Target type: molecularfunction
Any gap junction channel activity that is involved in cell communication by electrical coupling. [GO_REF:0000061, GOC:BHF, GOC:mtg_cardiac_conduct_nov11, GOC:rl, GOC:TermGenie, PMID:24587307]
Gap junction channels, formed by the close apposition of connexin proteins from adjacent cells, are specialized membrane channels that enable direct intercellular communication by allowing the passage of ions and small molecules. This process, known as electrical coupling, facilitates rapid and synchronized signaling between cells. The molecular function of gap junction channel activity in cell communication by electrical coupling can be described in detail as follows:
1. **Connexin protein assembly and channel formation:** Gap junction channels are composed of connexin proteins, which assemble into hexameric structures called connexons. Two connexons from adjacent cells align to form a channel that spans the intercellular space.
2. **Selective permeability:** Gap junction channels exhibit size and charge selectivity, allowing the passage of small molecules, such as ions (e.g., Na+, K+, Ca2+), metabolites (e.g., glucose, amino acids), and second messengers (e.g., cAMP, IP3).
3. **Electrical signal propagation:** The passage of ions through gap junction channels creates an electrical connection between cells, allowing the rapid spread of electrical signals, such as action potentials. This direct communication enables synchronized activity among connected cells, playing a critical role in various physiological processes, including:
* **Cardiac muscle contraction:** Gap junctions in the heart allow the coordinated spread of electrical signals, ensuring synchronized contraction of cardiomyocytes and efficient blood pumping.
* **Smooth muscle contraction:** Electrical coupling through gap junctions enables the coordinated contraction of smooth muscle cells, regulating functions such as blood vessel constriction and gastrointestinal motility.
* **Neural signaling:** Gap junctions in the brain allow for the rapid propagation of electrical signals between neurons, contributing to neuronal network activity and information processing.
4. **Metabolic coupling:** The passage of metabolites through gap junction channels facilitates the exchange of nutrients and energy between cells, contributing to cellular homeostasis and tissue function.
5. **Regulation of channel activity:** Gap junction channel activity can be regulated by various factors, including intracellular Ca2+ concentration, pH, and phosphorylation. These mechanisms ensure appropriate and controlled intercellular communication.
6. **Role in development and disease:** Gap junction channels play crucial roles in development and tissue homeostasis. Dysregulation of gap junction channel activity is implicated in various diseases, such as heart disease, cancer, and neurodevelopmental disorders.'
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Protein | Definition | Taxonomy |
---|---|---|
Gap junction beta-2 protein | A gap junction beta-2 protein that is encoded in the genome of human. [PRO:DNx] | Homo sapiens (human) |
Gap junction alpha-1 protein | A gap junction alpha-1 protein that is encoded in the genome of human. [PRO:DNx, UniProtKB:P17302] | Homo sapiens (human) |
Compound | Definition | Classes | Roles |
---|---|---|---|
kanamycin a | kanamycin : Kanamycin is a naturally occurring antibiotic complex from Streptomyces kanamyceticus that consists of several components: kanamycin A, the major component (also usually designated as kanamycin), and kanamycins B, C, D and X the minor components. Kanamycin: Antibiotic complex produced by Streptomyces kanamyceticus from Japanese soil. Comprises 3 components: kanamycin A, the major component, and kanamycins B and C, the minor components. | kanamycins | bacterial metabolite |