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Alzheimer's Disease Abnormally Phosphorylated τ Is Dephosphorylated by Protein Phosphatase‐2B (Calcineurin)
Author(s) -
Gong ChengXin,
Singh Toolsee J.,
GrundkeIqbal Inge,
Iqbal Khalid
Publication year - 1994
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1046/j.1471-4159.1994.62020803.x
Subject(s) - phosphatase , calcineurin , phosphorylation , protein phosphatase 2 , protein phosphorylation , protein phosphatase 1 , alzheimer's disease , chemistry , microbiology and biotechnology , disease , neuroscience , biochemistry , biology , medicine , protein kinase a , transplantation
Abnormally hyperphosphorylated τ is the major protein subunit of paired helical filaments in Alzheimer brains. We have examined its site‐specific dephosphorylation by different protein phosphatases. Dephosphorylation of τ was monitored by its interaction with several phosphorylation‐dependent antibodies. Alzheimer τ was dephosphorylated by brain protein phosphatase‐2B at the abnormally phosphorylated sites Ser 46 , Ser 199 , Ser 202 , Ser 235 , Ser 396 , and Ser 404 , and its relative mobility on sodium dodecyl sulfate‐polyacrylamide gel electrophoresis shifted to that of normal τ. Protein phosphatases‐1 and ‐2A could dephosphorylate only some of the above six phosphorylation sites. These results indicate that protein phosphatase‐2B might be involved in hyperphosphorylation of τ in Alzheimer's disease.