P35558 · PCKGC_HUMAN
- ProteinPhosphoenolpyruvate carboxykinase, cytosolic [GTP]
- GenePCK1
- StatusUniProtKB reviewed (Swiss-Prot)
- Organism
- Amino acids622 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Cytosolic phosphoenolpyruvate carboxykinase that catalyzes the reversible decarboxylation and phosphorylation of oxaloacetate (OAA) and acts as the rate-limiting enzyme in gluconeogenesis (PubMed:24863970, PubMed:26971250, PubMed:28216384, PubMed:30193097).
Regulates cataplerosis and anaplerosis, the processes that control the levels of metabolic intermediates in the citric acid cycle (PubMed:24863970, PubMed:26971250, PubMed:28216384, PubMed:30193097).
At low glucose levels, it catalyzes the cataplerotic conversion of oxaloacetate to phosphoenolpyruvate (PEP), the rate-limiting step in the metabolic pathway that produces glucose from lactate and other precursors derived from the citric acid cycle (PubMed:30193097).
At high glucose levels, it catalyzes the anaplerotic conversion of phosphoenolpyruvate to oxaloacetate (PubMed:30193097).
Acts as a regulator of formation and maintenance of memory CD8+ T-cells: up-regulated in these cells, where it generates phosphoenolpyruvate, via gluconeogenesis (By similarity).
The resultant phosphoenolpyruvate flows to glycogen and pentose phosphate pathway, which is essential for memory CD8+ T-cells homeostasis (By similarity).
In addition to the phosphoenolpyruvate carboxykinase activity, also acts as a protein kinase when phosphorylated at Ser-90: phosphorylation at Ser-90 by AKT1 reduces the binding affinity to oxaloacetate and promotes an atypical serine protein kinase activity using GTP as donor (PubMed:32322062).
The protein kinase activity regulates lipogenesis: upon phosphorylation at Ser-90, translocates to the endoplasmic reticulum and catalyzes phosphorylation of INSIG proteins (INSIG1 and INSIG2), thereby disrupting the interaction between INSIG proteins and SCAP and promoting nuclear translocation of SREBP proteins (SREBF1/SREBP1 or SREBF2/SREBP2) and subsequent transcription of downstream lipogenesis-related genes (PubMed:32322062).
Regulates cataplerosis and anaplerosis, the processes that control the levels of metabolic intermediates in the citric acid cycle (PubMed:24863970, PubMed:26971250, PubMed:28216384, PubMed:30193097).
At low glucose levels, it catalyzes the cataplerotic conversion of oxaloacetate to phosphoenolpyruvate (PEP), the rate-limiting step in the metabolic pathway that produces glucose from lactate and other precursors derived from the citric acid cycle (PubMed:30193097).
At high glucose levels, it catalyzes the anaplerotic conversion of phosphoenolpyruvate to oxaloacetate (PubMed:30193097).
Acts as a regulator of formation and maintenance of memory CD8+ T-cells: up-regulated in these cells, where it generates phosphoenolpyruvate, via gluconeogenesis (By similarity).
The resultant phosphoenolpyruvate flows to glycogen and pentose phosphate pathway, which is essential for memory CD8+ T-cells homeostasis (By similarity).
In addition to the phosphoenolpyruvate carboxykinase activity, also acts as a protein kinase when phosphorylated at Ser-90: phosphorylation at Ser-90 by AKT1 reduces the binding affinity to oxaloacetate and promotes an atypical serine protein kinase activity using GTP as donor (PubMed:32322062).
The protein kinase activity regulates lipogenesis: upon phosphorylation at Ser-90, translocates to the endoplasmic reticulum and catalyzes phosphorylation of INSIG proteins (INSIG1 and INSIG2), thereby disrupting the interaction between INSIG proteins and SCAP and promoting nuclear translocation of SREBP proteins (SREBF1/SREBP1 or SREBF2/SREBP2) and subsequent transcription of downstream lipogenesis-related genes (PubMed:32322062).
Miscellaneous
In eukaryotes there are two isozymes: a cytoplasmic one and a mitochondrial one.
Catalytic activity
- GTP + oxaloacetate = CO2 + GDP + phosphoenolpyruvateThis reaction proceeds in the forward and the backward directions.
- GTP + L-seryl-[protein] = GDP + H+ + O-phospho-L-seryl-[protein]This reaction proceeds in the forward direction.
Cofactor
Note: Binds 1 Mn2+ ion per subunit.
Activity regulation
Phosphoenolpyruvate carboxykinase activity is regulated by acetylation and glucose levels (PubMed:20167786, PubMed:30193097).
The anaplerotic conversion of phosphoenolpyruvate to oxaloacetate is improved by PCK1 acetylation on Lys-91 (K91ac), Lys-473 (K473ac) and Lys-521 (K521ac) (By similarity).
High glucose concentrations favor PCK1 anaplerotic activity by triggering acetylation on Lys-91 (K91ac). At low glucose levels, SIRT1-mediated deacetylation of Lys-91 promotes the cataplerotic conversion of oxaloacetate to phosphoenolpyruvate (PubMed:30193097).
Phosphorylation at Ser-90 reduces the binding affinity to oxaloacetate and converts the enzyme into an atypical protein kinase using GTP as donor (PubMed:32322062).
The anaplerotic conversion of phosphoenolpyruvate to oxaloacetate is improved by PCK1 acetylation on Lys-91 (K91ac), Lys-473 (K473ac) and Lys-521 (K521ac) (By similarity).
High glucose concentrations favor PCK1 anaplerotic activity by triggering acetylation on Lys-91 (K91ac). At low glucose levels, SIRT1-mediated deacetylation of Lys-91 promotes the cataplerotic conversion of oxaloacetate to phosphoenolpyruvate (PubMed:30193097).
Phosphorylation at Ser-90 reduces the binding affinity to oxaloacetate and converts the enzyme into an atypical protein kinase using GTP as donor (PubMed:32322062).
Kinetics
KM | SUBSTRATE | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|---|
35 μM | oxaloacetate (for the enzyme purified from cells exposed to 10 mM glucose) | |||||
46 μM | oxaloacetate (for the enzyme purified from cells exposed to 15 mM glucose) | |||||
170 μM | GTP (for the enzyme purified from cells exposed to 10 mM glucose) | |||||
151 μM | GTP (for the enzyme purified from cells exposed to 15 mM glucose) | |||||
208 μM | phosphoenolpyruvate (for the enzyme purified from cells exposed to 10 mM glucose) | |||||
87 μM | phosphoenolpyruvate (for the enzyme purified from cells exposed to 15 mM glucose) | |||||
63 μM | GDP (for the enzyme purified from cells exposed to 10 mM glucose) | |||||
29 μM | GDP (for the enzyme purified from cells exposed to 15 mM glucose) | |||||
1.15 mM | GTP | in a protein kinase activity assay when not phosphorylated Ser-90 | ||||
0.21 mM | GTP | in a protein kinase activity assay when using a phosphomimetic mutant Ser-90 |
kcat is 33 sec-1 with oxaloacetate as substrate (for the enzyme purified from cells exposed to 10 mM glucose) (PubMed:30193097).
kcat is 21 sec-1 with oxaloacetate as substrate (for the enzyme purified from cells exposed to 15 mM glucose) (PubMed:30193097).
kcat is 17 sec-1 with phosphoenolpyruvate as substrate (for the enzyme purified from cells exposed to 10 mM glucose) (PubMed:30193097).
kcat is 11 sec-1with phosphoenolpyruvate as substrate (for the enzyme purified from cells exposed to 15 mM glucose) (PubMed:30193097).
kcat is 40 sec-1 with GTP as substrate (for the enzyme purified from cells exposed to 10 mM glucose) (PubMed:30193097).
kcat is 22 sec-1 with GTP as substrate (for the enzyme purified from cells exposed to 15 mM glucose) (PubMed:30193097).
kcat is 16 sec-1 with GDP as substrate (for the enzyme purified from cells exposed to 10 mM glucose) (PubMed:30193097).
kcat is 11 sec-1 with GDP as substrate (for the enzyme purified from cells exposed to 15 mM glucose) (PubMed:30193097).
kcat is 21 sec-1 with oxaloacetate as substrate (for the enzyme purified from cells exposed to 15 mM glucose) (PubMed:30193097).
kcat is 17 sec-1 with phosphoenolpyruvate as substrate (for the enzyme purified from cells exposed to 10 mM glucose) (PubMed:30193097).
kcat is 11 sec-1with phosphoenolpyruvate as substrate (for the enzyme purified from cells exposed to 15 mM glucose) (PubMed:30193097).
kcat is 40 sec-1 with GTP as substrate (for the enzyme purified from cells exposed to 10 mM glucose) (PubMed:30193097).
kcat is 22 sec-1 with GTP as substrate (for the enzyme purified from cells exposed to 15 mM glucose) (PubMed:30193097).
kcat is 16 sec-1 with GDP as substrate (for the enzyme purified from cells exposed to 10 mM glucose) (PubMed:30193097).
kcat is 11 sec-1 with GDP as substrate (for the enzyme purified from cells exposed to 15 mM glucose) (PubMed:30193097).
Pathway
Carbohydrate biosynthesis; gluconeogenesis.
Features
Showing features for binding site, active site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Binding site | 87 | substrate | ||||
Sequence: R | ||||||
Binding site | 235-237 | substrate | ||||
Sequence: YGG | ||||||
Binding site | 244 | Mn2+ (UniProtKB | ChEBI) | ||||
Sequence: K | ||||||
Binding site | 264 | Mn2+ (UniProtKB | ChEBI) | ||||
Sequence: H | ||||||
Binding site | 286 | substrate | ||||
Sequence: S | ||||||
Binding site | 287-292 | GTP (UniProtKB | ChEBI) | ||||
Sequence: ACGKTN | ||||||
Active site | 288 | |||||
Sequence: C | ||||||
Binding site | 311 | Mn2+ (UniProtKB | ChEBI) | ||||
Sequence: D | ||||||
Binding site | 403-405 | substrate | ||||
Sequence: NSR | ||||||
Binding site | 405 | GTP (UniProtKB | ChEBI) | ||||
Sequence: R | ||||||
Binding site | 436 | GTP (UniProtKB | ChEBI) | ||||
Sequence: R | ||||||
Binding site | 530-533 | GTP (UniProtKB | ChEBI) | ||||
Sequence: FGEN |
GO annotations
Keywords
- Molecular function
- Biological process
- Ligand
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended namePhosphoenolpyruvate carboxykinase, cytosolic [GTP]
- EC number
- Short namesPEPCK-C
- Alternative names
Gene names
Organism names
- Organism
- Taxonomic lineageEukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Mammalia > Eutheria > Euarchontoglires > Primates > Haplorrhini > Catarrhini > Hominidae > Homo
Accessions
- Primary accessionP35558
- Secondary accessions
Proteomes
Organism-specific databases
Subcellular Location
UniProt Annotation
GO Annotation
Note: Phosphorylation at Ser-90 promotes translocation to the endoplasmic reticulum.
Keywords
- Cellular component
Disease & Variants
Involvement in disease
Phosphoenolpyruvate carboxykinase deficiency, cytosolic (PCKDC)
- Note
- DescriptionAn autosomal recessive metabolic disorder characterized by impaired gluconeogenesis, hypoglycemia, hypotonia, hepatomegaly, hepatic dysfunction, failure to thrive, lactic acidosis, and elevated tricarboxylic acid intermediates, particularly fumarate, in urine.
- See alsoMIM:261680
Natural variants in PCKDC
Variant ID | Position(s) | Change | Description | |
---|---|---|---|---|
VAR_079633 | 45 | I>T | in PCKDC; decreased stability; no effect on phosphoenolpyruvate carboxykinase activity; dbSNP:rs202197769 | |
VAR_079634 | 309 | G>R | in PCKDC; uncertain significance; decreased phosphoenolpyruvate carboxykinase activity; dbSNP:rs201186470 | |
VAR_079635 | 440-443 | missing | in PCKDC; decreased phosphoenolpyruvate carboxykinase activity |
Features
Showing features for natural variant, mutagenesis.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Natural variant | VAR_079633 | 45 | in PCKDC; decreased stability; no effect on phosphoenolpyruvate carboxykinase activity; dbSNP:rs202197769 | |||
Sequence: I → T | ||||||
Natural variant | VAR_021072 | 55 | in dbSNP:rs28383585 | |||
Sequence: R → Q | ||||||
Natural variant | VAR_021073 | 60 | in dbSNP:rs28383586 | |||
Sequence: M → T | ||||||
Mutagenesis | 70 | Abolishes acetylation and increases protein stability; when associated with R-71 and R-594. | ||||
Sequence: K → R | ||||||
Mutagenesis | 71 | Abolishes acetylation and increases protein stability; when associated with R-70 and R-594. | ||||
Sequence: K → R | ||||||
Mutagenesis | 90 | Abolished phosphorylation by AKT1, interaction with INSIG proteins (INSIG1 and INSIG2) and ability to regulate lipogenesis. | ||||
Sequence: S → A | ||||||
Mutagenesis | 90 | Phosphomimetic mutant, promotes the serine protein kinase activity by reducing the binding affinity to oxaloacetate. | ||||
Sequence: S → E | ||||||
Natural variant | VAR_021074 | 138 | in dbSNP:rs28359542 | |||
Sequence: T → I | ||||||
Natural variant | VAR_021075 | 184 | in dbSNP:rs707555 | |||
Sequence: V → L | ||||||
Natural variant | VAR_015575 | 267 | in dbSNP:rs8192708 | |||
Sequence: I → V | ||||||
Natural variant | VAR_021076 | 276 | in dbSNP:rs11552145 | |||
Sequence: E → K | ||||||
Mutagenesis | 288 | Abolished both phosphoenolpyruvate carboxykinase and protein kinase activities. | ||||
Sequence: C → S | ||||||
Natural variant | VAR_079634 | 309 | in PCKDC; uncertain significance; decreased phosphoenolpyruvate carboxykinase activity; dbSNP:rs201186470 | |||
Sequence: G → R | ||||||
Natural variant | VAR_021077 | 368 | in dbSNP:rs1804160 | |||
Sequence: V → I | ||||||
Natural variant | VAR_021078 | 427 | in dbSNP:rs28359550 | |||
Sequence: P → S | ||||||
Natural variant | VAR_079635 | 440-443 | in PCKDC; decreased phosphoenolpyruvate carboxykinase activity | |||
Sequence: Missing | ||||||
Natural variant | VAR_042444 | 586 | in dbSNP:rs1042529 | |||
Sequence: E → D | ||||||
Mutagenesis | 594 | Abolishes acetylation and increases protein stability; when associated with R-70 and R-71. | ||||
Sequence: K → R |
Variants
We now provide the "Disease & Variants" viewer in its own tab.
The viewer provides 1,079 variants from UniProt as well as other sources including ClinVar and dbSNP.
Organism-specific databases
Miscellaneous
Chemistry
Genetic variation databases
PTM/Processing
Features
Showing features for chain, modified residue, modified residue (large scale data).
Type | ID | Position(s) | Source | Description | |||
---|---|---|---|---|---|---|---|
Chain | PRO_0000103627 | 1-622 | UniProt | Phosphoenolpyruvate carboxykinase, cytosolic [GTP] | |||
Sequence: MPPQLQNGLNLSAKVVQGSLDSLPQAVREFLENNAELCQPDHIHICDGSEEENGRLLGQMEEEGILRRLKKYDNCWLALTDPRDVARIESKTVIVTQEQRDTVPIPKTGLSQLGRWMSEEDFEKAFNARFPGCMKGRTMYVIPFSMGPLGSPLSKIGIELTDSPYVVASMRIMTRMGTPVLEAVGDGEFVKCLHSVGCPLPLQKPLVNNWPCNPELTLIAHLPDRREIISFGSGYGGNSLLGKKCFALRMASRLAKEEGWLAEHMLILGITNPEGEKKYLAAAFPSACGKTNLAMMNPSLPGWKVECVGDDIAWMKFDAQGHLRAINPENGFFGVAPGTSVKTNPNAIKTIQKNTIFTNVAETSDGGVYWEGIDEPLASGVTITSWKNKEWSSEDGEPCAHPNSRFCTPASQCPIIDAAWESPEGVPIEGIIFGGRRPAGVPLVYEALSWQHGVFVGAAMRSEATAAAEHKGKIIMHDPFAMRPFFGYNFGKYLAHWLSMAQHPAAKLPKIFHVNWFRKDKEGKFLWPGFGENSRVLEWMFNRIDGKASTKLTPIGYIPKEDALNLKGLGHINMMELFSISKEFWEKEVEDIEKYLEDQVNADLPCEIEREILALKQRISQM | |||||||
Modified residue | 19 | UniProt | Phosphoserine | ||||
Sequence: S | |||||||
Modified residue (large scale data) | 19 | PRIDE | Phosphoserine | ||||
Sequence: S | |||||||
Modified residue | 70 | UniProt | N6-acetyllysine; by p300/EP300 | ||||
Sequence: K | |||||||
Modified residue | 71 | UniProt | N6-acetyllysine; by p300/EP300 | ||||
Sequence: K | |||||||
Modified residue | 90 | UniProt | Phosphoserine; by PKB/AKT1 | ||||
Sequence: S | |||||||
Modified residue | 91 | UniProt | N6-acetyllysine; by p300/EP300 | ||||
Sequence: K | |||||||
Modified residue | 118 | UniProt | Phosphoserine | ||||
Sequence: S | |||||||
Modified residue | 178 | UniProt | Phosphothreonine | ||||
Sequence: T | |||||||
Modified residue | 286 | UniProt | Phosphoserine | ||||
Sequence: S | |||||||
Modified residue | 473 | UniProt | N6-acetyllysine | ||||
Sequence: K | |||||||
Modified residue | 521 | UniProt | N6-acetyllysine | ||||
Sequence: K | |||||||
Modified residue | 524 | UniProt | N6-acetyllysine | ||||
Sequence: K | |||||||
Modified residue | 594 | UniProt | N6-acetyllysine; by p300/EP300 | ||||
Sequence: K |
Post-translational modification
Acetylated. Lysine acetylation by p300/EP300 is increased on high glucose conditions (PubMed:20167786, PubMed:21726808, PubMed:30193097).
Lysine acetylation promotes ubiquitination by UBR5 (PubMed:21726808).
Acetylation is enhanced in the presence of BAG6. Deacetylated by SIRT2. Deacetylation of Lys-91 is carried out by SIRT1 and depends on PCK1 phosphorylation levels (PubMed:30193097).
Lysine acetylation promotes ubiquitination by UBR5 (PubMed:21726808).
Acetylation is enhanced in the presence of BAG6. Deacetylated by SIRT2. Deacetylation of Lys-91 is carried out by SIRT1 and depends on PCK1 phosphorylation levels (PubMed:30193097).
Phosphorylated in a GSK3B-mediated pathway; phosphorylation affects the efficiency of SIRT1-mediated deacetylation, and regulates PCK1 ubiquitination and degradation (PubMed:30193097).
Phosphorylation at Ser-90 by AKT1 reduces the binding affinity to oxaloacetate and promotes the protein kinase activity: phosphorylated PCK1 translocates to the endoplasmic reticulum, where it phosphorylates INSIG1 and INSIG2 (PubMed:32322062).
Phosphorylation at Ser-90 by AKT1 reduces the binding affinity to oxaloacetate and promotes the protein kinase activity: phosphorylated PCK1 translocates to the endoplasmic reticulum, where it phosphorylates INSIG1 and INSIG2 (PubMed:32322062).
Ubiquitination by UBR5 leads to proteasomal degradation.
Keywords
- PTM
Proteomic databases
PTM databases
Structure
Family & Domains
Features
Showing features for region.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Region | 457-487 | Omega-loop | ||||
Sequence: GAAMRSEATAAAEHKGKIIMHDPFAMRPFFG |
Sequence similarities
Belongs to the phosphoenolpyruvate carboxykinase [GTP] family.
Phylogenomic databases
Family and domain databases
Sequence & Isoform
- Sequence statusComplete
This entry describes 2 isoforms produced by Alternative splicing.
P35558-1
This isoform has been chosen as the canonical sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.
- Name1
- Length622
- Mass (Da)69,195
- Last updated2006-03-07 v3
- Checksum78D309E0845CC181
P35558-2
- Name2
Features
Showing features for alternative sequence, sequence conflict.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Alternative sequence | VSP_057073 | 1-3 | in isoform 2 | |||
Sequence: MPP → MTT | ||||||
Alternative sequence | VSP_057074 | 4-320 | in isoform 2 | |||
Sequence: Missing | ||||||
Sequence conflict | 250 | in Ref. 2; AAA02558 | ||||
Sequence: M → N | ||||||
Sequence conflict | 256 | in Ref. 1; AAA60084 | ||||
Sequence: K → E | ||||||
Sequence conflict | 291 | in Ref. 2; AAA02558 | ||||
Sequence: T → S | ||||||
Sequence conflict | 551-552 | in Ref. 1; AAA60084 | ||||
Sequence: KL → NV | ||||||
Sequence conflict | 597 | in Ref. 1; AAA60084 | ||||
Sequence: E → V |
Keywords
- Coding sequence diversity
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
L05144 EMBL· GenBank· DDBJ | AAA60084.1 EMBL· GenBank· DDBJ | mRNA | ||
L12760 EMBL· GenBank· DDBJ | AAA02558.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
AY794987 EMBL· GenBank· DDBJ | AAV50001.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
AK290802 EMBL· GenBank· DDBJ | BAF83491.1 EMBL· GenBank· DDBJ | mRNA | ||
AK300072 EMBL· GenBank· DDBJ | BAG61876.1 EMBL· GenBank· DDBJ | mRNA | ||
AL035541 EMBL· GenBank· DDBJ | - | Genomic DNA | No translation available. | |
CH471077 EMBL· GenBank· DDBJ | EAW75514.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
BC023978 EMBL· GenBank· DDBJ | AAH23978.1 EMBL· GenBank· DDBJ | mRNA | ||
U31519 EMBL· GenBank· DDBJ | AAA91026.1 EMBL· GenBank· DDBJ | Genomic DNA |