Abstract
Tau protein was evaluated as a substrate for a proline-directed protein kinase (p34cdc2/p58cyclin A) which recognizes the phosphorylation site motif X-Ser/Thr-Pro-X. The shortest human tau isoform, expressed as a recombinant protein, was phosphorylated to a stoichiometry of 2 mol phosphate/mol tau. Phosphoamino acid analysis revealed phosphorylation of both serine and threonine residues. Phosphorylation of recombinant tau resulted in a decreased ability to induce microtubule assembly but had no effect on the final extent of microtubule formation or on the rate of cold-induced microtubule disassembly. Phosphorylation of tau by the proline-directed protein kinase completely blocked immunoreactivity with antibody SMI33. Phosphorylation did not create the epitopes for the phosphate-dependent antibodies SMI31 or SMI34. Antibody SMI33 recognizes neurofibrillary tangles after treatment with alkaline phosphatase, suggesting that the proline-directed protein kinase may phosphorylate tau at sites that are phosphorylated in Alzheimer's disease.
Original language | English (US) |
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Pages (from-to) | 237-242 |
Number of pages | 6 |
Journal | Brain Research |
Volume | 611 |
Issue number | 2 |
DOIs | |
State | Published - May 21 1993 |
Keywords
- Alzheimer's disease
- Cytoskeleton
- Microtubule-associated protein
ASJC Scopus subject areas
- Developmental Biology
- Molecular Biology
- Clinical Neurology
- Neuroscience(all)