Target type: cellularcomponent
The Y-shaped region of a nuclear replicating DNA molecule, resulting from the separation of the DNA strands and in which the synthesis of new strands takes place. Also includes associated protein complexes. [GOC:jl, GOC:mtg_sensu]
The nuclear replication fork is a complex molecular machine responsible for replicating DNA during the S phase of the cell cycle. It is composed of a multitude of proteins that work together to unwind the DNA double helix, separate the strands, and synthesize new complementary strands. The cellular components of the replication fork can be broadly categorized into three main groups:
1. **DNA unwinding and stabilization:**
- **Helicases:** These enzymes unwind the DNA double helix, breaking the hydrogen bonds between the two strands. In eukaryotes, the primary helicase involved is CMG (composed of Cdc45, Mcm2-7, and GINS).
- **Single-strand binding proteins (SSBs):** Once the strands are separated, SSBs bind to the single-stranded DNA, preventing them from re-annealing and protecting them from degradation. Replication protein A (RPA) is the major SSB in eukaryotes.
- **Topoisomerases:** These enzymes relieve the torsional stress that builds up ahead of the replication fork as the DNA unwinds. Type I topoisomerases cleave one strand of DNA to allow rotation, while type II topoisomerases cleave both strands to pass another DNA segment through the break.
2. **DNA synthesis:**
- **DNA polymerase alpha/primase:** This complex initiates DNA synthesis by laying down a short RNA primer, which is then extended by DNA polymerase alpha.
- **DNA polymerase epsilon and delta:** These are the main replicative DNA polymerases in eukaryotes. They extend the primer and synthesize the new DNA strand in a 5' to 3' direction.
- **PCNA (Proliferating Cell Nuclear Antigen):** This ring-shaped protein acts as a sliding clamp, keeping the DNA polymerase associated with the template strand during DNA synthesis.
3. **DNA repair and checkpoint control:**
- **DNA repair proteins:** These proteins ensure the fidelity of DNA replication by detecting and correcting errors that may arise during the process.
- **Checkpoint proteins:** These proteins monitor the progress of DNA replication and activate cell cycle checkpoints if errors occur, pausing the cell cycle until the errors are repaired.
The replication fork is highly dynamic and constantly moving along the DNA molecule as it replicates. Its structure and components are tightly regulated to ensure that DNA is copied accurately and efficiently. These components work together in a coordinated manner to achieve the essential task of replicating the genome, ensuring the faithful transmission of genetic information from one generation to the next.'"
| Protein | Definition | Taxonomy |
|---|---|---|
| Poly [ADP-ribose] polymerase 1 | A poly [ADP-ribose] polymerase 1 that is encoded in the genome of cow. [OMA:P18493, PRO:DNx] | Bos taurus (cattle) |
| Histone-arginine methyltransferase CARM1 | A histone-arginine methyltransferase CARM1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q86X55] | Homo sapiens (human) |
| Proliferating cell nuclear antigen | A proliferating cell nuclear antigen that is encoded in the genome of human. [PRO:DNx] | Homo sapiens (human) |
| Poly [ADP-ribose] polymerase 1 | A poly [ADP-ribose] polymerase 1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:P09874] | Homo sapiens (human) |
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| niacinamide | nicotinamide : A pyridinecarboxamide that is pyridine in which the hydrogen at position 3 is replaced by a carboxamide group. | pyridine alkaloid; pyridinecarboxamide; vitamin B3 | anti-inflammatory agent; antioxidant; cofactor; EC 2.4.2.30 (NAD(+) ADP-ribosyltransferase) inhibitor; EC 3.5.1.98 (histone deacetylase) inhibitor; Escherichia coli metabolite; geroprotector; human urinary metabolite; metabolite; mouse metabolite; neuroprotective agent; Saccharomyces cerevisiae metabolite; Sir2 inhibitor |
| 1,5-dihydroxyisoquinoline | 1,5-dihydroxyisoquinoline: structure in first source isoquinoline-1,5-diol : An isoquinolinol that is isoquinoline in which the hydrogens at positions 1 and 5 are replaced by hydroxy groups. | isoquinolinol | EC 2.4.2.30 (NAD(+) ADP-ribosyltransferase) inhibitor |
| 3-aminobenzamide | benzamides; substituted aniline | EC 2.4.2.30 (NAD(+) ADP-ribosyltransferase) inhibitor | |
| 4-amino-1,8-naphthalimide | 4-amino-1,8-naphthalimide: inhibits ADP-ribosylation; sometimes abreviated as 4-AN; | benzoisoquinoline; dicarboximide | |
| phenanthridone | phenanthridone : A member of the class of phenanthridines that is phenanthridine with an oxo substituent at position 6. A poly(ADP-ribose) polymerase (PARP) inhibitor, it has been shown to exhibit immunosuppressive activity. phenanthridone: coal tar derivative; structure given in first source | lactam; phenanthridines | EC 2.4.2.30 (NAD(+) ADP-ribosyltransferase) inhibitor; immunosuppressive agent; mutagen |
| 5-aminoisoquinolinone | 5-aminoisoquinolinone: structure in first source | isoquinolines | |
| benzamide | benzamide : An aromatic amide that consists of benzene bearing a single carboxamido substituent. The parent of the class of benzamides. | benzamides | |
| pj-34 | PJ34 : A member of the class of phenanthridines that is 5,6-dihydrophenanthridine substituted at positions 2 and 6 by (N,N-dimethylglycyl)amino and oxo groups, respectively. It is a potent inhibitor of poly(ADP-ribose) polymerases PARP1 and PARP2 (IC50 of 110 nM and 86 nM, respectively) and exhibits anti-cancer, cardioprotective and neuroprotective properties. | phenanthridines; secondary carboxamide; tertiary amino compound | angiogenesis inhibitor; anti-inflammatory agent; antiatherosclerotic agent; antineoplastic agent; apoptosis inducer; cardioprotective agent; EC 2.4.2.30 (NAD(+) ADP-ribosyltransferase) inhibitor; neuroprotective agent |
| 3,3',5-triiodothyroacetic acid | tiratricol : A monocarboxylic acid that is (4-hydroxy-3,5-diiodophenyl)acetic acid in which the phenolic hydroxy group has been replaced by a 4-hydroxy-3-iodophenoxy group. It is a thyroid hormone analogue that has been used in the treatment of thyroid hormone resistance syndrome. | ||
| 3,3',5-triiodothyropropionic acid | aromatic ether | ||
| thyroxine | thyroxine : An iodothyronine compound having iodo substituents at the 3-, 3'-, 5- and 5'-positions. Thyroxine: The major hormone derived from the thyroid gland. Thyroxine is synthesized via the iodination of tyrosines (MONOIODOTYROSINE) and the coupling of iodotyrosines (DIIODOTYROSINE) in the THYROGLOBULIN. Thyroxine is released from thyroglobulin by proteolysis and secreted into the blood. Thyroxine is peripherally deiodinated to form TRIIODOTHYRONINE which exerts a broad spectrum of stimulatory effects on cell metabolism. | 2-halophenol; iodophenol; L-phenylalanine derivative; non-proteinogenic L-alpha-amino acid; thyroxine; thyroxine zwitterion | antithyroid drug; human metabolite; mouse metabolite; thyroid hormone |
| triiodothyronine | 3,3',5-triiodo-L-thyronine : An iodothyronine compound having iodo substituents at the 3-, 3'- and 5-positions. Although some is produced in the thyroid, most of the 3,3',5-triiodo-L-thyronine in the body is generated by mono-deiodination of L-thyroxine in the peripheral tissues. Its metabolic activity is about 3 to 5 times that of L-thyroxine. The sodium salt is used in the treatment of hypothyroidism. Triiodothyronine: A T3 thyroid hormone normally synthesized and secreted by the thyroid gland in much smaller quantities than thyroxine (T4). Most T3 is derived from peripheral monodeiodination of T4 at the 5' position of the outer ring of the iodothyronine nucleus. The hormone finally delivered and used by the tissues is mainly T3. | 2-halophenol; amino acid zwitterion; iodophenol; iodothyronine | human metabolite; mouse metabolite; thyroid hormone |
| 1-hydroxyphthalazine | 1-hydroxyphthalazine: RN given refers to cpd with unspecified locants; do not confuse with cpd phthalazinol RN: 56611-65-5 | phthalazines | |
| chlorthenoxazin | chlorthenoxazin: RN given refers to parent cpd; structure | benzoxazine | |
| isocarbostyril | isoquinolinone : An isoquinoline containing one or more oxo groups. | isoquinolines | |
| flavone | flavone : The simplest member of the class of flavones that consists of 4H-chromen-4-one bearing a phenyl substituent at position 2. flavone: RN given refers to unlabeled cpd; structure given in first source | flavones | metabolite; nematicide |
| 2,4(1h,3h)-quinazolinedione | 2,4(1H,3H)-quinazolinedione: structure given in first source | ||
| 4-hydroxybenzamide | |||
| naphthalimides | Naphthalimides: Compounds with three fused rings that appear like a naphthalene fused to piperidone or like a benz(de)isoquinoline-1,3-dione (not to be confused with BENZYLISOQUINOLINES which have a methyl separating the naphthyl from the benzyl rings). Members are CYTOTOXINS. | ||
| 4-fluorobenzamide | 4-fluorobenzamide: structure in first source | ||
| 5-iodo-6-amino-1,2-benzopyrone | |||
| alantolactone | alantolactone : A sesquiterpene lactone that is 3a,5,6,7,8,8a,9,9a-octahydronaphtho[2,3-b]furan-2-one bearing two methyl substituents at positions 5 and 8a as well as a methylidene substituent at position 3. alantolactone: allergenic sesquiterpene lactone; crystalline mixture of alantolactones from group of sesquiterpenes; structure | naphthofuran; olefinic compound; sesquiterpene lactone | antineoplastic agent; apoptosis inducer; plant metabolite |
| 4-aminobenzamide | benzamides | ||
| 4-Methoxybenzamide | benzamides | ||
| 3,5-diiodothyronine, (l)-isomer | phenylalanine derivative | ||
| 3-methoxybenzamide | |||
| 3,3'-diiodothyronine | 3,3'-diiodothyronine: RN given refers to unlabeled cpd without isomeric designation | 3,3'-diiodothyronine; amino acid zwitterion | human metabolite |
| furamidine | furamidine: RN given refers to parent cpd; WR 199385 refers to di-HCl; pafuramidine is a prodrug of this | ||
| 3',4'-dihydroxyflavone | 3',4'-dihydroxyflavone: inhibitors of arachidonic acid peroxidation | ||
| 3,4-dihydro-5-methyl-1(2h)-isoquinolinone | 3,4-dihydro-5-methyl-1(2H)-isoquinolinone: structure given in first source | isoquinolines | |
| 1-oxo-1,2,3,4-tetrahydroisoquinoline | 1-oxo-1,2,3,4-tetrahydroisoquinoline: structure given in first source | ||
| 3,5-diiodothyropropionic acid | 3,5-diiodothyropropionic acid : A monocarboxylic acid that is (4-hydroxy-3,5-diiodophenyl)propanoic acid in which the phenolic hydroxy group has been replaced by a 4-hydroxyphenyl group. An ionotropic analogue of L-thyroxine. 3,5-diiodothyropropionic acid: a cardiotonic thyroid hormone analog | aromatic ether; monocarboxylic acid; organoiodine compound; phenols | |
| cyclo(alanylalanyl) | |||
| s-adenosylhomocysteine | S-adenosyl-L-homocysteine : An organic sulfide that is the S-adenosyl derivative of L-homocysteine. S-Adenosylhomocysteine: 5'-S-(3-Amino-3-carboxypropyl)-5'-thioadenosine. Formed from S-adenosylmethionine after transmethylation reactions. | adenosines; amino acid zwitterion; homocysteine derivative; homocysteines; organic sulfide | cofactor; EC 2.1.1.72 [site-specific DNA-methyltransferase (adenine-specific)] inhibitor; EC 2.1.1.79 (cyclopropane-fatty-acyl-phospholipid synthase) inhibitor; epitope; fundamental metabolite |
| N-[4-[[[4-(4-methoxyphenyl)-4-oxanyl]methylamino]-oxomethyl]phenyl]-2-furancarboxamide | aromatic amide; furans | ||
| ha 1100 | HA 1100: intracellular calcium antagonist | ||
| apigenin | Chamomile: Common name for several daisy-like plants (MATRICARIA; TRIPLEUROSPERMUM; ANTHEMIS; CHAMAEMELUM) native to Europe and Western Asia, now naturalized in the United States and Australia. | trihydroxyflavone | antineoplastic agent; metabolite |
| luteolin | 3'-hydroxyflavonoid; tetrahydroxyflavone | angiogenesis inhibitor; anti-inflammatory agent; antineoplastic agent; apoptosis inducer; c-Jun N-terminal kinase inhibitor; EC 2.3.1.85 (fatty acid synthase) inhibitor; immunomodulator; nephroprotective agent; plant metabolite; radical scavenger; vascular endothelial growth factor receptor antagonist | |
| amentoflavone | biflavonoid; hydroxyflavone; ring assembly | angiogenesis inhibitor; antiviral agent; cathepsin B inhibitor; P450 inhibitor; plant metabolite | |
| 3',4',7-trihydroxyflavone | 3',4',7-trihydroxyflavone: from the Sudanese medicinal plant Albizia zygia; structure in first source | flavones | |
| stilbamidine | stilbamidine: RN given refers to parent cpd | ||
| adenosine diphosphate (hydroxymethyl)pyrrolidinediol | dihydroxypyrrolidine; purine ribonucleoside 5'-diphosphate | ||
| ag 14361 | benzimidazoles | ||
| gpi 6150 | |||
| rucaparib | AG14447: Poly(ADP-ribose) polymerase inhibitor; structure in first source | azepinoindole; caprolactams; organofluorine compound; secondary amino compound | antineoplastic agent; EC 2.4.2.30 (NAD(+) ADP-ribosyltransferase) inhibitor |
| 3,4-dihydro-5-(4-(1-piperidinyl)butoxy)-1(2h)-isoquinolinone | |||
| veliparib | benzimidazoles | EC 2.4.2.30 (NAD(+) ADP-ribosyltransferase) inhibitor | |
| olaparib | cyclopropanes; monofluorobenzenes; N-acylpiperazine; phthalazines | antineoplastic agent; apoptosis inducer; EC 2.4.2.30 (NAD(+) ADP-ribosyltransferase) inhibitor | |
| niraparib | 2-[4-(piperidin-3-yl)phenyl]-2H-indazole-7-carboxamide : A member of the class of indazoles that is 2H-indazole substituted by 4-(piperidin-3-yl)phenyl and aminocarbonyl groups at positions 2 and 7, respectively. It is a potent PARP1 inhibitor with IC50 of 3.2 nM. | benzenes; indazoles; piperidines; primary carboxamide | antineoplastic agent; EC 2.4.2.30 (NAD(+) ADP-ribosyltransferase) inhibitor |
| niraparib | niraparib : A 2-[4-(piperidin-3-yl)phenyl]-2H-indazole-7-carboxamide that has S-configuration. It is a potent inhibitor of PARP1 and PARP2 (IC50 of 3.8 and 2.1 nM, respectively) and approved as a first-line maintenance treatment for women with advanced ovarian cancer after responding to platinum-based chemotherapy. niraparib: structure in first source | 2-[4-(piperidin-3-yl)phenyl]-2H-indazole-7-carboxamide | antineoplastic agent; apoptosis inducer; EC 2.4.2.30 (NAD(+) ADP-ribosyltransferase) inhibitor; radiosensitizing agent |
| cep 26401 | pyridazines; ring assembly | ||
| iwr-1 endo | IWR-1-endo : A dicarboximide having an endo bridged phthalimide structure, substituted at nitrogen by a 4-(quinolin-8-ylcarbamoyl)benzoyl group. | benzamides; bridged compound; dicarboximide; quinolines | axin stabilizer; Wnt signalling inhibitor |
| nms-p118 | NMS-P118: a PARP-1 inhibitor; structure in first source | ||
| g007-lk | G007-LK: potent and specific small-molecule tankyrase inhibitor; structure in first source | ||
| gsk343 | GSK343 : A member of the class of indazoles that is 1-isopropyl-1H-indazole-4-carboxamide in which the nitrogen of the carboxamide group is substituted by a (6-methyl-2-oxo-4-propyl-1,2-dihydropyridin-3-yl)methyl group and in which the indazole ring is substituted at position 6 by a 2-(4-methylpiperazin-1-yl)pyridin-4-yl group. A highly potent and selective EZH2 inhibitor (IC50 = 4 nM). GSK343: an EZH2 methyltransferase inhibitor | aminopyridine; indazoles; N-alkylpiperazine; N-arylpiperazine; pyridone; secondary carboxamide | antineoplastic agent; apoptosis inducer; EC 2.1.1.43 (enhancer of zeste homolog 2) inhibitor |
| nu 1025 | NU 1064: structure in first source | phenols; quinazolines | EC 2.4.2.30 (NAD(+) ADP-ribosyltransferase) inhibitor |
| 2-methyl-4(3h)-quinazolinone | 2-methyl-4(3H)-quinazolinone: from Bacillus cereus; structure given in first source | ||
| 4-hydroxyquinazoline | 4-oxo-3,4-dihydroquinazoline: structure in first source | quinazolines | |
| 1,4-Dihydrothieno[3,2-d]pyrimidin-4-one | organic heterobicyclic compound; organonitrogen heterocyclic compound; organosulfur heterocyclic compound | ||
| xav939 | XAV939 : A thiopyranopyrimidine in which a 7,8-dihydro-5H-thiopyrano[4,3-d]pyrimidine skeleton is substituted at C-4 by a hydroxy group and at C-2 by a para-(trifluoromethyl)phenyl group. XAV939: selectively inhibits beta-catenin-mediated transcription; structure in first source | (trifluoromethyl)benzenes; thiopyranopyrimidine | tankyrase inhibitor |
| 2-(4-methoxyphenyl)-1H-quinazolin-4-one | quinazolines | ||
| bmn 673 | talazoparib: inhibits both PARP1 and PARP2; structure in first source | ||
| me0328 | ME0328: inhibits ARTD3; structure in first source | ||
| nvp-tnks656 |