ArticlePloS one2012
CK2-mediated hyperphosphorylation of topoisomerase I targets serine 506, enhances topoisomerase I-DNA binding, and increases cellular camptothecin sensitivity.
Article in PloS one, 2012. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 17 papers.
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Who cites it
17 citing papers in PubMed, 27 citations in OpenAlex.
- A CHK1-mediated phosphorylation switch suppresses human Topoisomerase 1-associated genomic instability.The EMBO journal · 2026Article
- Arginine methylation of human DNA topoisomerase I by PRMT5 facilitates DNA relaxation.Nucleic acids research · 2026Article
- CK2 activity is crucial for proper glucagon expression.Diabetologia · 2024Article
- Inhibition of CK2 Reduces NG2 Expression in Juvenile Angiofibroma.Biomedicines · 2022Article
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- Role of protein kinase CK2 in antitumor drug resistance.Journal of experimental & clinical cancer research : CR · 2019Review
- Topoisomerases and cancer chemotherapy: recent advances and unanswered questions.F1000Research · 2019Review
- Characterization and antitumor activity of camptothecin from endophytic fungusAfrican health sciences · 2017Article
- Molecular characterization of irinotecan (SN-38) resistant human breast cancer cell lines.BMC cancer · 2016Article
- Protein kinase CK2 in breast cancer: the CK2β regulatory subunit takes center stage in epithelial plasticity.Cellular and molecular life sciences : CMLS · 2015Review
- Proteomic characterization of the nucleolar linker histone H1 interaction network.Journal of molecular biology · 2015Article
- Topoisomerase-I PS506 as a Dual Function Cancer Biomarker.PloS one · 2015Article
- Topoisomerase I as a biomarker: detection of activity at the single molecule level.Sensors (Basel, Switzerland) · 2014Article
- RNA-seq reveals determinants for irinotecan sensitivity/resistance in colorectal cancer cell lines.International journal of clinical and experimental pathology · 2014Article
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Corrections and comments
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Authors and funding
3 authors at 1 institution in 1 country.
Funding
Abstract
Topoisomerase I is the target for a potent class of chemotherapeutic drugs derived from the plant alkaloid camptothecin that includes irinotecan and topotecan. In this study we have identified a novel site of CK2-mediated topoisomerase I (topo I) phosphorylation at serine 506 (PS506) that is relevant to topo I function and to cellular responses to these topo I-targeted drugs. CK2 treatment induced hyperphosphorylation of recombinant topo I and expression of the PS506 epitope, and resulted in increased binding of topo I to supercoiled plasmid DNA. Hyperphosphorylated topo I was approximately three times more effective than the basal phosphorylated enzyme at relaxing plasmid supercoils but had similar DNA cleavage activity once bound to DNA. The PS506 epitope was expressed in cancer cell lines with elevated CK2 activity, hyperphosphorylated topo I, and increased sensitivity to camptothecin. In contrast, PS506 was not detected in normal cells or cancer cell lines with lower levels of CK2 activity. By experimentally manipulating CK2 activity in cancer cell lines, we demonstrate a cause and effect relationship between CK2 activity, PS506 expression, camptothecin-induced cellular DNA damage, and cellular camptothecin sensitivity. Our results show that the PS506 epitope is an indicator of dysregulated, hyperphosphorylated topo I in cancer cells, and may thus serve as a diagnostic or prognostic biomarker and predict tumor responsiveness to widely used topo I-targeted therapies.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.