PCNA trimer instability inhibits translesion synthesis by DNA polymerase η and by DNA polymerase δ

Lynne M Dieckman; M Todd Washington

doi:10.1016/j.dnarep.2013.02.007

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PCNA trimer instability inhibits translesion synthesis by DNA polymerase η and by DNA polymerase δ

Journal article

Peer reviewed

PCNA trimer instability inhibits translesion synthesis by DNA polymerase η and by DNA polymerase δ

Lynne M Dieckman and M Todd Washington

DNA repair, Vol.12(5), pp.367-376

05/01/2013

DOI: 10.1016/j.dnarep.2013.02.007

PMCID: PMC3636165

PMID: 23506842

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Abstract

Translesion synthesis (TLS), the process by which DNA polymerases replicate through DNA lesions, is the source of most DNA damage-induced mutations. Sometimes TLS is carried out by replicative polymerases that have evolved to synthesize DNA on non-damaged templates. Most of the time, however, TLS is carried out by specialized translesion polymerases that have evolved to synthesize DNA on damaged templates. TLS requires the mono-ubiquitylation of the replication accessory factor proliferating cell nuclear antigen (PCNA). PCNA and ubiquitin-modified PCNA (UbPCNA) stimulate TLS by replicative and translesion polymerases. Two mutant forms of PCNA, one with an E113G substitution and one with a G178S substitution, support normal cell growth but inhibit TLS thereby reducing mutagenesis in yeast. A re-examination of the structures of both mutant PCNA proteins revealed substantial disruptions of the subunit interface that forms the PCNA trimer. Both mutant proteins have reduced trimer stability with the G178S substitution causing a more severe defect. The mutant forms of PCNA and UbPCNA do not stimulate TLS of an abasic site by either replicative Pol δ or translesion Pol η. Normal replication by Pol η was also impacted, but normal replication by Pol δ was much less affected. These findings support a model in which reduced trimer stability causes these mutant PCNA proteins to occasionally undergo conformational changes that compromise their ability to stimulate TLS by both replicative and translesion polymerases.

Protein Multimerization

DNA Replication

Mutation Rate

Mutation, Missense

Saccharomyces cerevisiae Proteins - genetics

Proliferating Cell Nuclear Antigen - chemistry

Protein Subunits - metabolism

Saccharomyces cerevisiae - metabolism

Ubiquitination

Proliferating Cell Nuclear Antigen - genetics

DNA Repair

DNA, Fungal - metabolism

Saccharomyces cerevisiae Proteins - metabolism

Protein Binding

Saccharomyces cerevisiae - enzymology

Protein Subunits - chemistry

DNA-Directed DNA Polymerase - metabolism

Protein Stability

DNA Polymerase III - metabolism

Proliferating Cell Nuclear Antigen - metabolism

Binding Sites

Protein Subunits - genetics

Saccharomyces cerevisiae Proteins - chemistry

Details

Title: Subtitle: PCNA trimer instability inhibits translesion synthesis by DNA polymerase η and by DNA polymerase δ
Creators: Lynne M Dieckman - Department of Biochemistry, University of Iowa College of Medicine, Iowa City, IA 52242-1109, United States
M Todd Washington
Resource Type: Journal article
Publication Details: DNA repair, Vol.12(5), pp.367-376
DOI: 10.1016/j.dnarep.2013.02.007
PMID: 23506842
PMCID: PMC3636165
NLM abbreviation: DNA Repair (Amst)
ISSN: 1568-7864
eISSN: 1568-7856
Publisher: Netherlands
Grant note: GM081433 / NIGMS NIH HHS R01 GM081433 / NIGMS NIH HHS
Language: English
Date published: 05/01/2013
Academic Unit: Radiation Oncology; Biochemistry and Molecular Biology
Record Identifier: 9984025299802771

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