LOCALIZATION OF ALZHEIMER-ASSOCIATED PRESENILIN-1 IN TRANSFECTED COS-7 CELLS

Presenilin 1 (PS 1) is the recently identified gene, located on chromo some 14, of which missense mutations can cause early-onset familial Al zheimer's disease. To understand the normal biological function of pre senilin 1, we examined the subcellular localization by using a monoclo nal anti-presenilin 1 antibody. Immuno-electronmicroscopic and biochem ical analysis indicated that presenilin 1 is localized on cellular mem brane (plasma, endoplasmic reticulum, and perinuclear) in COS-7 cells overexpressing presenilin 1. Interestingly, the PS 1 immunoreactivity in the plasma membrane was concentrated in the regions with cell-cell contact. This observation suggests a possible role of PS 1 on the cell membrane as a cell adhesion molecule. (C) 1996 Academic Press, Inc.