Oliver P. Ernst
Professor
| Address | MSB, Room 5219A 1 King's College Circle Toronto, ON M5S 1A8 |
| Lab | Ernst Lab |
| Lab Phone | 416-978-3852 |
| Office Phone | 416-978-3849 |
| oliver.ernst@utoronto.ca |
Research Description
Transmembrane Signaling by GPCRs and Channelrhodopsins
Cell membranes are natural borders for signal transduction between cells and their environment. Different strategies to enable signals to cross the membrane barrier employ protein classes such as G protein-coupled receptors (GPCRs), ion channels, and transporters. Our research is directed at understanding transmembrane signaling by GPCRs. We investigate the inner workings of these proteins and their interaction with signaling proteins like G proteins and arrestins. Using cryo-EM, x-ray crystallography, and various spectroscopic techniques, including electron paramagnetic resonance (EPR), we aim to gain insight into the mechanism, specificity, and structural basis of these interactions. A focus of our work is on rhodopsin, a GPCR model system and the photoreceptor protein in the vertebrate retina. Understanding how GPCRs work on a molecular level will help us to comprehend their role in health and disease.
Channelrhodopsins are microbial rhodopsins that act as light-gated ion channels and are used for optogenetic activation or silencing of mammalian neurons. Using cryo-EM, we study their mechanism of channel gating and ion selectivity. Other microbial rhodopsins work as ion pumps, which we also study by x-ray crystallography and EPR.
Additionally, we are interested in the localization of proteasomes, their structure and function in response to metabolic changes, and their potential role in liquid-liquid phase separation.
Awards & Distinctions
2011-2017 — Canada Excellence Research Chair in Structural Neurobiology
2011-2021 — Anne and Max Tanenbaum Chair in Neuroscience at University of Toronto
2020 — Konrad Adenauer Research Award (Humboldt Research Award Programme)
Courses Taught
Membrane Proteomics in Biomedical Research MMG 1313H
BCH374Y1 Research Project in Biochemistry
BCH473Y Advanced Research Project in Biochemistry
BCH422H Membrane Proteins: Structure and Function
Publications
View all publications on PubMed
Structural insights into light-gating of potassium-selective channelrhodopsin.
Morizumi et al.
Nature Communications (2025) 1283. Read
Structures of channelrhodopsin paralogs in peptidiscs explain their contrasting K+ and Na+ selectivities.
Morizumi et al.
Nature Communications (2023) 4365. Read
Low pH structure of heliorhodopsin reveals chloride binding site and intramolecular signaling pathway.
Besaw et al.
Scientific Reports (2022) 12:13955. Read
Serial femtosecond and serial synchrotron crystallography can yield data of equivalent quality: A systematic comparison.
Mehrabi et al.
Science Advances (2021) 7:eabf1380 Read
High-throughput in situ X-ray screening of and data collection from protein crystals at room temperature and under cryogenic conditions
Broecker et al.
Nature Protocols (2018) 13:260-92. Read
Cryo-EM structure of the native rhodopsin dimer in nanodiscs
Zhao et al.
JBC (2019) 294:14215-14230 Read
Cryo-EM structure of human rhodopsin bound to an inhibitory G protein
Kang et al.
Nature (2018) 558:553-558 Read
Electron paramagnetic resonance spectroscopy on G-protein-coupled receptors: Adopting strategies from related model systems.
Reichenwallner et al.
Current Opinion in Structural Biology (2021) 69:177-186. Read
Stationary Phase EPR Spectroscopy for Monitoring Membrane Protein Refolding by Conformational Response.
Balo et al.
Analytical Chemistry (2019) 91:1071-1079. Read
Proteasome dynamics in response to metabolic changes.
Enenkel C & Ernst OP.
Frontiers in Cell and Developmental Biology (2025) 13:1523382. Read
Intracellular localization of the proteasome in response to stress conditions.
Enenkel C et al.
Journal of Biological Chemistry (2022) 298:102083. Read
Broadly neutralizing humanized SARS-CoV-2 antibody binds to a conserved epitope on Spike and provides antiviral protection through inhalation-based delivery in non-human primates.
Hermet et al.
PLoS Pathogens (2023) 19:e1011532. Read