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 to the Thylakoids01:22

Protein Transport to the Thylakoids

2.4K
Thylakoids are membrane-bound sac-like structures within the chloroplast that serve as sites for photosynthesis. Thylakoid lumen contains many electron transport proteins and is enclosed by a thylakoid membrane rich in the light-harvesting complex. Proteins targeted to the thylakoids are transported as precursors and are sorted by the general TOC/TIC import pathway. Once the precursor reaches the stroma, stromal processing peptidases remove their transit signal and expose thylakoid signal...
2.4K
Protein Transport to the Inner Chloroplast Membrane01:18

Protein Transport to the Inner Chloroplast Membrane

2.2K
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...
2.2K
Protein Transport to the Outer Chloroplast Membrane01:11

Protein Transport to the Outer Chloroplast Membrane

2.1K
Chloroplast outer membrane proteins encoded by the nucleus are synthesized in the cytosol. Soon after synthesis, they bind cytosolic factors such as 14-3-3 protein and the Hsp70 chaperones that keep these precursors in an unfolded state until their translocation.
Two models describe the mechanism of precursor recognition and entry across the outer membrane through the TOC complex. Model 1 suggests the newly synthesized precursor binds to the TOC receptor 159 and forms a complex.
2.1K
Protein Transport to the Stroma01:24

Protein Transport to the Stroma

1.9K
Chloroplasts are triple membrane structures with an outer membrane, an inner membrane, and a thylakoid membrane, each containing distinct metabolite transporters, membrane translocons, and enzymes. Appropriate sorting and translocating these proteins to their correct membrane systems is essential for chloroplast function.
Protein complexes called the translocon of the outer chloroplast membrane or TOC complex, and the translocon of the inner chloroplast membrane or TIC complex mediate the...
1.9K
Overview of Protein Sorting and Transport01:45

Overview of Protein Sorting and Transport

15.8K
Eukaryotic cells have different membrane-bound organelles with distinct protein requirements. The process by which proteins are targeted to a specific organelle is called protein sorting.
Protein sorting can be of two types: signal-based sorting and vesicle-based trafficking. In signal-based sorting, specific amino acid sequences called sorting signals target proteins to the proper location inside the cell either via gated transport or by protein translocation.  In gated transport, folded...
15.8K
Mitochondrial Protein Sorting01:39

Mitochondrial Protein Sorting

4.6K
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...
4.6K

You might also read

Related Articles

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

Sort by
Same author

Design, Synthesis, and Protective Activity against Doxorubicin-Induced Cardiotoxicity of Novel Water-Soluble Small-Molecule GPx Mimics.

ACS medicinal chemistry letters·2026
Same author

Advances in Heparin Reversal Agents: Design Strategies, Structural Features, and Pharmacological Insights.

Journal of medicinal chemistry·2026
Same author

Design, Synthesis, and Study of Protective Activity Against Stroke for Novel Water-Soluble Aldehyde Dehydrogenase 2 Activators.

Molecules (Basel, Switzerland)·2025
Same author

Design, Synthesis, and Protective Effect Evaluation on Myocardial Ischemia of New Triazole Aldehyde Dehydrogenase 2 Activators.

ACS medicinal chemistry letters·2025
Same author

Corrigendum to "Discovery of 3,5-diaryl-1H-pyrazol-based ureas as potent RET inhibitors" [Eur. J. Med. Chem. (2023), 251, 115237].

European journal of medicinal chemistry·2025
Same author

Quantum chemistry calculation-aided discovery of potent small-molecule mimics of glutathione peroxidases for the treatment of cisplatin-induced hearing loss.

European journal of medicinal chemistry·2024

Related Experiment Video

Updated: Oct 5, 2025

Isolation of Physiologically Active Thylakoids and Their Use in Energy-Dependent Protein Transport Assays
12:25

Isolation of Physiologically Active Thylakoids and Their Use in Energy-Dependent Protein Transport Assays

Published on: September 28, 2018

11.0K

Protein Targeting Into the Thylakoid Membrane Through Different Pathways.

Dan Zhu1, Haibo Xiong1, Jianghao Wu1

  • 1State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China.

Frontiers in Physiology
|January 31, 2022
PubMed
Summary

This review details how plant chloroplasts import proteins into thylakoid membranes. It highlights distinct pathways for nuclear and chloroplast-encoded proteins, advancing our understanding of chloroplast biogenesis.

Keywords:
chloroplast protein importcotranslational protein transportcpGet pathwaycpSRP pathwayspontaneous pathway

More Related Videos

Analysis of Thylakoid Membrane Protein Complexes by Blue Native Gel Electrophoresis
08:12

Analysis of Thylakoid Membrane Protein Complexes by Blue Native Gel Electrophoresis

Published on: September 28, 2018

13.1K
A New Approach for the Comparative Analysis of Multiprotein Complexes Based on 15N Metabolic Labeling and Quantitative Mass Spectrometry
08:04

A New Approach for the Comparative Analysis of Multiprotein Complexes Based on 15N Metabolic Labeling and Quantitative Mass Spectrometry

Published on: March 13, 2014

12.4K

Related Experiment Videos

Last Updated: Oct 5, 2025

Isolation of Physiologically Active Thylakoids and Their Use in Energy-Dependent Protein Transport Assays
12:25

Isolation of Physiologically Active Thylakoids and Their Use in Energy-Dependent Protein Transport Assays

Published on: September 28, 2018

11.0K
Analysis of Thylakoid Membrane Protein Complexes by Blue Native Gel Electrophoresis
08:12

Analysis of Thylakoid Membrane Protein Complexes by Blue Native Gel Electrophoresis

Published on: September 28, 2018

13.1K
A New Approach for the Comparative Analysis of Multiprotein Complexes Based on 15N Metabolic Labeling and Quantitative Mass Spectrometry
08:04

A New Approach for the Comparative Analysis of Multiprotein Complexes Based on 15N Metabolic Labeling and Quantitative Mass Spectrometry

Published on: March 13, 2014

12.4K

Area of Science:

  • Plant biology
  • Cellular organelle research
  • Photosynthesis and bioenergetics

Background:

  • Chloroplasts are vital organelles in plants, containing thylakoid membranes crucial for photosynthesis.
  • Thylakoid proteins are synthesized both in the cytosol (encoded by nuclear genes) and chloroplast stroma (encoded by chloroplast genome).
  • Nuclear-encoded proteins require import into chloroplasts via the Toc/Tic system and subsequent targeting to thylakoids.

Purpose of the Study:

  • To review the distinct protein transport systems from chloroplast stroma to thylakoid membranes.
  • To present recent advances in identifying novel components involved in these thylakoid protein targeting pathways.
  • To discuss unanswered questions and future research directions in chloroplast protein translocation.

Main Methods:

  • Literature review of existing research on protein targeting within chloroplasts.
  • Analysis of identified factors and pathways for thylakoid membrane protein insertion.
  • Synthesis of current knowledge on cotranslational and post-translational protein translocation.

Main Results:

  • Two main routes exist for thylakoid protein targeting: cotranslational insertion for chloroplast-encoded proteins and post-translational import for nuclear-encoded proteins.
  • The Toc/Tic system facilitates the initial import of nuclear-encoded proteins into the chloroplast.
  • Significant progress has been made in identifying new factors and understanding the mechanisms of distinct thylakoid targeting pathways.

Conclusions:

  • Understanding thylakoid protein targeting is key to chloroplast function and photosynthesis.
  • Recent discoveries have illuminated novel components and mechanisms in protein translocation pathways.
  • Further research is needed to fully elucidate the complexities and remaining questions in chloroplast protein targeting to thylakoids.