quinolinate metabolic process

Definition

Target type: biologicalprocess

The chemical reactions and pathways involving quinolinate, the anion of quinolinic acid, also known as 2,3-pyridinedicarboxylic acid. [GOC:ai]

Quinolinate metabolism is a complex and essential process in the body, primarily involving the synthesis and degradation of quinolinate, a precursor to NAD+. NAD+ (nicotinamide adenine dinucleotide) is a vital coenzyme involved in numerous metabolic reactions, including energy production, DNA repair, and cellular signaling.

The synthesis of quinolinate begins with the amino acid tryptophan. Tryptophan is first converted to kynurenine through the action of the enzyme tryptophan 2,3-dioxygenase (TDO) or indoleamine 2,3-dioxygenase (IDO). Kynurenine is then metabolized through a series of enzymatic steps, involving enzymes like kynurenine 3-monooxygenase (KMO) and kynurenine aminotransferase (KAT), leading to the formation of quinolinate.

The degradation of quinolinate is also a multi-step process. Quinolinate can be further metabolized to NAD+ through the action of the enzyme quinolinate phosphoribosyltransferase (QPRT). This pathway is essential for NAD+ biosynthesis. However, quinolinate can also be degraded via the kynurenine pathway, where it is converted to nicotinate and then to NAD+.

Disruptions in quinolinate metabolism are linked to various pathological conditions. Elevated levels of quinolinate have been implicated in neurodegenerative diseases like Alzheimer's and Parkinson's. Furthermore, dysregulation of quinolinate metabolism is associated with autoimmune disorders, cancer, and inflammatory conditions.

The intricate process of quinolinate metabolism plays a critical role in cellular homeostasis, impacting energy production, redox balance, and overall cell function. Further understanding of this pathway is crucial for developing therapeutic strategies for various diseases.'
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Proteins (1)

Compounds (1)