Related Experiment Video
Updated: Apr 15, 2026
08:51
The Microscopy-Based Assay to Study and Analyze the Recycling Endosomes using SNARE Trafficking
Published on: February 12, 2022
4.1K
EARP is a multisubunit tethering complex involved in endocytic recycling
Christina Schindler1, Yu Chen1, Jing Pu1
1Cell Biology and Metabolism Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA.
Nature Cell Biology
|March 24, 2015
Summary
Researchers identified a new protein complex, endosome-associated recycling protein (EARP), essential for recycling receptors back to the cell surface. This discovery sheds light on the poorly understood mechanisms of endocytic recycling.
Area of Science:
- Cell Biology
- Molecular Biology
- Protein Complexes
Background:
- Endocytic receptor recycling is crucial for cell function but its mechanisms remain unclear.
- The role of multisubunit tethering complexes in endocytic recycling is unknown.
- Previous research identified the Golgi-associated retrograde protein (GARP) complex involved in Golgi trafficking.
Purpose of the Study:
- To investigate the role of tethering complexes in endocytic recycling.
- To identify novel protein complexes involved in receptor recycling.
- To elucidate the molecular mechanisms underlying endocytic pathway trafficking.
Main Methods:
- Characterization of a novel tethering complex, endosome-associated recycling protein (EARP).
- Comparative analysis of EARP and Golgi-associated retrograde protein (GARP) complexes.
- Depletion studies using siRNA targeting syndetin and syntaxin 6.
- Analysis of transferrin recycling to the cell surface.
Main Results:
- A novel tethering complex, EARP, was identified, structurally related to GARP.
- EARP contains syndetin, distinguishing it from GARP which has Vps54.
- EARP localizes to recycling endosomes, while GARP localizes to the Golgi complex.
- EARP interacts with syntaxin 6 and other SNAREs.
- Depletion of syndetin or syntaxin 6 impairs transferrin recycling.
Conclusions:
- EARP functions in endocytic recycling, mediating membrane fusion events.
- The findings implicate EARP in the canonical pathway of endocytic receptor recycling.
- EARP represents a key component in the regulation of endocytic trafficking.
Related Concept Videos
00:58Recycling Endosomes and Transcytosis
3.9K
The recycling endosome, also known as the endosomal recycling compartment (ERC), is a part of the slow-recycling process of the endocytic pathway. Molecules internalized through receptor-mediated endocytosis are either degraded in the lysosomes or are recycled to the plasma membrane through the fast- or slow-recycling route.
The recycling endosome is not a single organelle but an extensively tubulated network of recycling pathways. It functions in storing molecules or transporting them across...
The recycling endosome is not a single organelle but an extensively tubulated network of recycling pathways. It functions in storing molecules or transporting them across...
3.9K
01:45Vesicular Tubular Clusters
3.4K
After budding out from the ER membrane, some COPII vesicles lose their coat and fuse with one another to form larger vesicles and interconnected tubules called vesicular tubular clusters or VTCs. These clusters constitute a compartment at the ER-Golgi interface known as ERGIC (Endoplasmic Reticulum Golgi Intermediate Compartment). The ERGIC is a mobile membrane-bound cargo transport system that sorts proteins secreted from ER and delivers them to the Golgi.
With the help of motor proteins such...
With the help of motor proteins such...
3.4K
01:38Intralumenal Vesicles and Multivesicular Bodies
5.3K
Intraluminal vesicles (ILVs) are small vesicles 50-80 nm in diameter formed during the maturation of early endosomes. A specialized endosome containing numerous ILVs is called a multivesicular body (MVB). ILVs contain internalized molecules such as antigens, nucleic acids, proteins, and metabolites. Some of these molecules are released from the MVBs inside exosomes and are transported to other cells. Other MVBs contain molecules that are retained in the ILVs and are later degraded within the...
5.3K
01:45ER Retrieval Pathway
5.1K
In the secretory pathway, vesicles transport proteins from one cellular compartment to another in forward transport to deliver the protein to its correct location. Occasionally, misfolded proteins and incorrect proteins escape their original compartments, and a retrieval pathway is used to return the escaped proteins to their original compartment.
The ER uses many checkpoints to prevent the entry of incorrectly folded or a resident protein as cargo onto a transport vesicle. These mechanisms...
The ER uses many checkpoints to prevent the entry of incorrectly folded or a resident protein as cargo onto a transport vesicle. These mechanisms...
5.1K
01:25Rab Cascades
3.8K
Rab GTPases act in a regulated cascade during membrane fusion, helping the lipid bilayers mix. The Rab family of proteins are active when bound to GTP, and inactive when bound to GDP. Hence, they act as guanine nucleotide-dependent molecular switches. Rab-GTP recognizes and binds to long or short-range tethering proteins to capture the target vesicle. These tethers coordinate with SNAREs on the vesicle and the target membrane to assemble the trans SNARE complex that locks the mixing bilayers.
3.8K
01:45Tail-anchoring of Proteins in the ER Membrane
4.1K
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...
4.1K