Cell surface expression of the Alzheimer disease-related presenilin proteins

摘要

The presenilin proteins PS-1 and PS-2 are crucially involved in Alzheimer disease (AD), but their mo- lecular functions are not known. They are integral membrane proteins, but whether they can be expressed at the surface of cells has been in dispute. Here we show by immunofluores- cence experiments, using anti-peptide antibodies specific for either PS-1 or PS-2, that live cultured DAMI cells and differentiated human NT2N neuronal cells are specifically immunolabeled for their endogenous as well as transfected presenilins, although the cells cannot be immunolabeled for their intracellular tubulin, unless they are first fixed and permeabilized.