25oligoadenylate

25oligoadenylate (2-5A) is a short, double-stranded RNA molecule that plays a crucial role in the innate immune response of eukaryotic cells. It is synthesized by the enzyme 2-5 oligoadenylate synthetase (2-5A synthetase) in response to viral infection or other stressors. The synthesis of 2-5A involves the polymerization of adenosine monophosphate (AMP) residues, resulting in a linear polymer with a 2',5' phosphodiester linkage.

2-5A acts as a second messenger in the innate immune response by activating latent ribonucleases, such as RNase L, which are crucial for the degradation of viral RNA. This process helps to limit viral replication and spread within the host cell. Additionally, 2-5A can inhibit protein synthesis by activating latent endonucleases, which cleave mRNA, thereby preventing the production of viral proteins.

The production of 2-5A is tightly regulated to avoid unnecessary activation of the innate immune response, which could lead to collateral damage to the host cell. The degradation of 2-5A by the enzyme 2-5 oligoadenylate phosphodiesterase (2-5A phosphodiesterase) is essential for the termination of the immune response and the restoration of normal cellular functions.

2-5A has also been studied for its potential therapeutic applications, particularly in the treatment of viral infections. However, the use of 2-5A as a therapeutic agent is limited by its short half-life and the potential for off-target effects. Ongoing research aims to develop more stable and selective analogs of 2-5A for potential use in antiviral therapies.