@article{ba9de5d2d2ab4f05a6a6b0af6328a935,
title = "Full-Length P2X7 Structures Reveal How Palmitoylation Prevents Channel Desensitization",
abstract = "P2X receptors are trimeric, non-selective cation channels activated by extracellular ATP. The P2X7 receptor subtype is a pharmacological target because of involvement in apoptotic, inflammatory, and tumor progression pathways. It is the most structurally and functionally distinct P2X subtype, containing a unique cytoplasmic domain critical for the receptor to initiate apoptosis and not undergo desensitization. However, lack of structural information about the cytoplasmic domain has hindered understanding of the molecular mechanisms underlying these processes. We report cryoelectron microscopy structures of full-length rat P2X7 receptor in apo and ATP-bound states. These structures reveal how one cytoplasmic element, the C-cys anchor, prevents desensitization by anchoring the pore-lining helix to the membrane with palmitoyl groups. They show a second cytoplasmic element with a unique fold, the cytoplasmic ballast, which unexpectedly contains a zinc ion complex and a guanosine nucleotide binding site. Our structures provide first insights into the architecture and function of a P2X receptor cytoplasmic domain.",
keywords = "Apoptosis, Cryoelectron microscopy, Cytoplasmic domain, Desensitization, Guanosine nucleotides, Ligand gated ion channels, Palmitoylation, Purinergic (P2X) receptors, Structural biology, Zinc ion complex",
author = "McCarthy, {Alanna E.} and Craig Yoshioka and Mansoor, {Steven E.}",
note = "Funding Information: We thank E. Gouaux, D. Farrens, M. Mayer, L. Anson, F. Jalali-Yazdi, W. L{\"u}, J. Du, M. Whorton, and J. Fay for feedback on the manuscript; L. Vaskalis for figures; and A. Goehring, H. Zhu, J. Elferich, and other members of the E. Gouaux and I. Baconguis laboratories for helpful discussions. We thank Schr{\"o}dinger, LLC for critical insight into ligand-receptor interactions. Electron microscopy was performed at the Multiscale Microscopy Core, part of the Oregon Health and Science University (OHSU) Center for Spatial Systems Biomedicine. ICP MS measurements were performed in the OHSU Elemental Analysis Core ( NIH core grant S10RR025512 ). We thank J. Luo and D. Koop for assistance with the GDP analysis, conducted in the OHSU Bioanalytical Shared Resource/Pharmacokinetics Core. All research other than cryo-EM was carried out in the Gouaux lab in the Vollum Institute, supported by the Howard Hughes Medical Institute (to E.G.) and the NIH . C.Y. was supported by funds from the Gouaux lab . This research was also supported by the National Heart, Lung and Blood Institute ( K99HL138129 to S.E.M.). Funding Information: We thank E. Gouaux, D. Farrens, M. Mayer, L. Anson, F. Jalali-Yazdi, W. L?, J. Du, M. Whorton, and J. Fay for feedback on the manuscript; L. Vaskalis for figures; and A. Goehring, H. Zhu, J. Elferich, and other members of the E. Gouaux and I. Baconguis laboratories for helpful discussions. We thank Schr?dinger, LLC for critical insight into ligand-receptor interactions. Electron microscopy was performed at the Multiscale Microscopy Core, part of the Oregon Health and Science University (OHSU) Center for Spatial Systems Biomedicine. ICP MS measurements were performed in the OHSU Elemental Analysis Core (NIH core grant S10RR025512). We thank J. Luo and D. Koop for assistance with the GDP analysis, conducted in the OHSU Bioanalytical Shared Resource/Pharmacokinetics Core. All research other than cryo-EM was carried out in the Gouaux lab in the Vollum Institute, supported by the Howard Hughes Medical Institute (to E.G.) and the NIH. C.Y. was supported by funds from the Gouaux lab. This research was also supported by the National Heart, Lung and Blood Institute (K99HL138129 to S.E.M.). S.E.M. designed the project. A.E.M. carried out sample preparation and performed the functional analyses. S.E.M. and C.Y. collected and processed the data. S.E.M. performed model building. A.E.M. and S.E.M. wrote and edited the manuscript. The authors declare no competing interests. Publisher Copyright: {\textcopyright} 2019 Elsevier Inc.",
year = "2019",
month = oct,
day = "17",
doi = "10.1016/j.cell.2019.09.017",
language = "English (US)",
volume = "179",
pages = "659--670.e13",
journal = "Cell",
issn = "0092-8674",
publisher = "Cell Press",
number = "3",
}