Cell cycle checkpoints (Homo sapiens)

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623, 31, 34, 372683511, 4620517, 29, 41426, 36351411924, 27, 30, 48264926209, 16, 443, 10, 22, 25, 45...13, 1839263, 22, 47142643Cyclin B [cytosol]CDC6:ORC:origincomplex[nucleoplasm]ATR-ATRIP[nucleoplasm]CyclinB:phospho-Cdc2(Thr14) [cytosol]RPA complexed tossDNA [nucleoplasm]Rad17-RFC complex[nucleoplasm]ATR-ATRIP[nucleoplasm]Mcm10:activepre-replicativecomplex[nucleoplasm]DDK [nucleoplasm]CDK:DDK:Mcm10:pre-replicativecomplex[nucleoplasm]CyclinB1:phospho-Cdc2(Thr161, Thr 14, Tyr 15)[nucleoplasm]Mad1:kinetochorecomplex [cytosol]ATR-ATRIP-RPA-ssDNAsignaling complex[nucleoplasm]Orc2 associated withMCM8 [nucleoplasm]CDC6:ORC:origincomplex[nucleoplasm]Rad9-Hus1-Rad1complex[nucleoplasm]ubiquitinatedphospho-COP1(ser-387)[cytosol]Mcm10:activepre-replicativecomplex[nucleoplasm]p53 tetramer[nucleoplasm]CDK [nucleoplasm]Kinetochore:Mad1:MAD2*Complex [cytosol]CDK [nucleoplasm]RPA heterotrimer[nucleoplasm]activepre-replicativecomplex[nucleoplasm]Mcm2-7 complex[nucleoplasm]phosphorylatedanaphase promotingcomplex (APC/C)[cytosol]Rad17-RFC complex[nucleoplasm]activepre-replicativecomplex[nucleoplasm]ORC:origin[nucleoplasm]p21/p27[nucleoplasm]Cyclin E:Cdk2complexes[nucleoplasm]Mcm2-7 complex[nucleoplasm]Ub [cytosol]activepre-replicativecomplex[nucleoplasm]Cyclin E:Cdk2complexes[nucleoplasm]Rad17-RFC complex[nucleoplasm]ORC:origin[nucleoplasm]Rad17-RFC complexbound to DNA[nucleoplasm]RPA heterotrimer[nucleoplasm]Cdc45:CDK:DDK:Mcm10:claspin:pre-replicativecomplex[nucleoplasm]26S proteasome[cytosol]CyclinE:Cdk2:p21/p27complex[nucleoplasm]p53 tetramer[nucleoplasm]Cyclin B:Cdc2complex [cytosol]Cdc45:CDK:DDK:Mcm10:Activatedclaspin:pre-replicativecomplex[nucleoplasm]Cdc45:CDK:DDK:Mcm10:pre-replicativecomplex[nucleoplasm]Rad9-Hus1-Rad1complex[nucleoplasm]Orc2 associated withMCM8 [nucleoplasm]Rad17-RFC complexbound to DNA[nucleoplasm]Cyclin B [cytosol]MAD2*CDC20 complex[cytosol]Cdc45:CDK:DDK:Mcm10:pre-replicativecomplex[nucleoplasm]hBUBR1:hBUB3:MAD2*:CDC20complex [cytosol]RPA complexed tossDNA [nucleoplasm]UbiquitinatedPhospho-Cdc25A[cytosol]RAD9 [nucleoplasm]cytosolRPA heterotrimer[nucleoplasm]MCC:APC/C complex[cytosol]DDK [nucleoplasm]CDK [nucleoplasm]Ub [cytosol]nucleoplasmOrc2 associated withMCM8 [nucleoplasm]Cdc45:CDK:DDK:Mcm10:pre-replicativecomplex[nucleoplasm]RPA complexed tossDNA [nucleoplasm]Mcm2-7 complex[nucleoplasm]phospho-Cdc25C:14-3-3protein complex[cytosol]Rad9-Hus1-Rad1 boundto DNA [nucleoplasm]CDK:DDK:Mcm10:pre-replicativecomplex[nucleoplasm]Mad1:kinetochorecomplex [cytosol]CyclinB1:phospho-Cdc2 (Thr14, Thr 161)[nucleoplasm]RPA complexed tossDNA [nucleoplasm]DDK [nucleoplasm]hBUBR1:hBUB3:MAD2*:CDC20complex [cytosol]CDK:DDK:Mcm10:pre-replicativecomplex[nucleoplasm]RAD9 [nucleoplasm]phosphorylatedanaphase promotingcomplex (APC/C)[cytosol]RPA heterotrimer[nucleoplasm]Mcm10:activepre-replicativecomplex[nucleoplasm]Phospho-COP1(Ser-387):p53complex[nucleoplasm]CDC6:ORC:origincomplex[nucleoplasm]Mad1:kinetochorecomplex [cytosol]Kinetochore:Mad1:MAD2Complex [cytosol]ORC:origin[nucleoplasm]RPA heterotrimer[nucleoplasm]PSMC3 [cytosol]MCM10 [nucleoplasm]PSMD4(2-377)[cytosol]ORC2 [nucleoplasm]PSMC5 [cytosol]RPA3 [nucleoplasm]ADPPSMD5 [cytosol]CDK2 [nucleoplasm]UBC(305-380)[cytosol]PSMA3 [cytosol]CyclinE:Cdk2:p21/p27complexPSME3 [cytosol]p-T916,S945-CLSPN[nucleoplasm]PSMA6 [cytosol]RAD1 [nucleoplasm]RPA1 [nucleoplasm]p-S216-CDC25C[cytosol]PSME2 [cytosol]UBC(533-608)[cytosol]PSMC1(2-440)[cytosol]p-CHEK2-12UBC(229-304)[cytosol]ADPRAD17 [nucleoplasm]ATPRAD9A [nucleoplasm]RFC2 [nucleoplasm]p53 tetramerRFC4 [nucleoplasm]RFC3 [nucleoplasm]UBB(77-152)[cytosol]Phospho-COP1(Ser-387):p53complexActivated MAD2L1[cytosol]UBC(77-152)[cytosol]PSMB4 [cytosol]MCM6 [nucleoplasm]CCNB1 [cytosol]ADPRPA heterotrimerDBF4 [nucleoplasm]MCC:APC/C complexp-S387-RFWD2UBA52(1-76)[cytosol]ADPMCM4(1-863)[nucleoplasm]ORC5 [nucleoplasm]RPA1 [nucleoplasm]p-T14,T161-CDK1[nucleoplasm]CDKN1ARPA1 [nucleoplasm]ANAPC5 [cytosol]CCNB2 [cytosol]CDC6 [nucleoplasm]ANAPC11 [cytosol]ANAPC1 [cytosol]MCM10 [nucleoplasm]ORC1 [nucleoplasm]UBE2D1 [cytosol]MAD2L1MCM8 [nucleoplasm]MCM4(1-863)[nucleoplasm]ATPp-S123-CDC25Ap-S123-CDC25A[cytosol]RFC4 [nucleoplasm]Ubiquitin ligaseRPA2 [nucleoplasm]ADPUBC(381-456)[cytosol]ADPPSMD7(2-324)[cytosol]CDKN1B [nucleoplasm]UBB(1-76) [cytosol]MCM4(1-863)[nucleoplasm]p-S387-RFWD2[nucleoplasm]CDKN1A [nucleoplasm]RFWD2UBC(533-608)[cytosol]MCM7 [nucleoplasm]UBA52(1-76)[cytosol]ANAPC2 [cytosol]CDC6 [nucleoplasm]CHEK2-12ANAPC4 [cytosol]Cyclin E:Cdk2complexesCyclin B:Cdc2complexMCM6 [nucleoplasm]MAD1L1RFC3 [nucleoplasm]TP53CDK2 [nucleoplasm]PSMD13 [cytosol]CLSPN [nucleoplasm]RPS27A(1-76)[cytosol]ATRIP [nucleoplasm]UBB(1-76) [cytosol]CDC16 [cytosol]phospho-Cdc25C:14-3-3protein complexCDK1 [cytosol]HUS1 [nucleoplasm]UBB(77-152)[cytosol]ADPATR [nucleoplasm]PSMC4 [cytosol]RAD9A [nucleoplasm]RPA2 [nucleoplasm]Kinetochore:Mad1:MAD2*ComplexMCM7 [nucleoplasm]ATR-ATRIPRPA2 [nucleoplasm]RAD17 [nucleoplasm]CDC7 [nucleoplasm]CDC25AATR-ATRIP-RPA-ssDNAsignaling complexCDC20 [cytosol]Activated MAD2L1[cytosol]DBF4 [nucleoplasm]PSMA7(2-248)[cytosol]UBE2E1(1-193)[cytosol]MCM3 [nucleoplasm]ANAPC7 [cytosol]RAD9B [nucleoplasm]CLSPNUBC(153-228)[cytosol]Kinetochore ComplexRPA3 [nucleoplasm]UBC(153-228)[cytosol]PSMD12 [cytosol]ADPCyclinB:phospho-Cdc2(Thr14)ATPPSMA2 [cytosol]PSMA5 [cytosol]ORC3 [nucleoplasm]MCM5 [nucleoplasm]Cdc45:CDK:DDK:Mcm10:Activatedclaspin:pre-replicativecomplexORC1 [nucleoplasm]p-MDM2CDC20MCM3 [nucleoplasm]p-WEE1CDC7 [nucleoplasm]UBC(457-532)[cytosol]p-T14-CDK1 [cytosol]PSME4 [cytosol]CDC23 [cytosol]CDC27 [cytosol]CDC23 [cytosol]Kinetochore:Mad1:MAD2Complexp-S15-TP53[nucleoplasm]Chk1/Ckk2(Cds1)MCM6 [nucleoplasm]ATPp-S216-CDC25Cp-S387-RFWD2RPA1 [nucleoplasm]PSMB2 [cytosol]Activated MAD2L1MAD1L1 [cytosol]RPA1 [nucleoplasm]RFC3 [nucleoplasm]RPA complexed tossDNARad17-RFC complexPSMB9 [cytosol]RAD17 [nucleoplasm]RPA2 [nucleoplasm]ORC2 [nucleoplasm]UBC(381-456)[cytosol]ANAPC1 [cytosol]UBB(153-228)[cytosol]ANAPC2 [cytosol]ORC6 [nucleoplasm]PSMC2 [cytosol]ORC4 [nucleoplasm]RFC4 [nucleoplasm]Activated MAD2L1[cytosol]Cdc45:CDK:DDK:Mcm10:pre-replicativecomplexATPp-S15-TP53[nucleoplasm]ORC6 [nucleoplasm]ATR [nucleoplasm]MCM2 [nucleoplasm]Rad9-Hus1-Rad1 boundto DNAUBE2D1 [cytosol]HUS1 [nucleoplasm]CHEK1CDC27 [cytosol]p21/p27ORC5 [nucleoplasm]MAD1L1 [cytosol]BUB3 [cytosol]MCM7 [nucleoplasm]BUB3 [cytosol]ADPCDC45 [nucleoplasm]ANAPC11 [cytosol]CCNB2 [cytosol]MCM5 [nucleoplasm]BUB1B [cytosol]UBB(153-228)[cytosol]PSMD9 [cytosol]PSMB5 [cytosol]CDK2 [nucleoplasm]ATPhBUBR1:hBUB3:MAD2*:CDC20complexORC3 [nucleoplasm]ANAPC7 [cytosol]PSMB3 [cytosol]ORC3 [nucleoplasm]CyclinB1:phospho-Cdc2(Thr161, Thr 14, Tyr 15)MCM3 [nucleoplasm]CyclinB1:phospho-Cdc2 (Thr14, Thr 161)ATPANAPC10 [cytosol]PSMD8 [cytosol]RAD9B [nucleoplasm]PSMB11 [cytosol]Mad1:kinetochorecomplexRPA2 [nucleoplasm]MCM2 [nucleoplasm]ORC4 [nucleoplasm]CDC25CCDK2 [nucleoplasm]BUB3CCNB1 [cytosol]MAD2*CDC20 complexp-S216-CDC25CBUB1B [cytosol]BUB1BPSMB6 [cytosol]CDC45 [nucleoplasm]UBC(77-152)[cytosol]PSMD2 [cytosol]PSMB8 [cytosol]RFC5 [nucleoplasm]PSMB1 [cytosol]CDC7 [nucleoplasm]MAD1L1 [cytosol]CDK2 [nucleoplasm]PSME1 [cytosol]ADPUBE2C [cytosol]RPA3 [nucleoplasm]UbActivated MAD2L1[cytosol]26S proteasomeMCM8 [nucleoplasm]CDC20 [cytosol]MCM5 [nucleoplasm]PSMA4 [cytosol]ATPRFC5 [nucleoplasm]p-S317,S345-CHEK1CCNB1 [nucleoplasm]Cdc45:CDK:DDK:Mcm10:claspin:pre-replicativecomplexPSMA1 [cytosol]MCM8 [nucleoplasm]PSMD11 [cytosol]RPA3 [nucleoplasm]Amino AcidPersistentsingle-stranded DNAANAPC5 [cytosol]ATPp-S123-CDC25AMAD2L1 [cytosol]ATPATPCDC6 [nucleoplasm]CDC20 [cytosol]UBC(1-76) [cytosol]ADPp-T14,Y15,T161-CDK1[nucleoplasm]UBE2C [cytosol]Rad17-RFC complexbound to DNARPS27A(1-76)[cytosol]PSMF1(2-271)[cytosol]PSMD1 [cytosol]ubiquitinatedphospho-COP1(ser-387)ORC4 [nucleoplasm]ATRIP [nucleoplasm]MCM2 [nucleoplasm]UBC(457-532)[cytosol]PSMB10 [cytosol]CDC45 [nucleoplasm]RFC2 [nucleoplasm]ORC1 [nucleoplasm]WEE1RFC2 [nucleoplasm]RPA3 [nucleoplasm]UBC(305-380)[cytosol]PSMD10 [cytosol]Rad9-Hus1-Rad1complexUBC(609-684)[cytosol]PSMB7 [cytosol]ORC6 [nucleoplasm]DBF4 [nucleoplasm]ANAPC10 [cytosol]p-S15-TP53PSMD6(2-389)[cytosol]CDC26 [cytosol]ANAPC4 [cytosol]UBC(1-76) [cytosol]ADPMDM2ORC5 [nucleoplasm]UBC(229-304)[cytosol]UbiquitinatedPhospho-Cdc25AUBE2E1(1-193)[cytosol]PSMA8 [cytosol]phosphorylatedanaphase promotingcomplex (APC/C)MCM10 [nucleoplasm]ATP14-3-3 proteinsPSMC6(2-389)[cytosol]UBC(609-684)[cytosol]p-S1981-ATMPSMD3 [cytosol]PSMD14 [cytosol]RAD1 [nucleoplasm]RFC5 [nucleoplasm]CDC26 [cytosol]CCNB1 [nucleoplasm]CDC16 [cytosol]ATPORC2 [nucleoplasm]p-S387-RFWD2[cytosol]ADP27, 30, 33217324028, 382, 12, 15, 23


Description

A hallmark of the human cell cycle in normal somatic cells is its precision. This remarkable fidelity is achieved by a number of signal transduction pathways, known as checkpoints, which monitor cell cycle progression ensuring an interdependency of S-phase and mitosis, the integrity of the genome and the fidelity of chromosome segregation.

Checkpoints are layers of control that act to delay CDK activation when defects in the division program occur. As the CDKs functioning at different points in the cell cycle are regulated by different means, the various checkpoints differ in the biochemical mechanisms by which they elicit their effect. However, all checkpoints share a common hierarchy of a sensor, signal transducers, and effectors that interact with the CDKs.<p>The stability of the genome in somatic cells contrasts to the almost universal genomic instability of tumor cells. There are a number of documented genetic lesions in checkpoint genes, or in cell cycle genes themselves, which result either directly in cancer or in a predisposition to certain cancer types. Indeed, restraint over cell cycle progression and failure to monitor genome integrity are likely prerequisites for the molecular evolution required for the development of a tumor. Perhaps most notable amongst these is the p53 tumor suppressor gene, which is mutated in >50% of human tumors. Thus, the importance of the checkpoint pathways to human biology is clear.Original Pathway at Reactome: http://www.reactome.org/PathwayBrowser/#DB=gk_current&FOCUS_SPECIES_ID=48887&FOCUS_PATHWAY_ID=69620Original Pathway at Reactome: http://www.reactome.org/PathwayBrowser/#DB=gk_current&FOCUS_SPECIES_ID=48887&FOCUS_PATHWAY_ID=69620</div>

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  70. Fang G, Yu H, Kirschner MW.; ''The checkpoint protein MAD2 and the mitotic regulator CDC20 form a ternary complex with the anaphase-promoting complex to control anaphase initiation.''; PubMed Europe PMC Scholia
  71. Lee CH, Chung JH.; ''The hCds1 (Chk2)-FHA domain is essential for a chain of phosphorylation events on hCds1 that is induced by ionizing radiation.''; PubMed Europe PMC Scholia
  72. Chen J, Marechal V, Levine AJ.; ''Mapping of the p53 and mdm-2 interaction domains.''; PubMed Europe PMC Scholia
  73. Wei SJ, Williams JG, Dang H, Darden TA, Betz BL, Humble MM, Chang FM, Trempus CS, Johnson K, Cannon RE, Tennant RW.; ''Identification of a specific motif of the DSS1 protein required for proteasome interaction and p53 protein degradation.''; PubMed Europe PMC Scholia
  74. Zou L, Elledge SJ.; ''Sensing DNA damage through ATRIP recognition of RPA-ssDNA complexes.''; PubMed Europe PMC Scholia
  75. Cheng Q, Chen L, Li Z, Lane WS, Chen J.; ''ATM activates p53 by regulating MDM2 oligomerization and E3 processivity.''; PubMed Europe PMC Scholia
  76. McGowan CH, Russell P.; ''Human Wee1 kinase inhibits cell division by phosphorylating p34cdc2 exclusively on Tyr15.''; PubMed Europe PMC Scholia
  77. Scoumanne A, Cho SJ, Zhang J, Chen X.; ''The cyclin-dependent kinase inhibitor p21 is regulated by RNA-binding protein PCBP4 via mRNA stability.''; PubMed Europe PMC Scholia
  78. Niida H, Nakanishi M.; ''DNA damage checkpoints in mammals.''; PubMed Europe PMC Scholia
  79. Galaktionov K, Beach D.; ''Specific activation of cdc25 tyrosine phosphatases by B-type cyclins: evidence for multiple roles of mitotic cyclins.''; PubMed Europe PMC Scholia
  80. Cai Z, Chehab NH, Pavletich NP.; ''Structure and activation mechanism of the CHK2 DNA damage checkpoint kinase.''; PubMed Europe PMC Scholia
  81. Pereg Y, Shkedy D, de Graaf P, Meulmeester E, Edelson-Averbukh M, Salek M, Biton S, Teunisse AF, Lehmann WD, Jochemsen AG, Shiloh Y.; ''Phosphorylation of Hdmx mediates its Hdm2- and ATM-dependent degradation in response to DNA damage.''; PubMed Europe PMC Scholia
  82. Sørensen CS, Syljuåsen RG, Lukas J, Bartek J.; ''ATR, Claspin and the Rad9-Rad1-Hus1 complex regulate Chk1 and Cdc25A in the absence of DNA damage.''; PubMed Europe PMC Scholia
  83. Maki CG.; ''Oligomerization is required for p53 to be efficiently ubiquitinated by MDM2.''; PubMed Europe PMC Scholia
  84. Cheng Q, Cross B, Li B, Chen L, Li Z, Chen J.; ''Regulation of MDM2 E3 ligase activity by phosphorylation after DNA damage.''; PubMed Europe PMC Scholia
  85. Ball HL, Myers JS, Cortez D.; ''ATRIP binding to replication protein A-single-stranded DNA promotes ATR-ATRIP localization but is dispensable for Chk1 phosphorylation.''; PubMed Europe PMC Scholia
  86. Ellison V, Stillman B.; ''Biochemical characterization of DNA damage checkpoint complexes: clamp loader and clamp complexes with specificity for 5' recessed DNA.''; PubMed Europe PMC Scholia
  87. Iftode C, Daniely Y, Borowiec JA.; ''Replication protein A (RPA): the eukaryotic SSB.''; PubMed Europe PMC Scholia
  88. Wang W, Nacusi L, Sheaff RJ, Liu X.; ''Ubiquitination of p21Cip1/WAF1 by SCFSkp2: substrate requirement and ubiquitination site selection.''; PubMed Europe PMC Scholia
  89. Cordeiro-Stone M, Makhov AM, Zaritskaya LS, Griffith JD.; ''Analysis of DNA replication forks encountering a pyrimidine dimer in the template to the leading strand.''; PubMed Europe PMC Scholia
  90. Wu X, Bayle JH, Olson D, Levine AJ.; ''The p53-mdm-2 autoregulatory feedback loop.''; PubMed Europe PMC Scholia
  91. Wang B, Matsuoka S, Carpenter PB, Elledge SJ.; ''53BP1, a mediator of the DNA damage checkpoint.''; PubMed Europe PMC Scholia
  92. Zhao H, Watkins JL, Piwnica-Worms H.; ''Disruption of the checkpoint kinase 1/cell division cycle 25A pathway abrogates ionizing radiation-induced S and G2 checkpoints.''; PubMed Europe PMC Scholia
  93. Voges D, Zwickl P, Baumeister W.; ''The 26S proteasome: a molecular machine designed for controlled proteolysis.''; PubMed Europe PMC Scholia
  94. Bernardi R, Liebermann DA, Hoffman B.; ''Cdc25A stability is controlled by the ubiquitin-proteasome pathway during cell cycle progression and terminal differentiation.''; PubMed Europe PMC Scholia
  95. Das S, Raj L, Zhao B, Kimura Y, Bernstein A, Aaronson SA, Lee SW.; ''Hzf Determines cell survival upon genotoxic stress by modulating p53 transactivation.''; PubMed Europe PMC Scholia
  96. Dornan D, Shimizu H, Mah A, Dudhela T, Eby M, O'rourke K, Seshagiri S, Dixit VM.; ''ATM engages autodegradation of the E3 ubiquitin ligase COP1 after DNA damage.''; PubMed Europe PMC Scholia
  97. Chaturvedi P, Eng WK, Zhu Y, Mattern MR, Mishra R, Hurle MR, Zhang X, Annan RS, Lu Q, Faucette LF, Scott GF, Li X, Carr SA, Johnson RK, Winkler JD, Zhou BB.; ''Mammalian Chk2 is a downstream effector of the ATM-dependent DNA damage checkpoint pathway.''; PubMed Europe PMC Scholia
  98. Hupp TR, Lane DP.; ''Allosteric activation of latent p53 tetramers.''; PubMed Europe PMC Scholia
  99. Lovly CM, Yan L, Ryan CE, Takada S, Piwnica-Worms H.; ''Regulation of Chk2 ubiquitination and signaling through autophosphorylation of serine 379.''; PubMed Europe PMC Scholia
  100. Bochkareva E, Korolev S, Lees-Miller SP, Bochkarev A.; ''Structure of the RPA trimerization core and its role in the multistep DNA-binding mechanism of RPA.''; PubMed Europe PMC Scholia

History

View all...
CompareRevisionActionTimeUserComment
117674view12:00, 22 May 2021EweitzModified title
114649view16:11, 25 January 2021ReactomeTeamReactome version 75
113097view11:16, 2 November 2020ReactomeTeamReactome version 74
112331view15:25, 9 October 2020ReactomeTeamReactome version 73
101230view11:12, 1 November 2018ReactomeTeamreactome version 66
100768view20:39, 31 October 2018ReactomeTeamreactome version 65
100312view19:16, 31 October 2018ReactomeTeamreactome version 64
99858view15:59, 31 October 2018ReactomeTeamreactome version 63
99415view14:35, 31 October 2018ReactomeTeamreactome version 62 (2nd attempt)
93868view13:42, 16 August 2017ReactomeTeamreactome version 61
93434view11:23, 9 August 2017ReactomeTeamreactome version 61
86525view09:20, 11 July 2016ReactomeTeamreactome version 56
83240view10:28, 18 November 2015ReactomeTeamVersion54
81345view12:52, 21 August 2015ReactomeTeamVersion53
76816view08:03, 17 July 2014ReactomeTeamFixed remaining interactions
76806view14:21, 16 July 2014ReactomeTeamFixed remaining interactions
76805view14:20, 16 July 2014ReactomeTeamFixed remaining interactions
76520view11:45, 16 July 2014ReactomeTeamFixed remaining interactions
75853view09:50, 11 June 2014ReactomeTeamRe-fixing comment source
75848view06:23, 11 June 2014Anwesha
75553view10:34, 10 June 2014ReactomeTeamReactome 48 Update
74908view13:43, 8 May 2014AnweshaFixing comment source for displaying WikiPathways description
74552view08:35, 30 April 2014ReactomeTeamReactome46
69041view17:52, 8 July 2013MaintBotUpdated to 2013 gpml schema
44985view14:33, 6 October 2011MartijnVanIerselOntology Term : 'cell cycle checkpoint pathway' added !
42014view21:50, 4 March 2011MaintBotAutomatic update
39786view22:54, 18 January 2011KhanspersModified categories
39716view02:47, 14 January 2011AlexanderPicoAdded link to pathway
39714view02:35, 14 January 2011AlexanderPicoSpecify description
39703view02:08, 14 January 2011AlexanderPicoadded segmented line example
39702view01:54, 14 January 2011AlexanderPicoNew pathway

External references

DataNodes

View all...
NameTypeDatabase referenceComment
14-3-3 proteinsREACT_2548 (Reactome)
26S proteasomeComplexREACT_2353 (Reactome)
ADPMetaboliteCHEBI:16761 (ChEBI)
ANAPC1 [cytosol]ProteinQ9H1A4 (Uniprot-TrEMBL)
ANAPC10 [cytosol]ProteinQ9UM13 (Uniprot-TrEMBL)
ANAPC11 [cytosol]ProteinQ9NYG5 (Uniprot-TrEMBL)
ANAPC2 [cytosol]ProteinQ9UJX6 (Uniprot-TrEMBL)
ANAPC4 [cytosol]ProteinQ9UJX5 (Uniprot-TrEMBL)
ANAPC5 [cytosol]ProteinQ9UJX4 (Uniprot-TrEMBL)
ANAPC7 [cytosol]ProteinQ9UJX3 (Uniprot-TrEMBL)
ATPMetaboliteCHEBI:15422 (ChEBI)
ATR [nucleoplasm]ProteinQ13535 (Uniprot-TrEMBL)
ATR-ATRIP-RPA-ssDNA signaling complexComplexREACT_7037 (Reactome) While the ATR-ATRIP complex binds only poorly to RPA complexed with ssDNA lengths of 30 or 50 nt, binding is significantly enhanced in the presence of a 75 nt ssDNA molecule. Complex formation is primarily mediated by physical interaction between ATRIP and RPA. Multiple elements within the ATRIP molecule can bind to the RPA-ssDNA complex, including residues 1-107 (highest affinity), 218-390, and 390-791 (lowest afiinity). Although the full-length ATRIP is unable to bind ssDNA, an internal region (108-390) can weakly bind ssDNA when present in rabbit reticulocyte lysates. ATR can bind to the ssDNA directly independent of RPA, but this binding is inhibited by ATRIP. Upon binding, the ATR kinase becomes activated and can directly phosphorylate substrates such as Rad17.
ATR-ATRIPComplexREACT_7002 (Reactome) The ATR (ATM- and rad3-related) kinase is an essential checkpoint factor in human cells. In response to replication stress (i.e., stresses that cause replication fork stalling) or ultraviolet radiation, ATR becomes active and phosphorylates numerous factors involved in the checkpoint response including the checkpoint kinase Chk1. ATR is invariably associated with ATRIP (ATR-interacting protein) in human cells. Depletion of ATRIP by siRNA causes a loss of ATR without affecting ATR mRNA levels indicating that complex formation stabilizes ATR. ATRIP is also a substrate for the ATR kinase, but this modification does not play a significant role in the recruitment of ATR-ATRIP to sites of damage, the activation of Chk1, or the modification of p53.
ATRIP [nucleoplasm]ProteinQ8WXE1 (Uniprot-TrEMBL)
Activated MAD2L1 [cytosol]ProteinQ13257 (Uniprot-TrEMBL)
Activated MAD2L1ProteinQ13257 (Uniprot-TrEMBL)
Amino AcidREACT_2474 (Reactome)
BUB1B [cytosol]ProteinO60566 (Uniprot-TrEMBL)
BUB1BProteinO60566 (Uniprot-TrEMBL)
BUB3 [cytosol]ProteinO43684 (Uniprot-TrEMBL)
BUB3ProteinO43684 (Uniprot-TrEMBL)
CCNB1 [cytosol]ProteinP14635 (Uniprot-TrEMBL)
CCNB1 [nucleoplasm]ProteinP14635 (Uniprot-TrEMBL)
CCNB2 [cytosol]ProteinO95067 (Uniprot-TrEMBL)
CDC16 [cytosol]ProteinQ13042 (Uniprot-TrEMBL)
CDC20 [cytosol]ProteinQ12834 (Uniprot-TrEMBL)
CDC20ProteinQ12834 (Uniprot-TrEMBL)
CDC23 [cytosol]ProteinQ9UJX2 (Uniprot-TrEMBL)
CDC25AProteinP30304 (Uniprot-TrEMBL)
CDC25CProteinP30307 (Uniprot-TrEMBL)
CDC26 [cytosol]ProteinQ8NHZ8 (Uniprot-TrEMBL)
CDC27 [cytosol]ProteinP30260 (Uniprot-TrEMBL)
CDC45 [nucleoplasm]ProteinO75419 (Uniprot-TrEMBL)
CDC6 [nucleoplasm]ProteinQ99741 (Uniprot-TrEMBL)
CDC7 [nucleoplasm]ProteinO00311 (Uniprot-TrEMBL)
CDK1 [cytosol]ProteinP06493 (Uniprot-TrEMBL)
CDK2 [nucleoplasm]ProteinP24941 (Uniprot-TrEMBL)
CDKN1A [nucleoplasm]ProteinP38936 (Uniprot-TrEMBL)
CDKN1AProteinP38936 (Uniprot-TrEMBL)
CDKN1B [nucleoplasm]ProteinP46527 (Uniprot-TrEMBL)
CHEK1ProteinO14757 (Uniprot-TrEMBL)
CHEK2-12ProteinO96017-12 (Uniprot-TrEMBL)
CLSPN [nucleoplasm]ProteinQ9HAW4 (Uniprot-TrEMBL)
CLSPNProteinQ9HAW4 (Uniprot-TrEMBL)
Cdc45:CDK:DDK:Mcm10:Activated

claspin:pre-replicative

complex
ComplexREACT_7262 (Reactome)
Cdc45:CDK:DDK:Mcm10:claspin:pre-replicative complexComplexREACT_7273 (Reactome)
Cdc45:CDK:DDK:Mcm10:pre-replicative complexComplexREACT_4546 (Reactome)
Chk1/Ckk2(Cds1)REACT_5826 (Reactome)
Cyclin

B1:phospho-Cdc2 (Thr

14, Thr 161)
ComplexREACT_6474 (Reactome)
Cyclin

B1:phospho-Cdc2(Thr

161, Thr 14, Tyr 15)
ComplexREACT_6704 (Reactome)
Cyclin

B:phospho-Cdc2(Thr

14)
ComplexREACT_6524 (Reactome)
Cyclin

E:Cdk2:p21/p27

complex
ComplexREACT_3804 (Reactome)
Cyclin B:Cdc2 complexComplexREACT_6447 (Reactome)
Cyclin E:Cdk2 complexesComplexREACT_5247 (Reactome)
DBF4 [nucleoplasm]ProteinQ9UBU7 (Uniprot-TrEMBL)
HUS1 [nucleoplasm]ProteinO60921 (Uniprot-TrEMBL)
Kinetochore ComplexREACT_5901 (Reactome)
Kinetochore:Mad1:MAD2 ComplexComplexREACT_4828 (Reactome) Mad2 binds to the Mad1:Kinetochore and undergoes a major conformational change within the complex to assume the form Mad2*.
Kinetochore:Mad1:MAD2* ComplexComplexREACT_5238 (Reactome)
MAD1L1 [cytosol]ProteinQ9Y6D9 (Uniprot-TrEMBL)
MAD1L1ProteinQ9Y6D9 (Uniprot-TrEMBL)
MAD2*CDC20 complexComplexREACT_2295 (Reactome) Activated Mad2 upon release from kinetochores binds and sequesters Cdc20 from activating the APC.
MAD2L1 [cytosol]ProteinQ13257 (Uniprot-TrEMBL)
MAD2L1ProteinQ13257 (Uniprot-TrEMBL)
MCC:APC/C complexComplexREACT_3955 (Reactome)
MCM10 [nucleoplasm]ProteinQ7L590 (Uniprot-TrEMBL)
MCM2 [nucleoplasm]ProteinP49736 (Uniprot-TrEMBL)
MCM3 [nucleoplasm]ProteinP25205 (Uniprot-TrEMBL)
MCM4(1-863) [nucleoplasm]ProteinP33991 (Uniprot-TrEMBL)
MCM5 [nucleoplasm]ProteinP33992 (Uniprot-TrEMBL)
MCM6 [nucleoplasm]ProteinQ14566 (Uniprot-TrEMBL)
MCM7 [nucleoplasm]ProteinP33993 (Uniprot-TrEMBL)
MCM8 [nucleoplasm]ProteinQ9UJA3 (Uniprot-TrEMBL)
MDM2ProteinQ00987 (Uniprot-TrEMBL)
Mad1:kinetochore complexComplexREACT_5632 (Reactome) The molecules that directly interact with Mad1 is unknown. However molecular genetic data has defined an assembly pathway consisting of CENP-I, HEC1, Mps1 that specifies the assembly of Mad1.
ORC1 [nucleoplasm]ProteinQ13415 (Uniprot-TrEMBL)
ORC2 [nucleoplasm]ProteinQ13416 (Uniprot-TrEMBL)
ORC3 [nucleoplasm]ProteinQ9UBD5 (Uniprot-TrEMBL)
ORC4 [nucleoplasm]ProteinO43929 (Uniprot-TrEMBL)
ORC5 [nucleoplasm]ProteinO43913 (Uniprot-TrEMBL)
ORC6 [nucleoplasm]ProteinQ9Y5N6 (Uniprot-TrEMBL)
PSMA1 [cytosol]ProteinP25786 (Uniprot-TrEMBL)
PSMA2 [cytosol]ProteinP25787 (Uniprot-TrEMBL)
PSMA3 [cytosol]ProteinP25788 (Uniprot-TrEMBL)
PSMA4 [cytosol]ProteinP25789 (Uniprot-TrEMBL)
PSMA5 [cytosol]ProteinP28066 (Uniprot-TrEMBL)
PSMA6 [cytosol]ProteinP60900 (Uniprot-TrEMBL)
PSMA7(2-248) [cytosol]ProteinO14818 (Uniprot-TrEMBL)
PSMA8 [cytosol]ProteinQ8TAA3 (Uniprot-TrEMBL)
PSMB1 [cytosol]ProteinP20618 (Uniprot-TrEMBL)
PSMB10 [cytosol]ProteinP40306 (Uniprot-TrEMBL)
PSMB11 [cytosol]ProteinA5LHX3 (Uniprot-TrEMBL)
PSMB2 [cytosol]ProteinP49721 (Uniprot-TrEMBL)
PSMB3 [cytosol]ProteinP49720 (Uniprot-TrEMBL)
PSMB4 [cytosol]ProteinP28070 (Uniprot-TrEMBL)
PSMB5 [cytosol]ProteinP28074 (Uniprot-TrEMBL)
PSMB6 [cytosol]ProteinP28072 (Uniprot-TrEMBL)
PSMB7 [cytosol]ProteinQ99436 (Uniprot-TrEMBL)
PSMB8 [cytosol]ProteinP28062 (Uniprot-TrEMBL)
PSMB9 [cytosol]ProteinP28065 (Uniprot-TrEMBL)
PSMC1(2-440) [cytosol]ProteinP62191 (Uniprot-TrEMBL)
PSMC2 [cytosol]ProteinP35998 (Uniprot-TrEMBL)
PSMC3 [cytosol]ProteinP17980 (Uniprot-TrEMBL)
PSMC4 [cytosol]ProteinP43686 (Uniprot-TrEMBL)
PSMC5 [cytosol]ProteinP62195 (Uniprot-TrEMBL)
PSMC6(2-389) [cytosol]ProteinP62333 (Uniprot-TrEMBL)
PSMD1 [cytosol]ProteinQ99460 (Uniprot-TrEMBL)
PSMD10 [cytosol]ProteinO75832 (Uniprot-TrEMBL)
PSMD11 [cytosol]ProteinO00231 (Uniprot-TrEMBL)
PSMD12 [cytosol]ProteinO00232 (Uniprot-TrEMBL)
PSMD13 [cytosol]ProteinQ9UNM6 (Uniprot-TrEMBL)
PSMD14 [cytosol]ProteinO00487 (Uniprot-TrEMBL)
PSMD2 [cytosol]ProteinQ13200 (Uniprot-TrEMBL)
PSMD3 [cytosol]ProteinO43242 (Uniprot-TrEMBL)
PSMD4(2-377) [cytosol]ProteinP55036 (Uniprot-TrEMBL)
PSMD5 [cytosol]ProteinQ16401 (Uniprot-TrEMBL)
PSMD6(2-389) [cytosol]ProteinQ15008 (Uniprot-TrEMBL)
PSMD7(2-324) [cytosol]ProteinP51665 (Uniprot-TrEMBL)
PSMD8 [cytosol]ProteinP48556 (Uniprot-TrEMBL)
PSMD9 [cytosol]ProteinO00233 (Uniprot-TrEMBL)
PSME1 [cytosol]ProteinQ06323 (Uniprot-TrEMBL)
PSME2 [cytosol]ProteinQ9UL46 (Uniprot-TrEMBL)
PSME3 [cytosol]ProteinP61289 (Uniprot-TrEMBL)
PSME4 [cytosol]ProteinQ14997 (Uniprot-TrEMBL)
PSMF1(2-271) [cytosol]ProteinQ92530 (Uniprot-TrEMBL)
Persistent single-stranded DNAREACT_7801 (Reactome)
Phospho-COP1(Ser-387):p53 complexComplexREACT_21189 (Reactome)
RAD1 [nucleoplasm]ProteinO60671 (Uniprot-TrEMBL)
RAD17 [nucleoplasm]ProteinO75943 (Uniprot-TrEMBL)
RAD9A [nucleoplasm]ProteinQ99638 (Uniprot-TrEMBL)
RAD9B [nucleoplasm]ProteinQ6WBX8 (Uniprot-TrEMBL)
RFC2 [nucleoplasm]ProteinP35250 (Uniprot-TrEMBL)
RFC3 [nucleoplasm]ProteinP40938 (Uniprot-TrEMBL)
RFC4 [nucleoplasm]ProteinP35249 (Uniprot-TrEMBL)
RFC5 [nucleoplasm]ProteinP40937 (Uniprot-TrEMBL)
RFWD2ProteinQ8NHY2 (Uniprot-TrEMBL)
RPA complexed to ssDNAComplexREACT_7172 (Reactome) RPA associates with ssDNA in distinct complexes that can be distinguished by the length of ssDNA occluded by each RPA molecule. These complexes reflect the progressive association of distinct DNA-binding domains present in the RPA heterotrimeric structure. Binding is coupled to significant conformational changes within RPA that are observable at the microscopic level. Presumably, the different conformations of free and ssDNA-bound RPA allow the protein to selectively interact with factors such as ATR-ATRIP when bound to DNA.
RPA heterotrimerComplexREACT_3427 (Reactome)
RPA1 [nucleoplasm]ProteinP27694 (Uniprot-TrEMBL)
RPA2 [nucleoplasm]ProteinP15927 (Uniprot-TrEMBL)
RPA3 [nucleoplasm]ProteinP35244 (Uniprot-TrEMBL)
RPS27A(1-76) [cytosol]ProteinP62979 (Uniprot-TrEMBL)
Rad17-RFC complex bound to DNAComplexREACT_7502 (Reactome) Rad17-RFC complex associates with DNA substrates containing ssDNA regions including gapped or primed DNA in an ATP-independent reaction. Loading of the Rad9-Hus1-Rad1 (9-1-1) complex occurs preferentially on DNA substrates containing a 5' recessed end. This contrasts with the loading of PCNA by RFC which preferentially occurs on DNA with 3' recessed ends.
Rad17-RFC complexComplexREACT_7804 (Reactome) The Rad17-RFC complex is a heteropentamer structurally similar to RFC. The Rad17-RFC complex contains the four smaller RFC subunits (Rfc2 [p37], Rfc3 [p36], Rfc4 [p40], and Rfc5 [p38]) and the 75 kDa Rad17 subunit in place of the Rfc1 [p140] subunit. The Rad17 complex contains a weak ATPase that is poorly stimulated by primed DNA. Along with binding the 9-1-1 complex and RPA, the Rad17-RFC complex interacts with human MCM7 protein. Each of these interactions is critical for Chk1 activation.

The Rad17 subunit is conserved evolutionarily with the protein showing 49% identity at the amino acid level with the S. pombe rad17 protein. Targeted deletion of the N-terminal region of mouse Rad17 leads to embryonic lethality, strongly suggesting that human Rad17 is also essential for long-term viability.

Rad9-Hus1-Rad1 complexComplexREACT_7593 (Reactome) The Rad9-Hus1-Rad1 (9-1-1) complex is a ring-shaped heterotrimeric complex. Under genotoxic stress conditions, it can be loaded onto DNA at sites of damage or stalled forks by the Rad17 complex.
Rad9-Hus1-Rad1 bound to DNAComplexREACT_7267 (Reactome) A major known function of the 9-1-1 complex is to recruit Chk1 to stalled replication forks for activation by ATR. However, the presence of the 9-1-1 complex also alters the ability of Rad17 to become phoshorylated, perhaps suggesting that 9-1-1 may also serve to recruit a subset of ATR substrates. The 9-1-1 complex has also been found to interact with base excision repair factors human DNA polymerase beta, flap endonuclease FEN1, and the S. pombe MutY homolog (SpMYH), indicating that 9-1-1 also plays a direct role in DNA repair.
TP53ProteinP04637 (Uniprot-TrEMBL)
UBA52(1-76) [cytosol]ProteinP62987 (Uniprot-TrEMBL)
UBB(1-76) [cytosol]ProteinP0CG47 (Uniprot-TrEMBL)
UBB(153-228) [cytosol]ProteinP0CG47 (Uniprot-TrEMBL)
UBB(77-152) [cytosol]ProteinP0CG47 (Uniprot-TrEMBL)
UBC(1-76) [cytosol]ProteinP0CG48 (Uniprot-TrEMBL)
UBC(153-228) [cytosol]ProteinP0CG48 (Uniprot-TrEMBL)
UBC(229-304) [cytosol]ProteinP0CG48 (Uniprot-TrEMBL)
UBC(305-380) [cytosol]ProteinP0CG48 (Uniprot-TrEMBL)
UBC(381-456) [cytosol]ProteinP0CG48 (Uniprot-TrEMBL)
UBC(457-532) [cytosol]ProteinP0CG48 (Uniprot-TrEMBL)
UBC(533-608) [cytosol]ProteinP0CG48 (Uniprot-TrEMBL)
UBC(609-684) [cytosol]ProteinP0CG48 (Uniprot-TrEMBL)
UBC(77-152) [cytosol]ProteinP0CG48 (Uniprot-TrEMBL)
UBE2C [cytosol]ProteinO00762 (Uniprot-TrEMBL)
UBE2D1 [cytosol]ProteinP51668 (Uniprot-TrEMBL)
UBE2E1(1-193) [cytosol]ProteinP51965 (Uniprot-TrEMBL)
UbProteinREACT_3316 (Reactome)
Ubiquitin ligaseREACT_4282 (Reactome)
Ubiquitinated Phospho-Cdc25AComplexREACT_4164 (Reactome) A number of ubiquitin moeities are covalently added to the Cdc25A, which marks it for proteolytic degradation.
WEE1ProteinP30291 (Uniprot-TrEMBL)
hBUBR1:hBUB3:MAD2*:CDC20 complexComplexREACT_5836 (Reactome)
p-CHEK2-12ProteinO96017-12 (Uniprot-TrEMBL)
p-MDM2ProteinQ00987 (Uniprot-TrEMBL)
p-S123-CDC25A [cytosol]ProteinP30304 (Uniprot-TrEMBL)
p-S123-CDC25AProteinP30304 (Uniprot-TrEMBL)
p-S15-TP53 [nucleoplasm]ProteinP04637 (Uniprot-TrEMBL)
p-S15-TP53ProteinP04637 (Uniprot-TrEMBL)
p-S1981-ATMProteinQ13315 (Uniprot-TrEMBL)
p-S216-CDC25C [cytosol]ProteinP30307 (Uniprot-TrEMBL)
p-S216-CDC25CProteinP30307 (Uniprot-TrEMBL)
p-S317,S345-CHEK1ProteinO14757 (Uniprot-TrEMBL)
p-S387-RFWD2 [cytosol]ProteinQ8NHY2 (Uniprot-TrEMBL)
p-S387-RFWD2 [nucleoplasm]ProteinQ8NHY2 (Uniprot-TrEMBL)
p-S387-RFWD2ProteinQ8NHY2 (Uniprot-TrEMBL)
p-T14,T161-CDK1 [nucleoplasm]ProteinP06493 (Uniprot-TrEMBL)
p-T14,Y15,T161-CDK1 [nucleoplasm]ProteinP06493 (Uniprot-TrEMBL)
p-T14-CDK1 [cytosol]ProteinP06493 (Uniprot-TrEMBL)
p-T916,S945-CLSPN [nucleoplasm]ProteinQ9HAW4 (Uniprot-TrEMBL)
p-WEE1ProteinP30291 (Uniprot-TrEMBL)
p21/p27ProteinREACT_8306 (Reactome)
p53 tetramerComplexREACT_20792 (Reactome)
phospho-Cdc25C:14-3-3 protein complexComplexREACT_4474 (Reactome)
phosphorylated

anaphase promoting

complex (APC/C)
ComplexREACT_7058 (Reactome)
ubiquitinated phospho-COP1(ser-387)ComplexREACT_21146 (Reactome)

Annotated Interactions

View all...
SourceTargetTypeDatabase referenceComment
14-3-3 proteinsREACT_205 (Reactome)
26S proteasomemim-catalysisREACT_20637 (Reactome)
26S proteasomemim-catalysisREACT_873 (Reactome)
ADPArrowREACT_1170 (Reactome)
ADPArrowREACT_128 (Reactome)
ADPArrowREACT_1603 (Reactome)
ADPArrowREACT_1680 (Reactome)
ADPArrowREACT_1756 (Reactome)
ADPArrowREACT_20543 (Reactome)
ADPArrowREACT_264 (Reactome)
ADPArrowREACT_302 (Reactome)
ADPArrowREACT_43 (Reactome)
ADPArrowREACT_6178 (Reactome)
ADPArrowREACT_6217 (Reactome)
ADPArrowREACT_6750 (Reactome)
ADPArrowREACT_6869 (Reactome)
ADPArrowREACT_845 (Reactome)
ATPREACT_1170 (Reactome)
ATPREACT_128 (Reactome)
ATPREACT_1603 (Reactome)
ATPREACT_1680 (Reactome)
ATPREACT_1756 (Reactome)
ATPREACT_20543 (Reactome)
ATPREACT_264 (Reactome)
ATPREACT_302 (Reactome)
ATPREACT_43 (Reactome)
ATPREACT_6178 (Reactome)
ATPREACT_6217 (Reactome)
ATPREACT_6750 (Reactome)
ATPREACT_6869 (Reactome)
ATPREACT_845 (Reactome)
ATR-ATRIP-RPA-ssDNA signaling complexArrowREACT_6939 (Reactome)
ATR-ATRIPREACT_6939 (Reactome)
ATR-ATRIPmim-catalysisREACT_6750 (Reactome)
ATR-ATRIPmim-catalysisREACT_6869 (Reactome)
Activated MAD2L1ArrowREACT_88 (Reactome)
Activated MAD2L1REACT_36 (Reactome)
Activated MAD2L1REACT_433 (Reactome)
Amino AcidArrowREACT_873 (Reactome)
BUB1BREACT_36 (Reactome)
BUB3REACT_36 (Reactome)
CDC20REACT_36 (Reactome)
CDC20REACT_433 (Reactome)
CDC25AREACT_1680 (Reactome)
CDC25AREACT_43 (Reactome)
CDC25AREACT_845 (Reactome)
CDC25CREACT_1170 (Reactome)
CDC25CREACT_128 (Reactome)
CDKN1AArrowREACT_9064 (Reactome)
CHEK1REACT_302 (Reactome)
CHEK1REACT_6869 (Reactome)
CHEK1mim-catalysisREACT_264 (Reactome)
CHEK1mim-catalysisREACT_845 (Reactome)
CHEK2-12REACT_1603 (Reactome)
CHEK2-12mim-catalysisREACT_43 (Reactome)
CLSPNREACT_6738 (Reactome)
Cdc45:CDK:DDK:Mcm10:Activated

claspin:pre-replicative

complex
ArrowREACT_6750 (Reactome)
Cdc45:CDK:DDK:Mcm10:claspin:pre-replicative complexArrowREACT_6738 (Reactome)
Cdc45:CDK:DDK:Mcm10:claspin:pre-replicative complexREACT_6750 (Reactome)
Cdc45:CDK:DDK:Mcm10:pre-replicative complexREACT_6738 (Reactome)
Chk1/Ckk2(Cds1)mim-catalysisREACT_128 (Reactome)
Chk1/Ckk2(Cds1)mim-catalysisREACT_1680 (Reactome)
Cyclin

B1:phospho-Cdc2 (Thr

14, Thr 161)
REACT_6178 (Reactome)
Cyclin

B1:phospho-Cdc2(Thr

161, Thr 14, Tyr 15)
ArrowREACT_6178 (Reactome)
Cyclin

B:phospho-Cdc2(Thr

14)
ArrowREACT_6217 (Reactome)
Cyclin

E:Cdk2:p21/p27

complex
ArrowREACT_334 (Reactome)
Cyclin B:Cdc2 complexREACT_6217 (Reactome)
Cyclin E:Cdk2 complexesREACT_334 (Reactome)
Kinetochore ComplexREACT_914 (Reactome)
Kinetochore:Mad1:MAD2 ComplexArrowREACT_1922 (Reactome)
Kinetochore:Mad1:MAD2 ComplexREACT_2215 (Reactome)
Kinetochore:Mad1:MAD2* ComplexArrowREACT_2215 (Reactome)
Kinetochore:Mad1:MAD2* ComplexREACT_88 (Reactome)
MAD1L1REACT_914 (Reactome)
MAD2*CDC20 complexArrowREACT_433 (Reactome)
MAD2L1REACT_1922 (Reactome)
MCC:APC/C complexArrowREACT_1951 (Reactome)
MDM2REACT_988 (Reactome)
Mad1:kinetochore complexArrowREACT_88 (Reactome)
Mad1:kinetochore complexArrowREACT_914 (Reactome)
Mad1:kinetochore complexREACT_1922 (Reactome)
Persistent single-stranded DNAREACT_6936 (Reactome)
Phospho-COP1(Ser-387):p53 complexREACT_20554 (Reactome)
REACT_100 (Reactome) Cdc25C is phosphorylated by Chk1 at ser-216 (Blasina et al.,1999 ) resulting in both inhibition of the Cdc25 phosphatase activity and creation of a 14-3-3 docking site (Peng et al., 1997). Association of 14-3-3 protein is believed to exclude Cdc25C from the nucleus via cytoplasmic retention of the Cdc25C:14-3-3 complex.
REACT_1170 (Reactome) Phosphorylation of Cdc25C at Ser 216 results in both the inhibition of Cdc25C phosphatase activity and the creation of a 14-3-3 docking site (Peng et al. 1997).
REACT_128 (Reactome) Cdc25C is negatively regulated by phosphorylation on Ser 216, the 14-3-3-binding site. This is an important regulatory mechanism used by cells to block mitotic entry under normal conditions and after DNA damage (Bulavin et al., 2003).
REACT_1603 (Reactome) At the beginning of this reaction, 1 molecule of 'ATP', and 1 molecule of 'Chk2' are present. At the end of this reaction, 1 molecule of 'phospho-Chk2', and 1 molecule of 'ADP' are present.

This reaction takes place in the 'nucleus' and is mediated by the 'kinase activity' of 'phospho-ATM (Ser 1981)'.

REACT_1680 (Reactome) Chk1 directly phosphorylates Cdc25A at Ser-123. Chk1 phosphorylation is required for cells to delay cell cycle progression in response to double-strand DNA breaks (Zhao et al., 2002).
REACT_1756 (Reactome) In response to DNA damage due to ionizing radiation, the serine at position 15 of the p53 tumor suppressor protein is rapidly phosphorylated by the ATM kinase. This serves to stabilize the p53 protein. A rise in the levels of the p53 protein induce the expression of the p21 cyclin-dependent kinase inhibitor. This prevents the normal progression from G1 to S phase, thus providing a check on replication of damaged DNA.
REACT_1922 (Reactome) Mad2 is recruited to the kinetochore through an interaction with Mad1.
REACT_1951 (Reactome) In the direct inhibition model, association of the MCC with APCC results in the inactivation of APC/C. However, the affinity between MCC and APC/C is not high, so that the inhibition is readily reversible. The role of unattached kinetochores is to sensitize the APC/C to prolonged inhibition by the MCC.
REACT_20527 (Reactome) Ionizing radiation results in an ATM-dependent movement of COP1 from the nucleus to the cytoplasm (Dornan et al., 2006).
REACT_20543 (Reactome) ATM phosphorylates COP1 on Ser387 in response to DNA damage (Dornan et al., 2006).
REACT_20554 (Reactome) ATM-dependent phosphorylation of COP1 on Ser(387) results in disruption of the COP1-p53 complex (Dornan et al., 2006)
REACT_20581 (Reactome) ATM phosphorylation promotes autoubiquitination of COP1 in vitro (Dornan et al., 2006). The number of ubiquitin molecules shown in this reaction is set arbitrarily at 4.
REACT_205 (Reactome) Association of Cdc25C with 14-3-3 proteins with phospho-Cdc25C (Ser216) is believed to result in retention of this complex within the cytoplasm ( Dalal et al., 1999)
REACT_20637 (Reactome) Autoubiquitinated COP1 is degraded by the proteasome. The number of ubiquitin molecules shown in this reaction is arbitrarily set at 4. (Dornan et al., 2006).
REACT_2215 (Reactome) In vitro structural studies have shown that Mad2 undergoes a major conformational change upon binding to Mad1. This conformational change is postulated to activate Mad2 into a high affinity state which can bind and sequester Cdc20 from the APC.
REACT_264 (Reactome) Phosphorylation of Wee1 by Chk1 stimulates Wee1 kinase activity.
REACT_302 (Reactome) At the beginning of this reaction, 1 molecule of 'ATP', and 1 molecule of 'Chk1' are present. At the end of this reaction, 1 molecule of 'phospho-Chk1', and 1 molecule of 'ADP' are present.

This reaction takes place in the 'nucleus' and is mediated by the 'kinase activity' of 'phospho-ATM (Ser 1981)'.

REACT_334 (Reactome) During G1, the activity of cyclin-dependent kinases (CDKs) is kept in check by the CDK inhibitors (CKIs) p27 and p21, thereby preventing premature entry into S phase (see Guardavaccaro and Pagano, 2006). The efficient recognition and ubiquitination of p27 by the SCF(Skp2) complex requires the formation of a trimeric complex containing p27 and cyclin E/A:Cdk2.
REACT_36 (Reactome) Upon release from the kinetochore, Mad2 associates with Cdc20, hBUBR1, and hBUB3 to form the Mitotic Checkpoint Complex (MCC). Assembly of this complex does not depend on kinetochores but this complex can only inhibit APC/C that has undergone mitotic modifications.
REACT_433 (Reactome) In the sequestration model, the Mad2 molecules that dissociate from unattached kinetochores are perceived to bind to Cdc20, a protein that recruits specific substrates to the APC/C. Consequently, Mad2 indirectly inhibits the APC/C by sequestering its activator, Cdc20. This requires interaction between Mad1 and Mad2. Cdc20 and Mad1 bind to the same site on Mad2.
REACT_43 (Reactome) Detection of DNA damage caused by ionizing radiation results in the phosphorylation of Cdc25A at Ser-123 by Chk2.
REACT_6178 (Reactome) Wee1, a nuclear kinase, phosphorylates cyclin B1:Cdc2 on tyrosine 15 inactivating the complex.
REACT_6217 (Reactome) Myt1, which localizes preferentially to the endoplasmic reticulum and Golgi complex, phosphorylates Cdc2 on threonine 14 ( Liu et al., 1997).
REACT_6729 (Reactome) The 9-1-1 complex is a heterotrimeric ring-shaped structure that is loaded onto DNA by the Rad17-RFC complex. In vitro studies indicate that loading is preferred onto DNA substrates containing ssDNA gaps that presumably resemble structures found upon replication fork stalling and DNA polymerase/helicase uncoupling. The Rad17-RFC and 9-1-1 complexes are structurally similar to the RFC (replication factor C) clamp loader and PCNA sliding clamp, respectively, and similar mechanisms are thought to be used during loading of the 9-1-1 complex and PCNA. Upon loading, the 9-1-1 complex can recruit Chk1 onto sites of replication fork uncoupling or DNA damage.

The purified Rad17 and Rad9-Hus1-Rad1 (9-1-1) complexes can form a stable co-complex in the presence of ATP, using Rad17-Rad9 interactions. From computer modeling studies, the Rad17 subunit of the complex is also proposed to interact with the C-terminus of Rad1, p36 with the C-terminus of Hus1, and p38 with the C-terminus of Rad9. A major known function of the 9-1-1 complex is to recruit Chk1 to stalled replication forks for activation by ATR. However, the presence of the 9-1-1 complex also alters the ability of Rad17 to become phosphorylated, perhaps suggesting that 9-1-1 may regulate the recruiment of additional ATR substrates. The 9-1-1 complex has also been found to interact with base excision repair factors human DNA polymerase beta, flap endonuclease FEN1, and the S. pombe MutY homolog (SpMYH), indicating that 9-1-1 also plays a direct role in DNA repair.

REACT_6738 (Reactome) Claspin is loaded onto DNA replication origins during replication initiation. Studies in Xenopus egg extracts indicate claspin loading requires the presence of Cdc45, a factor that promotes the initial unwinding of the origin DNA in the presence of Cdk2. This step is followed by RPA binding which is a prerequisite for recruitment of PCNA and DNA polymerases alpha and delta. As RPA is not required for claspin binding, it is postulated that claspin binds at the time of initial origin unwinding but prior to the initiation of DNA synthesis. Claspin would then continue to associate with replication fork machinery where it can serve as a checkpoint sensor protein. Even though associated with the replication fork, claspin is not an essential DNA replication factor.

Studies of Xenopus claspin indicate that it can physically associate with cognate Cdc45, DNA polymerase epsilon, RPA, RFC, and Rad17-RFC on chromatin. Studies of purified human claspin indicate that it binds with high affinity to branched (or forked) DNA structures that resemble stalled replication forks. Electron microscopy of these complexes indicates that claspin binds as a ring-like structure near the branch. The protein is hypothesized to encircle the DNA at these sites.

REACT_6750 (Reactome) Claspin is a replication fork-associated protein important for Chk1 activation. Claspin loads onto the fork during replication origin firing and travels with the fork during DNA synthesis. Upon fork uncoupling and ATR-ATRIP binding to persistent ssDNA, the activated ATR kinase phosphorylates claspin at two primary sites. Modification increases the affinity of claspin for Chk1. Studies of human or Xenopus claspin indicate that phosphorylation of both sites is essential for significant claspin-Chk1 association. Following claspin modification by ATR, Chk1 can be transiently recruited to the stalled replication fork for subsequent phosphorylation and activation by ATR. Activation of Chk1 allows modification of additional downstream targets, thus amplifying the checkpoint signal. While much of the mechanistic information concerning claspin action has been obtained using Xenopus laevis egg extracts and Xenopus claspin, factors with similar activity have been found in various eukaryotic species including S. cerevisiae (MRC1), S. pombe (mrc1), and humans.

Activated ATR phosphorylates human claspin on two sites, threonine 916 and serine 945.

REACT_6798 (Reactome) The Rad17-RFC complex is involved in an early stage of the genotoxic stress response. The major function of the protein complex is to load the Rad9-Hus1-Rad1 (9-1-1) complex onto DNA at sites of damage and/or stalled replication forks. This reaction is conceptually similar to the loading of the PCNA sliding clamp onto DNA by RFC. The association of the Rad17-RFC complex with ssDNA or gapped or primed DNA is significantly stimulated by RPA, but not by the heterologous E. coli SSB. Loading of the human 9-1-1 complex onto such DNA templates is also strongly stimulated by cognate RPA, but not yeast RPA. Although Rad17 and Rad9 are substrates of the ATR kinase activity, loading of the Rad17 and 9-1-1 complexes onto DNA occurs independent of ATR.

The Rad17-RFC complex is a heteropentamer structurally similar to RFC. The complex contains the four smaller RFC subunits (Rfc2 [p37], Rfc3 [p36], Rfc4 [p40], and Rfc5 [p38]) and the 75 kDa Rad17 subunit in place of the Rfc1 [p140] subunit. The Rad17 complex contains a weak ATPase that is slightly stimulated by primed DNA. Along with binding the 9-1-1 complex and RPA, the Rad17-RFC complex interacts with human MCM7 protein. Each of these interactions is critical for Chk1 activation.

The Rad17 subunit is conserved evolutionarily with the protein showing 49% identity at the amino acid level with the S. pombe rad17 protein. Targeted deletion of the N-terminal region of mouse Rad17 leads to embryonic lethality, strongly suggesting that human Rad17 is also essential for long-term viability.

Rad17-RFC complex associates with DNA substrates containing ssDNA regions including gapped or primed DNA in an ATP-independent reaction. Loading of the Rad9-Hus1-Rad1 (9-1-1) complex occurs preferentially on DNA substrates containing a 5' recessed end. This contrasts with the loading of PCNA by RFC which preferentially occurs on DNA with 3' recessed ends.

REACT_6869 (Reactome) Chk1 is a checkpoint kinase activated during genotoxic stress. Like ATR, Chk1 is essential for viability in mammals. Targeted gene disruption in mice shows that loss of Chk1 causes peri-implantation embryonic lethality. Even though ATR-ATRIP not bound to ssDNA can phosphorylate Chk1, Chk1 activation is greatly enhanced when recruited to stalled replication forks by physical interaction with a modified form of claspin and the Rad9-Hus1-Rad1 sliding clamp. Activation of Chk1 occurs following phosphorylation of two sites (serine 317 and serine 345). Mutational analysis indicates that modification of both sites is essential for maximal kinase activity, while phosphorylation of only a single site causes only weak activation of Chk1. Following phosphorylation, Chk1 can diffuse away from the complex to further amplify the checkpoint signal. ATR appears to be the primary kinase activating Chk1 as conditions that activate ATR (ultraviolet irradiation or treatment with hydroxyurea) also activate Chk1. Stresses that activate ATM, e.g., ionizing irradiation, do not cause significant Chk1 activation. While the ATR and ATM pathways are distinct, there is interplay between the two. For example, double-strand DNA breaks can be processed in an ATM-dependent manner to generate structures that can cause ATR and hence Chk1 activation. The ATR and ATM pathways also have mechanistic similarities. Analogous to the Chk1 kinase existing downstream of ATR, the Chk2 checkpoint kinase is modified and activated by ATM. Although having distinct structures, Chk1 and Chk2 also have overlapping targets with some substrate sites phosphorylatable by both kinases (e.g., serine 20 of p53).
REACT_6936 (Reactome) When a DNA replication fork encounters DNA lesions (e.g., cyclobutane pyrimidine dimers or alkylated bases) stalling of the replicative DNA polymerase may occur. This can lead to dissociation or 'uncoupling' of the DNA polymerase from the DNA helicase and generation of long regions of persistent ssDNA. Uncoupling can also occur in response to other genotoxic stresses such as reduced dNTP pools caused by hydroxyurea treatment which inhibits cellular ribonucleotide diphosphate reductase. The exposed ssDNA is bound by the single-stranded DNA binding protein RPA. The persistent nature of this RPA-ssDNA complex (as opposed to a more-transient complex found at an active replication fork) allows it to serve as a signal for replication stress that can be recognized by the ATR-ATRIP and Rad17-Rfc2-5 complexes.

RPA associates with ssDNA in distinct complexes that can be distinguished by the length of ssDNA occluded by each RPA molecule. These complexes reflect the progressive association of distinct DNA-binding domains present in the RPA heterotrimeric structure. Binding is coupled to significant conformational changes within RPA that are observable at the microscopic level. Presumably, the different conformations of free and ssDNA-bound RPA allow the protein to selectively interact with factors such as ATR-ATRIP when bound to DNA.

REACT_6939 (Reactome) ATR kinase activity is stimulated upon binding of the ATR-ATRIP complex to an RPA-ssDNA complex. ATR can subsequently phosphorylate and activate the checkpoint kinase Chk1, allowing further amplification of the checkpoint signal. The ATR and Chk1 kinases then modify a variety of factors that can lead to stabilization of stalled DNA replication forks, inhibition of origin firing, inhibition of cell cycle progression, mobilization of DNA repair factors, and induction of apoptosis. This checkpoint signaling mechanism is highly conserved in eukaryotes, and homologues of ATR and ATRIP are found in such organisms as S. cerevisiae (Mec1 and Ddc2, respectively), S. pombe (rad3 and rad26, respectively), and X. laevis (Xatr and Xatrip, respectively).

The ATR (ATM- and rad3-related) kinase is an essential checkpoint factor in human cells. In response to replication stress (i.e., stresses that cause replication fork stalling) or ultraviolet radiation, ATR becomes active and phosphorylates numerous factors involved in the checkpoint response including the checkpoint kinase Chk1. ATR is invariably associated with ATRIP (ATR-interacting protein) in human cells. Depletion of ATRIP by siRNA causes a loss of ATR protein without affecting ATR mRNA levels indicating that complex formation stabilizes the ATR protein. ATRIP is also a substrate for the ATR kinase, but modification of ATRIP does not significantly regulate the recruitment of ATR-ATRIP to sites of damage, the activation of Chk1, or the modification of p53.

While the ATR-ATRIP complex binds only poorly to RPA complexed with ssDNA lengths of 30 or 50 nt, binding is significantly enhanced in the presence of a 75 nt ssDNA molecule. Complex formation is primarily mediated by physical interaction between ATRIP and RPA. Multiple elements within the ATRIP molecule can bind to the RPA-ssDNA complex, including residues 1-107 (highest affinity), 218-390, and 390-791 (lowest affinity). Although the full-length ATRIP is unable to bind ssDNA, an internal region (108-390) can weakly bind ssDNA when present in rabbit reticulocyte lysates. ATR can bind to the ssDNA directly independent of RPA, but this binding is inhibited by ATRIP. Upon binding, the ATR kinase becomes activated and can directly phosphorylate substrates such as Rad17.

REACT_845 (Reactome) Detection of DNA damage caused by ionizing radiation results in the phosphorylation of Cdc25A at Ser-123 by Chk1, inhibiting Cdc25A.
REACT_873 (Reactome) At the beginning of this reaction, 1 molecule of 'Ubiquitinated Phospho-Cdc25A' is present. At the end of this reaction, 1 molecule of 'Amino Acid' is present.

This reaction takes place in the 'cytosol' and is mediated by the 'endopeptidase activity' of '26S proteasome'.

REACT_88 (Reactome) The mechanism by which the conformationally altered inhibitory form of Mad2 is released from its association with Mad1 at the kinetochore is not known. Mad1 and Cdc20 have a common 10 residue Mad2 binding motif. Therefore, one possibility is that Mad2 is transferred competitively from Mad1 to Cdc20 (Luo et al., 2002; Sironi et al., 2002).
REACT_9064 (Reactome) p21 is transcriptionally activated by p53 after DNA damage.
REACT_914 (Reactome) The association of Mad1 with the kinetochore is the first step in the process of Mad2 mediated amplification of the signal from defective kinetochores.
REACT_93 (Reactome) At the beginning of this reaction, 1 molecule of 'ubiquitin', and 1 molecule of 'phospho-Cdc25A' are present. At the end of this reaction, 1 molecule of 'Ubiquitinated Phospho-Cdc25A' is present.

This reaction takes place in the 'cytosol' and is mediated by the 'ubiquitin-protein ligase activity' of 'Ubiquitin ligase'.

REACT_988 (Reactome) At the beginning of this reaction, 1 molecule of 'Mdm2' is present. At the end of this reaction, 1 molecule of 'phospho-MDM2' is present.

This reaction takes place in the 'nucleoplasm' and is mediated by the 'kinase activity' of 'phospho-ATM (Ser 1981)'.

RFWD2REACT_20543 (Reactome)
RPA complexed to ssDNAArrowREACT_6936 (Reactome)
RPA complexed to ssDNAREACT_6798 (Reactome)
RPA complexed to ssDNAREACT_6939 (Reactome)
RPA heterotrimerREACT_6936 (Reactome)
Rad17-RFC complex bound to DNAArrowREACT_6798 (Reactome)
Rad17-RFC complex bound to DNAREACT_6729 (Reactome)
Rad17-RFC complex bound to DNAmim-catalysisREACT_6729 (Reactome)
Rad17-RFC complexREACT_6798 (Reactome)
Rad9-Hus1-Rad1 complexREACT_6729 (Reactome)
Rad9-Hus1-Rad1 bound to DNAArrowREACT_6729 (Reactome)
TP53REACT_1756 (Reactome)
UbArrowREACT_20637 (Reactome)
UbREACT_20581 (Reactome)
UbREACT_93 (Reactome)
Ubiquitin ligasemim-catalysisREACT_93 (Reactome)
Ubiquitinated Phospho-Cdc25AArrowREACT_93 (Reactome)
Ubiquitinated Phospho-Cdc25AREACT_873 (Reactome)
WEE1REACT_264 (Reactome)
WEE1mim-catalysisREACT_6178 (Reactome)
hBUBR1:hBUB3:MAD2*:CDC20 complexArrowREACT_36 (Reactome)
hBUBR1:hBUB3:MAD2*:CDC20 complexREACT_1951 (Reactome)
p-CHEK2-12ArrowREACT_1603 (Reactome)
p-MDM2ArrowREACT_988 (Reactome)
p-S123-CDC25AArrowREACT_1680 (Reactome)
p-S123-CDC25AArrowREACT_43 (Reactome)
p-S123-CDC25AArrowREACT_845 (Reactome)
p-S123-CDC25AREACT_93 (Reactome)
p-S15-TP53ArrowREACT_1756 (Reactome)
p-S15-TP53ArrowREACT_9064 (Reactome)
p-S1981-ATMmim-catalysisREACT_1603 (Reactome)
p-S1981-ATMmim-catalysisREACT_1756 (Reactome)
p-S1981-ATMmim-catalysisREACT_20543 (Reactome)
p-S1981-ATMmim-catalysisREACT_302 (Reactome)
p-S1981-ATMmim-catalysisREACT_988 (Reactome)
p-S216-CDC25CArrowREACT_1170 (Reactome)
p-S216-CDC25CArrowREACT_128 (Reactome)
p-S216-CDC25CREACT_205 (Reactome)
p-S317,S345-CHEK1ArrowREACT_302 (Reactome)
p-S317,S345-CHEK1ArrowREACT_6869 (Reactome)
p-S317,S345-CHEK1mim-catalysisREACT_1170 (Reactome)
p-S387-RFWD2ArrowREACT_20527 (Reactome)
p-S387-RFWD2ArrowREACT_20543 (Reactome)
p-S387-RFWD2ArrowREACT_20554 (Reactome)
p-S387-RFWD2REACT_20527 (Reactome)
p-S387-RFWD2REACT_20581 (Reactome)
p-S387-RFWD2mim-catalysisREACT_20581 (Reactome)
p-WEE1ArrowREACT_264 (Reactome)
p21/p27REACT_334 (Reactome)
p21/p27mim-catalysisREACT_334 (Reactome)
p53 tetramerArrowREACT_20554 (Reactome)
phospho-Cdc25C:14-3-3 protein complexArrowREACT_100 (Reactome)
phospho-Cdc25C:14-3-3 protein complexArrowREACT_205 (Reactome)
phospho-Cdc25C:14-3-3 protein complexREACT_100 (Reactome)
phosphorylated

anaphase promoting

complex (APC/C)
REACT_1951 (Reactome)
ubiquitinated phospho-COP1(ser-387)ArrowREACT_20581 (Reactome)
ubiquitinated phospho-COP1(ser-387)REACT_20637 (Reactome)