Journal article
Functions of alternative Replication Protein A (aRPA) in initiation and elongation
Biochemistry (Easton), Vol.49(28), pp.5919-5928
07/20/2010
DOI: 10.1021/bi100380n
PMCID: PMC2912413
PMID: 20545304
Abstract
Replication protein A (RPA) is a single-stranded DNA-binding complex that is essential for DNA replication, repair and recombination in eukaryotic cells. In addition to this canonical complex, we have recently characterized an alternative Replication Protein A complex (aRPA) that is unique to primates. aRPA is composed of three subunits: RPA1 and RPA3, also present in canonical RPA, and a primate-specific subunit RPA4, homologous to canonical RPA2. aRPA has biochemical properties similar to the canonical RPA complex but does not support DNA replication. We describe studies to identify what properties of aRPA prevent it from functioning in DNA replication. We show aRPA has reduced interaction with DNA polymerase α (pol α) and that aRPA is not able to efficiently stimulate DNA synthesis by pol α on aRPA-coated DNA. Additionally, we show that aRPA is unable to support de novo priming by pol α. Because pol α activity is essential for both initiation and for Okazaki strand synthesis, we conclude that the inability of aRPA to support pol α loading causes aRPA to be defective in DNA replication. We also show that aRPA stimulates synthesis by DNA polymerase α in the presence of PCNA and RFC. This indicates that aRPA can support extension of DNA strands by DNA polymerase α. This finding along with the previous observation that aRPA supports early steps of nucleotide excision repair and recombination, indicate that aRPA can support DNA repair synthesis that requires polymerase δ, PCNA and RFC and support a role for aRPA in DNA repair.
Details
- Title: Subtitle
- Functions of alternative Replication Protein A (aRPA) in initiation and elongation
- Creators
- Aaron C Mason - Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242Rupa Roy - Department of Biological Sciences, University of Delaware, Newark, Delaware 19716Daniel T Simmons - Department of Biological Sciences, University of Delaware, Newark, Delaware 19716Marc S Wold - Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
- Resource Type
- Journal article
- Publication Details
- Biochemistry (Easton), Vol.49(28), pp.5919-5928
- DOI
- 10.1021/bi100380n
- PMID
- 20545304
- PMCID
- PMC2912413
- NLM abbreviation
- Biochemistry
- ISSN
- 0006-2960
- eISSN
- 1520-4995
- Language
- English
- Date published
- 07/20/2010
- Academic Unit
- Radiation Oncology; Biochemistry and Molecular Biology
- Record Identifier
- 9984025282902771
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