SHIFT FROM FETAL-TYPE TO ALZHEIMER-TYPE PHOSPHORYLATED TAU-PROTEINS IN SKNSH-SY 5Y CELLS TREATED WITH OKADAIC ACID

Tau proteins are abnormally phosphorylated in Alzheimer's disease. Pat hological Tau proteins named PHF-Tau 55, PHF-Tau 64, and PHF-Tau 69, a re the main constituents of the paired helical filaments (PHF). When t reating SKNSH-SY 5Y cells with okadaic acid (OA), Tau 55 protein was c learly induced whereas Tau 64 protein was only faintly induced. Here, me show that the absence of Tau 69 could be explained by the fact that adult isoforms containing N-terminal inserts are not detected. Phosph orylation is similar for untreated cellular Tau proteins and fetal Tau proteins, while OA cell treatment transformed fetal-type into Alzheim er-type phosphorylated proteins.