TAU PHOSPHORYLATION IN CELLS TRANSFECTED WITH WILD-TYPE OR AN ALZHEIMERS-DISEASE MUTANT PRESENILIN-1

We have studied the effect of overexpressing either wild-type or an Al zheimer's disease mutant Presenilin 1 (PS1) on tau phosphorylation in transfected Chinese hamster ovary (CHO) and COS cells. Tau transfected into these cells is predominantly non-phosphorylated at many PHF-tau sites but co-transfection with the tan kinase glycogen synthase kinase -3 beta (GSK-3 beta) induces phosphorylation that generates epitopes f or several phosphorylation-dependent antibodies. Co-transfection of ta u with either wild-type or mutant PS1 did not alter tau phosphorylatio n as detected by five different antibodies. Likewise, co-transfection of the PS1s did not influence GSK-3 beta-mediated tau phosphorylation. The implications of these results for the pathogenesis of Alzheimer's disease are discussed. (C) 1997 Elsevier Science Ireland Ltd.