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

Endoplasmic Reticulum01:39

Endoplasmic Reticulum

95.8K
The Endoplasmic Reticulum (ER) in eukaryotic cells is a substantial network of interconnected membranes with diverse functions, from calcium storage to biomolecule synthesis. A primary component of the endomembrane system, the ER manufactures phospholipids critical for membrane function throughout the cell. Additionally, the two distinct regions of the ER specialize in the manufacture of specific lipids and proteins.
95.8K
Post-translational Translocation of Proteins to the RER01:27

Post-translational Translocation of Proteins to the RER

5.9K
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...
5.9K
Overview of Protein Sorting and Transport01:45

Overview of Protein Sorting and Transport

11.8K
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...
11.8K
Assembly of the Lipid Bilayer in the ER01:28

Assembly of the Lipid Bilayer in the ER

3.3K
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...
3.3K
Cotranslational Protein Translocation01:20

Cotranslational Protein Translocation

7.5K
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...
7.5K
Cholesterol: Significance and Regulation01:29

Cholesterol: Significance and Regulation

657
Although not a source of energy, cholesterol plays a significant role as a foundational structure for bile salts, steroid hormones, and vitamin D, as well as being a crucial component of plasma membranes. Approximately 15% of blood cholesterol is derived from our diet, with the remainder synthesized from acetyl CoA by the liver and intestines. Cholesterol is eliminated from the body through its conversion into bile salts, which are eventually discarded in the feces.
Considering cholesterol and...
657

You might also read

Related Articles

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

Sort by
Same author

Adipose Tissue Plasticity, Lipoprotein Metabolism, and Cardiovascular Risk: The Emerging Role of the GLP-1 Axis.

Circulation research·2026
Same author

Photosensitizer proximity labeling captures the lipid and protein interactomes.

Nature chemical biology·2026
Same author

Bile acids regulate lipid metabolism through selective actions on fatty acid absorption.

Cell metabolism·2025
Same author

NK2R signaling governs intestinal lipid mobilization and mucosal inflammation.

bioRxiv : the preprint server for biology·2025
Same author

T cell cholesterol transport links intestinal immune responses to dietary lipid absorption.

Science (New York, N.Y.)·2025
Same author

Dietary control of peripheral adipose storage capacity through membrane lipid remodelling.

Nature metabolism·2025

Related Experiment Video

Updated: Sep 2, 2025

Cholesterol Efflux Assay
07:54

Cholesterol Efflux Assay

Published on: March 6, 2012

30.0K

Cholesterol Transport to the Endoplasmic Reticulum.

John P Kennelly1, Peter Tontonoz1

  • 1Department of Pathology and Laboratory Medicine, Department of Biological Chemistry, Molecular Biology Institute, University of California, Los Angeles, California 90095, USA.

Cold Spring Harbor Perspectives in Biology
|August 8, 2022
PubMed
Summary

Asters facilitate cholesterol movement from the plasma membrane to the endoplasmic reticulum in cells. This process is crucial for maintaining cholesterol homeostasis and steroid hormone production.

More Related Videos

LDL Cholesterol Uptake Assay Using Live Cell Imaging Analysis with Cell Health Monitoring
08:45

LDL Cholesterol Uptake Assay Using Live Cell Imaging Analysis with Cell Health Monitoring

Published on: November 17, 2018

13.5K
Using Caco-2 Cells to Study Lipid Transport by the Intestine
07:00

Using Caco-2 Cells to Study Lipid Transport by the Intestine

Published on: August 20, 2015

19.0K

Related Experiment Videos

Last Updated: Sep 2, 2025

Cholesterol Efflux Assay
07:54

Cholesterol Efflux Assay

Published on: March 6, 2012

30.0K
LDL Cholesterol Uptake Assay Using Live Cell Imaging Analysis with Cell Health Monitoring
08:45

LDL Cholesterol Uptake Assay Using Live Cell Imaging Analysis with Cell Health Monitoring

Published on: November 17, 2018

13.5K
Using Caco-2 Cells to Study Lipid Transport by the Intestine
07:00

Using Caco-2 Cells to Study Lipid Transport by the Intestine

Published on: August 20, 2015

19.0K

Area of Science:

  • Cellular Biology
  • Biochemistry
  • Molecular Biology

Background:

  • Cholesterol is primarily stored in the plasma membrane (PM) of mammalian cells.
  • Cholesterol transport from the PM to the endoplasmic reticulum (ER) regulates cellular cholesterol levels and is vital for various metabolic processes.
  • The ER-resident Aster proteins (Aster-A, -B, and -C) mediate cholesterol transfer from the PM to the ER.

Purpose of the Study:

  • To review the molecular characteristics of Aster proteins.
  • To elucidate the role of Asters in cholesterol movement from high-density lipoprotein (HDL) and low-density lipoprotein (LDL).
  • To discuss the cellular utilization of ER-transferred cholesterol and the broader context of cholesterol homeostasis.

Main Methods:

  • Literature review of Aster proteins and cholesterol transport mechanisms.
  • Analysis of studies on Aster-deficient mice, particularly Aster-B knockout models.
  • Examination of the functional roles of Asters in cellular lipid metabolism.

Main Results:

  • Aster proteins establish physical contacts between the PM and ER to facilitate cholesterol transport.
  • Mice lacking Aster-B exhibit impaired steroidogenesis due to defective cholesterol transport from HDL to the ER.
  • Asters play a significant role in regulating cholesterol flux between cellular compartments and tissues.

Conclusions:

  • Aster proteins are essential for efficient cholesterol transfer to the ER, impacting steroidogenesis and overall cholesterol homeostasis.
  • Understanding Aster function provides insights into lipid transport disorders and metabolic diseases.
  • The study highlights the importance of lipid transporters and membrane organization in maintaining cellular and organismal cholesterol balance.