A dynamic model for replication protein A (RPA) function in DNA processing pathways

Abstract

Processing of DNA in replication, repair and recombination pathways in cells of all organisms requires the participation of at least one major single-stranded DNA (ssDNA)-binding protein. This protein protects ssDNA from nucleolytic damage, prevents hairpin formation and blocks DNA reannealing until the processing pathway is successfully completed. Many ssDNA-binding proteins interact physically and functionally with a variety of other DNA processing proteins. These interactions are thought to temporally order and guide the parade of proteins that ‘trade places’ on the ssDNA, a model known as ‘hand-off’, as the processing pathway progresses. How this hand-off mechanism works remains poorly understood. Recent studies of the conserved eukaryotic ssDNA-binding protein replication protein A (RPA) suggest a novel mechanism by which proteins may trade places on ssDNA by binding to RPA and mediating conformation changes that alter the ssDNA-binding properties of RPA. This article reviews the structure and function of RPA, summarizes recent studies of RPA in DNA replication and other DNA processing pathways, and proposes a general model for the role of RPA in protein-mediated hand-off.

Cell cycle specific distribution of killin: evidence for negative regulation of both DNA and RNA synthesis

“…We show that indeed as expected, Killin always adopts a mutually exclusive punctuated nuclear expression pattern with the 2 important accessory proteins in DNA replication. [19][20][21][22][23] Furthermore, we also notice that in non-S-phase cells, RFP-Killin congregates in the nucleolus where rRNA transcription is known to be most active. 24 We provide evidence that throughout the cell cycle, RFPKillin is tightly associated with the nucleic acids.…”

“…The mutually exclusive patterns of DNA replication foci labeled by BrdU with RFP-Killin foci strongly support that Killin inhibits DNA replication during the S-phase. Given the fact that the K d of Killin to ssDNA template is very similar to that of RPA, 17,21 both of which are in the sub mM range, it is possible that Killin could interfere with DNA replication by competitively inhibit RPA binding to ssDNA templates during the onset of DNA replication. To this end, we conducted confocal fluorescent microscopy by looking at the precise RFP-Killin expression pattern in relationship with DNA replication foci marked by immunofluorescent staining of endogenous RPA.…”

Interactions of Human O6-Alkylguanine-DNA Alkyltransferase (AGT) with Short Single-stranded DNAs

“…Other DNA repair proteins and factors that bind and/or repair single-stranded DNA include the human and vaccinia virus uracil-DNA glycosylases (49,50), human DNA glycosylases NEIL1 and NEIL2 (51), human apurinic/apyrimidinic endonuclease (APE1) (52), and Xeroderma pigmentosum group A correcting protein (XP-A) (53,54). In addition, XP-A is associated with the replication protein A single strand-binding protein (55,56), whereas components of the transcription-coupled nucleotide excision repair complex are associated with XP-B and XP-D DNA helicases (57). It seems reasonable to expect that these interaction partners increase the availability of single-stranded templates for repair.…”

Replication Protein A (RPA1a) Is Required for Meiotic and Somatic DNA Repair But Is Dispensable for DNA Replication and Homologous Recombination in Rice

“…Interactions of RPA with those proteins are critical in this process (Wold, 1997;Iftode et al, 1999). A great deal of protein dynamics research has indicated that the interactions between RPA and other DNA-metabolism proteins are choreographed on the ssDNA to recruit the required protein present at the proper time (Fanning et al, 2006). Human, animals, and fungi have single copy for each subunit of RPA (http://www.ncbi.nlm.nih.gov/ sutils/genom_table.cgi).…”