Xanthohumol impairs autophagosome maturation through direct inhibition of valosin-containing protein.
ABSTRACT Autophagy is a bulk, nonspecific protein degradation pathway that is involved in the pathogenesis of cancer and neurodegenerative disease. Here, we observed that xanthohumol (XN), a prenylated chalcone present in hops (Humulus lupulus L.) and beer, modulates autophagy. By using XN-immobilized beads, valosin-containing protein (VCP) was identified as a XN-binding protein. VCP has been reported to be an essential protein for autophagosome maturation. Using an in vitro pull down assay, we showed that XN bound directly to the N domain, which is known to mediate cofactor and substrate binding to VCP. These data indicated that XN inhibited the function of VCP, thereby allowing the impairment of autophagosome maturation and resulting in the accumulation of microtubule-associated protein 1 light chain 3-II (LC3-II). This is the first report demonstrating XN as a VCP inhibitor that binds directly to the N domain of VCP. Our finding that XN bound to and inactivated VCP not only reveals the molecular mechanism of XN-modulated autophagy but may also explain how XN exhibits various biological activities that have been reported previously.
- SourceAvailable from: Delphine Fessart[show abstract] [hide abstract]
ABSTRACT: P97/CDC-48 is a prominent member of a highly evolutionary conserved Walker cassette - containing AAA+ ATPases. It has been involved in numerous cellular processes ranging from the control of protein homeostasis to membrane trafficking through the intervention of specific accessory proteins. Expression of p97/CDC-48 in cancers has been correlated with tumor aggressiveness and prognosis, however the precise underlying molecular mechanisms remain to be characterized. Moreover p97/CDC-48 inhibitors were developed and are currently under intense investigation as anticancer drugs. Herein, we discuss the role of p97/CDC-48 in cancer development and its therapeutic potential in tumor cell biology.Cancer letters 05/2013; · 4.86 Impact Factor