# Project 2: The proteasome in aging and neurodegenerative disease

> **NIH NIH P01** · NORTHWESTERN UNIVERSITY · 2021 · $126,750

## Abstract

Project Summary / Abstract (Project 2)
A marked decline in proteasome activity is observed as humans and other mammals age. This has been
observed in many tissues, including the brain and motor neurons. Aging is characterized by compromised
proteostasis, and declining proteasome activity may play a significant role in aging-associated deficiencies of
proteostasis, given the pivotal role of the proteasome in protein dynamics. By degrading ubiquitin conjugates,
the proteasome controls protein stability on a global level. There has historically been little interest in the
potential role of the proteasome in determining the overall output of the ubiquitin-proteasome pathway (UPS).
Through recent work, however, it is now recognized that the proteasome is on the contrary a focal point of
regulation of the UPS. Indeed, the level of proteasome activity controls protein breakdown rates and stress
resistance. Remarkably, the proteasome can in general be up-regulated without toxicity. Extensive work has
also shown that the proteasome is compromised in many disease states, particularly in aging-associated and
neurodegenerative diseases. However, a deeper and more reliable understanding of the relevance of the
proteasome to aging and neurodegeneration in humans clearly requires the use of in vivo mammalian model
systems. To directly test whether the proteasome becomes limiting in aged animals, three transgenic mouse
lines have been designed to allow conditional elevation of proteasome levels; two of these lines have already
been generated. Each mouse line will conditionally express the wild-type murine form of a different proteasome
subunit–either Rpn6, Rpn11, or 5. These subunits were chosen because they are expected from existing data
to be rate-limiting for proteasome assembly. The multiplicity of strategies to elevate proteasome levels
increases the likelihood of success, and if more than one method succeeds it will enhance confidence in
subsequent results. For each transgene, a floxed and dox-suppressible construct is integrated into the Rosa26
locus via CRISPR/Cas9. The transgenes should be expressed in a tissue-specific and temporally-controlled
manner. Our first objective will be to validate the strategy for elevating proteasome levels in the brain, spinal
cord, and in Flp-In™-3T3 cells with transgenes similarly targeted to Rosa26. Excellent biochemical and
proteomic methods exist for quantifying alterations in proteasome levels. Remarkably, global proteomics can
now quantify the impact of elevated proteasome levels on the control of hundreds of substrate proteins in these
settings. We will proceed to assess the effects of elevated proteasome expression on the health and aging of
these animals. We will test whether elevated proteasome levels influence autophagy and the proteostasis
network (PN) as a whole, and seek to identify age-dependent vulnerabilities in the PN by applying specific
stresses to the system. A central focus of the work on transgeni...

## Key facts

- **NIH application ID:** 10411684
- **Project number:** 3P01AG054407-04S1
- **Recipient organization:** NORTHWESTERN UNIVERSITY
- **Principal Investigator:** RICHARD I MORIMOTO
- **Activity code:** P01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $126,750
- **Award type:** 3
- **Project period:** 2018-09-30 → 2023-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10411684

## Citation

> US National Institutes of Health, RePORTER application 10411684, Project 2: The proteasome in aging and neurodegenerative disease (3P01AG054407-04S1). Retrieved via AI Analytics 2026-05-21 from https://api.ai-analytics.org/grant/nih/10411684. Licensed CC0.

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