SMER28 binding to VCP/p97 enhances both autophagic and proteasomal neurotoxic protein clearance.

The ability to maintain a functional proteome by clearing damaged or misfolded proteins is critical for cell survival, and aggregate-prone proteins accumulate in many neurodegenerative diseases, such as Huntington, Alzheimer, and Parkinson diseases. The removal of such proteins is mainly mediated by the ubiquitin-proteasome system and autophagy, and the activity of these systems declines in disease or with age. We recently found that targeting VCP/p97 with compounds like SMER28 enhances macroautophagy/autophagy flux mediated by the increased activity of the PtdIns3K complex I. Additionally, we found that SMER28 binding to VCP stimulates aggregate-prone protein clearance via the ubiquitin-proteasome system. This concurrent action of SMER28 on both degradation pathways resulted in the selective decrease in disease-causing proteins but not their wild-type counterparts. These results reveal a promising mode of VCP activation to counteract the toxicity caused by aggregate-prone proteins.