Axonal transport of amyloid precursor protein is mediated by direct binding to the kinesin light chain subunit of kinesin-I.
We analyzed the mechanism of axonal transport of the amyloid precursor protein (APP), which plays a major role in the development of Alzheimer's disease. Coimmunoprecipitation, sucrose gradient, and direct in vitro binding demonstrated that APP forms a complex with the microtubule motor, conventional kinesin (kinesin-I), by binding directly to the TPR domain of the kinesin light chain (KLC) subunit. The estimated apparent Kd for binding is 15-20 nM, with a binding stoichiometry of two APP per KLC. In addition, association of APP with microtubules and axonal transport of APP is greatly decreased in a gene-targeted mouse mutant of the neuronally enriched KLC1 gene. We propose that one of the normal functions of APP may be as a membrane cargo receptor for kinesin-I and that KLC is important for kinesin-I-driven transport of APP into axons.
Pubmed ID: 11144355 RIS Download
Alzheimer Disease | Amyloid beta-Protein Precursor | Animals | Axonal Transport | Binding, Competitive | Blotting, Western | Brain Chemistry | Centrifugation, Density Gradient | Epitopes | Gene Targeting | Kinesin | Mice | Mice, Mutant Strains | Microtubule-Associated Proteins | Microtubules | Precipitin Tests | Protein Structure, Tertiary | Recombinant Fusion Proteins | Sciatic Nerve