title: Topoisomerase 1 Regulates Gene Expression in Neurons through Cleavage Complex-Dependent and -Independent Mechanisms.
abstract: Topoisomerase 1 (TOP1) inhibitors, including camptothecin and topotecan, covalently trap TOP1 on DNA, creating cleavage complexes (cc's) that must be resolved before gene transcription and DNA replication can proceed. We previously found that topotecan reduces the expression of long (>100 kb) genes and unsilences the paternal allele of Ube3a in neurons. Here, we sought to evaluate overlap between TOP1cc-dependent and -independent gene regulation in neurons. To do this, we utilized Top1 conditional knockout mice, Top1 knockdown, the CRISPR-Cas9 system to delete Top1, TOP1 catalytic inhibitors that do not generate TOP1cc's, and a TOP1 mutation (T718A) that stabilizes TOP1cc's. We found that topotecan treatment significantly alters the expression of many more genes, including long neuronal genes, immediate early genes, and paternal Ube3a, when compared to Top1 deletion. Our data show that topotecan has a stronger effect on neuronal transcription than Top1 deletion, and identifies TOP1cc-dependent and -independent contributions to gene expression.
authors.affiliation: Department of Cell Biology and Physiology, UNC Neuroscience Center, Carolina Institute for Developmental Disabilities, The University of North Carolina, Chapel Hill, North Carolina, United States of America.|Neuroscience Institute, Georgia State University, Atlanta, Georgia, United States of America.
authors.forename: Angela M
authors.initials: AM
authors.lastname: Mabb
authors.affiliation: Department of Cell Biology and Physiology, UNC Neuroscience Center, Carolina Institute for Developmental Disabilities, The University of North Carolina, Chapel Hill, North Carolina, United States of America.
authors.forename: Jeremy M
authors.initials: JM
authors.lastname: Simon
authors.affiliation: Department of Cell Biology and Physiology, UNC Neuroscience Center, Carolina Institute for Developmental Disabilities, The University of North Carolina, Chapel Hill, North Carolina, United States of America.
authors.forename: Ian F
authors.initials: IF
authors.lastname: King
authors.affiliation: Department of Cell Biology and Physiology, UNC Neuroscience Center, Carolina Institute for Developmental Disabilities, The University of North Carolina, Chapel Hill, North Carolina, United States of America.
authors.forename: Hyeong-Min
authors.initials: HM
authors.lastname: Lee
authors.affiliation: School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China.
authors.forename: Lin-Kun
authors.initials: LK
authors.lastname: An
authors.affiliation: Department of Cell Biology and Physiology, UNC Neuroscience Center, Carolina Institute for Developmental Disabilities, The University of North Carolina, Chapel Hill, North Carolina, United States of America.
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Philpot
authors.affiliation: Department of Cell Biology and Physiology, UNC Neuroscience Center, Carolina Institute for Developmental Disabilities, The University of North Carolina, Chapel Hill, North Carolina, United States of America.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Zylka
mesh_terms: D000818:Animals; D004247:DNA / Q000378:metabolism*; D004264:DNA Topoisomerases, Type I / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D055786:Gene Knockout Techniques; D051379:Mice; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D013569:Synapses / Q000187:drug effects / Q000378:metabolism; D019772:Topotecan / Q000494:pharmacology; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism
chemical_list: D019772:Topotecan; D004247:DNA; C502429:Ube3a protein, mouse; D044767:Ubiquitin-Protein Ligases; D004264:DNA Topoisomerases, Type I