RNA-seq of C. neoformans H99 sre1 deletion mutant in RPMI

Nickel (Ni) is an abundant element on Earth. Unlike our knowledge of other metals, the biochemical response to Ni is unknown. Previous studies in mammals have shown that Ni is capable of inducing various physiological changes including redox stress, hypoxic responses, as well as cancer progression pathways, indicating that Ni is toxic to mammalian cells. Like other metals, homeostasis mechanisms must be in place to ensure that intracellular Ni concentrations remain low. We sought to use Cryptococcus neoformans as a model organism to elucidate the cellular response to exogenous Ni. Here, we found Ni causes alterations in ergosterol (the fungal equivalent of mammalian cholesterol) and lipid biosynthesis, and the transcription factor Sre1 is required for growth on Ni-supplemented media.