monoatomic ion channel complex

Definition

Target type: cellularcomponent

A protein complex that spans a membrane and forms a water-filled channel across the phospholipid bilayer allowing selective monoatomic ion transport down its electrochemical gradient. [GOC:mah, ISBN:071673706X]

A monoatomic ion channel complex is a specialized cellular structure that facilitates the selective and controlled passage of single ions across cell membranes. These complexes are typically formed by transmembrane proteins that assemble into intricate structures, creating a pore through which ions can flow. The key components of this structure are as follows:

1. **Pore Domain:** This is the central component of the channel, forming the pathway through which ions traverse the membrane. The pore is highly selective, allowing only specific ions to pass, such as sodium (Na+), potassium (K+), calcium (Ca2+), or chloride (Cl-).

2. **Selectivity Filter:** Located within the pore domain, this region determines the specificity of the channel. It's composed of amino acid residues that interact with ions based on their charge, size, and hydration shell. This interaction ensures that only the appropriate ions can pass through.

3. **Gating Mechanism:** This mechanism controls the opening and closing of the pore, regulating ion flow across the membrane. Gating can be triggered by various factors, including voltage changes, ligand binding, or mechanical forces.

4. **Transmembrane Domains:** These regions of the channel proteins span the cell membrane, anchoring the complex within the lipid bilayer. They are often composed of alpha helices that interact with the surrounding lipids, ensuring stability and structural integrity.

5. **Cytosolic and Extracellular Domains:** These domains extend into the cytoplasm and extracellular space, respectively. They often play a role in signal transduction, mediating interactions with other cellular components or external stimuli.

The cellular component of a monoatomic ion channel complex is essential for maintaining cell homeostasis, regulating membrane potential, and facilitating signal transduction. It's a highly dynamic and complex structure, with its function tightly controlled by various factors. Understanding the organization and function of this complex is crucial for understanding cellular physiology and developing therapeutic strategies targeting ion channel dysfunction.'
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Proteins (9)

Compounds (44)