Mutations in the RECQL4 helicase cause three different diseases (Rothmund-Thomson syndrome, Baller-Gerold syndrome, and RAPADILINO), yet RECQL4 remains the least-studied human RecQ due to difficulties in working with the protein both in vivo and in vitro. However, RecQ4 subfamily helicases are the only RecQs found in all three domains of life, which yields a wealth of experimental models to help understand RECQL4.
Using the yeast homolog Hrq1, we’ve found that it displays the same biochemical activities as RECQL4, regulates telomerase activity (see Project 2), and functions in DNA inter-strand crosslink (ICL) repair in a Fanconi Anemia-independent pathway. Our ongoing work is focusing on ICL repair and the role of Hrq1 in transcription using biochemistry, mass spec, click chemistry, yeast genetics, and next-gen sequencing technologies.
Mechanism of the first post-incision step of FA-independent ICL repair.
The Hrq1 helicase and Pso2 nuclease are recruited to sites of ICL damage. On undamaged DNA, Pso2 alone can begin to degrade one strand of duplex DNA, as shown by single-molecule FRET analysis, but Hrq1 stimulates this activity. On a substrate containing a site-specific ICL (XL-DNA), Pso2 completely lacks translesion nuclease activity in the absence of Hrq1.
A deep dive into the RecQ interactome: something old and something new. Simmons RH 3rd, Rogers CM, Bochman ML. Curr Genet. 2021 Oct;67(5):761-767. doi: 10.1007/s00294-021-01190-3. Epub 2021 May 7. PMID: 33961099 Review.
The Genetic and Physical Interactomes of the Saccharomyces cerevisiae Hrq1 Helicase. Rogers CM, Sanders E, Nguyen PA, Smith-Kinnaman W, Mosley AL, Bochman ML. G3 (Bethesda). 2020 Dec 3;10(12):4347-4357. doi: 10.1534/g3.120.401864. PMID: 33115721 Free PMC article.
Comprehensive Synthetic Genetic Array Analysis of Alleles That Interact with Mutation of the Saccharomyces cerevisiae RecQ Helicases Hrq1 and Sgs1. Sanders E, Nguyen PA, Rogers CM, Bochman ML. G3 (Bethesda). 2020 Dec 3;10(12):4359-4368. doi: 10.1534/g3.120.401709. PMID: 33115720 Free PMC article.
Fanconi anemia-independent DNA inter-strand crosslink repair in eukaryotes. Rogers CM, Simmons Iii RH, Fluhler Thornburg GE, Buehler NJ, Bochman ML. Prog Biophys Mol Biol. 2020 Dec;158:33-46. doi: 10.1016/j.pbiomolbio.2020.08.005. Epub 2020 Aug 30. PMID: 32877700 Free PMC article. Review.
The yeast Hrq1 helicase stimulates Pso2 translesion nuclease activity and thereby promotes DNA interstrand crosslink repair. Rogers CM, Lee CY, Parkins S, Buehler NJ, Wenzel S, Martínez-Márquez F, Takagi Y, Myong S, Bochman ML. J Biol Chem. 2020 Jul 3;295(27):8945-8957. doi: 10.1074/jbc.RA120.013626. Epub 2020 May 5. PMID: 32371399 Free PMC article.
The Saccharomyces cerevisiae Hrq1 and Pif1 DNA helicases synergistically modulate telomerase activity in vitro. Nickens DG, Rogers CM, Bochman ML. J Biol Chem. 2018 Sep 14;293(37):14481-14496. doi: 10.1074/jbc.RA118.004092. Epub 2018 Aug 1. PMID: 30068549 Free PMC article.
Saccharomyces cerevisiae Hrq1 helicase activity is affected by the sequence but not the length of single-stranded DNA. Rogers CM, Bochman ML. Biochem Biophys Res Commun. 2017 May 13;486(4):1116-1121. doi: 10.1016/j.bbrc.2017.04.003. Epub 2017 Apr 3. PMID: 28385527
Yeast Hrq1 shares structural and functional homology with the disease-linked human RecQ4 helicase. Rogers CM, Wang JC, Noguchi H, Imasaki T, Takagi Y, Bochman ML. Nucleic Acids Res. 2017 May 19;45(9):5217-5230. doi: 10.1093/nar/gkx151. PMID: 28334827 Free PMC article.
Hrq1, a homolog of the human RecQ4 helicase, acts catalytically and structurally to promote genome integrity. Bochman ML, Paeschke K, Chan A, Zakian VA. Cell Rep. 2014 Jan 30;6(2):346-56. doi: 10.1016/j.celrep.2013.12.037. Epub 2014 Jan 16. PMID: 24440721 Free PMC article.