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

Circadian Rhythms and Gene Regulation02:19

Circadian Rhythms and Gene Regulation

4.7K
The biological clock is involved in many aspects of regulating complex physiology in all animals. It was in 1935 when German zoologists, Hans Kalmus and Erwin Bünning, discovered the existence of circadian rhythm in Drosophila melanogaster. However, the internal molecular mechanisms behind the circadian clock remained a mystery until 1984, when Jeffrey C. Hall, Michael Rosbash, and Michael W. Young discovered the expression of the Per gene oscillating over a 24-hour cycle. In subsequent...
4.7K
Circadian Rhythms and Gene Regulation02:19

Circadian Rhythms and Gene Regulation

2.5K
2.5K
Regulation of Nuclear Protein Sorting01:45

Regulation of Nuclear Protein Sorting

3.5K
Nuclear protein sorting regulates nucleus composition and gene expression, crucial for determining the fate of a eukaryotic cell. Hence, the entry and exit of molecules across the nuclear envelope is a tightly controlled process. Nuclear protein sorting can be inhibited by one of the following ways: 1) masking cargo signal sequences, 2) modifying the nuclear receptor's affinity for cargo, 3) controlling the nuclear pore size, 4) retaining the cargo during its transit to the cytosol or the...
3.5K
Nuclear Protein Sorting01:34

Nuclear Protein Sorting

6.6K
Nuclear protein sorting is the selective trafficking of histones, polymerases, gene regulatory proteins into the nucleus and exporting RNAs and ribosomes to the cytosol. It is a tightly controlled process that regulates gene expression within a cell.
Proteins targeted to the nucleus carry nuclear localization signals or NLS recognized by import receptors in the cytosol. Similarly, proteins with nuclear export signals are recognized by export receptors. Import and export receptors are...
6.6K
Nuclear Export01:42

Nuclear Export

5.2K
The nucleus restricts several proteins within and allows others to pass. The restricted proteins possess a nuclear retention sequence or NRS, anchoring them to the nuclear lamins and preventing their transport to the cytosol. The non-restricted proteins, after their synthesis, are transported to their site of action, such as the cytosol or other organelles, with the help of nuclear export signals or NES.
NES are of three types- the canonical 10-residue long leucine-rich signal and other...
5.2K
Biological Clocks and Seasonal Responses02:45

Biological Clocks and Seasonal Responses

42.1K
The circadian—or biological—clock is an intrinsic, timekeeping, molecular mechanism that allows plants to coordinate physiological activities over 24-hour cycles called circadian rhythms. Photoperiodism is a collective term for the biological responses of plants to variations in the relative lengths of dark and light periods. The period of light-exposure is called the photoperiod.
42.1K

You might also read

Related Articles

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

Sort by
Same author

Clock gene signature predicts insomnia and links to sleep/circadian parameters.

Translational psychiatry·2026
Same author

Purine Metabolism Regulates the Severity of APOL1 Nephropathy.

Journal of the American Society of Nephrology : JASN·2026
Same author

Diurnal Regulation and Gene-Specific Vulnerability of Oxidative Alcohol-Metabolizing Enzymes to Circadian Disruption.

International journal of molecular sciences·2026
Same author

Sleep-dependent clearance of brain lipids by peripheral blood cells.

Nature·2026
Same author

Astrocyte FABP7 Modulates Seizure Activity-Dependent Protein Expression in Mouse Brain.

Neuroglia (Basel, Switzerland)·2025
Same author

Regulation of Metabolic Rhythms by Glial Clocks.

Journal of biological rhythms·2025

Related Experiment Video

Updated: Apr 4, 2026

In Vitro Bioluminescence Assay to Characterize Circadian Rhythm in Mammary Epithelial Cells
11:56

In Vitro Bioluminescence Assay to Characterize Circadian Rhythm in Mammary Epithelial Cells

Published on: September 28, 2017

10.5K

KPNB1 mediates PER/CRY nuclear translocation and circadian clock function.

Yool Lee1, A Reum Jang2, Lauren J Francey1

  • 1Department of Systems Pharmacology and Translational Therapeutics, Institute for Translational Medicine and Therapeutics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, United States.

Elife
|August 31, 2015
PubMed
Summary
This summary is machine-generated.

Karyopherin beta 1 (KPNB1) is essential for the circadian clock. It facilitates the nuclear entry of PER/CRY proteins, ensuring proper clock function and daily rhythms.

Keywords:
CRYD. melanogasterKPNB1PERcell biologycircadian clockevolutionary biologygenomicshumanmousenuclear entry

More Related Videos

Monitoring Cell-autonomous Circadian Clock Rhythms of Gene Expression Using Luciferase Bioluminescence Reporters
10:38

Monitoring Cell-autonomous Circadian Clock Rhythms of Gene Expression Using Luciferase Bioluminescence Reporters

Published on: September 27, 2012

23.3K
A Filtration-based Method of Preparing High-quality Nuclei from Cross-linked Skeletal Muscle for Chromatin Immunoprecipitation
10:04

A Filtration-based Method of Preparing High-quality Nuclei from Cross-linked Skeletal Muscle for Chromatin Immunoprecipitation

Published on: July 6, 2017

9.4K

Related Experiment Videos

Last Updated: Apr 4, 2026

In Vitro Bioluminescence Assay to Characterize Circadian Rhythm in Mammary Epithelial Cells
11:56

In Vitro Bioluminescence Assay to Characterize Circadian Rhythm in Mammary Epithelial Cells

Published on: September 28, 2017

10.5K
Monitoring Cell-autonomous Circadian Clock Rhythms of Gene Expression Using Luciferase Bioluminescence Reporters
10:38

Monitoring Cell-autonomous Circadian Clock Rhythms of Gene Expression Using Luciferase Bioluminescence Reporters

Published on: September 27, 2012

23.3K
A Filtration-based Method of Preparing High-quality Nuclei from Cross-linked Skeletal Muscle for Chromatin Immunoprecipitation
10:04

A Filtration-based Method of Preparing High-quality Nuclei from Cross-linked Skeletal Muscle for Chromatin Immunoprecipitation

Published on: July 6, 2017

9.4K

Area of Science:

  • Molecular Biology
  • Chronobiology
  • Cell Biology

Background:

  • The circadian clock relies on the PER/CRY repressor complex for negative feedback.
  • The exact molecular mechanisms governing PER/CRY nuclear translocation remain unclear.

Purpose of the Study:

  • To elucidate the role of KPNB1 in the nuclear import of the PER/CRY complex.
  • To understand KPNB1's mechanism in regulating circadian clock function.

Main Methods:

  • RNA interference (RNAi) to deplete KPNB1 in human cells.
  • Co-immunoprecipitation to study protein interactions.
  • Inhibition of Drosophila importin beta in lateral neurons.
  • Assessment of behavioral rhythms in flies.

Main Results:

  • KPNB1 depletion sequesters PER/CRY in the cytoplasm, blocking PER protein nuclear entry.
  • KPNB1 directly interacts with PER proteins, mediating circadian-regulated nuclear transport.
  • KPNB1 functions independently of importin alpha for PER/CRY nuclear import.
  • Inhibition of Drosophila importin beta disrupts fly behavioral rhythms.

Conclusions:

  • KPNB1 is a key mediator of PER/CRY nuclear translocation.
  • KPNB1 is crucial for the timely nuclear import of PER/CRY, essential for circadian clock regulation.
  • This mechanism is conserved across species, highlighting KPNB1's fundamental role in circadian biology.