Protein phase separation at the synapse - Alpha-synuclein in health and disease
Alpha-synuclein is a presynaptic protein which has garnered attention due to its involvement in the formation of protein aggregates. These are known as Lewy bodies and are the pathological hallmark of Parkinson’s disease. Recent research suggests that protein phase separation and the subsequent formation of condensates could play a critical role for the function alpha-synuclein as well as its aggregation. To gain a comprehensive understanding of this phenomenon, it is essential to understand how alpha-synuclein phase separation is regulated within its biological context. Combining in-vitro biochemical studies, cellular phase separation assays and super-resolution imaging in the lamprey reticulospinal giant synapse model we delve into the principles of synapse compartmentalization, studying alpha-synuclein function and dysfunction in disease.
Strategic CIMR themes: Neurological diseases, Rare genetic diseases, Membrane trafficking, Protein folding & quality control
Funding: The Royal Society, Leverhulme Trust, Addenbrooke’s Charitable Trust
Research Group Members: Dr Aishwarya Agarwal, Thabiso Shaun Ncube, Celia Antico, Shiyue Chen, Sicheng Han, Dr Aswathy Chandran
Research
The functioning of neuronal synapses is crucial for the communication between neurons and dysregulation has been implicated in various neurological disorders. Our lab investigates a new phenomenon, protein phase separation, responsible for regulating synapse function supporting the formation of subsynaptic compartments.
Our current work focuses on alpha-synuclein, a presynaptic protein involved in Parkinson’s disease. We have identified that alpha-synuclein phase separation is regulated by VAMP2, a protein which interacts with alpha-synuclein’s negatively charged and intrinsically disordered C-terminus. While VAMP2 is a well-known player in synaptic function and SNARE complex formation, our research unveils a molecular mechanism for VAMP2 in controlling alpha-synuclein phase separation during vesicle cycling (Agarwal et al. 2023 bioRxiv). We show that both electrostatic and hydrophobic interactions are important for alpha-synuclein phase separation and demonstrate that alpha-synuclein condensates enable vesicle clustering.
Combining in vitro biochemical assays, cellular models of alpha-synuclein phase separation, functional studies in iPSC-derived neurons and super-resolution imaging in the lamprey reticulospinal giant synapse model we delve into the principles of synapse compartmentalization. Not only examining alpha-synuclein phase separation, but considering the synapse as a system of distinct subsynaptic compartments, our research will offer crucial insights into the fundamental principles and intricate regulation of synapse compartmentalisation (Lautenschläger 2022 Open Biology). These discoveries hold the significance to understand molecular mechanisms involved in neurological disorders, including Parkinson's disease, Lewy body dementia, and others.
Publications
Agarwal A, Raza F, Hilcenko C, Stott K, Morone N, Warren AJ, Lautenschläger J. VAMP2 regulates alpha-synuclein phase separation. BioRxiv. 2023, doi: 10.1101/2023.06.16.545277
Lautenschläger J. Protein phase separation hot spots at the presynapse. Open Biol. 2022; Vol. 12: 210334.
Lautenschläger J, Wagner-Valladolid S, Stephens AD, Fernández-Villegas A, Hockings C, Mishra A, Manton JD, Fantham MJ, Lu M, Rees EJ, Kaminski CF, Kaminski Schierle GS. Intramitochondrial proteostasis is directly coupled to a-synuclein and amyloid beta 1-42 pathologies. J Biol Chem 2020; Vol. 295: 1038-10152, doi: 10.1074/jbc.RA119.011650
Lautenschläger J & Kaminski Schierle GS. Mitochondrial degradation of amyloidogenic proteins - A new perspective for neurodegenerative diseases. Prog Neurobiol 2019; Vol. 181: 101660, doi: 10.1016/j.pneurobio.2019.101660
Lautenschläger J, Stephens AD, Fusco G, Ströhl F, Curry N, Zacharopoulou M, Michel CH, Laine R, Nespovitaya N, Fantham M, Pinotsi D, Zago W, Fraser P, Tandon A, St Georg-Hyslop P, Rees E, Phillips JJ, De Simone A, Kaminski CF, Kaminski Schierle GS. C-terminal calcium binding of alpha-synuclein modulates synaptic vesicle interaction. Nat Commun 2018; Vol. 9: 712, doi: 10.1038/s41467-018-03111-4
Lautenschläger J, Mosharov E V., Kanter E, Sulzer D & Kaminski Schierle GS. An Easy-to-Implement Protocol for Preparing Postnatal Ventral Mesencephalic Cultures. Front Cell Neurosci 2018; Vol. 12: 1–10, doi: 10.3389/fncel.2018.00044
Lautenschläger J, Kaminski CF, Kaminski-Schierle GS. Alpha-synuclein - regulator of exocytosis, endocytosis or both? Trends Cell Biol 2017; Vol. 27: 468-479, doi: 10.1016/j.tcb.2017.02.002
