[URE3] Prion formation by the Candida albicans Ure2p (but not by C. glabrata Ure2p)-CgUre2

[URE3] is a prion (infectious protein) of the Saccharomyces cerevisiae Ure2p, a regulator of nitrogen catabolism. We find that the Ure2p of Candida albicans and C. glabrata also regulate nitrogen catabolism. Conservation of amino acid sequence within the prion domain of Ure2p has been proposed as evidence that the [URE3] prion helps its host. We show that the C. albicans Ure2p, which does not conserve this sequence, can nonetheless form a [URE3] prion, but the C. glabrata Ure2p, which does have the conserved sequence, cannot form [URE3]. These results suggest that the sequence is not conserved to preserve prion forming ability. Two groups (Wild type and ure2 mutants) consisted of 4 biological replicates in which a Ure2 mutant sample was paired with the wild type strain BG14 sample. Each group included 1 reciprocally labeled sample.