Nelson WJ
中科院分区：
文献类型：
--
作者：
Hartsock A;Nelson WJ
p120-Catenin结合和hakai介导的E-cadherin近膜结构域（JMD）泛素化被认为参与了E-cadherin内化和降解的调节。然而，这两种途径之间的关系尚不清楚。我们将E-cadherin JMD定位于线粒体（WT-JMD），从质膜中分离出该结构域并内化，并检测蛋白质的修饰和降解。WT-JMD定位于线粒体，但除非蛋白酶体活性受到抑制，否则不会在线粒体中积累。我们发现WT-JMD被泛素化，在5号位置（K5R）和83号位置（K83R）赖氨酸的精氨酸替代导致突变体JMD在线粒体中稳定积累。即使在蛋白酶体抑制下，p120-Catenin也没有定位或结合到WT-JMD上，而k5,83r - jmd突变体将p120-Catenin结合并定位到线粒体上。p120-catenin结合位点的突变与这些赖氨酸突变联合抑制了p120-catenin的结合，但没有降低JMD的稳定性或其在线粒体中的积累。因此，JMD赖氨酸突变体稳定性的提高是由于抑制泛素化而不是p120-catenin结合。最后，全长E-cadherin中这些关键赖氨酸的突变对蛋白质稳定性的影响与WT-JMD相似。我们的研究结果表明，JMD的泛素化抑制p120-catenin结合，并靶向E-cadherin降解。
p120-Catenin binding to, and Hakai-mediated ubiquitination of the E-cadherin juxtamembrane domain (JMD) are thought to be involved in regulating E-cadherin internalization and degradation. However, the relationship between these two pathways is not understood. We targeted the E-cadherin JMD to mitochondria (WT-JMD) to isolate this domain from the plasma membrane and internalization, and to examine protein modifications and degradation. WT-JMD localized to mitochondria, but did not accumulate there except when proteasome activity was inhibited. We found WT-JMD was ubiquitinated, and arginine substitution of lysines at position 5 (K5R) and 83 (K83R) resulted in the stable accumulation of mutant JMD at mitochondria. p120-Catenin did not localize, or bind to WT-JMD even upon proteasome inhibition, whereas the K5,83R-JMD mutant bound and localized p120-catenin to mitochondria. Mutation of the p120-catenin binding site in combination with these lysine mutations inhibited p120-catenin binding, but did not decrease JMD stability or its accumulation at mitochondria. Thus, increased stability of JMD lysine mutants was due to inhibition of ubiquitination and not to p120-catenin binding. Finally, mutation of these critical lysines in full length E-cadherin had similar effects on protein stability as WT-JMD. Our results indicate that ubiquitination of the JMD inhibits p120-catenin binding, and targets E-cadherin for degradation.
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影响因子：
7.5
作者：
Harris ES;Nelson WJ
通讯作者：
Nelson WJ
影响因子：
8
作者：
Maeda, M.;Johnson, E.;Johnson, K. R.
通讯作者：
Johnson, K. R.
影响因子：
11.4
作者：
Staub, O;Gautschi, I;Rotin, D
通讯作者：
Rotin, D
DOI：
10.1083/jcb.130.5.1105
发表时间：
1995-09
期刊：
The Journal of cell biology
影响因子：
--
作者：
Mays RW;Siemers KA;Fritz BA;Lowe AW;van Meer G;Nelson WJ
通讯作者：
Nelson WJ
DOI：
10.1083/jcb.148.1.189
发表时间：
2000-01-10
期刊：
The Journal of cell biology
影响因子：
--
作者：
Thoreson MA;Anastasiadis PZ;Daniel JM;Ireton RC;Wheelock MJ;Johnson KR;Hummingbird DK;Reynolds AB
通讯作者：
Reynolds AB