You are here: Home :: Area NEM :: Life sciences :: Biochemistry

R. Tikkanen, A. Icking, P. Beicht, G.L. Waneck, V. Herzog

The Receptor-Bound N-Terminal Ectodomain of the Amyloid Precursor Protein Is Associated with Membrane Rafts

The soluble Nterminal ectodomain of amyloid precursor protein (sAPP), resulting from secretasemediated proteolytic processing, has been shown to function as a growth factor for epithelial cells, including keratinocytes and thyrocytes. Extracellularly applied sAPP binds to a cell surface receptor and exhibits a patchy binding pattern reminiscent of that observed for raft proteins. Here we show that (i) the receptorbound sAPP resides in a detergentinsoluble membrane microdomain which cofractionates in density gradients with cholesterolrich membrane rafts and caveolae; (ii) the sAPPbinding microdomains are different from caveolae; and (iii) sAPP is capable of binding to isolated rafts and inducing tyrosine phosphorylation of some raft proteins. These observations suggest that a novel type of membrane raft is involved in sAPP signaling.

Biological Chemistry, Walter de Gruyter

Print ISSN: 1431-6730
Volume: 383, 12/2002
Pages: 1855 - 1864

Show full article (external site)

Show all available items of this journal

 

Area NEM