TY - JOUR TI - Tonic inhibition of the chloride/proton antiporter ClC-7 by PI(3,5)P2 is crucial for lysosomal pH maintenance AU - Leray, Xavier AU - Hilton, Jacob K AU - Nwangwu, Kamsi AU - Becerril, Alissa AU - Mikusevic, Vedrana AU - Fitzgerald, Gabriel AU - Amin, Anowarul AU - Weston, Mary R AU - Mindell, Joseph A A2 - Maduke, Merritt A2 - Aldrich, Richard W A2 - Xu, Haoxing A2 - Oancea, Elena VL - 11 PY - 2022 DA - 2022/06/07 SP - e74136 C1 - eLife 2022;11:e74136 DO - 10.7554/eLife.74136 UR - https://doi.org/10.7554/eLife.74136 AB - The acidic luminal pH of lysosomes, maintained within a narrow range, is essential for proper degrative function of the organelle and is generated by the action of a V-type H+ ATPase, but other pathways for ion movement are required to dissipate the voltage generated by this process. ClC-7, a Cl-/H+ antiporter responsible for lysosomal Cl- permeability, is a candidate to contribute to the acidification process as part of this ‘counterion pathway’ The signaling lipid PI(3,5)P2 modulates lysosomal dynamics, including by regulating lysosomal ion channels, raising the possibility that it could contribute to lysosomal pH regulation. Here, we demonstrate that depleting PI(3,5)P2 by inhibiting the kinase PIKfyve causes lysosomal hyperacidification, primarily via an effect on ClC-7. We further show that PI(3,5)P2 directly inhibits ClC-7 transport and that this inhibition is eliminated in a disease-causing gain-of-function ClC-7 mutation. Together, these observations suggest an intimate role for ClC-7 in lysosomal pH regulation. KW - lysosome KW - ClC-7 KW - phosphoinositide KW - chloride KW - pH JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -