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 Experiment Videos

Regulating c-Ras function. cholesterol depletion affects caveolin association, GTP loading, and signaling.

O Kranenburg1, I Verlaan, W H Moolenaar

  • 1Division of Cellular Biochemistry, The Netherlands Cancer Institute, Center for Biomedical Genetics, Plesmanlaan 121, 1066CX Amsterdam, The Netherlands.

Current Biology : CB
|December 1, 2001
PubMed
Summary

Plasma membrane cholesterol regulates Ras signaling. Cholesterol depletion enables epidermal growth factor (EGF) to activate K-Ras and N-Ras, revealing cholesterol

Related Concept Videos

You might also read

Related Articles

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

Sort by
Same author

Anti-PD-1 treatment response is associated with the influx of circulating myeloid and T-cell subsets into the metastatic melanoma tumor microenvironment.

British journal of cancer·2025
Same author

Peritoneal resident macrophages constitute an immunosuppressive environment in peritoneal metastasized colorectal cancer.

Nature communications·2025
Same author

Rational design of alternative treatment options for radioresistant rectal cancer using patient-derived organoids.

British journal of cancer·2025
Same author

Organoids from colorectal peritoneal metastases as a platform for improving hyperthermic intraperitoneal chemotherapy.

The British journal of surgery·2019
Same author

Histopathological and molecular classification of colorectal cancer and corresponding peritoneal metastases.

The British journal of surgery·2018
Same author

Neoadjuvant chemotherapy affects molecular classification of colorectal tumors.

Oncogenesis·2017

Area of Science:

  • Cell biology
  • Molecular signaling
  • Membrane biophysics

Background:

  • Caveolae, cholesterol-rich plasma membrane microdomains, are involved in signal transduction.
  • The role of caveolae in regulating the Ras-MAP kinase cascade is not fully understood.
  • Mammalian Ras isoforms (H, N, K) may localize to distinct microdomains due to different membrane anchors, potentially explaining isoform-specific signaling.

Purpose of the Study:

  • To investigate the role of caveolae and plasma membrane cholesterol in regulating Ras isoform signaling.
  • To determine how Ras isoform localization to caveolae affects their activation by epidermal growth factor (EGF).
  • To elucidate the mechanism by which cholesterol influences Ras-MAP kinase pathway activation.

Main Methods:

  • Immunofluorescence microscopy to assess colocalization of Ras isoforms with caveolin in Cos epithelial cells.

Related Experiment Videos

  • Biochemical assays to measure Ras GTP-loading and downstream MEK-MAP kinase activation.
  • Cholesterol depletion using methyl-beta-cyclodextrin to disrupt caveolae and assess its effects on Ras signaling.

    • Main Results:

    • Endogenous K-Ras colocalized with caveolin, while N-Ras localized to both caveolar and noncaveolar domains in Cos cells.
    • EGF activated N-Ras but not K-Ras in untreated cells.
    • Cholesterol depletion disrupted caveolin-Ras complexes and enabled EGF-induced activation of both K-Ras and N-Ras.
    • Cholesterol depletion enhanced total c-Ras GTP-loading but inhibited downstream MEK-MAP kinase activation by EGF and lysophosphatidic acid.

    Conclusions:

    • Plasma membrane cholesterol is essential for the negative regulation of caveolin-bound Ras isoforms.
    • Cholesterol depletion disrupts Ras-caveolin interactions, leading to altered Ras activation.
    • Cholesterol plays a critical role in both negative regulation of Ras and positive regulation of downstream mitogenic signaling.