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

Activation Energy01:26

Activation Energy

83.1K
Activation energy is the minimum amount of energy necessary for a chemical reaction to move forward. The higher the activation energy, the slower the rate of the reaction. However, adding heat to the reaction will increase the rate, since it causes molecules to move faster and increase the likelihood that molecules will collide. The collision and breaking of bonds represents the uphill phase of a reaction and generates the transition state. The transition state is an unstable high-energy state...
83.1K
Amplifying Signals via Enzymatic Cascade01:22

Amplifying Signals via Enzymatic Cascade

12.9K
When a ligand binds to a cell-surface receptor, the receptor's intracellular domain changes shape, which may either activate its enzyme function or allow its binding to other molecules. The initial signal is amplified by most signal transduction pathways. This means that a single ligand molecule can activate multiple molecules of a downstream target. Proteins that relay a signal are most commonly phosphorylated at one or more sites, activating or inactivating the protein. Kinases catalyze...
12.9K
Activation of Integrins01:15

Activation of Integrins

3.7K
Integrins bind ligands and transmit information from outside the cell to inside or vice-versa through an "outside-in signaling" or "inside-out signaling."
In "outside-in signaling," external factors in the extracellular space bind to exposed ligand binding sites on integrins. This causes the inactive protein to undergo a conformational change to become active. Integrins are often clustered on the cell membrane. Repetitive and regularly spaced ligand binding...
3.7K
Accelerators01:17

Accelerators

114
Accelerators in concrete serve as admixtures to speed up the hardening process, enabling the concrete to achieve early strength faster. Although accelerators do not necessarily impact the time it takes concrete to set, they reduce this time in practice. A common accelerator is calcium chloride, which is particularly useful for hastening early strength development in cold weather or for rapid repair jobs that require quick heat generation after mixing.
The effectiveness of calcium chloride can...
114
Maximum Power Transfer01:16

Maximum Power Transfer

481
Numerous practical applications within engineering disciplines, such as telecommunications, necessitate optimizing power delivery to a connected load. This pursuit, however, entails inherent internal losses, which can either equal or exceed the power supplied to the load. The Thevenin equivalent circuit is helpful in finding the maximum power a linear circuit can deliver to a load. It is assumed in this context that the load resistance can be adjusted.
By substituting the entire circuit with...
481
tRNA Activation02:26

tRNA Activation

20.4K
Aminoacyl-tRNA synthetases are present in both eukaryotes and bacteria. Though eukaryotes have 20 different aminoacyl-tRNA synthetases to couple to 20 amino acids, many bacteria do not have genes for all of these aminoacyl-tRNA synthetases. Despite this, they still use all 20 amino acids to synthesize their proteins. For instance, some bacteria do not have the gene encoding the enzyme that couples glutamine with its partner tRNA. In these organisms, one enzyme adds glutamic acid to all of the...
20.4K

You might also read

Related Articles

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

Sort by
Same author

Evolutionarily conserved hydrophobicity and sterics in TM3/TM4 balance Orai1 pore opening.

Protein science : a publication of the Protein Society·2026
Same author

STIM1 GoF Mutants: Genotype-Phenotype Relationships Across the Stormorken/TAM/YPS Spectrum.

Cells·2026
Same author

Iontronic click-to-release enables electrically controlled delivery of drugs and biomolecules beyond charge and size limitations.

Nature communications·2026
Same author

Mechanistic insights into Orai dynamics during pore opening.

Channels (Austin, Tex.)·2026
Same author

Distances and charges along the Orai1 nexus-TM3 interface control STIM1 binding and pore opening.

Cell reports·2026
Same author

Quantitative Mapping of the Lipid Nanoenvironment around Transmembrane Proteins in Living Cells.

ACS nano·2026

Related Experiment Video

Updated: Oct 9, 2025

Western Blotting Using the Invitrogen NuPage Novex Bis Tris MiniGels
22:45

Western Blotting Using the Invitrogen NuPage Novex Bis Tris MiniGels

Published on: August 22, 2007

37.9K

Orai1 Boosts SK3 Channel Activation.

Adéla Tiffner1, Valentina Hopl1, Romana Schober1,2

  • 1JKU Life Science Center, Institute of Biophysics, Johannes Kepler University Linz, A-4020 Linz, Austria.

Cancers
|December 24, 2021
PubMed
Summary

The calcium-sensitive potassium channel SK3 and the calcium channel Orai1 interact to enhance SK3 currents, a mechanism crucial for cancer cell proliferation. This study reveals how Orai1 modulates SK3 activity, offering insights into cancer progression.

Keywords:
CRAC channelCa2+ activated K+ ion channelsLNCaP cellsOrai1SK channelsSK3STIM1calmodulin

More Related Videos

Spatiotemporal Control of Protein Activity through Optogenetic Allosteric Regulation
08:00

Spatiotemporal Control of Protein Activity through Optogenetic Allosteric Regulation

Published on: October 4, 2024

746
Isolation of Human Myoblasts, Assessment of Myogenic Differentiation, and Store-operated Calcium Entry Measurement
10:45

Isolation of Human Myoblasts, Assessment of Myogenic Differentiation, and Store-operated Calcium Entry Measurement

Published on: July 26, 2017

10.3K

Related Experiment Videos

Last Updated: Oct 9, 2025

Western Blotting Using the Invitrogen NuPage Novex Bis Tris MiniGels
22:45

Western Blotting Using the Invitrogen NuPage Novex Bis Tris MiniGels

Published on: August 22, 2007

37.9K
Spatiotemporal Control of Protein Activity through Optogenetic Allosteric Regulation
08:00

Spatiotemporal Control of Protein Activity through Optogenetic Allosteric Regulation

Published on: October 4, 2024

746
Isolation of Human Myoblasts, Assessment of Myogenic Differentiation, and Store-operated Calcium Entry Measurement
10:45

Isolation of Human Myoblasts, Assessment of Myogenic Differentiation, and Store-operated Calcium Entry Measurement

Published on: July 26, 2017

10.3K

Area of Science:

  • Ion channel biology
  • Molecular cell biology
  • Cancer research

Background:

  • The interaction between SK3 (a Ca2+-sensitive K+ channel) and Orai1 (a Ca2+ channel) is known to increase cytosolic Ca2+ levels, promoting cancer cell proliferation.
  • The precise molecular mechanisms underlying this interplay and its effect on SK3 channel activity have remained unclear.

Purpose of the Study:

  • To elucidate the molecular mechanism by which Orai1 modulates SK3 channel activity.
  • To investigate the role of STIM1 in the regulation of the SK3-Orai1 interaction.
  • To explore the functional relevance of this interplay in cancer cells.

Main Methods:

  • Heterologous protein expression systems were used to study SK3 and Orai1 interactions.
  • Electrophysiological recordings were performed to measure SK3 K+ currents.
  • Site-directed mutagenesis and co-localization studies were employed to map interaction sites and assess STIM1's role.
  • Experiments were conducted in human prostate cancer cell line LNCaP.

Main Results:

  • Orai1 potentiates SK3 K+ currents, particularly at low cytosolic Ca2+ levels, through close co-localization.
  • Orai1 can restore SK3 channel activity impaired by calmodulin mutants, suggesting interaction at the SK3-CaM binding site.
  • Cytosolic strands and pore residues of Orai1 are critical for functional communication with SK3.
  • STIM1 exhibits a bimodal regulatory role, impeding the SK3-Orai1 interplay under physiological conditions but promoting it upon forced activation.
  • Orai1 dynamically enhances endogenous SK3 channels in LNCaP cells.

Conclusions:

  • Orai1 enhances SK3 channel activity via a positive feedback mechanism, driven by their co-localization and interplay.
  • Specific regions of Orai1 are essential for its functional interaction with SK3.
  • STIM1 dynamically regulates the SK3-Orai1 complex, influencing SK3 currents.
  • The findings provide a molecular basis for the SK3-Orai1 interplay in cancer cell physiology and suggest potential therapeutic targets.