adenosine biosynthetic process

Definition

Target type: biologicalprocess

The chemical reactions and pathways resulting in the formation of adenosine, adenine riboside, a ribonucleoside found widely distributed in cells of every type as the free nucleoside and in combination in nucleic acids and various nucleoside coenzymes. [GOC:go_curators]

Adenosine biosynthesis is the process by which the nucleoside adenosine is synthesized from its precursor, inosine monophosphate (IMP). This process is crucial for the production of ATP, a vital energy carrier in cells, as well as other essential molecules like cAMP and NAD.

**The process can be broadly divided into three key steps:**

1. **IMP synthesis:** IMP is synthesized via the purine nucleotide biosynthesis pathway. This pathway involves a series of complex enzymatic reactions that utilize amino acids like glycine, glutamine, aspartate, and formate as building blocks.
2. **IMP conversion to AMP:** IMP is converted to AMP (adenosine monophosphate) by the enzyme adenylosuccinate synthetase. This reaction involves the addition of aspartate to IMP, followed by the release of fumarate, resulting in AMP.
3. **Phosphorylation to ADP and ATP:** AMP is subsequently phosphorylated to ADP (adenosine diphosphate) by the enzyme adenylate kinase, utilizing ATP as the phosphate donor. Further phosphorylation of ADP by ATP synthase, using energy derived from oxidative phosphorylation or other metabolic processes, generates ATP.

**The adenosine biosynthetic process is tightly regulated to ensure the proper balance of purine nucleotides within the cell. This regulation occurs at multiple levels, including:**

* **Feedback inhibition:** The end product of the pathway, AMP, can inhibit key enzymes involved in the earlier stages of the pathway, such as IMP dehydrogenase and adenylosuccinate synthetase.
* **Allosteric regulation:** The availability of other nucleotides, like GTP and ATP, can also influence the activity of enzymes involved in the pathway.
* **Transcriptional regulation:** The expression of genes encoding enzymes involved in adenosine biosynthesis can be regulated by various factors, including the availability of nutrients and cellular growth signals.

**In addition to its role in ATP production, adenosine is involved in a range of other cellular processes, including:**

* **Signaling:** Adenosine acts as a neurotransmitter and neuromodulator, influencing processes like sleep, cognition, and pain perception.
* **Immune regulation:** Adenosine plays a role in modulating immune cell function and suppressing inflammation.
* **Cell growth and development:** Adenosine is involved in the regulation of cell proliferation and differentiation.

Dysregulation of adenosine biosynthesis can lead to various pathological conditions, including genetic disorders that affect purine metabolism, autoimmune diseases, and cancer.'
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Proteins (1)

Compounds (16)