Chemical-genetic profiling of imidazo[1,2-a]pyridines and -pyrimidines reveals target pathways conserved between yeast and human cells

• Published in: PLoS genetics 2008-11, Vol.4 (11), p.e1000284-e1000284
• Main Authors: Yu, Lisa, Lopez, Andres, Anaflous, Abderrahmane, El Bali, Brahim, Hamal, Abdellah, Ericson, Elke, Heisler, Lawrence E, McQuibban, Angus, Giaever, Guri, Nislow, Corey, Boone, Charles, Brown, Grant W, Bellaoui, Mohammed
• Format: Article
• Language: English
• Subjects: Antifungal Agents - chemistry; Antifungal Agents - pharmacology; Brewer's yeast; Cells, Cultured; Chemical Biology; Cyclin-dependent kinases; Deoxyribonucleic acid; DNA; DNA Damage; DNA Repair; Evacuations & rescues; Experiments; Genetic aspects; Genetics; Genetics and Genomics/Functional Genomics; Genetics and Genomics/Pharmacogenomics; Humans; Imidazole; Medical research; Mitochondria - metabolism; Physiological aspects; Pyridines - chemistry; Pyridines - pharmacology; Pyrimidines - chemistry; Pyrimidines - pharmacology; Saccharomyces cerevisiae; Saccharomyces cerevisiae - drug effects; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - metabolism; Signal Transduction; Studies; Yeast
• ISSN: 1553-7404; 1553-7390; 1553-7404
• DOI: 10.1371/journal.pgen.1000284

Small molecules have been shown to be potent and selective probes to understand cell physiology. Here, we show that imidazo[1,2-a]pyridines and imidazo[1,2-a]pyrimidines compose a class of compounds that target essential, conserved cellular processes. Using validated chemogenomic assays in Saccharomyces cerevisiae, we discovered that two closely related compounds, an imidazo[1,2-a]pyridine and -pyrimidine that differ by a single atom, have distinctly different mechanisms of action in vivo. 2-phenyl-3-nitroso-imidazo[1,2-a]pyridine was toxic to yeast strains with defects in electron transport and mitochondrial functions and caused mitochondrial fragmentation, suggesting that compound 13 acts by disrupting mitochondria. By contrast, 2-phenyl-3-nitroso-imidazo[1,2-a]pyrimidine acted as a DNA poison, causing damage to the nuclear DNA and inducing mutagenesis. We compared compound 15 to known chemotherapeutics and found resistance required intact DNA repair pathways. Thus, subtle changes in the structure of imidazo-pyridines and -pyrimidines dramatically alter both the intracellular targeting of these compounds and their effects in vivo. Of particular interest, these different modes of action were evident in experiments on human cells, suggesting that chemical-genetic profiles obtained in yeast are recapitulated in cultured cells, indicating that our observations in yeast can: (1) be leveraged to determine mechanism of action in mammalian cells and (2) suggest novel structure-activity relationships.