title: PolDIP2 interacts with human PrimPol and enhances its DNA polymerase activities.
abstract: Translesion synthesis (TLS) employs specialized DNA polymerases to bypass replication fork stalling lesions. PrimPol was recently identified as a TLS primase and polymerase involved in DNA damage tolerance. Here, we identify a novel PrimPol binding partner, PolDIP2, and describe how it regulates PrimPol's enzymatic activities. PolDIP2 stimulates the polymerase activity of PrimPol, enhancing both its capacity to bind DNA and the processivity of the catalytic domain. In addition, PolDIP2 stimulates both the efficiency and error-free bypass of 8-oxo-7,8-dihydrodeoxyguanosine (8-oxoG) lesions by PrimPol. We show that PolDIP2 binds to PrimPol's catalytic domain and identify potential binding sites. Finally, we demonstrate that depletion of PolDIP2 in human cells causes a decrease in replication fork rates, similar to that observed in PrimPol(-/-)cells. However, depletion of PolDIP2 in PrimPol(-/-)cells does not produce a further decrease in replication fork rates. Together, these findings establish that PolDIP2 can regulate the TLS polymerase and primer extension activities of PrimPol, further enhancing our understanding of the roles of PolDIP2 and PrimPol in eukaryotic DNA damage tolerance.
authors.affiliation: Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton BN1 9RQ, UK.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Guilliam
authors.affiliation: Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton BN1 9RQ, UK.
authors.forename: Laura J
authors.initials: LJ
authors.lastname: Bailey
authors.affiliation: Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton BN1 9RQ, UK.
authors.forename: Nigel C
authors.initials: NC
authors.lastname: Brissett
authors.affiliation: Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton BN1 9RQ, UK a.j.doherty@sussex.ac.uk.
authors.forename: Aidan J
authors.initials: AJ
authors.lastname: Doherty
mesh_terms: D002478:Cells, Cultured; D004247:DNA / Q000378:metabolism; D004249:DNA Damage; D019915:DNA Primase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000378:metabolism; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism*; D006147:Guanine / Q000031:analogs & derivatives; D006801:Humans; D064251:Multifunctional Enzymes / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism*; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; D064251:Multifunctional Enzymes; D009687:Nuclear Proteins; C473592:POLDIP2 protein, human; D018809:Proliferating Cell Nuclear Antigen; C024829:8-hydroxyguanine; D006147:Guanine; D004247:DNA; D019915:DNA Primase; C585901:PrimPol protein, human; D004259:DNA-Directed DNA Polymerase