#PS1 TRASH IT PS2#

#PS1 TRASH IT PS2#

The researchers made the leap to look at presenilins based on immunocytochemistry studies that revealed full-length PS1 and PS2 in the endoplasmic reticulum ( Zhang et al., 1998), where the proteins have been proposed to serve as ion channels ( Tu et al., 2006 and ARF related news story). Prior immunolabeling and electron microscopy studies by the Nixon lab suggested that autophagy revs up in AD ( Nixon et al., 2005) and leads to increased Aβ production ( Yu et al., 2005).

In that study, Tony Wyss-Coray of Stanford University, Palo Alto, California, and colleagues report that beclin-1 regulates turnover of amyloid precursor protein (APP), the source of the toxic Aβ peptides littering AD brains. The second study, published June 15 in PLoS ONE, also connects autophagy and AD but does so by looking at how deficiency of an autophagy regulator worsens AD pathology. This study found its autophagy tie-in by examining neurons that lack, or have mutations in, an AD-related gene. Instead, it has to do, surprisingly, with glycosylation of a proton pump. The study identifies a novel function for PS1 that is critical for neuronal survival and does not necessarily depend on Aβ or amyloid, said principal investigator Ralph Nixon of the NYU-affiliated Nathan Kline Institute for Psychiatric Research. In a study published online June 10 in Cell, New York University researchers with collaborators elsewhere report that the AD-linked protein presenilin-1 (PS1) is needed for lysosomal degradation during autophagy, and that pathogenic PS1 mutations stymie the process. Perhaps they keel over when they get overloaded with junk? This view of Alzheimer disease draws support from two new papers highlighting the importance in AD of autophagy, a means by which cells dispose of unwanted proteins.

Perhaps nerve cells are simply neurotic about neatness.

Ps1 trash it