Abstract: The paired helical filament (PHF), which makes up the major fibrous component of the neurofibrillary lesions of Alzheimer's disease, is composed of hyperphosphorylated and abnormally phosphorylated microtubule‐associated protein τ. Previous studies have identified serine and threonine residues phosphorylated in PHF‐τ and have shown that τ can be phosphorylated at several of these sites by proline‐directed protein kinases and cyclic AMP‐dependent protein kinase. Here we have investigated which protein phosphatase activities can dephosphorylate recombinant τ phosphorylated with mitogen‐activated protein kinase, glycogen synthase kinase‐3β, neuronal cdc2‐like kinase, or cyclic AMP‐dependent protein kinase. We show that protein phosphatase 2A is by far the major protein phosphatase activity in brain that dephosphorylates τ phosphorylated in this manner.
|Number of pages||4|
|Journal||Journal of Neurochemistry|
|Publication status||Published - Dec 1995|
- Paired helical filaments
- Protein phosphatase 2A
- τ protein