Related Experiment Video
Updated: Aug 8, 2026
16:36
Proteomics to Identify Proteins Interacting with P2X2 Ligand-Gated Cation Channels
Published on: May 18, 2009
Biophysics of P2X receptors
Terrance M Egan1, Damien S K Samways, Zhiyuan Li
1Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, 1402 S. Grand Boulevard, St. Louis, MO 63104, USA. egantm@slu.edu
Pflugers Archiv : European Journal of Physiology
|May 19, 2006
Summary
This study reviews P2X receptor channel biophysics, focusing on ion transport and gating. Understanding these ligand-gated ion channels is key to their role in human physiology.
Area of Science:
- Biophysics
- Molecular Biology
- Human Physiology
Background:
- P2X receptors are part of the ligand-gated ion channel superfamily.
- Their precise function in human physiology and ion transport mechanisms are not fully understood.
Purpose of the Study:
- To review P2X channel biophysics, focusing on ion permeation and gating.
- To explore the structural basis of P2X channel function.
Main Methods:
- Review of existing literature on P2X channel biophysics.
- Analysis of ion transport properties of wild-type and mutant P2X receptors.
Main Results:
- P2X channels transport various cations and anions.
- Ion transport is influenced by receptor subunit composition and experimental conditions.
- Mutant receptor phenotypes provide insights into pore structure.
Conclusions:
- Further research into P2X channel biophysics is needed.
- Understanding ion permeation and gating is crucial for elucidating P2X receptor function.
- Structural modeling based on mutant phenotypes can advance knowledge of the P2X pore.
Related Concept Videos
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...
01:34ATP Driven Pumps II: P-type Pumps
The P-type pumps are a large family of integral membrane transporter ATPases. They are divided into five major types based on substrate specificity, from I to V.
A typical P-type pump has three cytosolic domains: nucleotide-binding (N), phosphorylation (P), and activator (A) domains. These domains are connected to the membrane-spanning helices by short amino acid segments. ATP hydrolysis and covalent phosphoenzyme intermediate formation are crucial parts of the catalytic cycle. At the highly...
A typical P-type pump has three cytosolic domains: nucleotide-binding (N), phosphorylation (P), and activator (A) domains. These domains are connected to the membrane-spanning helices by short amino acid segments. ATP hydrolysis and covalent phosphoenzyme intermediate formation are crucial parts of the catalytic cycle. At the highly...
01:11IP3/DAG Signaling Pathway
Membrane lipids such as phosphatidylinositol (PI) are precursors for several membrane-bound and soluble second messengers. Specific kinases phosphorylate PI and produce phosphorylated inositol phospholipids. One such inositol phospholipids are the phosphatidylinositol-4,5 bisphosphate [PI(4,5)P2], present in the inner half of the lipid bilayer. Upon ligand binding, GPCR stimulates Gq proteins to turn on phospholipase Cꞵ. Activated phospholipase Cꞵ cleaves PI(4,5)P2 and produces two-second...
01:24Non-gated Ion Channels
Ion channels are specialized proteins on the plasma membrane that allow charged ions to pass down their electrochemical gradient. Their main function is to maintain the membrane potential which is critical for cell viability. These channels are either gated or non-gated and can transport more than a thousand ions within milliseconds for the cellular event to occur.
Compared to the gated ion channels, the non-gated channels, also known as leakage or passive channels, have no gating mechanism.
Compared to the gated ion channels, the non-gated channels, also known as leakage or passive channels, have no gating mechanism.
01:15G Protein-coupled Receptors
G Protein-Coupled Receptors or GPCRs are membrane-bound receptors that transiently associate with heterotrimeric G proteins and induce an appropriate response to sensory stimuli such as light, odors, hormones, cytokines, or neurotransmitters.
GPCRs are also called heptahelical, 7TM, or serpentine receptors, and consist of seven (H1-H7) transmembrane alpha-helices that span the bilayer to form a cylindrical core. The transmembrane helices are connected by three extracellular loops and three...
GPCRs are also called heptahelical, 7TM, or serpentine receptors, and consist of seven (H1-H7) transmembrane alpha-helices that span the bilayer to form a cylindrical core. The transmembrane helices are connected by three extracellular loops and three...
01:21G-protein Coupled Receptors
G-protein coupled receptors are ligand binding receptors that indirectly affect changes in the cell. The actual receptor is a single polypeptide that transverses the cell membrane seven times creating intracellular and extracellular loops. The extracellular loops create a ligand specific pocket which binds to neurotransmitters or hormones. The intracellular loops holds onto the G-protein.