scholarly journals A Proximity Ligation Method to Detect Proteins Bound to Single-Stranded DNA after DNA End Resection at DNA Double-Strand Breaks

2021 ◽  
Vol 5 (1) ◽  
pp. 3
Author(s):  
Faith C. Fowler ◽  
Jessica K. Tyler

After a DNA double-strand break, cells utilize either non-homologous end joining or homologous recombination to repair the broken DNA ends. Homologous recombination requires extensive nucleolytic processing of one of the DNA strands, resulting in long stretches of 3′ single-strand DNA overhangs. Typically, single-stranded DNA is measured using immunofluorescence microscopy to image the foci of replication protein A, a single-stranded DNA-binding protein. Microscopy analysis of bromodeoxyuridine foci under nondenaturing conditions has also been used to measure single-stranded DNA. Here, we describe a proximity ligation assay which uses genome-wide bromodeoxyuridine incorporation to label single-stranded DNA in order to measure the association of a protein of interest with single-stranded DNA. This method is advantageous over traditional foci analysis because it is more direct and specific than traditional foci co-localization microscopy methods, uses only one color channel, and can reveal protein-single-stranded DNA interactions that are rare and potentially undetectable using traditional microscopy methods. We show here the association of replication protein A and bromodeoxyuridine as proof-of-concept.

2008 ◽  
Vol 190 (17) ◽  
pp. 5766-5780 ◽  
Author(s):  
Yuyen Lin ◽  
Li-Jung Lin ◽  
Palita Sriratana ◽  
Kelli Coleman ◽  
Taekjip Ha ◽  
...  

ABSTRACT The bacterial single-stranded DNA-binding protein (SSB) and the archaeal/eukaryotic functional homolog, replication protein A (RPA), are essential for most aspects of DNA metabolism. Structural analyses of the architecture of SSB and RPA suggest that they are composed of different combinations of a module called the oligonucleotide/oligosaccharide-binding (OB) fold. Members of the domains Bacteria and Eukarya, in general, contain one type of SSB or RPA. In contrast, organisms in the archaeal domain have different RPAs made up of different organizations of OB folds. Interestingly, the euryarchaeon Methanosarcina acetivorans harbors multiple functional RPAs named MacRPA1 (for M. acetivorans RPA 1), MacRPA2, and MacRPA3. Comparison of MacRPA1 with related proteins in the publicly available databases suggested that intramolecular homologous recombination might play an important role in generating some of the diversity of OB folds in archaeal cells. On the basis of this information, from a four-OB-fold-containing RPA, we engineered chimeric modules to create three-OB-fold-containing RPAs to mimic a novel form of RPA found in Methanococcoides burtonii and Methanosaeta thermophila. We further created two RPAs that mimicked the RPAs in Methanocaldococcus jannaschii and Methanothermobacter thermautotrophicus through fusions of modules from MacRPA1 and M. thermautotrophicus RPA. Functional studies of these engineered proteins suggested that fusion and shuffling of OB folds can lead to well-folded polypeptides with most of the known properties of SSB and RPAs. On the basis of these results, different models that attempt to explain how intramolecular and intermolecular homologous recombination can generate novel forms of SSB or RPAs are proposed.


2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Luke A. Yates ◽  
Ricardo J. Aramayo ◽  
Nilisha Pokhrel ◽  
Colleen C. Caldwell ◽  
Joshua A. Kaplan ◽  
...  

1998 ◽  
Vol 273 (7) ◽  
pp. 3932-3936 ◽  
Author(s):  
Elena Bochkareva ◽  
Lori Frappier ◽  
Aled M. Edwards ◽  
Alexey Bochkarev

2004 ◽  
Vol 78 (4) ◽  
pp. 1605-1615 ◽  
Author(s):  
Yueh-Ming Loo ◽  
Thomas Melendy

ABSTRACT With the exception of viral proteins E1 and E2, papillomaviruses depend heavily on host replication machinery for replication of their viral genome. E1 and E2 are known to recruit many of the necessary cellular replication factors to the viral origin of replication. Previously, we reported a physical interaction between E1 and the major human single-stranded DNA (ssDNA)-binding protein, replication protein A (RPA). E1 was determined to bind to the 70-kDa subunit of RPA, RPA70. In this study, using E1-affinity coprecipitation and enzyme-linked immunosorbent assay-based interaction assays, we show that E1 interacts with the major ssDNA-binding domain of RPA. Consistent with our previous report, no measurable interaction between E1 and the two smaller subunits of RPA was detected. The interaction of E1 with RPA was substantially inhibited by ssDNA. The extent of this inhibition was dependent on the length of the DNA. A 31-nucleotide (nt) oligonucleotide strongly inhibited the E1-RPA interaction, while a 16-nt oligonucleotide showed an intermediate level of inhibition. In contrast, a 10-nt oligonucleotide showed no observable effect on the E1-RPA interaction. This inhibition was not dependent on the sequence of the DNA. Furthermore, ssDNA also inhibited the interaction of RPA with papillomavirus E2, simian virus 40 T antigen, human polymerase alpha-primase, and p53. Taken together, our results suggest a potential role for ssDNA in modulating RPA-protein interactions, in particular, the RPA-E1 interactions during papillomavirus DNA replication. A model for recruitment of RPA by E1 during papillomavirus DNA replication is proposed.


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