A common telomeric gene silencing assay is affected by nucleotide metabolism.

TitleA common telomeric gene silencing assay is affected by nucleotide metabolism.
Publication TypeJournal Article
Year of Publication2011
AuthorsRossmann MP, Luo W, Tsaponina O, Chabes A, Stillman B
JournalMol Cell
Volume42
Issue1
Pagination127-36
Date Published2011 Apr 08
ISSN1097-4164
KeywordsAntigens, Nuclear, Chromosomal Position Effects, Genes, Fungal, Gene Silencing, Histone-Lysine N-Methyltransferase, Models, Genetic, Mutation, Nuclear Proteins, Orotic Acid, Proliferating Cell Nuclear Antigen, Ribonucleotide Reductases, Saccharomyces cerevisiae, Saccharomyces cerevisiae Proteins, Telomere
Abstract

<p>Telomere-associated position-effect variegation (TPEV) in budding yeast has been used as a model for understanding epigenetic inheritance and gene silencing. A widely used assay to identify mutants with improper TPEV employs the URA3 gene at the telomere of chromosome VII-L that can be counterselected with 5-fluoroorotic acid (5-FOA). 5-FOA resistance has been inferred to represent lack of transcription of URA3 and therefore to represent heterochromatin-induced gene silencing. For two genes implicated in telomere silencing, POL30 and DOT1, we show that the URA3 telomere reporter assay does not reflect their role in heterochromatin formation. Rather, an imbalance in ribonucleotide reductase (RNR), which is induced by 5-FOA, and the specific promoter of URA3 fused to ADH4 at telomere VII-L are jointly responsible for the variegated phenotype. We conclude that metabolic changes caused by the drug employed and certain mutants being studied are incompatible with the use of certain prototrophic markers for TPEV.</p>

DOI10.1016/j.molcel.2011.03.007
Alternate JournalMol. Cell
PubMed ID21474074
PubMed Central IDPMC3086572
Grant ListCA13106 / CA / NCI NIH HHS / United States
R01 GM045436-20 / GM / NIGMS NIH HHS / United States
P01 CA013106 / CA / NCI NIH HHS / United States
GM45436 / GM / NIGMS NIH HHS / United States
R01 GM045436 / GM / NIGMS NIH HHS / United States
P01 CA013106-40 / CA / NCI NIH HHS / United States