@article{3fb9204c1bfb4f4fb526efdfd678af28,
title = "A Cholesterol Dimer Stabilizes the Inactivated State of an Inward-Rectifier Potassium Channel",
abstract = "Cholesterol oligomers reside in multiple membrane protein X-ray crystal structures. Yet, there is no direct link between these oligomers and a biological function. Here we present the structural and functional details of a cholesterol dimer that stabilizes the inactivated state of an inward-rectifier potassium channel KirBac1.1. K+ efflux assays confirm that high cholesterol concentration reduces K+ conductance. We then determine the structure of the cholesterol-KirBac1.1 complex using Xplor-NIH simulated annealing calculations driven by solid-state NMR distance measurements. These calculations identified an α–α cholesterol dimer docked to a cleft formed by adjacent subunits of the homotetrameric protein. We compare these results to coarse grain molecular dynamics simulations. This is one of the first examples of a cholesterol oligomer performing a distinct biological function and structural characterization of a conserved promiscuous lipid binding region.",
keywords = "Cholesterol, Inward-Rectifier K Channels, Membrane Proteins, NMR Structure, Solid-State NMR",
author = "Collin Borcik and Isaac Eason and Maryam Yekefallah and Reza Amani and Ruixian Han and Boden Vanderloop and Benjamin Wylie",
note = "Funding Information: This study made use of the National Magnetic Resonance Facility at Madison (NMRFAM), which is supported by NIH grant P41GM136463. The 600 MHz solid-state NMR spectrometer at NMRFAM was installed with financial support of the Wisconsin Alumni Research Foundation and University of Wisconsin-Madison, and Prof. Chad M. Rienstra collected the data. All Xplor-NIH simulated annealing calculations were performed on NMRbox: National Center for Biomolecular NMR Data Processing and Analysis, a Biomedical Technology Research Resource (BTRR), which is supported by NIH grant P41GM111135 (NIGMS). We also thank the Texas Tech High Performance Computing Center (HPCC) and Dr. Thomas Brown for generously providing computational time for CG-MD and PyLipID analysis. We thank Dr. Charles Schwieters for help with new simulations parameters in Xplor-NIH. We thank Prof. Michael Latham for plate reader access. We thank Prof. Howard Reizman for the gift of the RH6829 yeast strain, Prof. Colin Nichols for his gift of the I131C KirBac1.1 plasmid, and Evan van Aalst for his assistance in revising the text. This research was supported by the National Institutes of Health (Maximizing Investigators{\textquoteright} Research Award (MIRA, R35, 1R35GM124979). Funding Information: This study made use of the National Magnetic Resonance Facility at Madison (NMRFAM), which is supported by NIH grant P41GM136463. The 600 MHz solid‐state NMR spectrometer at NMRFAM was installed with financial support of the Wisconsin Alumni Research Foundation and University of Wisconsin‐Madison, and Prof. Chad M. Rienstra collected the data. All Xplor‐NIH simulated annealing calculations were performed on NMRbox: National Center for Biomolecular NMR Data Processing and Analysis, a Biomedical Technology Research Resource (BTRR), which is supported by NIH grant P41GM111135 (NIGMS). We also thank the Texas Tech High Performance Computing Center (HPCC) and Dr. Thomas Brown for generously providing computational time for CG‐MD and PyLipID analysis. We thank Dr. Charles Schwieters for help with new simulations parameters in Xplor‐NIH. We thank Prof. Michael Latham for plate reader access. We thank Prof. Howard Reizman for the gift of the RH6829 yeast strain, Prof. Colin Nichols for his gift of the I131C KirBac1.1 plasmid, and Evan van Aalst for his assistance in revising the text. This research was supported by the National Institutes of Health (Maximizing Investigators{\textquoteright} Research Award (MIRA, R35, 1R35GM124979). Publisher Copyright: {\textcopyright} 2022 Wiley-VCH GmbH",
year = "2022",
month = mar,
day = "21",
doi = "10.1002/anie.202112232",
language = "English",
volume = "61",
journal = "Default journal",
issn = "1433-7851",
publisher = "ANGEWANDTE CHEMIE-INTERNATIONAL EDITION",
number = "13",
}