Journal Article

Tetrandrine regulates NAADP-mediated calcium signaling through a LIMP-2-dependent and sphingosine-mediated mechanism

Ruan, Ye Chun, Sun, Kailei, Ma, Cong, Ho, Yu-Hin, Li, Xiang David, Ye, Xiang-Yang, Chow, Larry M. C., Zhao, Yan Xiang, Wong, Koon Ho, Chau, Mary P., Ma, Xiyang, Wong, Ka-Hing, Mok, Chin Yu, Zhao, Qian, Wong, Clarence T. T., Chan, Ka Ying, Liu, Jiang, Chan, Wing-Cheung, Mok, Daniel Kam-Wah, Ko, Ben C. B., Tse, Gary M., Tang, Hok-Him, Pardeshi, Lakhansing, Zhao, Yong-Juan, Leung, Franco King-Chi, Wong, Man-Kin, Au, Shannon Wing-Ngor, Wang, Fang, Chiu, Pauline, Yang, Yang, Shen, Xiao, Yin, Zengsheng, Lui, Ying-Ying, Yeung, Man Lung, Wong, Chi-Ming, Leung, Howard Ho-Wai, Zhang, Yajing

2025

Overview

Tetrandrine (Tet) is a potent inhibitor of Ebola virus replication by blocking NAADP-dependent calcium release through endolysosomal two-pore channels (TPCs) and a moderately potent anti-tumor agent. Using a clickable photoaffinity probe, we identify lysosomal integral membrane protein-2 (LIMP-2) as a direct target of Tet and a key regulator of this calcium signaling. Tet binds LIMP-2’s ectodomain, inhibiting lysosomal cholesterol and sphingosine transport, which alters lipid metabolism. Tet treatment and LIMP-2 depletion inhibit NAADP-dependent calcium release, reversible by removing lysosomal cholesterol and sphingosine. Sphingosine triggers lysosomal calcium release via TPCs and restores this signaling in Tet-treated or LIMP-2-deficient cells, revealing a LIMP-2-regulated, sphingosine-dependent lysosomal calcium pathway. At higher doses, Tet induces apoptosis through unfolded protein response activation independently of LIMP-2. These findings highlight Tet as a LIMP-2 inhibitor, elucidate its role in calcium signaling and cell death, and suggest therapeutic potential for Tet and LIMP-2 inhibitors in antiviral treatments. Tetrandrine is one of the most potent inhibitors of Ebola Virus infection. Here the authors identify LIMP-2 as a direct cellular target of Tetrandrine and establish a functional connection between lysosomal sphingosine homeostasis and calcium regulation.

• Publisher: Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
• Subject: 13/89 / 14/19 / 45/77 / 45/90 / 45/91 / 631/45/287 / 631/80/86/1999 / 631/92/555 / 64/60 / 82/1 / 96/106 / 96/34 / Animals / Apoptosis / Apoptosis - drug effects / Benzylisoquinolines - pharmacology / Calcium / Calcium - metabolism / Calcium Channels - metabolism / Calcium homeostasis / Calcium Signaling - drug effects / Calcium signalling / Cell culture / Cell death / Chemistry / Cholesterol / Cholesterol - metabolism / Ebola virus / Ebolavirus / Endoplasmic reticulum / HEK293 Cells / Homeostasis / Humanities and Social Sciences / Humans / Labeling / Lipid metabolism / Lipids / Localization / Lysosomal Membrane Proteins - genetics / Lysosomal Membrane Proteins - metabolism / Lysosomes - drug effects / Lysosomes - metabolism / Mitochondria / multidisciplinary / NAADP / NADP - analogs & derivatives / NADP - metabolism / Peptides / Protein folding / Proteins / Science / Science (multidisciplinary) / Sphingosine - metabolism / Tetrandrine / Unfolded Protein Response - drug effects / Viral diseases