PUBLICATION

In vivo aggregation of presynaptic alpha-synuclein is not influenced by its phosphorylation at serine-129

Authors
Weston, L.J., Cook, Z.T., Stackhouse, T.L., Sal, M.K., Schultz, B., Tobias, Z.J.C., Osterberg, V.R., Brockway, N.L., Pizano, S., Glover, G., Weissman, T.A., Unni, V.K.
ID
ZDB-PUB-210209-22
Date
2021
Source
Neurobiology of disease   152: 105291 (Journal)
Registered Authors
Glover, Greta, Weissman, Tamily
Keywords
Alpha-synuclein, FRAP, Parkinson's disease, Phosphorylation, Polo-like kinase, Protein aggregation, Zebrafish, in vivo imaging
MeSH Terms
  • Animals
  • Animals, Genetically Modified
  • Disease Models, Animal*
  • Humans
  • Parkinson Disease*
  • Phosphorylation
  • Presynaptic Terminals/pathology*
  • Protein Aggregation, Pathological/metabolism*
  • Serine/metabolism
  • Zebrafish
  • alpha-Synuclein/metabolism*
PubMed
33556542 Full text @ Neurobiol. Dis.
Abstract
Abnormal aggregation of the α-synuclein protein is a key molecular feature of Parkinson's disease and other neurodegenerative diseases. The precise mechanisms that trigger α-synuclein aggregation are unclear, and it is not known what role aggregation plays in disease pathogenesis. Here we use an in vivo zebrafish model to express several different forms of human α-synuclein and measure its aggregation in presynaptic terminals. We show that human α-synuclein tagged with GFP can be expressed in zebrafish neurons, localizing normally to presynaptic terminals and undergoing phosphorylation at serine-129, as in mammalian neurons. The visual advantages of the zebrafish system allow for dynamic in vivo imaging to study α-synuclein, including the use of fluorescence recovery after photobleaching (FRAP) techniques to probe protein mobility. These experiments reveal three distinct terminal pools of α-synuclein with varying mobility, likely representing different subpopulations of aggregated and non-aggregated protein. Human α-synuclein is phosphorylated by an endogenous zebrafish Polo-like kinase activity, and there is a heterogeneous population of neurons containing either very little or extensive phosphorylation throughout the axonal arbor. Both pharmacological and genetic manipulations of serine-129 show that phosphorylation of α-synuclein at this site does not significantly affect its mobility. This suggests that serine-129 phosphorylation alone does not promote α-synuclein aggregation. Together our results show that human α-synuclein can be expressed and measured quantitatively in zebrafish, and that disease-relevant post-translational modifications occur within neurons. The zebrafish model provides a powerful in vivo system for measuring and manipulating α-synuclein function and aggregation, and for developing new treatments for neurodegenerative disease.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping