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

3.3K
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...
3.3K
Structure of Porins01:21

Structure of Porins

3.2K
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...
3.2K
The Inner Mitochondrial Membrane01:28

The Inner Mitochondrial Membrane

3.6K
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...
3.6K
Protein Transport into the Inner Mitochondrial Membrane01:34

Protein Transport into the Inner Mitochondrial Membrane

4.1K
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...
4.1K
Mitochondrial Membranes01:45

Mitochondrial Membranes

12.0K
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,...
12.0K
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

You might also read

Related Articles

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

Sort by
Same author

Dimeric architecture and membrane thinning govern substrate recognition by human signal peptide peptidase.

Research square·2026
Same author

Generation of a recipient line for Rubisco engineering by multiplex genome editing in tobacco.

The Plant journal : for cell and molecular biology·2026
Same author

Feline leukocyte immunophenotyping: an optimised whole-blood flow cytometry protocol.

MethodsX·2026
Same author

Artificial Intelligence Enhanced Analysis of Coronary CT Angiography to Facilitate Chronic Total Occlusion Percutaneous Coronary Intervention.

Catheterization and cardiovascular interventions : official journal of the Society for Cardiac Angiography & Interventions·2025
Same author

Organization of the yeast Seipin complex reveals differential recruitment of regulatory proteins.

Molecular biology of the cell·2025
Same author

Emerging Materials for Durable and Sustainable Design of Aeronautic Structures.

Materials (Basel, Switzerland)·2025

Related Experiment Video

Updated: Sep 3, 2025

Reconstitution of Msp1 Extraction Activity with Fully Purified Components
05:52

Reconstitution of Msp1 Extraction Activity with Fully Purified Components

Published on: August 10, 2021

2.6K

Making and breaking the inner nuclear membrane proteome.

Lilli Hahn1, Pedro Carvalho1

  • 1Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.

Current Opinion in Cell Biology
|July 23, 2022
PubMed
Summary

The inner nuclear membrane (INM) is crucial for eukaryotic cell function and homeostasis. Understanding INM protein organization and quality control is key to preventing diseases linked to INM defects.

More Related Videos

High-Resolution Complexome Profiling by Cryoslicing BN-MS Analysis
09:33

High-Resolution Complexome Profiling by Cryoslicing BN-MS Analysis

Published on: October 15, 2019

7.3K
A Model Membrane Platform for Reconstituting Mitochondrial Membrane Dynamics
10:31

A Model Membrane Platform for Reconstituting Mitochondrial Membrane Dynamics

Published on: September 2, 2020

7.7K

Related Experiment Videos

Last Updated: Sep 3, 2025

Reconstitution of Msp1 Extraction Activity with Fully Purified Components
05:52

Reconstitution of Msp1 Extraction Activity with Fully Purified Components

Published on: August 10, 2021

2.6K
High-Resolution Complexome Profiling by Cryoslicing BN-MS Analysis
09:33

High-Resolution Complexome Profiling by Cryoslicing BN-MS Analysis

Published on: October 15, 2019

7.3K
A Model Membrane Platform for Reconstituting Mitochondrial Membrane Dynamics
10:31

A Model Membrane Platform for Reconstituting Mitochondrial Membrane Dynamics

Published on: September 2, 2020

7.7K

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Biochemistry

Background:

  • The nuclear envelope (NE) defines eukaryotic cells, enclosing the nucleus with two distinct lipid bilayers.
  • The inner nuclear membrane (INM) has a unique protein composition vital for nuclear organization, gene regulation, and DNA repair.
  • INM protein dysfunction is linked to muscular dystrophies and premature aging.

Purpose of the Study:

  • To review recent advancements in understanding INM protein localization.
  • To explore the quality control mechanisms maintaining INM protein homeostasis.

Main Methods:

  • Literature review of recent research on INM protein dynamics.
  • Analysis of cellular mechanisms for protein concentration and quality control at the INM.

Main Results:

  • Specific proteins are shown to concentrate at the INM through defined mechanisms.
  • Quality control pathways actively remodel and maintain INM protein composition.
  • INM architecture is critical for cellular homeostasis and preventing disease.

Conclusions:

  • Continued research into INM protein dynamics and quality control is essential.
  • Understanding these processes can provide insights into age-related and genetic disorders.
  • Maintaining INM integrity is fundamental for eukaryotic cell function.