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Details on Person UniProt:Q9Y617 PSAT1

Class:IdReferenceGeneProduct:64336
_chainChangeLogchain:1-370 added on Fri February 6 2015
_displayNameUniProt:Q9Y617 PSAT1
_timestamp2026-02-20 22:49:03
chainchain:1-370
checksumBAF9A10E71B165B4
commentFUNCTION Involved in L-serine biosynthesis via the phosphorylated pathway, a three-step pathway converting the glycolytic intermediate 3-phospho-D-glycerate into L-serine (PubMed:36851825, PubMed:37627284). Catalyzes the second step, that is the pyridoxal 5'-phosphate-dependent transamination of 3-phosphohydroxypyruvate and L-glutamate to O-phosphoserine (OPS) and alpha-ketoglutarate (PubMed:36851825, PubMed:37627284). Acts as an inhibitor of ferroptosis in response to interferon-gamma (IFNG) by promoting GPX4 stability: following phosphorylation by CAMK2A, PSAT1 interacts with GPX4 and provides 2-oxoglutarate to EGLN3, leading to GPX4 hydroxylation and stability (PubMed:40281343).CATALYTIC ACTIVITY O-phospho-L-serine + 2-oxoglutarate = 3-phosphooxypyruvate + L-glutamateCOFACTOR Binds 2 pyridoxal phosphate molecules per dimer, each cofactor is bound at the monomer-monomer interface and forms contacts with residues from both chains.ACTIVITY REGULATION Phosphoserine transaminase activity is strongly stimulated by increasing the ionic strength.BIOPHYSICOCHEMICAL PROPERTIES kcat is 23.8 sec (-1) for the transaminase reaction with 3-phosphooxypyruvate and L-glutamate as substrates. kcat is 8.6 sec (-1) for the transaminase reaction with 2-oxoglutarate and O-phospho-L-serine as substrates.PATHWAY Amino-acid biosynthesis; L-serine biosynthesis; L-serine from 3-phospho-D-glycerate: step 2/3.SUBUNIT Homodimer.ALTERNATIVE PRODUCTS Expressed at high levels in the brain, liver, kidney and pancreas, and very weakly expressed in the thymus, prostate, testis and colon.PTM Phosphorylated at Ser-337 by CAMK2A in response to interferon-gamma (IFNG), promoting interaction with GPX4 and GPX4 hydroxylation by EGLN3.DISEASE The disease is caused by variants affecting the gene represented in this entry.DISEASE The disease is caused by variants affecting the gene represented in this entry.SIMILARITY Belongs to the class-V pyridoxal-phosphate-dependent aminotransferase family. SerC subfamily.
descriptionrecommendedName: fullName evidence="14"Phosphoserine aminotransferase ecNumber evidence="7 8"2.6.1.52 alternativeName: Phosphohydroxythreonine aminotransferase shortName: PSAT
geneNamePSAT1
PSA
identifierQ9Y617
isSequenceChangedFALSE
keyword3D-structure
Acetylation
Alternative splicing
Amino-acid biosynthesis
Aminotransferase
Disease variant
Phosphoprotein
Proteomics identification
Pyridoxal phosphate
Reference proteome
Serine biosynthesis
Transferase
modified[InstanceEdit:9836292] Weiser, Joel, 2023-05-25
[InstanceEdit:9852000] Weiser, Joel, 2023-11-03
[InstanceEdit:9862192] Weiser, Joel, 2024-02-26
[InstanceEdit:9926675] Weiser, Joel, 2024-11-03
[InstanceEdit:9939033] Weiser, Joel, 2025-02-21
[InstanceEdit:9983091] Weiser, Joel, 2026-02-20
namePSAT1
referenceDatabase[ReferenceDatabase:2] UniProt
referenceGene[ReferenceDNASequence:8960212] ENSEMBL:ENSG00000135069 PSAT1 [Homo sapiens]
secondaryIdentifierSERC_HUMAN
Q5T7G5
Q5T7G6
Q96AW2
Q9BQ12
sequenceLength370
species[Species:48887] Homo sapiens
(isoformParent)[ReferenceIsoform:153724] UniProt:Q9Y617-2 PSAT1 [Homo sapiens]
[ReferenceIsoform:416106] UniProt:Q9Y617-1 PSAT1 [Homo sapiens]
(referenceEntity)[EntityWithAccessionedSequence:977330] PXLP-K200-PSAT1 [cytosol] [Homo sapiens]
[EntityWithAccessionedSequence:8960703] PSAT1 [extracellular region] [Homo sapiens]
(referenceSequence)[ModifiedResidue:9644718] N6-pyridoxal phosphate-L-lysine at 200
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No pathways have been reviewed or authored by UniProt:Q9Y617 PSAT1 (64336)