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

YT Tung, BJ Wang, WM Hsu, MK Hu, GM Her… - Molecular …, 2014 - Springer
YT Tung, BJ Wang, WM Hsu, MK Hu, GM Her, WP Huang, YF Liao
Molecular neurobiology, 2014Springer
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 …
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.
Springer