potassium channel activating, G protein-coupled receptor signaling pathway

Definition

Target type: biologicalprocess

The series of molecular signals generated as a consequence of a G protein-coupled receptor binding to its physiological ligand, where the pathway proceeds activation of a potassium ion channel. [GOC:dos, PMID:9429760]

The potassium channel activating, G protein-coupled receptor (GPCR) signaling pathway is a complex cascade of events involving the interaction of GPCRs, G proteins, and ion channels. This pathway is critical for a wide range of physiological processes, including neuronal signaling, muscle contraction, and hormone release.

1. **Ligand Binding and Receptor Activation:** The pathway initiates when a ligand binds to a specific GPCR. Ligands can include neurotransmitters, hormones, and other signaling molecules. This binding event causes a conformational change in the GPCR, exposing a binding site for a G protein.

2. **G Protein Activation:** The activated GPCR interacts with a heterotrimeric G protein, composed of alpha, beta, and gamma subunits. This interaction promotes the exchange of GDP for GTP on the alpha subunit, leading to its dissociation from the beta-gamma dimer.

3. **Effector Activation:** The activated alpha subunit, now bound to GTP, interacts with and activates downstream effector proteins. In the case of potassium channel activation, the effector is typically a potassium channel.

4. **Potassium Channel Opening:** Activation of the potassium channel by the G protein leads to increased potassium permeability across the cell membrane. This outward potassium flow can alter the membrane potential, contributing to various physiological responses depending on the cell type.

5. **Signal Termination:** The signaling cascade is terminated by the intrinsic GTPase activity of the alpha subunit, which hydrolyzes GTP back to GDP. This hydrolysis event causes the alpha subunit to reassociate with the beta-gamma dimer, effectively deactivating the G protein and the downstream effector.

In summary, the potassium channel activating, GPCR signaling pathway involves the following steps: ligand binding to the GPCR, G protein activation, effector activation (potassium channel), potassium channel opening, and signal termination. This pathway plays a critical role in regulating cellular processes, including neuronal signaling, muscle contraction, and hormone release.'
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Proteins (1)

Compounds (4)