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

Golgi alkalinization by the papillomavirus E5 oncoprotein.

F Schapiro1, J Sparkowski, A Adduci

  • 1Division of Cell Biology, Research Institute, Hospital for Sick Children, Toronto, Ontario, M5G 1X8 Canada.

The Journal of Cell Biology
|January 29, 2000
PubMed
Summary

The bovine papillomavirus type I E5 oncoprotein disrupts Golgi complex pH homeostasis by impairing vacuolar H(+)-ATPase activity, leading to cellular transformation. This alkalinization mechanism is independent of PDGF receptor activation.

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

Editorial Expression of Concern: RING finger-dependent ubiquitination by PRAJA is dependent on TGF-ß and potentially defines the functional status of the tumor suppressor ELF.

Oncogene·2025
Same author

Two distinct superconducting phases in LiFeAs.

Scientific reports·2016
Same author

Observation of the waveguide resonance in a periodically patterned high refractive index broadband antireflection coating.

Applied optics·2014
Same author

Design and properties of a cryogenic dip-stick scanning tunneling microscope with capacitive coarse approach control.

The Review of scientific instruments·2014
Same author

Wheat specific repetitive DNA sequences - construction and characterization of four different genomic clones.

TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik·2013
Same author

Rye cytology, cytogenetics and genetics - current status.

TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik·2013

Area of Science:

  • Cell Biology
  • Virology
  • Oncology

Background:

  • The E5 oncoprotein of bovine papillomavirus type I is implicated in cellular transformation.
  • E5-mediated transformation is often linked to platelet-derived growth factor receptor (PDGF-R) activation.
  • Some E5 mutants transform cells without phosphorylating PDGF-R, suggesting alternative mechanisms.

Purpose of the Study:

  • To investigate the role of the E5 oncoprotein in Golgi complex pH homeostasis.
  • To determine if E5 interferes with the vacuolar H(+)-ATPase (V-ATPase) and affects Golgi pH (pH(G)).
  • To correlate Golgi alkalinization with cellular transformation.

Main Methods:

  • Utilized a pH-sensitive fluorescent bacterial toxin to measure Golgi pH (pH(G)) via ratio imaging in E5-transfected cells.

Related Experiment Videos

  • Assessed Golgi buffering power and H(+) leakage rates.
  • Generated and analyzed E5 mutants with altered V-ATPase binding or subcellular localization.

    • Main Results:

    • E5-transfected cells exhibited an alkalinized Golgi complex (pH ~7.0) compared to control cells (pH 6.5).
    • Impaired V-ATPase activity, not altered protein levels, caused the pH shift; buffering and leakage remained comparable.
    • Mutations preventing E5 binding to the V-ATPase 16-kD subunit or targeting E5 to the ER abolished Golgi alkalinization and transformation.
    • Transformation-competent E5 mutants defective in PDGF-R activation still caused Golgi alkalinization.

    Conclusions:

    • Golgi complex alkalinization is a novel biological activity of the E5 oncoprotein.
    • This alkalinization, mediated by V-ATPase dysfunction, correlates with cellular transformation.
    • The findings reveal a new mechanism for E5-driven oncogenesis independent of PDGF-R signaling.