Migfilin promotes autophagic flux through direct interaction with SNAP29 and Vamp8.

Abstract

Autophagy plays a crucial role in cancer cell survival by facilitating the elimination of detrimental cellular components and the recycling of nutrients. Understanding the molecular regulation of autophagy is critical for developing interventional approaches for cancer therapy. In this study, we report that migfilin, a focal adhesion protein, plays a novel role in promoting autophagy by increasing autophagosome-lysosome fusion. We found that migfilin is associated with SNAP29 and Vamp8, thereby facilitating Stx17-SNAP29-Vamp8 SNARE complex assembly. Depletion of migfilin disrupted the formation of the SNAP29-mediated SNARE complex, which consequently blocked the autophagosome-lysosome fusion, ultimately suppressing cancer cell growth. Restoration of the SNARE complex formation rescued migfilin-deficiency-induced autophagic flux defects. Finally, we found depletion of migfilin inhibited cancer cell proliferation. SNARE complex reassembly successfully reversed migfilin-deficiency-induced inhibition of cancer cell growth. Taken together, our study uncovers a new function of migfilin as an autophagy-regulatory protein and suggests that targeting the migfilin-SNARE assembly could provide a promising therapeutic approach to alleviate cancer progression.