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Membrane Interaction of α-Synuclein in Different Aggregation States

Grey, Marie LU ; Linse, Sara LU ; Nilsson, Hanna LU ; Brundin, Patrik LU and Sparr, Emma LU (2011) In Journal of Parkinson's Disease 1(4). p.359-371
Abstract
Aggregated α-synuclein in Lewy bodies is one of the hallmarks of Parkinson's disease (PD). Earlier observations of α-synuclein aggregates in neurons grafted into brains of PD patients suggested cell-to-cell transfer of α-synuclein and a prion-like mechanism. This prompted the current investigation of whether α-synuclein passes over model phospholipid bilayers. We generated giant unilamellar vesicles (GUVs) containing a small amount of a lipid-conjugated red emitting dye (rhodamine B) and varied the membrane charge by using different molar ratios of DOPC and DOPS or cardiolipin. We then used confocal fluorescence microscopy to examine how monomer, fibril as well as on-pathway α-synuclein species labeled with a green emitting fluorophore... (More)
Aggregated α-synuclein in Lewy bodies is one of the hallmarks of Parkinson's disease (PD). Earlier observations of α-synuclein aggregates in neurons grafted into brains of PD patients suggested cell-to-cell transfer of α-synuclein and a prion-like mechanism. This prompted the current investigation of whether α-synuclein passes over model phospholipid bilayers. We generated giant unilamellar vesicles (GUVs) containing a small amount of a lipid-conjugated red emitting dye (rhodamine B) and varied the membrane charge by using different molar ratios of DOPC and DOPS or cardiolipin. We then used confocal fluorescence microscopy to examine how monomer, fibril as well as on-pathway α-synuclein species labeled with a green emitting fluorophore (Alexa488) interacted with the phospholipid bilayers of the GUV. We defined conditions that yielded reproducible aggregation kinetics under basal conditions and with none or moderate shaking. We found that on-pathway α-synuclein species and equilibrium amyloid aggregates, but not α-synuclein monomers, bound to lipid membranes. α-Synuclein was particularly strongly associated with GUVs containing the anionic lipids cardiolipin or DOPS, whereas it did not associate with GUVs containing only zwitterionic DOPC. We found that α-synuclein progressively aggregated at the surface of the GUVs, typically in distinct domains rather than uniformly covering the membrane, and that both lipid and protein were incorporated in the aggregates. Importantly, we never observed transport of α-synuclein over the GUV bilayer. This suggests that α-synuclein transport over membranes requires additional molecular players and that it might rely on active transport. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Parkinson's Disease
volume
1
issue
4
pages
359 - 371
publisher
IOS Press
external identifiers
  • wos:000308484300006
  • scopus:84858268438
ISSN
1877-718X
DOI
10.3233/JPD-2011-11067
language
English
LU publication?
yes
id
8498f16b-600c-40e0-bac3-6f7dc7837587 (old id 3222691)
date added to LUP
2012-12-05 11:27:17
date last changed
2017-10-08 03:08:39
@article{8498f16b-600c-40e0-bac3-6f7dc7837587,
  abstract     = {Aggregated α-synuclein in Lewy bodies is one of the hallmarks of Parkinson's disease (PD). Earlier observations of α-synuclein aggregates in neurons grafted into brains of PD patients suggested cell-to-cell transfer of α-synuclein and a prion-like mechanism. This prompted the current investigation of whether α-synuclein passes over model phospholipid bilayers. We generated giant unilamellar vesicles (GUVs) containing a small amount of a lipid-conjugated red emitting dye (rhodamine B) and varied the membrane charge by using different molar ratios of DOPC and DOPS or cardiolipin. We then used confocal fluorescence microscopy to examine how monomer, fibril as well as on-pathway α-synuclein species labeled with a green emitting fluorophore (Alexa488) interacted with the phospholipid bilayers of the GUV. We defined conditions that yielded reproducible aggregation kinetics under basal conditions and with none or moderate shaking. We found that on-pathway α-synuclein species and equilibrium amyloid aggregates, but not α-synuclein monomers, bound to lipid membranes. α-Synuclein was particularly strongly associated with GUVs containing the anionic lipids cardiolipin or DOPS, whereas it did not associate with GUVs containing only zwitterionic DOPC. We found that α-synuclein progressively aggregated at the surface of the GUVs, typically in distinct domains rather than uniformly covering the membrane, and that both lipid and protein were incorporated in the aggregates. Importantly, we never observed transport of α-synuclein over the GUV bilayer. This suggests that α-synuclein transport over membranes requires additional molecular players and that it might rely on active transport.},
  author       = {Grey, Marie and Linse, Sara and Nilsson, Hanna and Brundin, Patrik and Sparr, Emma},
  issn         = {1877-718X},
  language     = {eng},
  number       = {4},
  pages        = {359--371},
  publisher    = {IOS Press},
  series       = {Journal of Parkinson's Disease},
  title        = {Membrane Interaction of α-Synuclein in Different Aggregation States},
  url          = {http://dx.doi.org/10.3233/JPD-2011-11067},
  volume       = {1},
  year         = {2011},
}