Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Porin Insertion in the Outer Mitochondrial Membrane01:12

Porin Insertion in the Outer Mitochondrial Membrane

3.2K
Porins are beta-barrel proteins translocated to the mitochondrial outer membrane through the TOM complex into the intermembrane space. Porin precursors bind TIM chaperones within the intermembrane space and are guided to the Sorting and Assembly Machinery complex or SAM complex on the outer mitochondrial membrane.
Three models describe the assembly of porins by the SAM complex and their insertion into the outer membrane. Model 1 suggests that porins are assembled outside the SAM channel as the...
3.2K
Translocation of Proteins into the Mitochondria01:19

Translocation of Proteins into the Mitochondria

3.2K
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,...
3.2K
Structure of Porins01:21

Structure of Porins

3.1K
Mitochondria, chloroplasts, and gram-negative bacteria have transmembrane, beta-barrel proteins called porins to mediate the free diffusion of ions and metabolites across the membrane. Mitochondrial porin precursors contain conserved amino acid sequences called beta signals at their C-terminal. Beta signals have a  motif of PoXGXXHyXHy (Po-Polar, X-Any amino acid, G-Glycine, Hy-LargeHydrophobic), which are crucial for precursor recognition to initiate precursor assembly. Beta-barrel...
3.1K
Protein Transport into the Inner Mitochondrial Membrane01:34

Protein Transport into the Inner Mitochondrial Membrane

4.0K
Nuclear encoded mitochondrial precursors are imported to the inner membrane in a multistep process involving two separate translocons, TIM22 and TIM23. TIM23 is a cation-selective pore that remains closed by the N terminal segment of the protein. Negative charges on the TIM23 act as a receptor for the incoming precursor, pulling the positively charged matrix-targeting sequence for peptide insertion and translocation.
Transport of mitochondrial precursors across the TIM23 channel is driven by...
4.0K
The Inner Mitochondrial Membrane01:28

The Inner Mitochondrial Membrane

3.5K
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...
3.5K
Mitochondrial Membranes01:45

Mitochondrial Membranes

11.7K
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,...
11.7K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Membrane insertion of mitochondrial-encoded proteins regulates ribosome decoding speed.

Nature structural & molecular biology·2026
Same author

Manipulating mitochondrial gene expression.

Biological chemistry·2025
Same author

Super-resolution microscopy of mitochondrial mRNAs.

Nature communications·2025
Same author

SMIM20 promotes complex IV biogenesis and Ca<sup>2+</sup> signaling in mice heart.

Cell reports·2025
Same author

Silencing mitochondrial gene expression in living cells.

Science (New York, N.Y.)·2025
Same author

Profiling the LAM Family of Contact Site Tethers Provides Insights into Their Regulation and Function.

Contact (Thousand Oaks (Ventura County, Calif.))·2025
Same journal

Horizontal transfer of mitochondria in cancer: The physiology reborn in disease?

Trends in cell biology·2026
Same journal

Spindle errors: A stress test for epithelial robustness.

Trends in cell biology·2026
Same journal

Multicellular ecosystems: Linking cellular diversity to tissue function and disease.

Trends in cell biology·2026
Same journal

Orchestrating the signaling-bias at the protease-activated receptor, PAR1.

Trends in cell biology·2026
Same journal

Crashing by design: Utilizing DNA damage for MCC differentiation.

Trends in cell biology·2026
Same journal

The value of a shared lab: Our insights.

Trends in cell biology·2026
See all related articles

Related Experiment Video

Updated: Aug 8, 2025

An In Vitro Approach to Study Mitochondrial Dysfunction: A Cybrid Model
06:05

An In Vitro Approach to Study Mitochondrial Dysfunction: A Cybrid Model

Published on: March 9, 2022

3.9K

The multifaceted mitochondrial OXA insertase.

Bettina Homberg1, Peter Rehling2, Luis Daniel Cruz-Zaragoza1

  • 1Department of Cellular Biochemistry, University Medical Center Göttingen, 37073 Göttingen, Germany.

Trends in Cell Biology
|March 2, 2023
PubMed
Summary
This summary is machine-generated.

The oxidase assembly (OXA) insertase is a multifunctional protein crucial for mitochondrial inner membrane function. It coordinates the insertion and assembly of both imported and mitochondrially encoded proteins, ensuring OXPHOS complex biogenesis and stability.

Keywords:
mitochondriaoxidase assemblyoxidative phosphorylationprotein translocationribosomes

More Related Videos

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

1.5K
Author Spotlight: Advancing Techniques and Discoveries in Protein Synthesis and Assembly Through Innovative Mitochondrial Research
09:53

Author Spotlight: Advancing Techniques and Discoveries in Protein Synthesis and Assembly Through Innovative Mitochondrial Research

Published on: June 7, 2024

1.1K

Related Experiment Videos

Last Updated: Aug 8, 2025

An In Vitro Approach to Study Mitochondrial Dysfunction: A Cybrid Model
06:05

An In Vitro Approach to Study Mitochondrial Dysfunction: A Cybrid Model

Published on: March 9, 2022

3.9K
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

1.5K
Author Spotlight: Advancing Techniques and Discoveries in Protein Synthesis and Assembly Through Innovative Mitochondrial Research
09:53

Author Spotlight: Advancing Techniques and Discoveries in Protein Synthesis and Assembly Through Innovative Mitochondrial Research

Published on: June 7, 2024

1.1K

Area of Science:

  • Mitochondrial biology
  • Molecular and cell biology
  • Protein biogenesis

Background:

  • Mitochondria possess their own genome and gene expression machinery.
  • Mitochondrial proteins are primarily synthesized in the cytosol and imported.
  • The inner mitochondrial membrane houses the oxidase assembly (OXA) insertase, essential for protein insertion.

Purpose of the Study:

  • To elucidate the multifaceted roles of the OXA insertase in mitochondrial protein biogenesis.
  • To understand the cooperation between OXA and the mitochondrial ribosome.
  • To investigate OXA's contribution to the assembly of oxidative phosphorylation (OXPHOS) complexes.

Main Methods:

  • Investigating protein targeting and insertion mechanisms.
  • Analyzing the interaction between OXA and mitochondrial ribosomes.
  • Studying the biogenesis of both imported and mitochondrial-encoded proteins.

Main Results:

  • OXA facilitates the insertion of proteins encoded by both mitochondrial and nuclear genomes.
  • OXA cooperates with mitochondrial ribosomes during the synthesis of mitochondrial proteins.
  • OXA is involved in the assembly of OXPHOS core subunits and other imported proteins.

Conclusions:

  • The OXA insertase is a multifunctional machine essential for mitochondrial inner membrane protein homeostasis.
  • OXA plays a key role in coordinating protein insertion, complex assembly, and overall mitochondrial function.
  • Understanding OXA's mechanisms provides insights into mitochondrial diseases and therapeutic strategies.