Resveratrol (trans-3,5,4′-truhydroxystilbene) possesses a strong anticancer activity exhibited as the induction of apoptosis through p53 activation. However, the molecular mechanism and direct target(s) of resveratrol-induced p53 activation remain elusive. Here, the Ras-GTPase-activating protein SH3 domain-binding protein 1 (G3BP1) was identified as a potential target of resveratrol, and in vitro binding assay results using resveratrol-conjugated Sepharose 4B beads confirmed their direct binding. Depletion of G3BP1 significantly diminishes resveratrol-induced p53 expression and apoptosis. We also found that G3BP1 negatively regulates p53 expression by interacting with ubiquitin-specific protease 10 (USP10), a deubiquitinating enzyme of p53. Disruption of the interaction of p53 with USP10 by G3BP1 interference leads to the suppression of p53 deubiquitination. Resveratrol, on the other hand, directly binds to G3BP1 and prevents the G3BP1/USP10 interaction, resulting in enhanced USP10-mediated deubiquitination of p53, and consequently increased p53 expression. These findings disclose a novel mechanism of resveratrol-induced p53 activation and resveratrol-induced apoptosis by direct targeting of G3BP1.
Bibliographical noteFunding Information:
We thank Dr Yibin Deng (The Hormel Institute, University of Minnesota, Austin, MN, USA) for kindly providing the expression vectors of shRNA p53. This work was supported by AgStar Minnesota (to ZD), The Hormel Foundation (to ZD) and National Institutes of Health Grants CA111536 (to ZD), CA172457 (to ZD), CA166011 (to ZD), R37 CA081064 (to ZD), CA148940 (to ZL), CA108961 (to ZL), the National Basic Research Program of China (973 Program, Grant No. 2013CB530700), National Natural Science Foundation of China (81102011, 81222029 and 31270806) and Kendall-Mayo Fellowship in Biochemistry, the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (81221001) and Shanghai Science and Technology Committee Modernization of Traditional Chinese Medicine special (11DZ1973801).
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