Related Experiment Video
Updated: Jun 20, 2026
11:25
Targeting Cysteine Thiols for in Vitro Site-specific Glycosylation of Recombinant Proteins
Published on: October 4, 2017
Mechanistic view on domains mediating STIM1-Orai coupling
Marc Fahrner1, Martin Muik, Isabella Derler
1Institute of Biophysics, University of Linz, Linz, Austria.
Immunological Reviews
|September 17, 2009
Summary
Store-operated calcium entry, crucial for cell functions, is mediated by STIM1 and Orai1. This review details STIM1/Orai1 interactions and the Orai1 channel
Area of Science:
- Cell Biology
- Molecular Biology
- Immunology
Background:
- Store-operated calcium (Ca2+) entry is vital for non-excitable cells, regulating transcription and growth.
- The Ca2+ release-activated Ca2+ (CRAC) current, a key store-operated current, is primarily found in T lymphocytes and mast cells.
- Stromal interaction molecule 1 (STIM1) acts as the Ca2+ sensor in the endoplasmic reticulum, while Orai1 forms the CRAC channel pore.
Purpose of the Study:
- To review the roles of STIM1 and Orai1 domains in cellular calcium influx.
- To elucidate the STIM1/Orai1 coupling mechanism.
- To provide a molecular interpretation of STIM1-Orai1 interactions and Orai1 channel function.
Main Methods:
- Review of existing literature on STIM1 and Orai1.
- Analysis of molecular interactions between STIM1 and Orai1.
- Examination of Orai1 pore mutant properties and permeation.
Main Results:
- STIM1 puncta formation upon ER store depletion triggers Orai1-mediated Ca2+ influx.
- Specific domains within STIM1 and Orai1 are critical for their coupling and function.
- The severe combined immunodeficiency (SCID)-linked Orai1 R91W mutant exhibits loss of function.
- The selectivity filter architecture of Orai channels has been elucidated.
Conclusions:
- STIM1 and Orai1 are the key molecular components of the CRAC channel.
- Understanding STIM1/Orai1 interactions provides insights into calcium signaling regulation.
- Orai1 channel architecture and function are critical for cellular calcium homeostasis.
More Related Videos
10:45Isolation of Human Myoblasts, Assessment of Myogenic Differentiation, and Store-operated Calcium Entry Measurement
Published on: July 26, 2017
14:18Fluorescence-based Measurement of Store-operated Calcium Entry in Live Cells: from Cultured Cancer Cell to Skeletal Muscle Fiber
Published on: February 13, 2012
Related Concept Videos
01:30Ligand-Gated Ion Channel Receptor: Gating Mechanism
Ligand-gated ion channels are transmembrane proteins that play a vital role in intercellular communication and functions of the nervous system. They allow the influx of ions across the membrane once the neurotransmitter binds, allowing the subsequent transmission of electrical excitation across the neurons. Other ligand-gated ion channels, like the γ-aminobutyric acid (GABA) receptor, permit anions like chloride into the cells on the binding of the GABA molecule. Their entry into the cell...
01:30Transducer Mechanism: G Protein–Coupled Receptors
G Protein–Coupled Receptors (GPCRs) are membrane-bound receptors that transiently associate with heterotrimeric G proteins and induce an appropriate response to various stimuli. GPCRs regulate critical physiological pathways and are excellent drug targets for treating diseases such as diabetes, cancer, obesity, depression, or Alzheimer's. Nearly 35% of approved drugs implement their therapeutic effects by selectively interacting with specific GPCRs.
GPCRs are also called heptahelical, 7TM, or...
GPCRs are also called heptahelical, 7TM, or...
01:30Assembly of Signaling Complexes
Multiprotein signaling complexes are formed in a dynamic process involving protein-protein interactions at the cytoplasmic domain of transmembrane receptors or enzymatic and non-enzymatic proteins associated with the receptor. These complexes ensure the activation and propagation of intracellular signals that regulate cell functions.
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
01:12Mechanically-gated Ion Channels
Mechanically-gated ion channels are proteins found in eukaryotic and prokaryotic cell membranes that open in response to mechanical stress. Tension, compression, swelling, and shear stress can alter the conformation of the protein, opening a transmembrane channel that allows the passage of ions for signal transmission. In eukaryotes, mechanically-gated channels are distributed in several regions like the neurons, lungs, skin, bladder, and heart, where they play critical roles in numerous...
01:12Mechanically-gated Ion Channels
Mechanically-gated ion channels are proteins found in eukaryotic and prokaryotic cell membranes that open in response to mechanical stress. Tension, compression, swelling, and shear stress can alter the conformation of the protein, opening a transmembrane channel that allows the passage of ions for signal transmission. In eukaryotes, mechanically-gated channels are distributed in several regions like the neurons, lungs, skin, bladder, and heart, where they play critical roles in numerous...
01:27Transducer Mechanism: Enzyme-Linked Receptors
Enzyme-linked receptors are cell-surface receptors acting as an enzyme or associating with an enzyme intracellularly. They make excellent drug targets. Drugs can bind to the extracellular ligand-binding domain or directly affect their enzymatic domain and alter their activity.
Major types that are helpful drug targets include:
Major types that are helpful drug targets include: