nitric oxide storage

Definition

Target type: biologicalprocess

The accumulation and maintenance in cells or tissues of nitric oxide (NO). Nitric oxide is stored in the form of dinitrosyl-iron complexes, which are stabilized, and possibly sequestered, by binding to glutathione S-transferase proteins. [GOC:BHF, PMID:12871945]

Nitric oxide (NO) is a highly reactive and short-lived molecule that cannot be directly stored within cells. Instead, its biological effects are mediated through its rapid generation and diffusion to target cells. NO is primarily produced from the amino acid L-arginine by the enzyme nitric oxide synthase (NOS). There are three main isoforms of NOS: neuronal NOS (nNOS), endothelial NOS (eNOS), and inducible NOS (iNOS). Each isoform is regulated differently and plays a distinct role in various physiological processes.

While NO cannot be stored in its free form, there are several mechanisms by which its effects can be regulated and sustained:

1. **Regulation of NOS activity:** The activity of NOS enzymes can be regulated by various factors, including calcium influx, phosphorylation, and interactions with other proteins. This allows for rapid and localized NO production in response to specific stimuli.

2. **Formation of S-nitrosothiols (RSNOs):** NO can react with thiols, such as cysteine residues in proteins, to form S-nitrosothiols. RSNOs are considered a reservoir of NO and can release NO upon specific stimuli, prolonging its biological effects.

3. **Nitrosylation of iron-sulfur clusters:** NO can bind to iron-sulfur clusters in proteins, affecting their activity. This mechanism can act as a storage mechanism for NO and influence the function of various enzymes and signaling pathways.

4. **Formation of nitrotyrosine:** NO can react with tyrosine residues in proteins to form nitrotyrosine. This modification can alter protein function and is often associated with oxidative stress and inflammation.

In summary, NO is not stored in a specific compartment or as a stable molecule. Instead, its effects are regulated by the dynamic production and signaling mechanisms that involve the regulation of NOS activity, formation of NO-containing species like RSNOs, and the nitrosylation of target proteins. These mechanisms ensure the rapid and localized delivery of NO to its target cells and contribute to its diverse physiological roles.'
"

Proteins (1)

Compounds (10)