Expression data from Saccharomyces cerevisiae treated with gentamicin

Gentamicin is a highly efficacious antibiotic against gram-negative bacteria. However, its usefulness in treating infection is compromised by its poorly understood renal toxicity. This toxic effect is seen in a variety of organisms. While the yeast Saccharomyces cerevisiae is relatively insensitive to gentamicin, mutations in any one of 20 or so genes causes a dramatic increase in sensitivity. Many of these genes encode proteins important for translation termination or specific protein trafficking complexes. Here, we demonstrate by microarray analysis that gentamicin treatment leads to dramatic decreases in genes under the control of the MADS box protein Mcm1, including genes encoding products involved in mating, nitrogen utilization, and ribosome biogenesis. Furthermore, microarray analysis also demonstrates an increase in a Rlm1-dependent set of genes involved in maintaining the structure of the cell wall that are also induced by the antifungal agents caspofungin and calcofluor white. Subsequent inspection of the physical and genetic interactions of the remaining gentamicin sensitive mutants revealed a network centered around chitin synthase and the Arf Pathway. Furthermore, conditional arf1 mutants are hypersensitive to gentamicin even under permissive conditions. These results suggest that gentamicin may act as a cell wall stress, possibly by disrupting Arf-dependent trafficking of proteins involved in forming the cell wall.

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