# Unveiling the molecular architecture of the mitochondrial respiratory chain of Acanthamoeba castellanii

## TL;DR

This paper reviews the unique mitochondrial respiratory chain of Acanthamoeba castellanii and its role in the amoeba's survival under stressful conditions.

## Contribution

The paper provides a comprehensive overview of the alternative components of the respiratory chain in Acanthamoeba castellanii and their functional roles.

## Key findings

- The alternative oxidase (AOX) helps reduce oxidative stress in Acanthamoeba castellanii.
- Uncoupling protein (UCP) modulates proton gradients to adapt to environmental changes.
- Alternative NAD(P)H dehydrogenases aid in energy metabolism and stress response.

## Abstract

Acanthamoeba castellanii is a ubiquitous free-living amoeba that can cause severe infections in humans. Unlike most other organisms, A. castellanii possesses a "complete" mitochondrial respiratory chain, meaning it con-tains several additional enzymes that contribute to its metabolic versa-tility and survival in diverse environments. This review provides a com-prehensive overview of the mitochondrial respiratory chain in A. castellanii, focusing on the key alternative components in-volved in oxidative phosphorylation and their roles in energy metabo-lism, stress response, and adaptation to various conditions. The func-tional characterization of the alternative oxidase (AOX), uncoupling pro-tein (UCP), and alternative NAD(P)H dehydrogenases, highlight their roles in reducing oxidative stress, modulating proton gradients, and adapting to changes in temperature and nutrient availability. These pro-teins and systems serve a role in the survival of A. castel-lanii under stressful conditions such as starvation and cold con-ditions. Further knowledge of the respiratory chain of the amoeba has potential implications for understanding the evolution of mitochondrial respiration and developing new therapies for treating Acanthamoeba infections.