Jade-1 inhibits Wnt signalling by ubiquitylating β-catenin and mediates Wnt pathway inhibition by pVHL

VC Chitalia, RL Foy, MM Bachschmid, L Zeng… - Nature cell …, 2008 - nature.com
VC Chitalia, RL Foy, MM Bachschmid, L Zeng, MV Panchenko, MI Zhou, A Bharti, DC Seldin…
Nature cell biology, 2008nature.com
Abstract The von Hippel–Lindau protein pVHL suppresses renal tumorigenesis in part by
promoting the degradation of hypoxia-inducible HIF-α transcription factors; additional
mechanisms have been proposed. pVHL also stabilizes the plant homeodomain protein
Jade-1, which is a candidate renal tumour suppressor that may correlate with renal cancer
risk,,. Here we show that Jade-1 binds the oncoprotein β-catenin in Wnt-responsive fashion.
Moreover, Jade-1 destabilizes wild-type β-catenin but not a cancer-causing form of β …
Abstract
The von Hippel–Lindau protein pVHL suppresses renal tumorigenesis in part by promoting the degradation of hypoxia-inducible HIF-α transcription factors; additional mechanisms have been proposed. pVHL also stabilizes the plant homeodomain protein Jade-1, which is a candidate renal tumour suppressor that may correlate with renal cancer risk,,. Here we show that Jade-1 binds the oncoprotein β-catenin in Wnt-responsive fashion. Moreover, Jade-1 destabilizes wild-type β-catenin but not a cancer-causing form of β-catenin. Whereas the well-established β-catenin E3 ubiquitin ligase component β-TrCP ubiquitylates only phosphorylated β-catenin, Jade-1 ubiquitylates both phosphorylated and non-phosphorylated β-catenin and therefore regulates canonical Wnt signalling in both Wnt-off and Wnt-on phases. Thus, the different characteristics of β-TrCP and Jade-1 may ensure optimal Wnt pathway regulation. Furthermore, pVHL downregulates β-catenin in a Jade-1-dependent manner and inhibits Wnt signalling, supporting a role for Jade-1 and Wnt signalling in renal tumorigenesis. The pVHL tumour suppressor and the Wnt tumorigenesis pathway are therefore directly linked through Jade-1.
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