Genetic inactivation of p62 leads to accumulation of hyperphosphorylated tau and neurodegeneration

J Neurochem. 2008 Jul;106(1):107-20. doi: 10.1111/j.1471-4159.2008.05340.x. Epub 2008 Jul 1.

Abstract

The signaling adapter p62 plays a coordinating role in mediating phosphorylation and ubiquitin-dependent trafficking of interacting proteins. However, there is little known about the physiologic role of this protein in brain. Here, we report age-dependent constitutive activation of glycogen synthase kinase 3beta, protein kinase B, mitogen-activated protein kinase, and c-Jun-N-terminal kinase in adult p62(-/-) mice resulting in hyperphosphorylated tau, neurofibrillary tangles, and neurodegeneration. Biochemical fractionation of p62(-/-) brain led to recovery of aggregated K63-ubiquitinated tau. Loss of p62 was manifested by increased anxiety, depression, loss of working memory, and reduced serum brain-derived neurotrophic factor levels. Our findings reveal a novel role for p62 as a chaperone that regulates tau solubility thereby preventing tau aggregation. This study provides a clear demonstration of an Alzheimer-like phenotype in a mouse model in the absence of expression of human genes carrying mutations in amyloid-beta protein precursor, presenilin, or tau. Thus, these findings provide new insight into manifestation of sporadic Alzheimer disease and the impact of obesity.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adaptor Proteins, Signal Transducing / genetics*
  • Aging / genetics
  • Aging / metabolism
  • Animals
  • Brain / metabolism*
  • Brain / pathology
  • Brain / physiopathology
  • Brain-Derived Neurotrophic Factor / metabolism
  • Disease Models, Animal
  • Glycogen Synthase Kinase 3 / metabolism
  • Glycogen Synthase Kinase 3 beta
  • Heat-Shock Proteins / genetics*
  • Humans
  • JNK Mitogen-Activated Protein Kinases / metabolism
  • Metabolic Syndrome / complications
  • Metabolic Syndrome / genetics
  • Metabolic Syndrome / metabolism
  • Mice
  • Mice, Knockout
  • Mitogen-Activated Protein Kinase 1 / metabolism
  • Molecular Chaperones / genetics*
  • Nerve Degeneration / genetics*
  • Nerve Degeneration / metabolism
  • Nerve Degeneration / physiopathology
  • Neurofibrillary Tangles / genetics
  • Neurofibrillary Tangles / metabolism
  • Neurofibrillary Tangles / pathology
  • Neurons / metabolism*
  • Neurons / pathology
  • Obesity / complications
  • Obesity / metabolism
  • Obesity / physiopathology
  • Phosphorylation
  • Proto-Oncogene Proteins c-akt / metabolism
  • Sequestosome-1 Protein
  • Signal Transduction / physiology
  • Solubility
  • tau Proteins / metabolism*

Substances

  • Adaptor Proteins, Signal Transducing
  • Brain-Derived Neurotrophic Factor
  • Heat-Shock Proteins
  • Molecular Chaperones
  • Sequestosome-1 Protein
  • Sqstm1 protein, mouse
  • tau Proteins
  • GSK3B protein, human
  • Glycogen Synthase Kinase 3 beta
  • Gsk3b protein, mouse
  • Proto-Oncogene Proteins c-akt
  • JNK Mitogen-Activated Protein Kinases
  • Mitogen-Activated Protein Kinase 1
  • Glycogen Synthase Kinase 3