serine family amino acid metabolic process

Definition

Target type: biologicalprocess

The chemical reactions and pathways involving amino acids of the serine family, comprising cysteine, glycine, homoserine, selenocysteine and serine. [GOC:ai]

The serine family amino acid metabolic process is a fundamental pathway in biology, responsible for the synthesis, breakdown, and interconversion of serine, glycine, and cysteine, which are essential for various cellular functions. This process involves multiple enzymatic reactions and is tightly regulated to maintain cellular homeostasis.

**Serine biosynthesis:**

* **3-phosphoglycerate dehydrogenase (PHGDH)** catalyzes the first committed step, converting 3-phosphoglycerate to 3-phosphohydroxypyruvate.
* **Phosphoserine aminotransferase (PSAT1)** then converts 3-phosphohydroxypyruvate to phosphoserine.
* **Phosphoserine phosphatase (PSPH)** dephosphorylates phosphoserine to yield serine.

**Glycine biosynthesis:**

* **Serine hydroxymethyltransferase (SHMT)** converts serine to glycine, transferring a one-carbon unit to tetrahydrofolate.
* **Glycine cleavage system (GCS)** is a multienzyme complex that degrades glycine to carbon dioxide, ammonia, and a one-carbon unit.

**Cysteine biosynthesis:**

* **Cystathionine beta-synthase (CBS)** catalyzes the condensation of serine with homocysteine to form cystathionine.
* **Cystathionine gamma-lyase (CSE)** cleaves cystathionine to yield cysteine and alpha-ketobutyrate.

**Metabolic regulation:**

* The serine family amino acid metabolic process is tightly regulated by the availability of substrates, cofactors, and allosteric effectors.
* Feedback mechanisms control the activity of key enzymes, ensuring the appropriate levels of these amino acids are maintained.
* Transcriptional and post-translational modifications also play a role in regulating the expression and activity of enzymes involved in this pathway.

**Cellular functions:**

* Serine is a precursor for various molecules, including sphingolipids, purines, and pyrimidines.
* Glycine is involved in collagen synthesis, glutathione metabolism, and neurotransmission.
* Cysteine is a component of proteins and serves as a precursor for glutathione, a major antioxidant.

**Clinical relevance:**

* Dysregulation of the serine family amino acid metabolic process is associated with various diseases, including cancer, neurodevelopmental disorders, and metabolic disorders.
* Mutations in genes encoding enzymes involved in this pathway can lead to specific metabolic disorders, such as serine deficiency and hyperglycinemia.

Overall, the serine family amino acid metabolic process is essential for maintaining cellular homeostasis and plays a critical role in various physiological processes.'
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Proteins (2)

Compounds (10)