WWP2 is a physiological ubiquitin ligase for phosphatase and tensin homolog (PTEN) in mice.

The tumor suppressor phosphatase and tensin homolog (PTEN) plays a central role in regulating phosphatidylinositol 3-kinase (PI3K) signaling, and its gene is very frequently mutated in various human cancers. Numerous studies have revealed that PTEN levels are tightly regulated by both transcriptional and posttranslational modifications, with especially ubiquitylation significantly regulating PTEN protein levels. Although several ubiquitin ligases have been reported to mediate PTEN ubiquitylation in vitro, the ubiquitin ligase that promotes PTEN degradation in vivo has not been reported. Here we took advantage of specific knockout mouse models to demonstrate that WW domain-containing E3 ubiquitin protein ligase 2 (WWP2) promotes PTEN degradation under physiological conditions, whereas another ubiquitin ligase, carboxyl terminus of Hsp70-interacting protein (CHIP), had no such effect. WWP2 knockout mice exhibited reduced body size, elevated PTEN protein levels, and reduced phosphorylation levels of the serine/threonine kinase and PTEN target AKT. In contrast, we observed no elevation of PTEN protein levels in CHIP knockout tissues and mouse embryonic fibroblasts. Furthermore, PTEN protein levels in CHIP/WWP2 double knockout mice were very similar to those in WWP2 single knockout mice and significantly higher than in WT and CHIP knockout mice. Our results demonstrate that WWP2, rather than CHIP, is an ubiquitin ligase that promotes PTEN degradation in vivo Considering PTEN's significant role in tumor development, we propose that WWP2 may be a potential target for fine-tuning PTEN levels in anticancer therapies. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

Citation

Hongchang Li, Pengfei Zhang, Qiuyue Zhang, Chaonan Li, Weiguo Zou, Zhijie Chang, Chun-Ping Cui, Lingqiang Zhang. WWP2 is a physiological ubiquitin ligase for phosphatase and tensin homolog (PTEN) in mice. The Journal of biological chemistry. 2018 Jun 08;293(23):8886-8899

Mesh Tags

Substances

PMID: 29685889

search → result