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

Protein Transport into the Inner Mitochondrial Membrane01:34

Protein Transport into the Inner Mitochondrial Membrane

3.7K
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...
3.7K
Translocation of Proteins into the Mitochondria01:19

Translocation of Proteins into the Mitochondria

3.1K
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 Protein Sorting01:39

Mitochondrial Protein Sorting

4.3K
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
Mitochondrial Precursor Proteins01:39

Mitochondrial Precursor Proteins

2.6K
Mitochondrial precursors are partially unfolded or loosely folded polypeptide chains. Newly synthesized precursors are inhibited from spontaneously folding into their native conformation by the cytosolic chaperones, heat shock proteins 70 (Hsp70), and mitochondrial import stimulation factors (MSFs). Precursors bound to MSFs are guided to the TOM70-TOM37 receptors, while precursors bound to Hsp70  chaperones are targetted to TOM20-TOM22 receptor complexes.
Most of the mitochondrial...
2.6K
Energy to Drive Translocation01:37

Energy to Drive Translocation

2.1K
Mitochondrial protein import is powered by two distinct energy sources: ATP hydrolysis and electrochemical potential across the inner membrane. Newly synthesized precursors are bound by cytosolic chaperones of the Hsp70 family, which guide them to the import receptors on the mitochondrial surface. Utilizing the energy of ATP hydrolysis, Hsp70 chaperones transfer these precursors to the TOM receptors on the mitochondrial outer membrane.
Generally, polypeptides are unfolded by two distinct...
2.1K
Protein Transport to the Inner Chloroplast Membrane01:18

Protein Transport to the Inner Chloroplast Membrane

2.1K
Proteins targeted to the inner chloroplast membrane, or plastid proteins, are transported by two general pathways: the stop-transfer and the re-insertion or post-import pathways. Most plastid proteins carry N-terminal transit sequences and internal import sequences targeting it to the specific chloroplast subcompartment. Proteins targeted by the stop-transfer pathway have internal hydrophobic sequences that inhibit their translocation into the stroma. As a result, these precursors are arrested...
2.1K

You might also read

Related Articles

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

Sort by
Same author

Photonic waveguide chip-based nanoscopy visualizes rearrangements of the cortical actin cytoskeleton in activated Jurkat T cells.

Science advances·2026
Same author

Xylosyltransferase-II deficiency rewires innate immune signaling and destabilizes polarization in human macrophages.

Frontiers in immunology·2026
Same author

Intercellular mitochondrial transfer and trans-mitophagy in response to protein import dysfunction.

The Journal of cell biology·2026
Same author

Transmembrane domain switching controls PINK1 import and fate in mitochondria.

The EMBO journal·2026
Same author

Time to Death and Donation After Circulatory Death Kidney Transplant Outcomes: Opportunities for Improved Utilization in the United States.

Clinical transplantation·2026
Same author

Kinesin-1 conformational dynamics are controlled by a cargo-sensitive TPR switch.

eLife·2026

Related Experiment Video

Updated: Jul 4, 2025

MitoCeption: Transferring Isolated Human MSC Mitochondria to Glioblastoma Stem Cells
11:13

MitoCeption: Transferring Isolated Human MSC Mitochondria to Glioblastoma Stem Cells

Published on: February 22, 2017

12.9K

Rescue of mitochondrial import failure by intercellular organellar transfer.

Hope I Needs1, Emily Glover1, Gonçalo C Pereira1,2

  • 1School of Biochemistry, University of Bristol, Bristol, BS8 1TD, UK.

Nature Communications
|February 2, 2024
PubMed
Summary

Mitochondrial import failure disrupts cell energy but cells can rescue dysfunction. Healthy mitochondria are transferred between cells via tunnelling nanotubes to restore function.

More Related Videos

Author Spotlight: Bidirectional Mitochondrial Transfer between MSCs and Retinal Pigment Epithelium Cells — Pathways and In Vivo Challenges
06:50

Author Spotlight: Bidirectional Mitochondrial Transfer between MSCs and Retinal Pigment Epithelium Cells — Pathways and In Vivo Challenges

Published on: October 4, 2024

830
Measurement of Protein Import Capacity of Skeletal Muscle Mitochondria
09:01

Measurement of Protein Import Capacity of Skeletal Muscle Mitochondria

Published on: January 7, 2022

2.7K

Related Experiment Videos

Last Updated: Jul 4, 2025

MitoCeption: Transferring Isolated Human MSC Mitochondria to Glioblastoma Stem Cells
11:13

MitoCeption: Transferring Isolated Human MSC Mitochondria to Glioblastoma Stem Cells

Published on: February 22, 2017

12.9K
Author Spotlight: Bidirectional Mitochondrial Transfer between MSCs and Retinal Pigment Epithelium Cells — Pathways and In Vivo Challenges
06:50

Author Spotlight: Bidirectional Mitochondrial Transfer between MSCs and Retinal Pigment Epithelium Cells — Pathways and In Vivo Challenges

Published on: October 4, 2024

830
Measurement of Protein Import Capacity of Skeletal Muscle Mitochondria
09:01

Measurement of Protein Import Capacity of Skeletal Muscle Mitochondria

Published on: January 7, 2022

2.7K

Area of Science:

  • Cell Biology
  • Mitochondrial Biology
  • Neuroscience

Background:

  • Mitochondria generate cellular energy and rely on protein import from the cytosol.
  • Mitochondrial import machinery dysfunction is linked to cellular energy deficits and disease.
  • Energy-demanding tissues like the nervous system and muscles are particularly vulnerable to mitochondrial dysfunction.

Purpose of the Study:

  • To investigate the consequences of impaired mitochondrial protein import in mammalian cells.
  • To understand the cellular response to disrupted mitochondrial import machinery.

Main Methods:

  • Blocking mitochondrial protein import pathways in mammalian cells.
  • Analyzing mitochondrial ultra-structure and dynamics using advanced microscopy.
  • Observing intercellular communication and mitochondrial transfer via tunnelling nanotubes.

Main Results:

  • Blocking mitochondrial import machinery altered mitochondrial structure and dynamics.
  • Despite import blockage, mitochondrial import itself was not directly affected.
  • Cells exhibited intercellular mitochondrial transport through tunnelling nanotubes.
  • Healthy mitochondria were imported, while dysfunctional ones were expelled.

Conclusions:

  • Cells possess a mechanism to rescue mitochondrial dysfunction by transferring healthy mitochondria.
  • Intercellular mitochondrial transport via tunnelling nanotubes is a key component of this rescue pathway.
  • This process highlights a widespread cellular strategy for maintaining mitochondrial health and function.