Related Experiment Video

Updated: Dec 29, 2025

Delivery of Proteins, Peptides or Cell-impermeable Small Molecules into Live Cells by Incubation with the Endosomolytic Reagent dfTAT
10:30

Delivery of Proteins, Peptides or Cell-impermeable Small Molecules into Live Cells by Incubation with the Endosomolytic Reagent dfTAT

Published on: September 2, 2015

10.7K

Novel Tat-Dependent Protein Secretion

Volkmar Braun1, Klaus Hantke2

  • 1Max Planck Institute for Developmental Biology, Department of Protein Evolution, Tübingen, Germany volkmar.braun@tuebingen.mpg.de.

Journal of Bacteriology
|February 5, 2020
PubMed

Insights

Researchers discovered that the FecR protein, involved in ferric citrate transport, is secreted via the twin-arginine translocation (TAT) system. This finding reveals FecR as a novel type of bitopic membrane protein dependent on TAT for secretion.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Protein Secretion

Background:

  • Ferric citrate uptake in bacteria is regulated by a signaling pathway involving outer membrane protein FecA.
  • Signal transduction across the cytoplasmic membrane involves FecR protein and leads to the FecI extracytoplasmic function (ECF) sigma factor.
  • The mechanism of FecR protein secretion and its role in the signaling pathway were not fully understood.

Purpose of the Study:

  • To investigate the secretion pathway of the FecR protein.
  • To determine if FecR is secreted by the twin-arginine translocation (TAT) system.
  • To characterize FecR as a novel class of membrane protein.

Main Methods:

  • Sequence analysis of the FecR protein to identify signal motifs.
  • Experimental validation of FecR secretion using the TAT system.
  • Characterization of FecR as a bitopic membrane protein.

Main Results:

  • The FecR protein sequence contains the twin-arginine signal motif and a secretory (Sec) avoidance motif.
  • FecR is secreted by the TAT system, indicating a novel secretion pathway for this protein.
  • FecR is identified as a new class of bitopic Tat-dependent membrane proteins.

Conclusions:

  • The FecR protein utilizes the TAT system for secretion, a previously unrecognized pathway for this component of ferric citrate transport.
  • This study expands the known repertoire of proteins secreted by the TAT system and their functions.
  • The findings contribute to a deeper understanding of bacterial outer membrane protein transport and signal transduction mechanisms.
Keywords:
iron regulationprotein secretiontransport

More Related Videos

Biotinylated Cell-penetrating Peptides to Study Intracellular Protein-protein Interactions10:26

Biotinylated Cell-penetrating Peptides to Study Intracellular Protein-protein Interactions

Published on: December 20, 2017

9.8K
Engineering Cell-permeable Protein21:08

Engineering Cell-permeable Protein

Published on: December 28, 2009

14.9K

Related Concept Videos

Bacterial Translocation and Protein Secretion01:26

Bacterial Translocation and Protein Secretion

Bacterial protein secretion involves translocation systems to ensure proteins reach their designated locations, including the plasma membrane, periplasm, outer membrane, or the external environment. These translocation systems are vital for bacterial physiology, supporting processes like membrane assembly, enzymatic activity in the periplasm, and interactions with the external environment. The division of labor between Sec and Tat pathways ensures efficiency in handling proteins with diverse...
401
Overview of Secretory Vesicles01:33

Overview of Secretory Vesicles

Secretory vesicles, also known as dense core vesicles (DCVs), are membrane-bound vesicles that transport secretory proteins, such as hormones or neurotransmitters. Regulated secretory vesicles transport proteins from the trans-Golgi network to the exterior of the cell. Proteins present in regulated secretory vesicles are required to be rapidly exocytosed in large amounts upon a specific stimulus.
Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins...
9.2K
Cotranslational Protein Translocation01:20

Cotranslational Protein Translocation

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...
9.4K
Post-translational Translocation of Proteins to the RER01:27

Post-translational Translocation of Proteins to the RER

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...
7.3K
Tail-anchoring of Proteins in the ER Membrane01:45

Tail-anchoring of Proteins in the ER Membrane

Tail-anchored, or TA, proteins are estimated to make up to 3-5% of membrane proteins found in the eukaryotic cell. Such proteins have a single transmembrane domain located approximately 30 amino acid residues upstream from the C-terminal end. As a result, the signal recognition particle (SRP) cannot guide a TA protein to the ER membrane for cotranslational insertion. Hence, they are integrated into the ER membrane post-translationally using their C-terminal end as the anchor. TA proteins...
3.6K
Regulation of Nuclear Protein Sorting01:45

Regulation of Nuclear Protein Sorting

Nuclear protein sorting regulates nucleus composition and gene expression, crucial for determining the fate of a eukaryotic cell. Hence, the entry and exit of molecules across the nuclear envelope is a tightly controlled process. Nuclear protein sorting can be inhibited by one of the following ways: 1) masking cargo signal sequences, 2) modifying the nuclear receptor's affinity for cargo, 3) controlling the nuclear pore size, 4) retaining the cargo during its transit to the cytosol or the...
3.1K