Structural basis for cholesterol sensing of LYCHOS and its interaction with indoxyl sulfate.
Wang, Z., He, J., Yang, Y., He, Y., Qian, H.(2025) Nat Commun 16: 2815-2815
- PubMed: 40118871 
- DOI: https://doi.org/10.1038/s41467-025-58087-9
- Primary Citation of Related Structures:  
8WR3, 9J3X, 9J3Z, 9J40 - PubMed Abstract: 
The lysosome serves as an essential nutrient-sensing hub within the cell, where the mechanistic target of rapamycin complex 1 (mTORC1) is activated. Lysosomal cholesterol signaling (LYCHOS), a lysosome membrane protein, has been identified as a cholesterol sensor that couples cholesterol concentration to mTORC1 activation. However, the molecular basis is unknown. Here, we determine the cryo-electron microscopy (cryo-EM) structure of human LYCHOS at a resolution of 3.1??, revealing a cholesterol-like density at the interface between the permease and G-protein coupled receptor (GPCR) domains. Advanced 3D classification reveals two distinct states of LYCHOS. Comparative structural analysis between these two states demonstrated a cholesterol-related movement of GPCR domain relative to permease domain, providing structural insights into how LYCHOS senses lysosomal cholesterol levels. Additionally, we identify indoxyl sulfate (IS) as a binding ligand to the permease domain, confirmed by the LYCHOS-IS complex structure. Overall, our study provides a foundation and indicates additional directions for further investigation of the essential role of LYCHOS in the mTORC1 signaling pathway.
Organizational Affiliation: 
Department of Cardiology, The First Affiliated Hospital of USTC, MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Research Center for Interdisciplinary Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China.