Lysosomal LRRC8 complex regulates lysosomal pH, morphology and systemic glucose metabolism

Kumar, A.; Zhao, Y.; Xie, L.; Chadda, R.; Abraham, N.; Hong, J.; Feng, E.; Tranter, J. D.; Rawnsley, D.; Liu, H.; Henry, K. M.; Meyer, G.; Hu, M.; Xu, H.; Hinton, A.; Grueter, C. E.; Abel, E. D.; Norris, A. W.; Diwan, A.; Sah, R.

doi:10.1101/2024.09.22.614256

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bioRxiv · 10.1101/2024.09.22.614256

Lysosomal LRRC8 complex regulates lysosomal pH, morphology and systemic glucose metabolism

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Abstract

The lysosome integrates anabolic signalling 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 signalling, 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 LRRC8A regulates leucine-stimulated mTOR, lysosome size, number, pH, and expression of lysosomal proteins LAMP2, P62, LC3B, suggesting impaired autophagic flux. Mutating a LRRC8A lysosomal targeting dileucine motif sequence (LRRC8A-L706A;L707A) in myotubes recapitulates the abnormal AKT signalling and altered lysosomal morphology and pH observed in LRRC8A KO cells. In vivo, LRRC8A-L706A;L707A KI mice exhibit increased adiposity, impaired glucose tolerance and insulin resistance characterized by reduced skeletal muscle glucose-uptake, and impaired incorporation of glucose into glycogen. These data reveal a lysosomal LRRC8 mediated metabolic signalling function that regulates lysosomal activity, systemic glucose homeostasis and insulin-sensitivity.

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Kumar, A., Zhao, Y., Xie, L., Chadda, R., Abraham, N., Hong, J., Feng, E., Tranter, J. D., Rawnsley, D., Liu, H., Henry, K. M., Meyer, G., Hu, M., Xu, H., Hinton, A., Grueter, C. E., Abel, E. D., Norris, A. W., Diwan, A., Sah, R.. 2024-09-23. Lysosomal LRRC8 complex regulates lysosomal pH, morphology and systemic glucose metabolism. https://doi.org/10.1101/2024.09.22.614256

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