Efficacy of NPl in the rescue of baseline 𝛾-secretase activity following knockdown with RNAi treatment
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Authors
Glista, Michael J.
Issue Date
2006
Type
Thesis
Language
en_US
Keywords
Alternative Title
Abstract
Alzheimer's disease, a neurodegenerative disorder that afflicts one in ten people
over the age of 65, is the most common cause of memory loss and dementia in the
elderly. Histologically characterized by amyloid plaques localized in the brain,
Alzheimer's results in a slow degeneration in cognitive ability due to neuronal death and
subsequent brain dysfunction. The amyloid plaques associated with this cell death result
from aggregation of protein fragments produced by enzymatic cleavage of the amyloid
precursor protein (APP) by 𝛾-secretase and 𝛽-secretase. These cleavage events release a
4 kD peptide known as A𝛽. NP1, a type I trafficking protein previously described
elsewhere but never before implicated in Alzheimer's disease, has been shown to bind
with all the components of the 𝛾-secretase enzymatic complex. RNAi knockdown of NPl
expression in human embryonic kidney cells increases AP secretion, suggesting a
possible link between normal NP1 expression and basal levels of A𝛽 expression. In order
to explore this phenomenon, recombinant NP1 was expressed in E. coli and collected.
Two versions of the recombinant NPI were produced: N-terminally-tagged NPI and C-terminally
tagged NPI. In addition, the N-terminally-tagged NPI were purified using
two different methods. It was expected that addition of exogenously produced
recombinant NPI could restore A𝛽 levels to normal after they had been elevated by RNAi
knockdown. This study indicates that producing recombinant NP1 in E. coli may be
ineffective in recovery of baseline A𝛽 secretion. However, prior results suggest that NPI
produced in eukaryotic cells can be effective in doing so, and therefore more research
into the role of NP1 in Alzheimer's disease is merited.
Description
vi, 23 p.
Citation
Publisher
Kalamazoo College
License
U.S. copyright laws protect this material. Commercial use or distribution of this material is not permitted without prior written permission of the copyright holder.