intracellularly cGMP-activated cation channel activity

Definition

Target type: molecularfunction

Enables the transmembrane transfer of a cation by a channel that opens when intracellular cGMP has been bound by the channel complex or one of its constituent parts. [GOC:mtg_transport]

Intracellularly cGMP-activated cation channel activity refers to the function of specific ion channels that are activated by the intracellular messenger cyclic guanosine monophosphate (cGMP). These channels are typically located on the plasma membrane or internal membranes of cells and are involved in regulating the flow of cations, such as sodium, potassium, and calcium ions, across these membranes. The activation of these channels by cGMP is a key step in various signaling pathways, ultimately leading to diverse cellular responses.

Here's a breakdown of the molecular function:

1. **cGMP Binding:** The channel protein contains a specific binding site for cGMP. When cGMP levels rise inside the cell, the molecule binds to this site.

2. **Conformational Change:** The binding of cGMP to the channel protein triggers a conformational change in the protein's structure. This change alters the shape and arrangement of the channel's pore, the passageway through which ions flow.

3. **Channel Opening:** The conformational change opens the channel pore, allowing cations to pass through the membrane. This movement of ions down their concentration gradient leads to changes in the membrane potential and intracellular ion concentrations.

4. **Cellular Response:** The influx of cations into the cell can trigger a variety of downstream events, depending on the specific type of cell and the signaling pathway involved. These responses can include:
* **Muscle contraction:** In smooth muscle cells, cGMP-activated channels contribute to relaxation.
* **Neurotransmitter release:** In neurons, these channels can play a role in synaptic transmission.
* **Cell growth and differentiation:** In some cell types, these channels are involved in regulating cell proliferation and differentiation.
* **Gene expression:** In certain cells, these channels can affect the expression of specific genes.

5. **Regulation:** The activity of cGMP-activated cation channels is tightly regulated to ensure proper cellular function. This regulation can involve:
* **cGMP production:** The intracellular concentration of cGMP is controlled by enzymes that synthesize and degrade it.
* **Channel phosphorylation:** Phosphorylation of the channel protein by kinases can modulate its activity.
* **Channel association with other proteins:** Interactions with other proteins can influence channel function.

Overall, cGMP-activated cation channel activity is a complex process that plays a crucial role in a wide variety of cellular processes. The precise function of these channels varies depending on the specific cell type and signaling pathway, but their ability to regulate ion flow makes them key players in cellular communication and response to stimuli.'
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Proteins (2)

Compounds (2)