TY - JOUR
T1 - Structural mechanism of allosteric activation of TRPML1 by PI(3,5)P2 and rapamycin
AU - Gan, Ninghai
AU - Han, Yan
AU - Zeng, Weizhong
AU - Wang, Yan
AU - Xue, Jing
AU - Jiang, Youxing
N1 - Funding Information:
ACKNOWLEDGMENTS. Single-particle cryo-EM data were collected at the University of Texas Southwestern Medical Center Cryo-EM Facility that is funded by Cancer Prevention and Research Institute of Texas Core Facility Support Award RP170644, the Pacific Northwest Center for Cryo-EM (PNCC), and the Howard Hughes Medical Institute (HHMI) Janelia Cryo-EM Facility. We thank Omar Davulcu for help in data collection at the PNCC under User Proposal 51776. A portion of this research was supported by NIH Grant U24GM129547 and performed at the PNCC at Oregon Health & Science University and accessed through the Environmental Molecular Sciences Laboratory (grid.436923.9), a Department of Energy Office of Science User Facility sponsored by the Office of Biological and Environmental Research. We thank Rui Yan at the Janelia Cryo-EM Facility for help in microscope operation and data collection. N.G. is an HHMI Fellow of the Jane Coffin Childs Memorial Fund. This work was supported in part by the HHMI and by grants from the NIH (R35GM140892 to Y.J.) and the Welch Foundation (I-1578 to Y.J.).
Publisher Copyright:
© 2022 National Academy of Sciences. All rights reserved.
PY - 2022/2/15
Y1 - 2022/2/15
N2 - Transient receptor potential mucolipin 1 (TRPML1) is a Ca2+permeable, nonselective cation channel ubiquitously expressed in the endolysosomes of mammalian cells and its loss-of-function mutations are the direct cause of type IV mucolipidosis (MLIV), an autosomal recessive lysosomal storage disease. TRPML1 is a ligand-gated channel that can be activated by phosphatidylinositol 3,5-bisphosphate [PI(3,5)P2] as well as some synthetic smallmolecule agonists. Recently, rapamycin has also been shown to directly bind and activate TRPML1. Interestingly, both PI(3,5)P2 and rapamycin have low efficacy in channel activation individually but together they work cooperatively and activate the channel with high potency. To reveal the structural basis underlying the synergistic activation of TRPML1 by PI(3,5)P2 and rapamycin, we determined the high-resolution cryoelectron microscopy (cryo- EM) structures of the mouse TRPML1 channel in various states, including apo closed, PI(3,5)P2-bound closed, and PI(3,5)P2/temsirolimus (a rapamycin analog)-bound open states. These structures, combined with electrophysiology, elucidate the molecular details of ligand binding and provide structural insight into how the TRPML1 channel integrates two distantly bound ligand stimuli and facilitates channel opening.
AB - Transient receptor potential mucolipin 1 (TRPML1) is a Ca2+permeable, nonselective cation channel ubiquitously expressed in the endolysosomes of mammalian cells and its loss-of-function mutations are the direct cause of type IV mucolipidosis (MLIV), an autosomal recessive lysosomal storage disease. TRPML1 is a ligand-gated channel that can be activated by phosphatidylinositol 3,5-bisphosphate [PI(3,5)P2] as well as some synthetic smallmolecule agonists. Recently, rapamycin has also been shown to directly bind and activate TRPML1. Interestingly, both PI(3,5)P2 and rapamycin have low efficacy in channel activation individually but together they work cooperatively and activate the channel with high potency. To reveal the structural basis underlying the synergistic activation of TRPML1 by PI(3,5)P2 and rapamycin, we determined the high-resolution cryoelectron microscopy (cryo- EM) structures of the mouse TRPML1 channel in various states, including apo closed, PI(3,5)P2-bound closed, and PI(3,5)P2/temsirolimus (a rapamycin analog)-bound open states. These structures, combined with electrophysiology, elucidate the molecular details of ligand binding and provide structural insight into how the TRPML1 channel integrates two distantly bound ligand stimuli and facilitates channel opening.
KW - Lysosomal channel
KW - PI(3,5)P2
KW - Rapamycin
KW - TRPML1
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U2 - 10.1073/pnas.2120404119
DO - 10.1073/pnas.2120404119
M3 - Article
C2 - 35131932
AN - SCOPUS:85124254875
VL - 119
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
SN - 0027-8424
IS - 7
M1 - e2120404119
ER -