Page last updated: 2024-10-24

traversing start control point of mitotic cell cycle

Definition

Target type: biologicalprocess

A cell cycle process by which a cell commits to entering S phase via a positive feedback mechanism between the regulation of transcription and G1 CDK activity. [GOC:mtg_cell_cycle]

The traversal of the Start (S) control point, also known as the restriction point, is a crucial step in the mitotic cell cycle. This transition marks the commitment of a cell to undergo a full round of division. Here's a detailed breakdown of the process:

1. **Signal Integration:** The decision to traverse the S control point depends on the integration of multiple intracellular and extracellular signals. These include growth factors, nutrients, and DNA damage status.
2. **Cyclin D and CDK4/6 Activation:** Growth factors stimulate the production of cyclin D, which complexes with CDK4/6 kinases. This complex phosphorylates the retinoblastoma protein (Rb).
3. **Rb Phosphorylation and E2F Release:** As Rb is phosphorylated, it undergoes a conformational change, releasing the transcription factor E2F.
4. **E2F Activation and Gene Expression:** Freed E2F activates the transcription of genes required for DNA replication, including cyclin E and A, as well as other proteins necessary for S phase entry.
5. **Cyclin E and CDK2 Activation:** Cyclin E accumulates and forms a complex with CDK2, which further phosphorylates Rb, leading to a sustained release of E2F.
6. **DNA Replication Initiation:** With the appropriate levels of cyclin E/CDK2 activity and E2F activation, the cell can now initiate DNA replication.
7. **Checkpoint Control:** The cell cycle progression through the S control point is tightly regulated by checkpoints. These mechanisms ensure that all conditions are favorable for DNA replication before the cell commits to this critical step. For example, DNA damage can activate checkpoint proteins that halt the cell cycle until the damage is repaired.

In summary, the traversal of the S control point is a complex process involving intricate signaling pathways, protein interactions, and checkpoint mechanisms that ensure the fidelity and proper timing of DNA replication in the mitotic cell cycle.'
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Proteins (2)

ProteinDefinitionTaxonomy
Cyclin-dependent kinase 10A cyclin-dependent kinase 10 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q15131]Homo sapiens (human)
E3 ubiquitin-protein ligase Mdm2An E3 ubiquitin-protein ligase Mdm2 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q00987]Homo sapiens (human)

Compounds (82)

CompoundDefinitionClassesRoles
catecholcatecholsallelochemical;
genotoxin;
plant metabolite
gossypolGossypol: A dimeric sesquiterpene found in cottonseed (GOSSYPIUM). The (-) isomer is active as a male contraceptive (CONTRACEPTIVE AGENTS, MALE) whereas toxic symptoms are associated with the (+) isomer.
4-(4'-hydroxyphenyl)-amino-6,7-dimethoxyquinazolineWHI P131: a quinazoline derivative, inhibitor of glioblastoma cell adhesion and migration
quinone1,4-benzoquinone : The simplest member of the class of 1,4-benzoquinones, obtained by the formal oxidation of hydroquinone to the corresponding diketone. It is a metabolite of benzene.

benzoquinone : The simplest members of the class of benzoquinones, consisting of cyclohexadiene which is substituted by two oxo groups.

quinone : Compounds having a fully conjugated cyclic dione structure, such as that of benzoquinones, derived from aromatic compounds by conversion of an even number of -CH= groups into -C(=O)- groups with any necessary rearrangement of double bonds (polycyclic and heterocyclic analogues are included).
1,4-benzoquinonescofactor;
human xenobiotic metabolite;
mouse metabolite
imatinibaromatic amine;
benzamides;
N-methylpiperazine;
pyridines;
pyrimidines
antineoplastic agent;
apoptosis inducer;
tyrosine kinase inhibitor
vorinostatvorinostat : A dicarboxylic acid diamide comprising suberic (octanedioic) acid coupled to aniline and hydroxylamine. A histone deacetylase inhibitor, it is marketed under the name Zolinza for the treatment of cutaneous T cell lymphoma (CTCL).

Vorinostat: A hydroxamic acid and anilide derivative that acts as a HISTONE DEACETYLASE inhibitor. It is used in the treatment of CUTANEOUS T-CELL LYMPHOMA and SEZARY SYNDROME.
dicarboxylic acid diamide;
hydroxamic acid
antineoplastic agent;
apoptosis inducer;
EC 3.5.1.98 (histone deacetylase) inhibitor
apomorphineApomorphine: A derivative of morphine that is a dopamine D2 agonist. It is a powerful emetic and has been used for that effect in acute poisoning. It has also been used in the diagnosis and treatment of parkinsonism, but its adverse effects limit its use.aporphine alkaloidalpha-adrenergic drug;
antidyskinesia agent;
antiparkinson drug;
dopamine agonist;
emetic;
serotonergic drug
cytarabinebeta-D-arabinoside;
monosaccharide derivative;
pyrimidine nucleoside
antimetabolite;
antineoplastic agent;
antiviral agent;
immunosuppressive agent
indirubin
picropodophyllinpicropodophyllin: isolated from American May apple (Podophyllum); inhibits IGF-I autophosphorylation without interfering with tyrosine kinase activity

picropodophyllotoxin : An organic heterotetracyclic compound that has a furonaphthodioxole skeleton bearing 3,4,5-trimethoxyphenyl and hydroxy substituents.
furonaphthodioxole;
lignan;
organic heterotetracyclic compound
antineoplastic agent;
insulin-like growth factor receptor 1 antagonist;
plant metabolite;
tyrosine kinase inhibitor
lestaurtinibindolocarbazole
vatalanibmonochlorobenzenes;
phthalazines;
pyridines;
secondary amino compound
angiogenesis inhibitor;
antineoplastic agent;
EC 2.7.10.1 (receptor protein-tyrosine kinase) inhibitor;
vascular endothelial growth factor receptor antagonist
canertinibmonochlorobenzenes;
morpholines;
organofluorine compound;
quinazolines
antineoplastic agent;
tyrosine kinase inhibitor
cyc 202seliciclib : 2,6-Diaminopurine carrying benzylamino, (2R)-1-hydroxybutan-2-yl and isopropyl substituents at C-6, C-2-N and N-9 respectively. It is an experimental drug candidate in the family of pharmacological cyclin-dependent kinase (CDK) inhibitors.2,6-diaminopurinesantiviral drug;
EC 2.7.11.22 (cyclin-dependent kinase) inhibitor
lapatinibfurans;
organochlorine compound;
organofluorine compound;
quinazolines
antineoplastic agent;
tyrosine kinase inhibitor
nutlin 3stilbenoid
bms 387032N-(5-(((5-(1,1-dimethylethyl)-2-oxazolyl)methyl)thio)-2-thiazolyl)-4-piperidinecarboxamide: a CDK2 inhibitor with antineoplastic activity; structure in first source

N-(5-{[(5-tert-butyl-1,3-oxazol-2-yl)methyl]sulfanyl}-1,3-thiazol-2-yl)piperidine-4-carboxamide : A secondary carboxamide resulting from the formal condensation of the carboxy group of piperidine-4-carboxylic acid with the amino group of 5-{[(5-tert-butyl-1,3-oxazol-2-yl)methyl]sulfanyl}-1,3-thiazol-2-amine. It is an ATP-competitive inhibitor of CDK2, CDK7 and CDK9 kinases and exhibits anti-cancer properties.
1,3-oxazoles;
1,3-thiazoles;
organic sulfide;
piperidinecarboxamide;
secondary carboxamide
angiogenesis inhibitor;
antineoplastic agent;
apoptosis inducer;
EC 2.7.11.22 (cyclin-dependent kinase) inhibitor
sf 2370K-252a : A organic heterooctacyclic compound that is a potent inhibitor of protein kinase C and is isolated from Nocardiopsis sp K-252a

SF 2370: indolocarbazole isolated from Actinomadura sp. SF-2370; structure given in first source
bridged compound;
gamma-lactam;
methyl ester;
organic heterooctacyclic compound
antimicrobial agent;
bacterial metabolite;
EC 2.7.11.13 (protein kinase C) inhibitor;
tropomyosin-related kinase B receptor antagonist
ha 1100HA 1100: intracellular calcium antagonist
alvocidibalvocidib : A synthetic dihydroxyflavone that is 5,7-dihydroxyflavone which is substituted by a 3-hydroxy-1-methylpiperidin-4-yl group at position 8 and by a chlorine at the 2' position (the (-)-3S,4R stereoisomer). A cyclin-dependent kinase 9 (CDK9) inhibitor, it has been studied for the treatment of acute myeloid leukaemia, arthritis and atherosclerotic plaque formation.

alvocidib: structure given in first source
dihydroxyflavone;
hydroxypiperidine;
monochlorobenzenes;
tertiary amino compound
antineoplastic agent;
antirheumatic drug;
apoptosis inducer;
EC 2.7.11.22 (cyclin-dependent kinase) inhibitor
nutlin 2
orantiniborantinib : An oxindole that is 3-methyleneoxindole in which one of the hydrogens of the methylene group is substituted by a 2-(2-carboxyethyl)-3,5-dimethylpyrrol-3-yl group. It is an ATP-competitive inhibitor of the tyrosine kinase activity of fibroblast growth factor receptor 1.

orantinib: an antiangiogenic agent
su 11248monocarboxylic acid amide;
pyrroles
angiogenesis inhibitor;
antineoplastic agent;
EC 2.7.10.1 (receptor protein-tyrosine kinase) inhibitor;
immunomodulator;
neuroprotective agent;
vascular endothelial growth factor receptor antagonist
olomoucine iiolomoucine II: structure in first source
ekb 569EKB 569: an EGF receptor kinase inhibitoraminoquinoline;
monocarboxylic acid amide;
monochlorobenzenes;
nitrile
protein kinase inhibitor
temsirolimusmacrolide lactam
telatinib
osi 930OSI 930: inhibits both receptor tyrosine kinase Kit and kinase insert domain receptor; structure in first sourcearomatic amide
tivozanibN-(2-chloro-4-((6,7-dimethoxy-4-quinolyl)oxy)phenyl)-N'-(5-methyl-3-isoxazolyl)urea: KNR-951 is the HCl, monohydrate salt; an antineoplastic agent; structure in first sourcearomatic ether
nutlin 1nutlin 1: an MDM2 antagonist; structure in first source
masitinib1,3-thiazoles;
benzamides;
N-alkylpiperazine;
pyridines
antineoplastic agent;
antirheumatic drug;
tyrosine kinase inhibitor
binimetinibbinimetinib : A member of the class of benzimidazoles that is 1-methyl-1H-benzimidazole which is substituted at positions 4, 5, and 6 by fluorine, (4-bromo-2-fluorophenyl)nitrilo, and N-(2-hydroxyethoxy)aminocarbonyl groups, respectively. It is a MEK1 and MEK2 inhibitor (IC50= 12 nM). Approved by the FDA for the treatment of patients with unresectable or metastatic melanoma with a BRAF V600E or V600K mutation in combination with encorafenib.benzimidazoles;
bromobenzenes;
hydroxamic acid ester;
monofluorobenzenes;
secondary amino compound
antineoplastic agent;
apoptosis inducer;
EC 2.7.11.24 (mitogen-activated protein kinase) inhibitor
sotrastaurinsotrastaurin : A member of the class of maleimides that is maleimide which is substituted at position 3 by an indol-3-yl group and at position 4 by a quinazolin-4-yl group, which in turn is substituted at position 2 by a 4-methylpiperazin-1-yl group. It is a potent and selective inhibitor of protein kinase C and has been investigated as an immunosuppresant in renal transplant patients.

sotrastaurin: a potent protein kinase C-selective inhibitor; structure in first source
indoles;
maleimides;
N-alkylpiperazine;
N-arylpiperazine;
quinazolines
anticoronaviral agent;
EC 2.7.11.13 (protein kinase C) inhibitor;
immunosuppressive agent
saracatinibaromatic ether;
benzodioxoles;
diether;
N-methylpiperazine;
organochlorine compound;
oxanes;
quinazolines;
secondary amino compound
anticoronaviral agent;
antineoplastic agent;
apoptosis inducer;
autophagy inducer;
EC 2.7.10.2 (non-specific protein-tyrosine kinase) inhibitor;
radiosensitizing agent
crenolanibaminopiperidine;
aromatic ether;
benzimidazoles;
oxetanes;
quinolines;
tertiary amino compound
angiogenesis inhibitor;
antineoplastic agent;
apoptosis inducer;
EC 2.7.10.1 (receptor protein-tyrosine kinase) inhibitor
volasertibBI 6727: a polo-like kinase inhibitor with broad antitumor activity; structure in first source
azd 7762aromatic amide;
thiophenes
regorafenib(trifluoromethyl)benzenes;
aromatic ether;
monochlorobenzenes;
monofluorobenzenes;
phenylureas;
pyridinecarboxamide
antineoplastic agent;
hepatotoxic agent;
tyrosine kinase inhibitor
mp470N-arylpiperazine
np 031112tideglusib : A member of the class of thiadiazolidines that is 1,2,4-thiadiazolidine-3,5-dione which is substituted by a naphthalen-1-yl group at position 2 and by a benzyl group at position 4. It is a non-ATP competitive inhibitor of glycogen synthase kinase 3beta (GSK3beta) and has neuroprotective effects. Currently under clinical investigation for the treatment of Alzheimer's disease and progressive supranuclear palsy.

tideglusib: an NSAID and neuroprotective agent
benzenes;
naphthalenes;
thiadiazolidine
anti-inflammatory agent;
apoptosis inducer;
EC 2.7.11.26 (tau-protein kinase) inhibitor;
neuroprotective agent
at 75194-(2,6-dichlorobenzamido)-N-(piperidin-4-yl)-pyrazole-3-carboxamide : A member of the class of pryrazoles that is 4-amino-1H-pyrazole-3-carboxylic acid in which the primary amino group has been acylated by a 2,6-dichlorobenzoyl group and in which the carboxylic acid has been converted into a carboxamide by formal condensation with the primary amino group of 4-aminopiperidine.dichlorobenzene;
piperidines;
pyrazoles;
secondary carboxamide
antineoplastic agent;
EC 2.7.11.22 (cyclin-dependent kinase) inhibitor
bi 2536
inno-406biaryl
kw 2449KW 2449: has both multikinase inhibitory activity and antineoplastic activity; structure in first source
nutlin-3anutlin 3: an MDM2 antagonist; structure in first sourcestilbenoid
danusertibpiperazines
MI-63MI-63 : An azaspiro compound resulting from the formal fusion of position 3 of 6-chloro-oxindole with position 3 of (2R,3SS5S)-3-(3-chloro-2-fluorophenyl)-5-(2,2-dimethylpropyl)-N-[2-(morpholin-4-yl)ethyl]pyrrolidine-2-carboxamide. It is a potent inhibitor of the MDM2-p53 interaction.azaspiro compound;
monochlorobenzenes;
monofluorobenzenes;
morpholines;
oxindoles;
pyrrolidines;
secondary carboxamide
apoptosis inducer
ridaforolimusmacrolide lactam
crizotinibcrizotinib : A 3-[1-(2,6-dichloro-3-fluorophenyl)ethoxy]-5-[1-(piperidin-4-yl)pyrazol-4-yl]pyridin-2-amine that has R configuration at the chiral centre. The active enantiomer, it acts as a kinase inhibitor and is used for the treatment of patients with locally advanced or metastatic non-small cell lung cancer (NSCLC)

Crizotinib: A piperidine and aminopyridine derivative that acts as an inhibitor of RECEPTOR PROTEIN-TYROSINE KINASES, including ANAPLASTIC LYMPHOMA KINASE (ALK) and HEPATOCYTE GROWTH FACTOR RECEPTOR (HGFR; c-Met). It is used in the treatment of NON-SMALL CELL LUNG CANCER.
3-[1-(2,6-dichloro-3-fluorophenyl)ethoxy]-5-[1-(piperidin-4-yl)pyrazol-4-yl]pyridin-2-amineantineoplastic agent;
biomarker;
EC 2.7.10.1 (receptor protein-tyrosine kinase) inhibitor
osi 906cyclobutanes;
quinolines
motesanibpyridinecarboxamide
trametinibacetamides;
aromatic amine;
cyclopropanes;
organofluorine compound;
organoiodine compound;
pyridopyrimidine;
ring assembly
anticoronaviral agent;
antineoplastic agent;
EC 2.7.11.24 (mitogen-activated protein kinase) inhibitor;
geroprotector
pf-562,271indoles
ly2603618ureas
tg100801
enmd 2076ENMD 2076: an antiangiogenic agent with aurora kinase inhibitory and antineoplastic activities
azd 1480
nutlin-3bNutlin;
piperazinone
anticoronaviral agent
gdc 0941pictrelisib : A sulfonamide composed of indazole, morpholine, and methylsulfonyl-substituted piperazine rings bound to a thienopyrimidine ring.indazoles;
morpholines;
piperazines;
sulfonamide;
thienopyrimidine
EC 2.7.1.137 (phosphatidylinositol 3-kinase) inhibitor
mln 8237MLN 8237: an aurora kinase A inhibitorbenzazepine
sns 314SNS 314: an aurora kinase inhibitor; structure in first sourceureas
entrectinibentrectinib : A member of the class of indazoles that is 1H-indazole substituted by [4-(4-methylpiperazin-1-yl)-2-(tetrahydro-2H-pyran-4-ylamino)benzoyl]amino and 3,5-difluorobenzyl groups at positions 3 and 5, respectively. It is a potent inhibitor of TRKA, TRKB, TRKC, ROS1, and ALK (IC50 values of 0.1 to 1.7 nM), and used for the treatment of NTRK, ROS1 and ALK gene fusion-positive solid tumours.

entrectinib: inhibits TRK, ROS1, and ALK receptor tyrosine kinases; structure in first source
benzamides;
difluorobenzene;
indazoles;
N-methylpiperazine;
oxanes;
secondary amino compound;
secondary carboxamide
antibacterial agent;
antineoplastic agent;
apoptosis inducer;
EC 2.7.10.1 (receptor protein-tyrosine kinase) inhibitor
TAK-580MLN 2480: brain-penetrant RAF dimer antagonist

TAK-580 : A 1,3-thiazolecarboxamide that is 2-[(1R)-1-aminoethyl]-1,3-thiazole-5-carboxylic acid in which the carboxy group undergoes formal condensation with the amino group of 5-chloro-4-(trifluoromethyl)pyridin-2-amine and in which the amino group undergoes formal condensation with the carboxy group of 6-amino-5-chloropyrimidine-4-carboxylic acid. It is a pan-RAF kinase inhibitor which is currently in clinical development for the treatment of radiographically recurrent or progressive low-grade glioma in children and young adults.
1,3-thiazolecarboxamide;
aminopyrimidine;
chloropyridine;
organofluorine compound;
pyrimidinecarboxamide;
secondary carboxamide
antineoplastic agent;
apoptosis inducer;
B-Raf inhibitor
pf 3758309PF 3758309: a PAK4 p21-activated kinase inhibitor; structure in first sourceorganic heterobicyclic compound;
organonitrogen heterocyclic compound;
organosulfur heterocyclic compound
plx4032aromatic ketone;
difluorobenzene;
monochlorobenzenes;
pyrrolopyridine;
sulfonamide
antineoplastic agent;
B-Raf inhibitor
as 703026pyridinecarboxamide
dabrafenib1,3-thiazoles;
aminopyrimidine;
organofluorine compound;
sulfonamide
anticoronaviral agent;
antineoplastic agent;
B-Raf inhibitor
n-(3-fluoro-4-((1-methyl-6-(1h-pyrazol-4-yl)-1h-indazol-5 yl)oxy)phenyl)-1-(4-fluorophenyl)-6-methyl-2-oxo-1,2-dihydropyridine-3-carboxamidemerestinib: in phase I clinical trials (2013); structure in first source
pb 12
jnj38877605quinolines
alectinibaromatic ketone;
morpholines;
nitrile;
organic heterotetracyclic compound;
piperidines
antineoplastic agent;
EC 2.7.10.1 (receptor protein-tyrosine kinase) inhibitor
encorafenibencorafenib: a BRAF inhibitor
spautin-1
nvp-cgm097NVP-CGM097: an MDM2 and HDM2 inhibitor; structure in first source
rg7388RG7388: structure in first source
sar405838SAR405838: an inhibitor of the interaction of MDM2 and p53; has antineoplastic activity; structure in first source
cep-32496agerafenib: inhibitor of RAF family kinases; structure in first source
rg7112
amg 232
at 9283
chir 258
nintedanibnintedanib : A member of the class of oxindoles that is a kinase inhibitor used (in the form of its ethylsulfonate salt) for the treatment of idiopathic pulmonary fibrosis and cancer.