Folliculin Encoded by the BHD Gene Interacts with a Binding Protein, FNIP1, and AMPK, and Is Involved in AMPK and mTOR Signaling

The study explored the role of folliculin (FLCN), a tumor-suppressor protein encoded by the BHD gene, in Birt–Hogg–Dubé syndrome, which is characterized by benign tumors, lung cysts, and renal neoplasia. Researchers identified FNIP1 as a protein that interacts with FLCN and demonstrated its involvement in the AMPK and mTOR signaling pathways, which are crucial for energy and nutrient sensing. FNIP1 was phosphorylated by AMPK, and this phosphorylation was influenced by AMPK inhibitors, which also affected FLCN phosphorylation. The study suggested that FLCN and FNIP1 might play a role in regulating energy and nutrient sensing, with potential implications for understanding the molecular mechanisms underlying Birt–Hogg–Dubé syndrome.