Title page for etd-0404117-114837


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URN etd-0404117-114837
Author Yin-Hsuan Wang
Author's Email Address No Public.
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Department Biological Sciences
Year 2016
Semester 2
Degree Master
Type of Document
Language zh-TW.Big5 Chinese
Title The cAMP/PKA-mediated Tau S409 phosphorylation
through GSKIP/GSK3 axis in SH-SY5Y and iPS cells.
Date of Defense 2017-04-28
Page Count 53
Keyword
  • PKA
  • Tau
  • Alzheimer disease
  • Human induced pluripotent stem (iPS) cells
  • Aβ precursor protein (
  • GSK3β
  • GSKIP
  • Abstract We previously described that PKA/GSKIP/GSK3β complex serves as a platform to anchor and phosphorylate Drp1 affecting mitochondria dynamics to provide neuroprotection. Recently, a known PKA/GSK3β substrate, Tau, has been revealed its S409 phosphorylation is associating with the termination of neuron cells in Alzheimer disease. In this study, we attempt to extend that Tau phosphorylation is also mediated by PKA/GSKIP/GSK3β working complex. Our data showed that GSKIP-WT overexpression in SH-SY5Y cells increased phosphorylation of Tau S409 site (not S214; S262; S396; S404; T205 and T212 sites) over that of PKA- and GSK3β binding-defective mutants (V41/L45 and L130) under forskolin challenge, indicating that both PKA and GSK3β bindings may be associated to phosphorylate Tau at S409 site. Surprisingly, treatment with foskion in GSKIP-WT-overexpressing SH-SY5Y cells were significantly increase Tau phosphorylation at S409, suggesting that only PKA kinase activity, but not GSK3β, is required in the GSKIP-mediated Tau phosphorylation. However, silencing of GSK3β resulted in a dramatic decrease in phosphorylation of Tau S409, revealing both GSKIP and GSK3β are crucial of PKA/GSKIP/GSK3β/Tau complex. Further, overexpressed kinase-dead GSK3β K85R (retains capacity to bind GSKIP) in SH-SY5Y cells, but not K85M (loss of capacity to bind GSKIP), has a higher Tau S409 phosphorylation, ensures that GSK3β acts solely as an anchor binding protein rather than its kinase activity in this signaling axis. Due to previous studies showed several different residues of Tau can be phosphorylated by PKA, we conducted In vitro kinase assay and provided two clear results: (1) As similar to early findings, PKA played a phosphorylation role on Ser409, Ser214 and Ser262 residues of Tau. (2) GSK3β provided a conformational shelter in PKA/GSKIP/GSK3β/Tau complex to harbor Tau Ser409 residue so that PKA is failed to phosphorylate Tau Ser409 residue. Furthermore, by using CRISPR/Cas9 system to produce APP WT/D678H and APP WT/WT 、 APP D678H/D678H multifunctional stem cells (modified from an APP patient WT/D678H genotype), the results of analysis showed phosphorylation in Tau Ser262 and Ser214 residues and the Tau Ser409 intense phosphorylation in the brain of Alzheimer’s patients.. Coupling with previous findings of PKA suggested that the PKA/GSKIP/GSK3β/Tau complex may plays a key role on the development of Alzheimer’s disease. Taken together, our data provide compelling evidence to implicate that both GSKIP and GSK3β function as anchoring proteins to enhance cAMP/PKA/Tau axis signaling during Alzheimer pathogenesis.
    Advisory Committee
  • Chiou Shean-jaw - chair
  • Cheng Jiin-Tsuey - co-chair
  • Huang Chi-Ying - co-chair
  • Hong Yi-Ren - advisor
  • Files
  • etd-0404117-114837.pdf
  • Indicate in-campus at 3 year and off-campus access at 3 year.
    Date of Submission 2017-05-04

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