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Details on Person UniProt:O14757 CHEK1

Class:IdReferenceGeneProduct:87284
_chainChangeLogchain:1-476 added on Sat February 7 2015
_displayNameUniProt:O14757 CHEK1
_timestamp2026-02-20 22:19:58
chainchain:1-476
checksum0ABD0FAB67E60F67
commentFUNCTION Serine/threonine-protein kinase which is required for checkpoint-mediated cell cycle arrest and activation of DNA repair in response to the presence of DNA damage or unreplicated DNA (PubMed:11535615, PubMed:12399544, PubMed:12446774, PubMed:14559997, PubMed:14988723, PubMed:15311285, PubMed:15650047, PubMed:15665856, PubMed:32357935). May also negatively regulate cell cycle progression during unperturbed cell cycles (PubMed:11535615, PubMed:12399544, PubMed:12446774, PubMed:14559997, PubMed:14988723, PubMed:15311285, PubMed:15650047, PubMed:15665856). This regulation is achieved by a number of mechanisms that together help to preserve the integrity of the genome (PubMed:11535615, PubMed:12399544, PubMed:12446774, PubMed:14559997, PubMed:14988723, PubMed:15311285, PubMed:15650047, PubMed:15665856). Recognizes the substrate consensus sequence [R-X-X-S/T] (PubMed:11535615, PubMed:12399544, PubMed:12446774, PubMed:14559997, PubMed:14988723, PubMed:15311285, PubMed:15650047, PubMed:15665856). Binds to and phosphorylates CDC25A, CDC25B and CDC25C (PubMed:12676583, PubMed:12676925, PubMed:12759351, PubMed:14559997, PubMed:14681206, PubMed:19734889, PubMed:9278511). Phosphorylation of CDC25A at 'Ser-178' and 'Thr-507' and phosphorylation of CDC25C at 'Ser-216' creates binding sites for 14-3-3 proteins which inhibit CDC25A and CDC25C (PubMed:9278511). Phosphorylation of CDC25A at 'Ser-76', 'Ser-124', 'Ser-178', 'Ser-279' and 'Ser-293' promotes proteolysis of CDC25A (PubMed:12676583, PubMed:12676925, PubMed:12759351, PubMed:14681206, PubMed:19734889, PubMed:9278511). Phosphorylation of CDC25A at 'Ser-76' primes the protein for subsequent phosphorylation at 'Ser-79', 'Ser-82' and 'Ser-88' by NEK11, which is required for polyubiquitination and degradation of CDCD25A (PubMed:19734889, PubMed:20090422, PubMed:9278511). Inhibition of CDC25 leads to increased inhibitory tyrosine phosphorylation of CDK-cyclin complexes and blocks cell cycle progression (PubMed:9278511). Also phosphorylates NEK6 (PubMed:18728393). Binds to and phosphorylates RAD51 at 'Thr-309', which promotes the release of RAD51 from BRCA2 and enhances the association of RAD51 with chromatin, thereby promoting DNA repair by homologous recombination (PubMed:15665856). Phosphorylates multiple sites within the C-terminus of TP53, which promotes activation of TP53 by acetylation and promotes cell cycle arrest and suppression of cellular proliferation (PubMed:10673501, PubMed:15659650, PubMed:16511572). Also promotes repair of DNA cross-links through phosphorylation of FANCE (PubMed:17296736). Binds to and phosphorylates TLK1 at 'Ser-743', which prevents the TLK1-dependent phosphorylation of the chromatin assembly factor ASF1A (PubMed:12660173, PubMed:12955071). This may enhance chromatin assembly both in the presence or absence of DNA damage (PubMed:12660173, PubMed:12955071). May also play a role in replication fork maintenance through regulation of PCNA (PubMed:18451105). May regulate the transcription of genes that regulate cell-cycle progression through the phosphorylation of histones (By similarity). Phosphorylates histone H3.1 (to form H3T11ph), which leads to epigenetic inhibition of a subset of genes (By similarity). May also phosphorylate RB1 to promote its interaction with the E2F family of transcription factors and subsequent cell cycle arrest (PubMed:17380128). Phosphorylates SPRTN, promoting SPRTN recruitment to chromatin (PubMed:31316063). Reduces replication stress and activates the G2/M checkpoint, by phosphorylating and inactivating PABIR1/FAM122A and promoting the serine/threonine-protein phosphatase 2A-mediated dephosphorylation and stabilization of WEE1 levels and activity (PubMed:33108758).FUNCTION Endogenous repressor of isoform 1, interacts with, and antagonizes CHK1 to promote the S to G2/M phase transition.CATALYTIC ACTIVITY L-seryl-[protein] + ATP = O-phospho-L-seryl-[protein] + ADP + H(+)CATALYTIC ACTIVITY L-threonyl-[protein] + ATP = O-phospho-L-threonyl-[protein] + ADP + H(+)ACTIVITY REGULATION Activated through phosphorylation predominantly by ATR but also by ATM in response to DNA damage or inhibition of DNA replication (PubMed:11390642, PubMed:12588868, PubMed:12676583, PubMed:12676962, PubMed:15665856, PubMed:19716789). Activation is modulated by several mediators including CLSPN, BRCA1 and FEM1B (PubMed:11836499, PubMed:12766152, PubMed:16963448, PubMed:19330022). Proteolytic cleavage at the C-terminus by SPRTN during normal DNA replication activates the protein kinase activity (PubMed:31316063).SUBUNIT Interacts (phosphorylated by ATR) with RAD51 (PubMed:15665856). Interacts with and phosphorylates CLSPN, an adapter protein that regulates the ATR-dependent phosphorylation of CHEK1 (PubMed:16963448). Interacts with BRCA1 (PubMed:11836499). Interacts with and phosphorylates CDC25A, CDC25B and CDC25C (PubMed:9278511). Interacts with FBXO6, which regulates CHEK1 (PubMed:19716789). Interacts with PPM1D, which regulates CHEK1 through dephosphorylation (PubMed:15870257). Interacts with TIMELESS; DNA damage-dependent (PubMed:15798197). Interacts with FEM1B; activates CHEK1 in response to stress (PubMed:19330022). Interacts with TLK1 (PubMed:12660173). Interacts with XPO1 and YWHAZ (PubMed:12676962). Interacts with CDK5RAP3; antagonizes CHEK1 (PubMed:19223857). Interacts with KRCC1; the interaction promotes CHEK1 phosphorylation at Ser-296 (PubMed:36243983).SUBUNIT Isoform 1 associates with isoform 2, the interaction is disrupted upon phosphorylation by ATR.INTERACTION Nuclear export is mediated at least in part by XPO1/CRM1 (PubMed:12676962). Also localizes to the centrosome specifically during interphase, where it may protect centrosomal CDC2 kinase from inappropriate activation by cytoplasmic CDC25B (PubMed:15311285). Proteolytic cleavage at the C-terminus by SPRTN promotes removal from chromatin (PubMed:31316063).ALTERNATIVE PRODUCTS Expressed ubiquitously with the most abundant expression in thymus, testis, small intestine and colon.DOMAIN The autoinhibitory region (AIR) inhibits the activity of the kinase domain.PTM Phosphorylated by ATR in a RAD17-dependent manner in response to ultraviolet irradiation and inhibition of DNA replication (PubMed:10859164, PubMed:11390642, PubMed:12446774, PubMed:12588868, PubMed:12676583, PubMed:12676925, PubMed:12676962, PubMed:14681223, PubMed:14988723, PubMed:15650047, PubMed:15707391, PubMed:15870257, PubMed:25083873, PubMed:31316063). Phosphorylated by ATM in response to ionizing irradiation (PubMed:12588868, PubMed:12676583). ATM and ATR can both phosphorylate Ser-317 and Ser-345 and this results in enhanced kinase activity (PubMed:11390642, PubMed:12446774, PubMed:12588868, PubMed:12660173, PubMed:12676583, PubMed:12676962, PubMed:14657349, PubMed:15665856, PubMed:15707391, PubMed:15870257, PubMed:25083873). Phosphorylation at Ser-345 induces a change in the conformation of the protein, activates the kinase activity and is a prerequisite for interaction with FBXO6 and subsequent ubiquitination at Lys-436 (PubMed:19716789). Phosphorylation at Ser-345 also increases binding to 14-3-3 proteins and promotes nuclear retention (PubMed:12676962). Conversely, dephosphorylation at Ser-345 by PPM1D may contribute to exit from checkpoint mediated cell cycle arrest (PubMed:15870257). Phosphorylation at Ser-280 by AKT1/PKB, may promote mono and/or diubiquitination. Also phosphorylated at undefined residues during mitotic arrest, resulting in decreased activity (By similarity).PTM Ubiquitinated. Mono or diubiquitination promotes nuclear exclusion (By similarity). The activated form (phosphorylated on Ser-345) is polyubiquitinated at Lys-436 by some SCF-type E3 ubiquitin ligase complex containing FBXO6 promoting its degradation. Ubiquitination and degradation are required to terminate the checkpoint and ensure that activated CHEK1 does not accumulate as cells progress through S phase, when replication forks encounter transient impediments during normal DNA replication. 'Lys-63'-mediated ubiquitination by TRAF4 at Lys-132 activates cell cycle arrest and activation of DNA repair (PubMed:32357935).PTM Proteolytically cleaved at the C-terminus by SPRTN during normal DNA replication, thereby promoting CHEK1 removal from chromatin and activating the protein kinase activity.DISEASE The disease is caused by variants affecting the gene represented in this entry.SIMILARITY Belongs to the protein kinase superfamily. CAMK Ser/Thr protein kinase family. NIM1 subfamily.
descriptionrecommendedName: Serine/threonine-protein kinase Chk1 ecNumber evidence="5 15 22 31 59"2.7.11.1 alternativeName: CHK1 checkpoint homolog alternativeName: Cell cycle checkpoint kinase alternativeName: Checkpoint kinase-1
geneNameCHEK1
CHK1
identifierO14757
isSequenceChangedFALSE
keyword3D-structure
Alternative splicing
ATP-binding
Cell cycle
Chromosome
Cytoplasm
Cytoskeleton
Disease variant
DNA damage
DNA repair
Isopeptide bond
Kinase
Nucleotide-binding
Nucleus
Phosphoprotein
Proteomics identification
Reference proteome
Serine/threonine-protein kinase
Transferase
Ubl conjugation
modified[InstanceEdit:9836292] Weiser, Joel, 2023-05-25
[InstanceEdit:9852000] Weiser, Joel, 2023-11-03
[InstanceEdit:9909836] Weiser, Joel, 2024-05-14
[InstanceEdit:9917590] Weiser, Joel, 2024-08-09
[InstanceEdit:9926675] Weiser, Joel, 2024-11-03
[InstanceEdit:9939033] Weiser, Joel, 2025-02-21
[InstanceEdit:9983091] Weiser, Joel, 2026-02-20
nameCHEK1
referenceDatabase[ReferenceDatabase:2] UniProt
referenceGene[ReferenceDNASequence:6797747] ENSEMBL:ENSG00000149554 CHEK1 [Homo sapiens]
secondaryIdentifierCHK1_HUMAN
A8K934
B4DDD0
B4DSK3
B5BTY6
F5H7S4
H2BI51
sequenceLength476
species[Species:48887] Homo sapiens
(isoformParent)[ReferenceIsoform:8976924] UniProt:O14757-1 CHEK1 [Homo sapiens]
[ReferenceIsoform:8976925] UniProt:O14757-2 CHEK1 [Homo sapiens]
[ReferenceIsoform:8976926] UniProt:O14757-3 CHEK1 [Homo sapiens]
(referenceEntity)[EntityWithAccessionedSequence:113826] CHEK1 [nucleoplasm] [Homo sapiens]
[EntityWithAccessionedSequence:113838] p-S317,S345-CHEK1 [nucleoplasm] [Homo sapiens]
[EntityWithAccessionedSequence:205285] CHEK1 [cytosol] [Homo sapiens]
(referenceSequence)[ModifiedResidue:69443] O-phospho-L-serine at 317
[ModifiedResidue:176347] O-phospho-L-serine at 345
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