Search results for WRN

Showing 22 results out of 45

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Species

Types

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Reaction types

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Protein (5 results from a total of 5)

WRN

Identifier: R-HSA-67387
Species: Homo sapiens
Compartment: nucleoplasm
Primary external reference: UniProt: WRN: Q14191
Identifier: R-HSA-4568904
Species: Homo sapiens
Compartment: nucleoplasm
Primary external reference: UniProt: WRN: Q14191
Identifier: R-HSA-4568845
Species: Homo sapiens
Compartment: nucleoplasm
Primary external reference: UniProt: P63165
Identifier: R-HSA-4568893
Species: Homo sapiens
Compartment: nucleoplasm
Primary external reference: UniProt: P63165
Identifier: R-HSA-4568906
Species: Homo sapiens
Compartment: nucleoplasm
Primary external reference: UniProt: P63165

Reaction (6 results from a total of 6)

Identifier: R-HSA-4568846
Species: Homo sapiens
Compartment: nucleoplasm
CDKN2A (p14-ARF) SUMOylates WRN at lysine-356, lysine-496, and lysine-898 with SUMO1 (Woods et al. 2004). SUMOylation of WRN causes it to be released from the nucleolus.
Identifier: R-HSA-5685985
Species: Homo sapiens
Compartment: nucleoplasm
After the initial resection of DNA double strand breaks (DSBs) by MRE11A and RBBP8 (CtIP), which creates short 3' ssDNA overhangs, a DNA exonuclease EXO1 or a DNA endonuclease DNA2 is recruited to perform long-range resection of DNA DSBs. The redundant function of EXO1 and DNA2 in resection of DNA DSBs is conserved in yeast (Zhu et al. 2008). BLM, the Bloom syndrome helicase, acts as an activator of DNA2 catalytic activity (Nimonkar et al. 2011) and increases affinity of EXO1 for DNA ends (Nimonkar et al. 2008). BLM directly interacts with the MRN complex, which can assist recruitment of either DNA2 or EXO1 to DNA DSBs (Nimonkar et al. 2011). EXO1 can also be recruited to DNA DSBs through its interaction with RBBP8 (CtIP) (Eid et al. 2010, Nimonkar et al. 2011). Another DNA helicase, WRN (Werner syndrome helicase) can function redundantly with BLM to facilitate/activate EXO1- or DNA2-mediated long range resection of DNA DSBs (Sturzenegger et al. 2014).

A DNA helicase BRIP1 (also known as BACH1 or FANCJ) is recruited to DNA DSBs through its interaction with BRCA1 (Cantor et al. 2001) and BLM (Suhasini et al. 2011, Suhasini and Brosh 2012). BRIP1 promotes DNA end processing events that stimulate recruitment of the RPA complex and RAD51 (Xie et al. 2012). The interaction with BRCA1 requires BRIP1 to be phosphorylated on serine residue S990 in a cell cycle-dependent manner (Yu et al. 2003). BRIP1 also has to be acetylated on lysine residue K1249 to be functional (Xie et al. 2012).

Identifier: R-HSA-5693580
Species: Homo sapiens
Compartment: nucleoplasm
RAD52 heptamers bind 3' overhanging ssDNA at resected DNA double strand breaks (DSBs) by simultaneously interacting with the DNA and the RPA complex. The conformation of the RAD52-ssDNA complex is thought to place the ssDNA on an exposed surface of the ring, in a configuration that may promote the DNA-DNA annealing of complementary DNA strands (Parsons et al. 2000). The interaction with RPA is necessary for RAD52-mediated homology driven repair (Park et al. 1996, Jackson et al. 2002). Phosphorylation of RAD52 at tyrosine residue Y104 by ABL1 in response to ATM signaling increases the affinity of RAD52 for DNA (Kitao et al. 2002, Cramer et al. 2008, Honda et al. 2011). Long range resection, which results in the activation of ATR/CHEK1 signaling, is needed for RAD52-mediated single strand annealing (SSA). RAD52 function may be promoted by a direct interaction with WRN helicase which participates in long-range resection of DNA DSBs (Baynton et al. 2003).
Identifier: R-HSA-5685994
Species: Homo sapiens
Compartment: nucleoplasm
DNA nucleases EXO1 and DNA2 function redundantly in yeast (Zhu et al. 2008) and humans (Nimonkar et al. 2011) in long-range resection of DNA double strand breaks (DSBs). Both DNA nucleases act after short 3' ssDNA overhangs are created by the initial resection of DNA DSBs mediated by MRE11A and RBBP8 (CtIP). The roles of BLM (Bloom syndrome helicase) and WRN (Werner syndrome helicase) in facilitation of EXO1- or DNA2-mediated resection of DNA DSBs are also redundant.

EXO1 possesses an intrinsic 5'->3' exonuclease activity. The ATPase activity of BLM DNA helicase is not required for EXO1 catalytic activity, but BLM increases the affinity of EXO1 for DNA ends (Nimonkar et al. 2008). WRN can also positively affect EXO1 exonuclease activity, although the mechanism is not clear (Sturzenegger et al. 2014).

The DNA endonuclease DNA2 has to form a complex with either BLM (Nimonkar et al. 2011) or WRN (Sturzenegger et al. 2014) in order to perform a 5'->3' directed resection of DNA DSBs. BLM forms an evolutionarily conserved complex with TOP3A, RMI1 and RMI2, known as the STR complex in yeast (Zhu et al. 2008) and the BTB or BTRR complex in humans. The entire BTRR complex participates in the activation of DNA2-mediated resection of DNA DSBs (Sturzenegger et al. 2014).

While ATR signaling may be detectable in the absence of long-range resection of DNA DSBs by EXO1 or DNA2 (Eid et al. 2010), EXO1 or DNA2 activity may be necessary to achieve biologically meaningful level of ATR activation (Gravel et al. 2008).

BRIP1 (BACH1, FANCJ) is a DNA helicase recruited to DNA DSBs by interaction with BRCA1 (Cantor et al. 2001) and BLM (Suhasini et al. 2011). BRIP1 is necessary for BRCA1-mediated homology-directed repair of DNA DSBs, and BRIP1 loss-of-function mutations are found in familial breast cancer (Cantor et al. 2001, Litman et al. 2005). The exact role of BRIP1 in DNA repair is not completely clear. BRIP1 is needed for the successful formation of RPA foci and, subsequently, RAD51 foci (Xie et al. 2012). The available evidence suggest that it cooperates with BLM in unwinding of DNA DSBs during resection (Suhasini et al. 2011, Sarkies et al. 2012), and may be especially important for unwinding of DNA that contains oxidative damage (Suhasini et al. 2009).

Identifier: R-HSA-174438
Species: Homo sapiens
Compartment: nucleoplasm
When the polymerase delta:PCNA complex reaches a downstream Okazaki fragment, strand displacement synthesis occurs. The primer containing 5'-terminus of the downstream Okazaki fragment is folded into a single-stranded flap (Podust et al. 1995, Bae et al. 2001, Maga et al. 2001). The helicase activity of either WRN (Werner syndrome protein) or BLM (Bloom syndrome helicase) is needed for DNA polymerase delta progression and strand displacement synthesis across G-rich telomeric repeats during lagging strand (C-strand) synthesis (Li et al. 2017).
Identifier: R-HSA-174446
Species: Homo sapiens
Compartment: nucleoplasm
The remaining flap, which is too short to support RPA binding, is then processed by FEN1. There is evidence that binding of RPA to the displaced end of the RNA-containing Okazaki fragment prevents FEN1 from accessing the substrate. FEN1 is a structure-specific endonuclease that cleaves near the base of the flap at a position one nucleotide into the annealed region. Biochemical studies have shown that the preferred substrate for FEN1 consists of a one-nucleotide 3'-tail on the upstream primer in addition to the 5'-flap of the downstream primer (Harrington and Lieber 1994, Harrington and Lieber 1995, Murante et al. 1996, Lieber 1997, Kaiser et al. 1999, Xu et al. 2000, Kao et al. 2002). The interaction of FEN1 with WRN, a RECQ family DNA helicase, is needed for successful flap cleavage during telomeric strand displacement synthesis (Saharia et al. 2010, Li et al. 2017).

Complex (6 results from a total of 29)

Identifier: R-HSA-5685969
Species: Homo sapiens
Compartment: nucleoplasm
Identifier: R-HSA-4568903
Species: Homo sapiens
Compartment: nucleoplasm
Identifier: R-HSA-5685976
Species: Homo sapiens
Compartment: nucleoplasm
Identifier: R-HSA-5685974
Species: Homo sapiens
Compartment: nucleoplasm
Identifier: R-HSA-5685972
Species: Homo sapiens
Compartment: nucleoplasm

Set (3 results from a total of 3)

Identifier: R-HSA-5685968
Species: Homo sapiens
Compartment: nucleoplasm
Identifier: R-HSA-9668968
Species: Homo sapiens
Compartment: nucleoplasm
Identifier: R-HSA-5685980
Species: Homo sapiens
Compartment: nucleoplasm

Pathway (2 results from a total of 2)

Identifier: R-HSA-5693607
Species: Homo sapiens
Compartment: nucleoplasm
Homology directed repair (HDR) through homologous recombination (HRR) or single strand annealing (SSA) requires extensive resection of DNA double strand break (DSB) ends (Thompson and Limoli 2003, Ciccia and Elledge 2010). The resection is performed in a two-step process, where the MRN complex (MRE11A:RAD50:NBN) and RBBP8 (CtIP) bound to BRCA1 initiate the resection. This step is regulated by the complex of CDK2 and CCNA (cyclin A), ensuring the initiation of HRR during S and G2 phases of the cell cycle, when sister chromatids are available. The initial resection is also regulated by ATM-mediated phosphorylation of RBBP8 and CHEK2-mediated phosphorylation of BRCA1 (Chen et al. 2008, Yun and Hiom 2009, Buis et al. 2012, Wang et al. 2013, Davies et al. 2015, Parameswaran et al. 2015). After the initial resection, DNA nucleases EXO1 and/or DNA2 perform long-range resection, which is facilitated by DNA helicases BLM or WRN, as well as BRIP1 (BACH1) (Chen et al. 2008, Nimonkar et al. 2011, Sturzenegger et al. 2014, Suhasini et al. 2011). The resulting long 3'-ssDNA overhangs are coated by the RPA heterotrimers (RPA1:RPA2:RPA3), which recruit ATR:ATRIP complexes to DNA DSBs and, in collaboration with RAD17:RFC and RAD9:HUS1:RAD1 complexes, and TOPBP1 and RHNO1, activate ATR signaling. Activated ATR phosphorylates RPA2 and activates CHEK1 (Cotta-Ramusino et al. 2011), both of which are necessary prerequisites for the subsequent steps in HRR and SSA.
Identifier: R-HSA-5685938
Species: Homo sapiens
Homology directed repair (HDR) through single strand annealing (SSA), similar to HDR through homologous recombination repair (HRR), involves extensive resection of DNA double strand break ends (DSBs), preceded by ATM activation and formation of the so-called ionizing radiation induced foci (IRIF) at DNA DSB sites. Following ATM activation and foci formation, the two-step resection is initiated by the MRN complex (MRE11A:RAD50:NBN) and RBBP8 (CtIP) associated with BRCA1:BARD1, and completed by EXO1 or DNA2 in cooperation with DNA helicases BLM, WRN and BRIP1 (BACH1) (Sartori et al. 2007, Yun and Hiom 2009, Eid et al. 2010, Nimonkar et al. 2011, Suhasini et al. 2011, Sturzenegger et al. 2014). Long 3'-ssDNA overhangs produced by extensive resection are coated by the RPA heterotrimer (RPA1:RPA2:RPA3), triggering ATR signaling. ATR signaling is needed for SSA, probably because of the related phosphorylation of RPA2 (Zou and Elledge 2003, Anantha et al. 2007, Liu et al. 2012).

RAD52 is the key mediator of SSA. Activated ATM phosphorylates and activates ABL1, and activated ABL1 subsequently phosphorylates pre-formed RAD52 heptameric rings, increasing their affinity for ssDNA (Honda et al. 2011). Phosphorylated RAD52 binds phosphorylated RPA heterotrimers on 3'-ssDNA overhangs at resected DNA DSBs. RAD52 also binds RAD51 and prevents formation of invasive RAD51 nucleofilaments involved in HRR (Chen et al. 1999, Van Dyck et al. 1999, Parsons et al. 2000, Jackson et al. 2002, Singleton et al. 2002).

RAD52 promotes annealing of two 3'-ssDNA overhangs when highly homologous directed repeats are present in both 3'-ssDNA overhangs. Nonhomologous regions lying 3' to the annealed repeats are displaced as 3'-flaps (Parsons et al. 2000, Van Dyck et al. 2001, Singleton et al. 2002, Stark et al. 2004, Mansour et al. 2008). The endonuclease complex composed of ERCC1 and ERCC4 (XPF) is subsequently recruited to SSA sites through direct interaction between RAD52 and ERCC4, leading to cleavage of 3' flaps (Motycka et al. 2004, Al-Minawi et al. 2008). The identity of a DNA ligase that closes the remaining single strand nicks (SSBs) to complete SSA-mediated repair is not known.

SSA results in deletion of one of the annealed repeats and the intervening DNA sequence between the two annealed repeats and is thus mutagenic.

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