Delta-Secretase Phosphorylation by SRPK2 Enhances Its Enzymatic Activity, Provoking Pathogenesis in Alzheimer's Disease.

Delta-secretase, a lysosomal asparagine endopeptidase (AEP), simultaneously cleaves both APP and tau, controlling the onset of pathogenesis of Alzheimer's disease (AD). However, how this protease is post-translationally regulated remains unclear. Here we report that serine-arginine protein kinase 2 (SRPK2) phosphorylates delta-secretase and enhances its enzymatic activity. SRPK2 phosphorylates serine 226 ...
on delta-secretase and accelerates its autocatalytic cleavage, leading to its cytoplasmic translocation and escalated enzymatic activities. Delta-secretase is highly phosphorylated in human AD brains, tightly correlated with SRPK2 activity. Overexpression of a phosphorylation mimetic (S226D) in young 3xTg mice strongly promotes APP and tau fragmentation and facilitates amyloid plaque deposits and neurofibrillary tangle (NFT) formation, resulting in cognitive impairment. Conversely, viral injection of the non-phosphorylatable mutant (S226A) into 5XFAD mice decreases APP and tau proteolytic cleavage, attenuates AD pathologies, and reverses cognitive defects. Our findings support that delta-secretase phosphorylation by SRPK2 plays a critical role in aggravating AD pathogenesis.
Mesh Terms:
Alzheimer Disease, Amyloid Precursor Protein Secretases, Animals, Behavior, Animal, Brain, Cognition, Disease Models, Animal, Genetic Predisposition to Disease, HEK293 Cells, HeLa Cells, Humans, Mice, Inbred C57BL, Mice, Transgenic, Mutation, Neurofibrillary Tangles, Phenotype, Phosphorylation, Plaque, Amyloid, Protein Processing, Post-Translational, Protein Transport, Protein-Serine-Threonine Kinases, RNA Interference, Serine, Substrate Specificity, Time Factors, Transfection, tau Proteins
Mol. Cell
Date: Sep. 07, 2017
Download Curated Data For This Publication
219610
Switch View:
  • Interactions 3