Genetic modulation of tau phosphorylation in the mouse.
The axonal microtubule stabilizing protein tau is hyperphosphorylated in several neurodegenerative conditions, including Alzheimer's disease, yet the genes that regulate tau phosphorylation are largely unknown. Disabled-1 (Dab1) is a cytoplasmic adapter protein that interacts with apolipoprotein E (ApoE) receptors and controls neuronal positioning during embryonic brain development. We have investigated the role of Dab1 in tau phosphorylation. We found that wild-type Dab1, but not a mutant lacking tyrosine phosphorylation sites, protects mice from the hyperphosphorylation of tau. However, the absence of Dab1 is not sufficient to cause tau hyperphosphorylation, because hyperphosphorylation is manifested only when Dab1 is mutated in specific mouse strain backgrounds. Tau hyperphosphorylation correlates with early death in susceptible mouse strains, and it occurs in the neurons of the hippocampus and dentate gyrus. By quantitative trait locus (QTL) analysis of Dab1-deficient mice on a hybrid strain background, we uncovered one significant and three suggestive chromosomal loci that modulate tau phosphorylation. Two of these QTL regions contain genes that are defective in early onset Alzheimer's disease. Our findings suggest that Dab1 gene disruption sensitizes mice to tau hyperphosphorylation contingent on specific haplotypes that are linked to Alzheimer's disease loci. Dab1 mutant mice provide an animal model for studying the relationships between ApoE receptors, tau hyperphosphorylation, and Alzheimer's disease.
Brich
Jochen
J
Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.
Shie
Feng-Shiun
FS
Howell
Brian W
BW
Li
Renhua
R
Tus
Katalin
K
Wakeland
Edward K
EK
Jin
Lee-Way
LW
Mumby
Marc
M
Churchill
Gary
G
Herz
Joachim
J
Cooper
Jonathan A
JA
D000544:Alzheimer Disease / Q000235:genetics; D000818:Animals; D002874:Chromosome Mapping; D006624:Hippocampus / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000235:genetics*; D010766:Phosphorylation; D040641:Quantitative Trait Loci; D013045:Species Specificity; D016019:Survival Analysis; D016875:tau Proteins / Q000378:metabolism*
C103773:Dab1 protein, mouse; D009419:Nerve Tissue Proteins; D016875:tau Proteins