# Investigating the role of autophagy inducers and peroxisomal proteins in pexophagy

> **NIH NIH F31** · RICE UNIVERSITY · 2024 · $48,974

## Abstract

Investigating the role of autophagy inducers and peroxisomal proteins in pexophagy
Peroxisomes are critical organelles that house fatty acid ꞵ-oxidation and antioxidative enzymes
that detoxify reactive oxygen and nitrogen species. Peroxins maintain peroxisomal proteostasis
by coordinating biogenesis, matrix protein import, and receptor recycling. Impairment of
peroxisome biogenesis can impact many physiological processes in plants and humans. Despite
the importance of peroxisomes, peroxisomal turnover, a key aspect of proteostasis, remains
poorly understood. The primary mechanism for organelle turnover is autophagy, and the selective
autophagy of peroxisomes is termed pexophagy. In this process, damaged or excess
peroxisomes are sequestered via encirclement of an isolation membrane to form
autophagosomes, which then fuse with a degradative organelle (the vacuole in plants and yeast).
In the vacuole, the peroxisome, now in the autophagic body, is lysed by vacuolar proteases and
lipases, and the nutrients from this degradation are exported to the cytosol for reuse by the cell.
Stress-inducing conditions, such as nutrient starvation, oxidative stress, etc. can induce general
autophagy; however, plant-specific pexophagy proteins and conditions remain to be identified. To
better understand plant pexophagy and the proteins involved, I plan to monitor autophagy and
pexophagy via western analysis of reporters that separately mark peroxisomal and
autophagosomal membranes and are cleaved upon delivery of autophagosomes to the vacuole.
I will also use the fluorescence of these reporters to visualize pexophagy using confocal
microscopy. Using the tools that I develop, I will elucidate the role various peroxisomal proteins
in pexophagy, including NBR1 (a selective autophagy receptor), peroxisomal proteins containing
ATG8-interacting motifs, LON2 (a peroxisomal chaperone and protease), and peroxisome-
associated ubiquitination enzymes. Beyond improving basic understanding of fundamental cell
biology, furthering our understanding of peroxisome regulation can improve our understanding of
metabolic illnesses in humans and provide targets for metabolic engineering in crops.

## Key facts

- **NIH application ID:** 10899140
- **Project number:** 1F31GM151803-01A1
- **Recipient organization:** RICE UNIVERSITY
- **Principal Investigator:** Makaela Jackson
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $48,974
- **Award type:** 1
- **Project period:** 2024-09-18 → 2026-09-17

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10899140

## Citation

> US National Institutes of Health, RePORTER application 10899140, Investigating the role of autophagy inducers and peroxisomal proteins in pexophagy (1F31GM151803-01A1). Retrieved via AI Analytics 2026-05-29 from https://api.ai-analytics.org/grant/nih/10899140. Licensed CC0.

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