PSAT1: Phosphoserine Aminotransferase 1
A key enzyme in serine biosynthesis, implicated in cancer metabolism and neurological disorders.
Gene Information Card
| Symbol | PSAT1 |
|---|---|
| Full Name | phosphoserine aminotransferase 1 |
| Gene Type | protein-coding |
| Chromosomal Location | 9q21.2 |
| NCBI Gene ID | 29968 ncbi.nlm.nih.gov/gene/29968 |
| Ensembl ID | ENSG00000135069 |
| UniProt ID | Q9Y617 |
| OMIM ID | 610936 |
| HGNC ID | 19129 |
| Aliases | EPIP, PSA, PSAT, PSATD |
Description
PSAT1 encodes phosphoserine aminotransferase 1, a pyridoxal phosphate-dependent enzyme that catalyzes the second step in the phosphorylated pathway of L-serine biosynthesis, converting 3-phosphohydroxypyruvate to 3-phosphoserine. This gene is essential for cellular serine and glycine production, and its overexpression is frequently observed in various cancers, where it supports tumor growth and proliferation. Mutations in PSAT1 are associated with phosphoserine aminotransferase deficiency, a rare autosomal recessive disorder characterized by neurological symptoms.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Phosphoserine aminotransferase deficiency (PSATD) | Loss-of-function mutations impair serine biosynthesis, leading to severe neurological impairment, microcephaly, and seizures. | OMIM #610936; ClinVar |
| Breast cancer | PSAT1 overexpression promotes serine synthesis, supporting cancer cell proliferation and survival under metabolic stress. | COSMIC; PubMed studies |
| Non-small cell lung cancer | Upregulation of PSAT1 correlates with poor prognosis and increased tumor growth via serine/glycine metabolism. | COSMIC; PubMed studies |
| Colorectal cancer | PSAT1 is frequently amplified and overexpressed, contributing to metabolic reprogramming and tumorigenesis. | COSMIC; PubMed studies |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Liver | 15.2 | Medium |
| Kidney | 12.8 | Medium |
| Small intestine | 10.5 | Medium |
| Pancreas | 8.9 | Low |
| Brain | 6.3 | Low |
| Testis | 5.1 | Low |
| Lung | 4.7 | Low |
| Breast | 3.2 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HepG2 (liver) | 18.4 | High expression |
| HEK293 (embryonic kidney) | 14.1 | Moderate expression |
| A549 (lung) | 6.8 | Low expression |
| MCF7 (breast) | 5.3 | Low expression |
| K562 (leukemia) | 2.1 | Very low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.43G>A (p.Gly15Arg) | Missense | Rare | Loss of function; associated with PSATD |
| c.205C>T (p.Arg69Trp) | Missense | Rare | Loss of function; associated with PSATD |
| c.296A>G (p.Asn99Ser) | Missense | Rare | Loss of function; associated with PSATD |
| Amplification | Copy number gain | Frequent in cancers | Gain of function; increased PSAT1 expression |
Mutation functional classification
Loss of Function (LOF)
Missense mutations (e.g., p.Gly15Arg, p.Arg69Trp, p.Asn99Ser) reduce or abolish enzymatic activity, causing phosphoserine aminotransferase deficiency.
Gain of Function (GOF)
Gene amplification and overexpression in multiple cancers enhance serine biosynthesis, promoting tumor growth.
Dominant Negative (DN)
No dominant-negative mutations have been reported for PSAT1.
View complete mutation data：
Gene Ontology (GO)
| • catalytic activity (GO:0003824) | • phosphoserine aminotransferase activity (GO:0004648) |
| • L-serine biosynthetic process (GO:0006564) | • L-serine catabolic process (GO:0006565) |
| • cytoplasm (GO:0005737) | • cytosol (GO:0005829) |
| • pyridoxal phosphate binding (GO:0030170) |
Pathways
• Serine biosynthesis (phosphorylated pathway)
• Glycine
• serine and threonine metabolism (KEGG: hsa00260)
• Metabolic reprogramming in cancer (Reactome: R-HSA-71291)
Protein Summary
PSAT1 is a 370-amino acid homodimeric enzyme that uses pyridoxal phosphate as a cofactor to catalyze the transamination of 3-phosphohydroxypyruvate to 3-phosphoserine, using glutamate as the amino donor. It is localized in the cytoplasm and is highly expressed in liver and kidney. The protein plays a critical role in serine and glycine homeostasis, and its dysregulation is linked to cancer metabolism and neurological disease.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| PSAT1 Knockout HEK293 Cell Line | EDJ-KQ9108 | Human | 29968 | Details Get a Quote |
| PSAT1 Knockout HeLa Cell Line | EDJ-KQ34368 | Human | 29968 | Details Get a Quote |
| PSAT1 Knockout A-549 Cell Line | EDJ-KQ35618 | Human | 29968 | Details Get a Quote |
| PSAT1 Knockout HCT 116 Cell Line | EDJ-KQ35619 | Human | 29968 | Details Get a Quote |
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