The Hippo Tumor Pathway Promotes TAZ Degradation by Phosphorylating a Phosphodegron and Recruiting the SCFβ-TrCP E3 Ligase

The TAZ transcription co-activator promotes cell proliferation and epithelial-mesenchymal transition. TAZ is inhibited by the Hippo tumor suppressor pathway, which promotes TAZ cytoplasmic localization by phosphorylation. We report here that TAZ protein stability is controlled by a phosphodegron recognized by the F-box protein β-TrCP and ubiquitylated by the SCF/CRL1β-TrCP E3 ligase. The interaction between TAZ and β-TrCP is regulated by the Hippo pathway. Phosphorylation of a phosphodegron in TAZ by LATS primes it for further phosphorylation by CK1ϵ and subsequent binding by β-TrCP. Therefore, the Hippo pathway negatively regulates TAZ function by both limiting its nuclear accumulation and promoting its degradation. The phosphodegron-mediated TAZ degradation plays an important role in negatively regulating TAZ biological functions.