Developmental regulation and possible alternative cleavage of presenilin 1 in the rat retina

Abstract

Presenilin 1 (PS1) is a multitransmembrane protein well known for being mutated in most cases of familial Alzheimer's disease. Although its pathological effect is clear, its biological functions are not yet fully understood, but it appears to be involved in development and apoptosis. To investigate the role of PS1 in developmental processes we have studied the expression and proteolytic processing of this protein in the developing rat retina. PS1 appears to be developmentally regulated in the retina, and the pattern of PS1 immunoreactivity is consistent with a role in retinal lamination and pattern formation. Interestingly, no correlation was observed between PS1-positive cells and cells undergoing programmed cell death, suggesting that PS1 does not play a role in apoptosis occurring during this period. Moreover, we observed a change in the pattern of PS1 proteolytic fragments suggestive of a novel alternative cleavage site in the PS1 molecule.