| Structural highlights
Function
[PCNA_HUMAN] Auxiliary protein of DNA polymerase delta and is involved in the control of eukaryotic DNA replication by increasing the polymerase's processibility during elongation of the leading strand. Induces a robust stimulatory effect on the 3'-5' exonuclease and 3'-phosphodiesterase, but not apurinic-apyrimidinic (AP) endonuclease, APEX2 activities. Has to be loaded onto DNA in order to be able to stimulate APEX2. Plays a key role in DNA damage response (DDR) by being conveniently positioned at the replication fork to coordinate DNA replication with DNA repair and DNA damage tolerance pathways. Acts as a loading platform to recruit DDR proteins that allow completion of DNA replication after DNA damage and promote postreplication repair: Monoubiquitinated PCNA leads to recruitment of translesion (TLS) polymerases, while 'Lys-63'-linked polyubiquitination of PCNA is involved in error-free pathway and employs recombination mechanisms to synthesize across the lesion.[1] [2] [DPOD4_HUMAN] As a component of the tetrameric DNA polymerase delta complex (Pol-delta4), plays a role in high fidelity genome replication and repair. Within this complex, increases the rate of DNA synthesis and decreases fidelity by regulating POLD1 polymerase and proofreading 3' to 5' exonuclease activity (PubMed:16510448, PubMed:19074196, PubMed:20334433). Pol-delta4 participates in Okazaki fragment processing, through both the short flap pathway, as well as a nick translation system (PubMed:24035200). Under conditions of DNA replication stress, required for the repair of broken replication forks through break-induced replication (BIR), a mechanism that may induce segmental genomic duplications of up to 200 kb (PubMed:24310611). Involved in Pol-delta4 translesion synthesis (TLS) of templates carrying O6-methylguanine or abasic sites (PubMed:19074196). Its degradation in response to DNA damage is required for the inhibition of fork progression and cell survival (PubMed:24022480).[3] [4] [5] [6] [7] [8]
Publication Abstract from PubMed
Human DNA polymerase delta is essential for DNA replication and acts in conjunction with the processivity factor proliferating cell nuclear antigen (PCNA). Besides its catalytic subunit (p125), pol delta comprises three regulatory subunits (p50, p68, and p12). PCNA interacts with all of these subunits, but only the interaction with p68 has been structurally characterized. Here, we report solution NMR-, isothermal titration calorimetry-, and X-ray crystallography-based analyses of the p12-PCNA interaction, which takes part in the modulation of the rate and fidelity of DNA synthesis by pol delta. We show that p12 binds with micromolar affinity to the classical PIP-binding pocket of PCNA via a highly atypical PIP-box located at the p12 N terminus. Unlike the canonical PIP-box of p68, the PIP-box of p12 lacks the conserved glutamine, binds through a 2-fork plug made of an isoleucine and a tyrosine residue at +3 and +8 positions, respectively, and is stabilized by an aspartate at +6 position, which creates a network of intra-molecular hydrogen bonds. These findings add to growing evidence that PCNA can bind a diverse range of protein sequences that may be broadly grouped as PIP-like motifs as has been previously suggested.
The p12 subunit of human polymerase delta uses an atypical PIP-box for molecular recognition of proliferating cell nuclear antigen (PCNA).,Gonzalez-Magana A, Ibanez de Opakua A, Romano-Moreno M, Murciano-Calles J, Merino N, Luque I, Rojas AL, Onesti S, Blanco FJ, De Biasio A J Biol Chem. 2019 Jan 17. pii: RA118.006391. doi: 10.1074/jbc.RA118.006391. PMID:30655288[9]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Burkovics P, Hajdu I, Szukacsov V, Unk I, Haracska L. Role of PCNA-dependent stimulation of 3'-phosphodiesterase and 3'-5' exonuclease activities of human Ape2 in repair of oxidative DNA damage. Nucleic Acids Res. 2009 Jul;37(13):4247-55. doi: 10.1093/nar/gkp357. Epub 2009, May 13. PMID:19443450 doi:10.1093/nar/gkp357
- ↑ Motegi A, Liaw HJ, Lee KY, Roest HP, Maas A, Wu X, Moinova H, Markowitz SD, Ding H, Hoeijmakers JH, Myung K. Polyubiquitination of proliferating cell nuclear antigen by HLTF and SHPRH prevents genomic instability from stalled replication forks. Proc Natl Acad Sci U S A. 2008 Aug 26;105(34):12411-6. Epub 2008 Aug 21. PMID:18719106 doi:0805685105
- ↑ Li H, Xie B, Zhou Y, Rahmeh A, Trusa S, Zhang S, Gao Y, Lee EY, Lee MY. Functional roles of p12, the fourth subunit of human DNA polymerase delta. J Biol Chem. 2006 May 26;281(21):14748-55. Epub 2006 Feb 28. PMID:16510448 doi:https://dx.doi.org/10.1074/jbc.M600322200
- ↑ Meng X, Zhou Y, Zhang S, Lee EY, Frick DN, Lee MY. DNA damage alters DNA polymerase delta to a form that exhibits increased discrimination against modified template bases and mismatched primers. Nucleic Acids Res. 2009 Feb;37(2):647-57. doi: 10.1093/nar/gkn1000. Epub 2008 Dec, 11. PMID:19074196 doi:https://dx.doi.org/10.1093/nar/gkn1000
- ↑ Meng X, Zhou Y, Lee EY, Lee MY, Frick DN. The p12 subunit of human polymerase delta modulates the rate and fidelity of DNA synthesis. Biochemistry. 2010 May 4;49(17):3545-54. doi: 10.1021/bi100042b. PMID:20334433 doi:https://dx.doi.org/10.1021/bi100042b
- ↑ Terai K, Shibata E, Abbas T, Dutta A. Degradation of p12 subunit by CRL4Cdt2 E3 ligase inhibits fork progression after DNA damage. J Biol Chem. 2013 Oct 18;288(42):30509-14. doi: 10.1074/jbc.C113.505586. Epub, 2013 Sep 10. PMID:24022480 doi:https://dx.doi.org/10.1074/jbc.C113.505586
- ↑ Lin SH, Wang X, Zhang S, Zhang Z, Lee EY, Lee MY. Dynamics of enzymatic interactions during short flap human Okazaki fragment processing by two forms of human DNA polymerase delta. DNA Repair (Amst). 2013 Nov;12(11):922-35. doi: 10.1016/j.dnarep.2013.08.008., Epub 2013 Sep 10. PMID:24035200 doi:https://dx.doi.org/10.1016/j.dnarep.2013.08.008
- ↑ Costantino L, Sotiriou SK, Rantala JK, Magin S, Mladenov E, Helleday T, Haber JE, Iliakis G, Kallioniemi OP, Halazonetis TD. Break-induced replication repair of damaged forks induces genomic duplications in human cells. Science. 2014 Jan 3;343(6166):88-91. doi: 10.1126/science.1243211. Epub 2013 Dec , 5. PMID:24310611 doi:https://dx.doi.org/10.1126/science.1243211
- ↑ Gonzalez-Magana A, Ibanez de Opakua A, Romano-Moreno M, Murciano-Calles J, Merino N, Luque I, Rojas AL, Onesti S, Blanco FJ, De Biasio A. The p12 subunit of human polymerase delta uses an atypical PIP-box for molecular recognition of proliferating cell nuclear antigen (PCNA). J Biol Chem. 2019 Jan 17. pii: RA118.006391. doi: 10.1074/jbc.RA118.006391. PMID:30655288 doi:https://dx.doi.org/10.1074/jbc.RA118.006391
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