Presenilin-1 regulates the expression of p62 to govern p62-dependent tau degradation

Mol Neurobiol. 2014 Feb;49(1):10-27. doi: 10.1007/s12035-013-8482-y. Epub 2013 Jun 23.

Abstract

Mutations in presenilin-1 (PS1) are tightly associated with early-onset familial Alzheimer's disease (FAD), which is characterized by extracellular amyloid plaques and the accumulation of intracellular Tau. In addition to being the catalytic subunit of γ-secretase, PS1 has been shown to regulate diverse cellular functions independent of its proteolytic activity. We found that cells deficient in PS1 exhibit reduced levels of p62 protein, a cargo-receptor shuttling Tau for degradation. The downregulation of PS1 led to a significant decrease in both the protein and mRNA transcript of p62, concomitant with attenuated p62 promoter activity. This PS1-dependent regulation of p62 expression was mediated through an Akt/AP-1 pathway independent of the proteolytic activity of PS1/γ-secretase. This p62-mediated Tau degradation was significantly impaired in PS1-deficient cells, which can be rescued by ectopic expression of either p62 or wild-type PS1 but not mutant PS1 containing FAD-linked mutations. Our study suggests a novel function for PS1 in modulating p62 expression to control the proteostasis of Tau.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / biosynthesis
  • Adaptor Proteins, Signal Transducing / genetics
  • Adaptor Proteins, Signal Transducing / physiology*
  • Animals
  • Cell Line, Tumor
  • Down-Regulation / genetics
  • Gene Expression Regulation*
  • HEK293 Cells
  • Humans
  • Mice
  • Mice, Knockout
  • Mutation
  • Phenotype
  • Presenilin-1 / deficiency
  • Presenilin-1 / genetics
  • Presenilin-1 / physiology*
  • Proteolysis*
  • Sequestosome-1 Protein
  • Zebrafish / genetics
  • tau Proteins / antagonists & inhibitors*
  • tau Proteins / genetics
  • tau Proteins / metabolism*

Substances

  • Adaptor Proteins, Signal Transducing
  • PSEN1 protein, human
  • Presenilin-1
  • SQSTM1 protein, human
  • Sequestosome-1 Protein
  • tau Proteins