Parkin, Edward and Hussain, I and Turner, A J and Hooper, N M (1997) The amyloid precursor protein is not enriched in caveolae-like, detergent-insoluble membrane microdomains. Journal of Neurochemistry, 69 (5). pp. 2179-2188. ISSN 0022-3042
Full text not available from this repository.Abstract
The amyloid precursor protein may be processed by several different pathways, one of which produces the amyloid beta-peptide betaA4 present in the amyloid plaques characteristic of Alzheimer's disease. A recent report suggested that axonal-amyloid precursor protein is present in a membrane fraction "with caveolae-like properties." In the present study we have isolated detergent-insoluble, caveolae-like membranes from both mouse cerebellum and the human neuroblastoma cell line SH-SY5Y. Detergent-insoluble membranes from mouse cerebellum retained nearly all of the glycosylphosphatidylinositol-anchored proteins--alkaline phosphatase, 5'-nucleotidase, and the F3 protein--while excluding the majority of the plasmalemmal marker protein alkaline phosphodiesterase I. Although the inositol trisphosphate receptor was highly enriched in this detergent-insoluble fraction, neither amyloid precursor protein nor clathrin immunoreactivity could be detected. Similar results were obtained with SH-SY5Y cells, where 5'-nucleotidase activity was enriched at least 30-fold in the detergent-insoluble membranes, but no amyloid precursor protein or clathrin immunoreactivity could be detected. Caveolin could not be detected in microsomal membranes from either mouse cerebellum or SH-SY5Y cells. These observations suggest that amyloid precursor protein is not normally present in detergent-insoluble, caveolae-like membrane microdomains.