# Mechanism and function of retrograde mitochondrial transport in axons

> **NIH NIH R01** · UNIVERSITY OF WISCONSIN-MADISON · 2024 · $364,167

## Abstract

Project Summary
Mitochondria are essential for cellular function and organism viability. These organelles are well known for their
production of ATP, the primary energy currency of most eukaryotic cells. Less well known are the plethora of
other functions these organelles have including production of signaling molecules, regulation of apoptotic
signaling cascades, serving as a calcium sink, and also being the primary storage and utilization site of iron in
the cell. To serve these diverse functions, mitochondria must be properly localized in all cells; however, this
organelle is particularly critical in neurons. Neurons are highly metabolically active, electrically polarized, and
can have an enormous volume making regulation of the mitochondrial population particularly challenging.
Likely due to the high metabolic demands of this cell, precise control of mitochondrial localization and
maintenance of mitochondrial health are essential for neuronal survival. Abnormal mitochondrial localization,
health, and function have been linked to many neurodegenerative diseases including Alzheimer’s disease. In
Alzheimer’s, defects in mitochondrial calcium load and contacts with the endoplasmic reticulum have both
been noted. Additionally, advanced neuroimaging of early-stage patients revealed defects in mitochondrial
function, making understanding how mitochondrial function is maintained in neurons paramount to
understanding disease biology. While the last several decades have revealed fascinating insights into
mitochondrial biology in neurons, we still do not have a thorough understanding of how the population of
mitochondria is maintained over the long life of the neuron. Anterograde transport is critical for bringing healthy
organelles from the cell body into the long axonal process which can extend a meter from the cell body in
humans. Conversely, retrograde transport moves aged or damaged organelles towards to cell body. Once
damaged organelles reach the cell body, some undergo targeted degradation. The fate of the bulk of these
organelles and the source of healthy mitochondria has not been defined. We have developed an in vivo system
to address these long-standing questions in the field. Using zebrafish neurons, we can image mitochondrial
localization, health, and transport in vivo in a fully intact neural circuit. We have developed transgenic lines,
genetic tools, and imaging approaches to individually label mitochondria to track them and follow their lifetime
and biogenesis in neurons. This will allow us to determine the source of healthy mitochondria necessary for
maintenance of the population in neurons (Aim 1). Independently, we designed a strategy to define the
mechanism of motor-mitochondria attachment specifically necessary for retrograde transport of the organelle
(Aim 2). Together, the proposed experiments will provide mechanistic insight into how and why mitochondria
move in the retrograde direction while also defining the source of healthy o...

## Key facts

- **NIH application ID:** 10799602
- **Project number:** 5R01NS124692-03
- **Recipient organization:** UNIVERSITY OF WISCONSIN-MADISON
- **Principal Investigator:** Catherine M Drerup
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $364,167
- **Award type:** 5
- **Project period:** 2022-02-15 → 2027-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10799602

## Citation

> US National Institutes of Health, RePORTER application 10799602, Mechanism and function of retrograde mitochondrial transport in axons (5R01NS124692-03). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10799602. Licensed CC0.

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