Direct High Affinity Interaction between Aβ42 and GSK3α Stimulates Hyperphosphorylation of Tau. A New Molecular Link in Alzheimer's Disease?

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Abstract

Amyloid β peptide (Aβ42) assemblies are considered central to the development of Alzheimer's disease, but the mechanism of this toxicity remains unresolved. We screened protein microarrays with on-pathway oligomeric Aβ42 to identify candidate proteins interacting with toxic Aβ42 species. Samples prepared from Alexa546-Aβ42 and Aβ42 monomers at 1:5 molar ratio were incubated with the array during a time window of the amyloid fibril formation reaction during which the maximum number of transient oligomers exist in the reaction flux. A specific interaction was detected between Aβ42 and glycogen synthase kinase 3α (GSK3α), a kinase previously implicated in the disease pathology. This interaction was validated with anti-GSK3α immunoprecipitation assays in neuronal cell lysates. Confocal microscopy studies further identified colocalization of Aβ42 and GSK3α in neurites of mature primary mouse neurons. A high binding affinity (KD = 1 nM) was measured between Alexa488-Aβ42 and GSK3α in solution using thermophoresis. An even lower apparent KD was estimated between GSK3α and dextran-immobilized Aβ42 in surface plasmon resonance experiments. Parallel experiments with GSK3β also identified colocalization and high affinity binding to this isoform. GSK3α-mediated hyperphosphorylation of the protein tau was found to be stimulated by Aβ42 in in vitro phosphorylation assays and identified a functional relationship between the proteins. We uncover a direct and functional molecular link between Aβ42 and GSK3α, which opens an important avenue toward understanding the mechanism of Aβ42-mediated neuronal toxicity in Alzheimer's disease.

Detaljer

Författare
  • Christopher Dunning
  • Gavin McGauran
  • Katarina Willén
  • Gunnar Gouras
  • David J O'Connell
  • Sara Linse
Enheter & grupper
Forskningsområden

Ämnesklassifikation (UKÄ) – OBLIGATORISK

  • Neurovetenskaper
Originalspråkengelska
Sidor (från-till)161-170
TidskriftACS Chemical Neuroscience
Volym7
Utgivningsnummer2
Tidigt onlinedatum2015 dec 15
StatusPublished - 2016
PublikationskategoriForskning
Peer review utfördJa