Related Experiment Video

Updated: Jun 27, 2025

Author Spotlight: Unveiling Mitochondrial Contact Sites and Architectural Insights
07:55

Author Spotlight: Unveiling Mitochondrial Contact Sites and Architectural Insights

Published on: June 16, 2023

1.4K

Mitofusin-mediated contacts between mitochondria and peroxisomes regulate mitochondrial fusion

Cynthia Alsayyah1, Manish K Singh1,2, Maria Angeles Morcillo-Parra1

  • 1Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes, Sorbonne Université, CNRS, UMR8226, Institut de Biologie Physico-Chimique, Paris, France.

Plos Biology
|April 26, 2024
PubMed

Insights

Yeast mitofusins (Fzo1) create peroxisome-mitochondria contacts, crucial for cell function. These contacts regulate citrate transport, maintaining mitochondrial fusion during fatty acid desaturation.

Area of Science:

  • Cell Biology
  • Mitochondrial Dynamics
  • Organelle Contact Sites

Background:

  • Mitofusins are GTPases essential for mitochondrial outer membrane fusion.
  • Yeast Fzo1, a mitofusin, induces peroxisome-mitochondria (PerMit) contacts upon overexpression.
  • The physiological role of PerMit contacts remains unclear.

Purpose of the Study:

  • To investigate the physiological role of Fzo1 in PerMit contacts.
  • To understand the regulation and function of Fzo1-mediated PerMit contacts.

Main Methods:

  • Yeast genetics and high-resolution cellular imaging.
  • High-throughput genetic screening.
  • Analysis of Fzo1 protein levels and fatty acid desaturation.

Main Results:

  • Fzo1 naturally localizes to peroxisomes, promoting PerMit contacts under physiological conditions.
  • Fzo1 levels are regulated by the ubiquitin-proteasome system (UPS) and fatty acid (FA) desaturation status.
  • PerMit contacts are maximal during high FA desaturation and facilitate peroxisomal citrate export to mitochondria.
  • Mitochondrial citrate import boosts the TCA cycle, enhancing membrane potential and mitochondrial fusion.

Conclusions:

  • Fzo1-mediated PerMit contacts are physiologically relevant and regulated by UPS and FA desaturation.
  • These contacts enable citrate transfer from peroxisomes to mitochondria, supporting mitochondrial fusion.
  • Inter-organelle contacts serve as a mechanism to maintain mitochondrial integrity.

More Related Videos

A Model Membrane Platform for Reconstituting Mitochondrial Membrane Dynamics10:31

A Model Membrane Platform for Reconstituting Mitochondrial Membrane Dynamics

Published on: September 2, 2020

7.6K
A Faster, High Resolution, mtPA-GFP-based Mitochondrial Fusion Assay Acquiring Kinetic Data of Multiple Cells in Parallel Using Confocal Microscopy10:45

A Faster, High Resolution, mtPA-GFP-based Mitochondrial Fusion Assay Acquiring Kinetic Data of Multiple Cells in Parallel Using Confocal Microscopy

Published on: July 20, 2012

16.6K

Related Concept Videos

Translocation of Proteins into the Mitochondria01:19

Translocation of Proteins into the Mitochondria

Mitochondrial precursors are translocated to the internal subcompartments via independent mechanisms involving distinct protein machineries called translocases.
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
3.1K
Mitochondrial Membranes01:45

Mitochondrial Membranes

A single mitochondrion is a bean-shaped organelle enclosed by a double-membrane system. The outer membrane of mitochondria is smooth and contains many porins - the integral membrane transporters. Porins enable free diffusion of ions and small uncharged molecules through the outer mitochondrial membrane but limit the transport of molecules larger than 5000 Daltons. Further, the outer mitochondrial membrane forms a unique structure called membrane contact sites with other subcellular organelles,...
10.1K
Peroxisomes and Mitochondria01:30

Peroxisomes and Mitochondria

Peroxisomes and mitochondria are two important oxygen-utilizing organelles in eukaryotic cells. Mitochondria carry out cellular respiration—the process that converts energy from food into ATP. Peroxisomes carry out a variety of functions, primarily breaking down different substances, such as fatty acids.
The peroxisome is a single membrane-bound cellular organelle that can perform several different functions, including lipid metabolism and chemical detoxification. The enzymes within...
87.1K
Peroxisomes01:24

Peroxisomes

Peroxisomes are specialized organelles present in fungi, plant, and animal cells. It can vary in number, size, morphology, and activity depending on the type of tissue and the nutritional state of the cell. For example, cells with active lipid metabolism, such as adipocytes, neurons, and hepatocytes, have more peroxisomes than other cells in the body. Besides their primary role in breaking down complex organic molecules, peroxisomes can also synthesize specific macromolecules and participate in...
12.1K
Mitochondrial Protein Sorting01:39

Mitochondrial Protein Sorting

Mitochondria are double-membrane organelles of the eukaryotes involved in cellular metabolism, signaling, ATP synthesis, and programmed cell death.  Each of these processes requires specific proteins and enzymes that must be correctly sorted to the right mitochondrial subcompartment for the proper functioning of the organelle.
Most of these mitochondrial proteins are encoded by the nucleus and imported to the mitochondria as unfolded or loosely folded precursors. Mitochondrial precursors...
4.3K
The Inner Mitochondrial Membrane01:28

The Inner Mitochondrial Membrane

The inner mitochondrial membrane is the primary site of ATP synthesis. The inner membrane domain that forms a smooth layer adjacent to the outer membrane is called the inner boundary membrane. This domain contains membrane transporters that drive metabolites in and out of the mitochondria.  In contrast, the inner membrane network that invaginates into the matrix space is called the cristae membrane. This domain accounts for principle mitochondrial function as it accommodates the protein...
3.3K