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Updated: Aug 6, 2026
Purification and Aggregation of the Amyloid Precursor Protein Intracellular Domain
Published on: August 28, 2012
APP processing and the APP-KPI domain involvement in the amyloid cascade
M Menéndez-González1, P Pérez-Pinera, M Martínez-Rivera
1Neurology Department, Hospital Universitario Central de Asturias, Oviedo, Spain. manuelmenendez@gmail.com
Abstract:
Alternative APP mRNA splicing can generate isoforms of APP containing a Kunitz protease inhibitor (KPI) domain. KPI is one of the main serine protease inhibitors. Protein and mRNA KPI(+)APP levels are elevated in Alzheimer's disease (AD) brain and are associated with increased amyloid beta deposition. In the last years increasing evidence on multiple points in the amyloid cascade where KPI(+)APP is involved has been accumulated, admitting an outstanding position in the pathogenesis of AD to the KPI domain. This review focuses on the APP processing, the molecular activity of KPI and its physiological and pathological roles and the KPI involvement in the amyloid cascade through the nerve growth factor, the lipoprotein receptor-related protein, the tumor necrosis factor-alpha converting enzyme and the Notch1 protein.
Insights
The Kunitz protease inhibitor (KPI) domain in amyloid precursor protein (APP) is elevated in Alzheimer's disease (AD) brains, contributing to amyloid beta deposition and disease pathogenesis.
Area of Science:
- Neuroscience
- Molecular Biology
- Biochemistry
Background:
- Alternative splicing of amyloid precursor protein (APP) mRNA generates isoforms containing a Kunitz protease inhibitor (KPI) domain.
- KPI is a significant serine protease inhibitor.
- Elevated levels of KPI(+)APP protein and mRNA are observed in Alzheimer's disease (AD) brains, correlating with increased amyloid beta deposition.
Purpose of the Study:
- To review the role of KPI(+)APP in Alzheimer's disease pathogenesis.
- To explore APP processing and the molecular activity of KPI.
- To examine the physiological and pathological roles of KPI.
Main Methods:
- Literature review focusing on APP processing.
- Analysis of KPI's molecular activity and its roles.
- Investigation of KPI's involvement in the amyloid cascade via specific pathways.
Main Results:
- Accumulating evidence highlights multiple points in the amyloid cascade where KPI(+)APP is implicated.
- The KPI domain holds a significant position in AD pathogenesis.
- KPI(+)APP influences the amyloid cascade through interactions with nerve growth factor, LRP, TACE, and Notch1.
Conclusions:
- The KPI domain is a key player in the pathogenesis of Alzheimer's disease.
- Understanding KPI's role in APP processing and the amyloid cascade is crucial for AD research.
- Further investigation into KPI's interactions may reveal novel therapeutic targets for AD.
