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 Translocation Machinery on the ER Membrane01:28

Protein Translocation Machinery on the ER Membrane

7.1K
The translocon complex situated on the ER membrane is the main gateway for the protein secretory pathway. It facilitates the transport of nascent peptides into the ER lumen and their insertion into the ER membrane.
Sec61 protein conducting channel
In eukaryotes, the translocon complex comprises a core heterotrimeric translocator channel called the Sec61 complex. This channel includes three transmembrane proteins, Sec61α, Sec61β, and Sec61γ, and is the largest subunit of the...
7.1K
Cotranslational Protein Translocation01:20

Cotranslational Protein Translocation

10.6K
Translocation of proteins across membranes is an ancient process that occurs even in bacteria and archaebacteria. In fact, the components of the translocation machinery are still conserved between prokaryotes and eukaryotes.
Sec61 channel partners for cotranslational translocation
During cotranslational translocation, the Sec61 channel partners with the signal recognition particle (SRP), the signal recognition particle receptor (SR), and the ribosomes to transport the nascent polypeptide chain...
10.6K
Post-translational Translocation of Proteins to the RER01:27

Post-translational Translocation of Proteins to the RER

7.9K
A sizable fraction of proteins destined for ER are first synthesized in the cell cytosol and then transported across the ER membrane–a process called post-translational translocation. Similar to cotranslationally translocated proteins, these proteins also use the Sec translocon complex to enter the ER lumen.
Targeting proteins to the ER
Hsp40 and Hsp70 chaperone molecules bind the translated proteins in the cytosol to prevent their folding. The chaperone binding helps to keep the signal...
7.9K
Protein Transport into the Inner Mitochondrial Membrane01:34

Protein Transport into the Inner Mitochondrial Membrane

5.1K
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...
5.1K
Insertion of Single-pass Transmembrane Proteins in the RER01:26

Insertion of Single-pass Transmembrane Proteins in the RER

18.5K
Integral membrane proteins are proteins adhered to the lipid bilayer of a cell organelle or membrane. They can be of two types: transmembrane integral proteins that span the lipid bilayer and monotopic proteins that are attached to either side of the membrane but do not pass through it.
Integral transmembrane proteins possess transmembrane and extra membrane domains. The transmembrane domains are primarily made of 20-25 hydrophobic amino acids arranged in a helical secondary confirmation. These...
18.5K
Clathrin Coated Vesicles01:12

Clathrin Coated Vesicles

9.8K
Clathrin-coated vesicles use endocytosis to transport receptors and lysosomal hydrolases from the Golgi to the lysosome in the late secretory pathway. Clathrin-mediated endocytosis was the first described endocytic process, and Clathrin-coated vesicles remain one of the most well-studied transport vesicles. The molecular machinery that generates clathrin-coated vesicles comprises over 50 proteins that precisely coordinate vesicle formation. Cell surface receptors concentrated in indented sites...
9.8K

You might also read

Related Articles

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

Sort by
Same author

Integrated omics reveal a unique antibacterial mechanism of action for the small molecule HSI#6.

Current research in microbial sciences·2026
Same author

Calcium controls type III secretion switch through an SctV-SctW interplay.

Frontiers in microbiology·2026
Same author

NEXT-FRET maps nonequilibrium rerouting of <i>Escherichia coli</i> maltose-binding protein folding by its signal peptide and chaperones.

Proceedings of the National Academy of Sciences of the United States of America·2026
Same author

A small molecule allosterically activates SecA dependent secretion.

Communications biology·2026
Same author

Effect of the Bacterial Chaperones SecB and Trigger Factor (TF) on the Folding Dynamics and In Vitro Translocation of Cytoplasmic and Secretory Model Proteins.

International journal of molecular sciences·2025
Same author

How SecB maintains clients in a translocation competent state.

Communications biology·2025

Related Experiment Video

Updated: Feb 28, 2026

Production of Disulfide-stabilized Transmembrane Peptide Complexes for Structural Studies
12:05

Production of Disulfide-stabilized Transmembrane Peptide Complexes for Structural Studies

Published on: March 6, 2013

14.7K

Preprotein Conformational Dynamics Drive Bivalent Translocase Docking and Secretion.

Marios Frantzeskos Sardis1, Alexandra Tsirigotaki1, Katerina Elias Chatzi1

  • 1KU Leuven, Department of Microbiology and Immunology, Rega Institute for Medical Research, 3000 Leuven, Belgium.

Structure (London, England : 1993)
|June 20, 2017
PubMed
Summary

Secretory proteins use a dual-key mechanism to bind the SecA receptor, involving signal peptides and mature domains. This interaction finely tunes preprotein structure, enabling efficient bacterial secretion via the translocase.

Keywords:
SecAbivalent ligandcooperative bindingmature domainnative disorderpreproteinssecretionsignal peptidesynergytargetingtranslocase

More Related Videos

SNARE-mediated Fusion of Single Proteoliposomes with Tethered Supported Bilayers in a Microfluidic Flow Cell Monitored by Polarized TIRF Microscopy
10:58

SNARE-mediated Fusion of Single Proteoliposomes with Tethered Supported Bilayers in a Microfluidic Flow Cell Monitored by Polarized TIRF Microscopy

Published on: August 24, 2016

11.5K
Application of I TASSER, trRosetta, UCSF Chimera, HADDOCK server, and HEX loria for De Novo and In Silico Design of Proteins
05:08

Application of I TASSER, trRosetta, UCSF Chimera, HADDOCK server, and HEX loria for De Novo and In Silico Design of Proteins

Published on: July 8, 2025

1.2K

Related Experiment Videos

Last Updated: Feb 28, 2026

Production of Disulfide-stabilized Transmembrane Peptide Complexes for Structural Studies
12:05

Production of Disulfide-stabilized Transmembrane Peptide Complexes for Structural Studies

Published on: March 6, 2013

14.7K
SNARE-mediated Fusion of Single Proteoliposomes with Tethered Supported Bilayers in a Microfluidic Flow Cell Monitored by Polarized TIRF Microscopy
10:58

SNARE-mediated Fusion of Single Proteoliposomes with Tethered Supported Bilayers in a Microfluidic Flow Cell Monitored by Polarized TIRF Microscopy

Published on: August 24, 2016

11.5K
Application of I TASSER, trRosetta, UCSF Chimera, HADDOCK server, and HEX loria for De Novo and In Silico Design of Proteins
05:08

Application of I TASSER, trRosetta, UCSF Chimera, HADDOCK server, and HEX loria for De Novo and In Silico Design of Proteins

Published on: July 8, 2025

1.2K

Area of Science:

  • Molecular Biology
  • Cellular Biology
  • Biochemistry

Background:

  • Bacterial secretory proteins are translocated across the plasma membrane by the Sec translocase.
  • The initial step involves preprotein targeting to the SecA receptor, the peripheral ATPase subunit of the translocase.

Purpose of the Study:

  • To elucidate the mechanism by which secretory preproteins target and bind to the SecA receptor.
  • To investigate the role of preprotein structure and SecA dynamics in efficient protein secretion.

Main Methods:

  • The study employed biochemical and biophysical techniques to analyze preprotein-SecA interactions.
  • Investigated conformational changes in preproteins and SecA during the targeting process.

Main Results:

  • Secretory preproteins utilize a dual-key mechanism, bridging signal peptide and mature domain receptor sites on SecA for enhanced binding affinity.
  • Amino-terminal mature domain regions act as conformational rheostats, tuning preprotein disorder and regulating long-range interactions.
  • Signal peptides regulate preprotein disorder, and SecA undergoes conformational changes to accommodate diverse preproteins.

Conclusions:

  • A novel intramolecular conformational crosstalk within preproteins is essential for SecA engagement.
  • The dynamic interaction between preproteins and SecA is mechanistically coupled to translocase engagement and protein secretion.
  • This mechanism ensures efficient and specific secretion of a wide range of bacterial proteins.