# Impacting mitochondrial function through altered protease activity

> **NIH NIH R01** · SCRIPPS RESEARCH INSTITUTE, THE · 2023 · $35,501

## Abstract

SUMMARY
Mitochondrial dysfunction is a pathologic hallmark in the onset and pathogenesis of nearly all neurodegenerative
diseases. One of the primary determinants in dictating mitochondrial function is the activity of inner membrane
(IM) proteases including the ATP-dependent AAA+ zinc metalloproteases YME1L and AFG3L2 and the ATP-
independent zinc metalloprotease OMA1. These proteases regulate many different aspects of mitochondrial
biology and function to protect mitochondria from pathologic insults. However, imbalances in the activity of IM
proteases induced by genetic or environmental factors are implicated in the pathogenesis of etiologically-diverse
diseases including many neurodegenerative disorders. Despite this, the molecular mechanisms by which IM
proteases regulate mitochondrial biology remain poorly understood. Here, we are applying a structure-driven
approach to determine the molecular mechanisms by which IM proteases regulate mitochondria in the context
of health and disease. We previously solved the first high-resolution structures of the IM AAA+ proteases YME1
and AFG3L2. Our structures showed that these two proteases employ a conserved nucleotide-driven, hand-
over-hand mechanism to translocate substrates into a privileged proteolytic chamber for proteolysis. Surprisingly,
we also identified unique structural features of YME1 and AFG3L2 that integrate into this conserved translocation
mechanism to distinctly influence protease activity and stability. Here, we hypothesize that these unique
structural differences endow IM proteases with different mechanistic and biologic functions important
for their regulation of mitochondria. To address this, we are using a combination of cryo-electron microscopy
and cell biology to determine how structural differences in IM AAA+ proteases influence their mechanochemical
cycle and enable proteases to perform distinct biological functions. This will reveal new insights into the molecular
mechanisms by which IM AAA+ proteases regulate mitochondria in health and disease. Furthermore, we are
extending this study utilizing both functional genomic and structural approaches to establish a structure-function
relationship that explains the activation and proteolytic activity of the ATP-independent, stress-activated IM
protease OMA1 – a protease whose dysregulation is implicated in the pathologic mitochondrial dysfunction
associated with many human diseases. Through these efforts, we will define how IM proteases utilize distinct
structural features to perform the myriad of biological functions required for the proper regulation of mitochondrial
proteostasis and function. Furthermore, we will reveal new insights into the pathologic and potentially therapeutic
implications of altered mitochondrial IM protease activity in human disease and identify new opportunities to
pharmacologically target IM proteases to mitigate mitochondrial dysfunction associated with many
neurodegenerative disorders.

## Key facts

- **NIH application ID:** 10741597
- **Project number:** 3R01NS095892-07S1
- **Recipient organization:** SCRIPPS RESEARCH INSTITUTE, THE
- **Principal Investigator:** Gabriel C Lander
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2023
- **Award amount:** $35,501
- **Award type:** 3
- **Project period:** 2016-04-01 → 2025-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10741597

## Citation

> US National Institutes of Health, RePORTER application 10741597, Impacting mitochondrial function through altered protease activity (3R01NS095892-07S1). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10741597. Licensed CC0.

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