These domains are formed by tight associations of ergosterol and sphingolipids, and aggregate specific proteins, GPI-anchored and non-GPI [19–21]. In accordance, ScGUP1 has been implicated

in the proper GPI-anchors remodelling [22]. Among various classes of lipids in C. albicans, membrane ergosterol is an important constituent, which is also the target of common antifungals like polyenes and SB525334 in vitro azoles [23–25]. Therefore, the action of antifungals is affected by changes in the membrane lipid composition, as well as its order (fluidity) and asymmetry in general, and by Cyclosporin A concentration ergosterol content/distribution in particular [19, 23, 24, 26–28]. Our group has shown [19], that the Scgup1Δ mutant displays a moderate sensitivity to sphingolipids biosynthesis inhibitors (SBIs), but a higher resistance to ergosterol biosynthesis inhibitors (EBIs), including azoles. Additionally, the same work shows that the Scgup1Δ mutant presents an abnormal sterol distribution in the plasma membrane, as well as internal membranes. In fact, GUP1

in S. cerevisiae has revealed to have a vast pleiotropic nature [19, 22, 29–32]. In mammals it was described as a negative regulator of the N-terminal palmitoylation of Sonic hedgehog pathway [33], which controls morphogenesis, differentiation and patterning during embryogenesis, including proliferation and cell fate. In order to explore the involvement of CaGUP1 in drug susceptibility, we tested the growth Rolziracetam of Cagup1Δ null mutant in the presence of these compounds. Although, in C. albicans, NSC 683864 manufacturer as in S. cerevisiae, it is not possible to identify the precise Gup1p acyltransferase dependent reaction/s, we show that the deletion of GUP1 in C. albicans changes ergosterol plasma membrane constitution/distribution, presenting an increased resistance to azoles. More importantly, CaGup1p strongly interferes with the capacity of

cells to develop hyphae, to adhere, to invade, and to form biofilms, all of which are significant virulence factors. To our knowledge, this work is the first study with GUP1 gene in Candida albicans, and it clearly shows a role for CaGUP1 gene in virulence. Results CaGUP1 deletion provokes resistance to antifungals The S. cerevisiae O-acyltransferase Gup1p acts on lipids metabolism affecting the plasma membrane sphingolipids-sterol ordered domains assembly/integrity, and influencing the susceptibility to antifungal drugs [19]. An association between altered lipid-ordered domains and antifungal resistance has been described before [23, 24, 34, 35]. Therefore, we examined the growth behaviour of several clones of Cagup1Δ null mutant (3-5) in the presence of some common antifungals and compare them with wt. We used four ergosterol biosynthesis inhibitors (EBIs), hampering different steps of ergosterol biosynthesis [26, 27] and two polyenes.