Open AccessDNA topoisomerase I controls the kinetics of promoter activation and DNA topology in Saccharomyces cerevisiae.
Author(s) -
Ernesto Di Mauro,
Giorgio Camilloni,
L Verdone,
Micaela Caserta
Publication year - 1993
Publication title -
molecular and cellular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.14
H-Index - 327
eISSN - 1067-8824
pISSN - 0270-7306
DOI - 10.1128/mcb.13.11.6702
Subject(s) - dna supercoil , biology , saccharomyces cerevisiae , topoisomerase , transcription (linguistics) , dna , microbiology and biotechnology , plasmid , mutant , gene , promoter , biochemistry , gene expression , dna replication , linguistics , philosophy
Inactivation of the nonessential TOP1 gene, which codes for Saccharomyces cerevisiae DNA topoisomerase I, affects the rate of transcription starting at the ADH2 promoter. For both the chromosomal gene and the plasmid-borne promoter, mRNA accumulation is kinetically favored in the mutant relative to a wild-type isogenic strain. The addition of ethanol causes in wild-type yeast strains a substantial increase in linking number both on the ADH2-containing plasmid and on the resident 2 microns DNA. Evidence has been obtained that such an in vivo increase in linking number depends on (i) the activity of DNA topoisomerase I and of no other enzyme and (ii) ethanol addition, not on the release from glucose repression. A direct cause-effect relationship between the change in supercoiling and alteration of transcription cannot be defined. However, the hypothesis that a metabolism-induced modification of DNA topology in a eukaryotic cell plays a role in regulating gene expression is discussed.