Lysosomal LRRC8 complex impacts lysosomal pH, morphology, and systemic glucose metabolism
- Ashutosh Kumar
- Yonghui Zhao
- Litao Xie
- Rahul Chadda
- John D. Tranter
- Ryan T. Mikami
- Nihil Abraham
- Juan Hong
- Ethan Feng
- David R. Rawnsley
- Haiyan Liu
- Kayla M. Henry
- Gretchen Meyer
- Meiqin Hu
- Haoxing Xu
- Antentor Hinton
- Chad E. Grueter
- E. Dale Abel
- Andrew W. Norris
- Abhinav Diwan
- Rajan Sah
2025-09-26
The lysosome integrates anabolic signaling and nutrient sensing to regulate intracellular growth pathways. The leucine-rich repeat–containing 8 (LRRC8) channel complex forms a lysosomal anion channel and regulates PI3K-AKT-mTOR signaling, skeletal muscle differentiation, growth, and systemic glucose metabolism. Here, we define the endogenous LRRC8 subunits localized to a subset of lysosomes in differentiated myotubes. We show that LRRC8A affects leucine-stimulated mTOR; lysosome size; number; pH; expression of lysosomal proteins LAMP2, P62, and LC3B; and lysosomal function. Mutating an LRRC8A lysosomal targeting dileucine motif sequence (LRRC8A-L706A;L707A) in myotubes recapitulates the abnormal AKT signaling and altered lysosomal morphology and pH observed in LRRC8A knockout cells. In vivo, LRRC8A-L706A;L707A knock-in mice exhibit increased adiposity, impaired glucose tolerance and insulin resistance associated with reduced skeletal muscle PI3K-AKT-mTOR signaling, glucose uptake, and impaired incorporation of glucose into glycogen. These data reveal a lysosomal LRRC8-mediated metabolic signaling function regulating lysosomal function, systemic glucose homeostasis, and insulin sensitivity.