Related Experiment Video
Updated: Jul 17, 2026
06:32
Reconstitution of Septin Assembly at Membranes to Study Biophysical Properties and Functions
Published on: July 28, 2022
Functional symmetry of endomembranes
1Section of Anatomy and Cell Biology, Department of Biomedicine, University of Bergen, N-5009 Bergen, Norway. jaakko.saraste@biomed.uib.no
Molecular Biology of the Cell
|February 3, 2007
Summary
This study reveals that the endocytic recycling compartment (ERC) and biosynthetic recycling compartment (BRC) act as mirror compartments in eukaryotic cells. These compartments are crucial for membrane recycling and cellular processes like division and differentiation.
Area of Science:
- Cell Biology
- Molecular Biology
- Membrane Trafficking
Background:
- Eukaryotic cells utilize pleiomorphic compartments for intracellular transport from the endoplasmic reticulum (ER) and plasma membrane.
- These compartments are vital for cargo delivery to the Golgi apparatus and lysosomes, and extensive membrane recycling.
- The endocytic membrane system includes early endosomes, late endosomes, and the endocytic recycling compartment (ERC).
Purpose of the Study:
- To investigate the structure and function of the intermediate compartment (IC) between the ER and Golgi.
- To propose a model for the endocytic recycling compartment (ERC) and the newly identified biosynthetic recycling compartment (BRC).
- To highlight the functional symmetry and dynamic nature of endomembrane compartments.
Main Methods:
- Comparative analysis of peripheral and centralized structures within the intermediate compartment.
- Functional characterization of the endocytic recycling compartment (ERC) and biosynthetic recycling compartment (BRC).
- Integration of existing knowledge on membrane trafficking pathways.
Main Results:
- The intermediate compartment (IC) comprises peripheral, centralized, and a novel biosynthetic recycling compartment (BRC).
- The ERC and BRC function as long-lived 'mirror compartments' at the cell center.
- Both ERC and BRC exhibit expansion and mobilization capabilities during cell activation.
Conclusions:
- The ERC and BRC represent functionally symmetrical compartments central to membrane recycling.
- These mirror compartments play a role in cellular processes such as cell division, polarization, and differentiation.
- Understanding these compartments provides insights into dynamic membrane rearrangements in eukaryotic cells.
Related Concept Videos
01:35Asymmetric Lipid Bilayer
Biological membranes show uneven distribution of different types of lipids in the inner and outer layers, resulting in transverse asymmetric membranes. The treatment of the erythrocyte membrane with the enzyme phospholipase confirmed the asymmetric nature of the lipid bilayer. The enzyme hydrolyzes lipids into fatty acids and hydrophilic groups. The phospholipase acts only on the outer layer of the membrane, while the inner layer remains intact. The phospholipase treatment resulted in 80%...
01:15Mechanisms of Membrane-bending
The living membranes are flexible due to their fluid mosaic nature; however, their bending into different shapes is an active process regulated by specific lipids and proteins. The membrane bending can be transient as seen in vesicles or stable for a long time as in microvilli. Cells regulate the size, location, and duration of the membrane curvature.
Membrane bending can happen due to intrinsic changes in lipid composition or extrinsic association with different proteins. The proteins involved...
Membrane bending can happen due to intrinsic changes in lipid composition or extrinsic association with different proteins. The proteins involved...
01:43The Endoplasmic Reticulum
The endoplasmic reticulum or ER makes up for more than half of the membranes in a cell and accounts for 10% of total cell volume. It is also the primary protein and lipid synthesis factory for most cell organelles, such as the Golgi apparatus, lysosomes, secretory vesicles, and the plasma membrane. Despite being the most extensive and functionally complex subcellular organelle, ER was the last to be discovered. After years of deliberation, Keith Porter and George Palade in the year 1954,...
01:43The Endoplasmic Reticulum
The endoplasmic reticulum or ER makes up for more than half of the membranes in a cell and accounts for 10% of total cell volume. It is also the primary protein and lipid synthesis factory for most cell organelles, such as the Golgi apparatus, lysosomes, secretory vesicles, and the plasma membrane. Despite being the most extensive and functionally complex subcellular organelle, ER was the last to be discovered. After years of deliberation, Keith Porter and George Palade in the year 1954,...
01:28Assembly of the Lipid Bilayer in the ER
Biological membranes are more than just a barrier separating cell cytoplasm from the outside environment. They are highly dynamic and help maintain the integrity and physiological stability of the cells as well as membrane-bound organelles. Membranes also play vital roles in cell-to-cell and intracellular communication.
A large chunk of any biological membrane is composed of phospholipids. These lipids have a heterogeneous distribution across different subcellular organelles and even between...
A large chunk of any biological membrane is composed of phospholipids. These lipids have a heterogeneous distribution across different subcellular organelles and even between...
01:49Golgi Apparatus
As they leave the Endoplasmic Reticulum (ER), properly folded and assembled proteins are selectively packaged into vesicles. These vesicles are transported by microtubule-based motor proteins and fuse together to form vesicular tubular clusters, subsequently arriving at the Golgi apparatus, a eukaryotic endomembrane organelle that often has a distinctive ribbon-like appearance.The Golgi apparatus is a major sorting and dispatch station for the products of the ER. Newly arriving vesicles enter...