Novel small-molecule inhibitors of RNA polymerase III.
A genetic approach utilizing the yeast Saccharomyces cerevisiae was used to identify the target of antifungal compounds. This analysis led to the identification of small molecule inhibitors of RNA polymerase (Pol) III from Saccharomyces cerevisiae. Three lines of evidence show that UK-118005 inhibits cell growth by targeting RNA Pol III in yeast. First, a dominant mutation in the g domain of Rpo31p, the largest subunit of RNA Pol III, confers resistance to the compound. Second, UK-118005 rapidly inhibits tRNA synthesis in wild-type cells but not in UK-118005 resistant mutants. Third, in biochemical assays, UK-118005 inhibits tRNA gene transcription in vitro by the wild-type but not the mutant Pol III enzyme. By testing analogs of UK-118005 in a template-specific RNA Pol III transcription assay, an inhibitor with significantly higher potency, ML-60218, was identified. Further examination showed that both compounds are broad-spectrum inhibitors, displaying activity against RNA Pol III transcription systems derived from Candida albicans and human cells. The identification of these inhibitors demonstrates that RNA Pol III can be targeted by small synthetic molecules.
Wu
Liping
L
Millennium Pharmaceuticals, Inc., Cambridge, Massachusetts. Pfizer Global Research and Development, Sandwich, United Kingdom.
Pan
Jing
J
Thoroddsen
Vala
V
Wysong
Deborah R
DR
Blackman
Ronald K
RK
Bulawa
Christine E
CE
Gould
Alexandra E
AE
Ocain
Timothy D
TD
Dick
Lawrence R
LR
Errada
Patrick
P
Dorr
Patrick K
PK
Parkinson
Tanya
T
Wood
Tony
T
Kornitzer
Daniel
D
Weissman
Ziva
Z
Willis
Ian M
IM
McGovern
Karen
K
D000935:Antifungal Agents / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects / Q000201:enzymology / Q000235:genetics; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D025141:Drug Resistance, Fungal / Q000235:genetics; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006801:Humans; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009154:Mutation / Q000235:genetics; D021122:Protein Subunits / Q000235:genetics; D012320:RNA Polymerase III / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D012343:RNA, Transfer / Q000096:biosynthesis / Q000235:genetics; D011930:Reaction Time / Q000187:drug effects / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic / Q000187:drug effects / Q000235:genetics
D000935:Antifungal Agents; D004791:Enzyme Inhibitors; D021122:Protein Subunits; D012343:RNA, Transfer; D012320:RNA Polymerase III