Background
Emerging evidence has demonstrated that SPOP functions as an oncoprotein in kidney cancer to promote tumorigenesis by ubiquitination-mediated degradation of multiple regulators of cellular proliferation and apoptosis. However, the detailed molecular mechanism underlying the oncogenic role of SPOP in kidney tumorigenesis remains elusive.
Methods
Multiple approaches such as Co-IP, Transfection, RT-PCR, Western blotting, and animal studies were utilized to explore the role of SPOP in kidney cancer. Findings: Here we identified LATS1, a critical component of the Hippo tumour suppressor pathway, as a novel ubiquitin substrate of SPOP. We found that LATS1 interacted with Cullin3, and depletion of Cullin 3 upregulated the abundance of LATS1 largely via prolonging LATS1 protein half-life. Mechanistically, SPOP specifically interacted with LATS1, and promoted the poly-ubiquitination and subsequent degradation of LATS1 in a degron-dependent manner. As such, over-expression of SPOP promoted cell proliferation partly through regulating cell cycle distribution in kidney cancer cells. Furthermore, SPOP also promoted kidney cancer cell invasion via degrading LATS1. Interpretation: Our study provides evidence for a novel mechanism of SPOP in kidney cancer progression in part through promoting degradation of the LATS1 tumour suppressor.