Module 12: Figure amyloid plaques and tangles
Amyloid processing and the formation of plaques.
The amyloid precursor protein (APP) is cleaved to form a C-terminal fragment that is embedded in the neuronal plasma membrane. This fragment is cleaved by a complex, which contains presenilin-1, APH-1, PEN-2 and nicastrin, to release β-amyloid peptide (Aβ) that then goes on to form external plaques. Internal tangles are formed by the polymerization of hyperphosphorylated tau proteins. Glycogen synthase kinase-3 (GSK-3) seems to play a critical role in the formation of plaques and tangles. Reproduced by permission from Macmillan Publishers Ltd: Nature, De Strooper, B. and Woodgett, J. (2003) Mental plaque removal. 423:392–393. Copyright (2003); http://www.nature.com; see De Strooper and Woodgett 2003.