title: Dissecting the Roles of Divergent and Convergent Transcription in Chromosome Instability.
abstract: The interplay of transcription, topological tension, and chromosome breakage is a subject of intense interest, but, with so many facets to the problem, it is difficult to test. Here, we vary the orientation of promoters relative to one another in a yeast system that permits sensitive detection of chromosome breaks. Interestingly, convergent transcription that would direct RNA polymerases into one another does not increase chromosome breakage. In contrast, divergent transcription that would create underwound and potentially single-stranded DNA does cause a marked increase in chromosome breakage. Furthermore, we examine the role that topoisomerases are playing in preventing genome instability at these promoters and find that Top2 is required to prevent instability at converging promoters.
authors.affiliation: USC Norris Comprehensive Center, University of Southern California Keck School of Medicine, 1441 Eastlake Avenue, Room 5428, Los Angeles, CA 90089, USA.
authors.forename: Nicholas R
authors.initials: NR
authors.lastname: Pannunzio
authors.affiliation: USC Norris Comprehensive Center, University of Southern California Keck School of Medicine, 1441 Eastlake Avenue, Room 5428, Los Angeles, CA 90089, USA. Electronic address: lieber@usc.edu.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Lieber
mesh_terms: D043171:Chromosomal Instability / Q000187:drug effects / Q000235:genetics*; D005690:Galactose / Q000494:pharmacology; D015321:Gene Rearrangement / Q000187:drug effects / Q000235:genetics; D056426:Genetic Loci; D008957:Models, Genetic; D011401:Promoter Regions, Genetic; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D029701:Saccharomyces cerevisiae Proteins; D005690:Galactose