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

Biochemical basis for the biological clock.

D James Morré1, Pin-Ju Chueh, Jake Pletcher

  • 1Department of Medicinal Chemistry and Molecular Pharmacology, 136 Hansen Life Sciences Research Building, Purdue University, West Lafayette, IN 47907, USA. morre@pharmacy.purdue.edu

Biochemistry
|October 3, 2002
PubMed
Summary

ECTO-NOX proteins, external cell surface NADH oxidases, act as the ultradian pacemakers for the cellular biological clock. Their oscillation periods directly determine the circadian rhythm of clock-regulated proteins.

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

Context-Aware Online Model Splitting and Device Association for Semi-Decentralized Federated Learning in Internet of Things.

Sensors (Basel, Switzerland)·2026
Same author

How Drawing Unlocks Students' Developing Mechanistic Reasoning about Complex Systems in Physiology.

Advances in physiology education·2026
Same author

Hydrogels in Autoimmune Disease: A Comprehensive Review of Current Research and Clinical Potentials.

International journal of nanomedicine·2026
Same author

Revolutionary Tools for Decoding the Complexity of Forest Trees: The Application of Single-Cell and Spatial Transcriptomics in Woody Plants.

Physiologia plantarum·2026
Same author

Network pharmacology, molecular docking, molecular dynamics and animal experimental validation to investigate the mechanism of hydrocortisone in treating sepsis-induced acute lung injury.

Scientific reports·2026
Same author

Enhancing clinically cardiovascular machine learning model for risk prediction via sample augmentation.

Frontiers in medicine·2026

Area of Science:

  • Biochemistry
  • Cell Biology
  • Chronobiology

Background:

  • External NADH oxidases (ECTO-NOX proteins) on plant and animal cells exhibit ultradian oscillations.
  • These oscillations have period lengths potentially related to biological clocks, showing entrainability and temperature compensation.

Purpose of the Study:

  • To investigate whether ECTO-NOX proteins function as the ultradian pacemakers of the cellular biological clock.
  • To determine if modifying ECTO-NOX protein oscillation periods affects circadian rhythms.

Main Methods:

  • COS cells were transfected with cDNAs encoding tNOX proteins with altered period lengths (22 min) or cysteine-to-alanine mutants (C575A, C558A) with longer periods (36-42 min).
  • The activity of glyceraldehyde-3-phosphate dehydrogenase, a known clock-regulated protein, was monitored in transfected cells.
Keywords:
NASA Discipline Cell BiologyNon-NASA Center

Related Experiment Videos

Main Results:

  • Transfected cells expressing modified ECTO-NOX proteins exhibited altered circadian patterns.
  • Observed circadian period lengths in glyceraldehyde-3-phosphate dehydrogenase activity were 22, 36, or 40-42 hours, correlating with the introduced ECTO-NOX protein periods.
  • The endogenous 24-hour circadian rhythm was also present.

Conclusions:

  • A single oscillatory ECTO-NOX protein dictates the period length of a circadian biochemical marker.
  • ECTO-NOX proteins serve as the biochemical ultradian drivers of the cellular biological clock.
  • This provides strong evidence for ECTO-NOX proteins as the pacemakers of circadian rhythms.