PbSP expression was higher in yeast cells submitted to nitrogen starvation condition, both in total protein extract (Figure 3A, lane 2) and culture supernatant (Figure 3A, lane 4) in comparison to the PbSP expression in the non-limiting nitrogen condition (Figures 3A, lanes 1 and 3). Figure 3 Analysis of Pb sp and Pb SP expression during nitrogen starvation and during infection in murine macrophages. A: Western blot assay using

the polyclonal antibody anti-PbSP of protein extracts of. Go6983 in vivo 1: yeast cells cultured in MMcM medium; 2: yeast cells cultured in the same medium deprived of nitrogen; 3: culture supernatant of yeast cells in MMcM medium; 4: the same as in 3 in the absence of nitrogen. B: Pbsp quantification by Real Time PCR. RNAs obtained were used to obtain cDNAs used to perform Pbsp quantification. Reactions were performed in triplicate and normalized by using α-tubulin

expression. 1: Pbsp ABT-737 mouse relative quantification in yeast cells eFT-508 clinical trial incubated in MMcM medium for 4 h; 2: Pbsp relative quantification in yeast cells incubated in MMcM medium without nitrogen sources for 4 h; 3: Pbsp relative quantification in yeast cells incubated in MMcM medium for 8 h; 4: Pbsp relative quantification in yeast cells incubated in MMcM medium without nitrogen sources for 8 h. C: Pbsp quantification by Real Time PCR. 1: Pbsp relative quantification in mycelium. 2: Pbsp relative quantification in yeast cells.

3: Pbsp relative quantification in yeast cells during infection in macrophages. Asterisk denotes values statistically different from control (P ≤ 0.05). Analysis of Pbsp expression by quantitative real-time PCR The Pbsp expression was evaluated by using real-time PCR in yeast cells submitted to nitrogen starvation. The Pbsp expression was strongly induced during limiting nitrogen condition in 4 and 8 h (Figure 3B, Bars 2 and 4), compared to the non-limiting condition (Figure 3B, Bars 1 and 3). The Pbsp expression was also evaluated in mycelium, yeast cells and yeast cells infecting macrophages. The results are presented in Figure 3C. The Pbsp expression in mycelium is strongly reduced (Figure 3C, Bar 1) compared to the Pbsp expression in yeast cells (Figure 3C, Bar 2). There is an increased Pbsp expression in yeast cells Arachidonate 15-lipoxygenase infecting macrophages (Figure 3C, Bar 3). Interaction of serine protease with other P. brasiliensis proteins The interaction of PbSP with other P. brasiliensis proteins was evaluated by two-hybrid system in S. cerevisiae. The proteins identified interacting with PbSP are described in Table 1. It was detected homologues of FKBP-peptidyl prolyl cis-trans isomerase, calnexin, HSP70 and a possible cytoskeleton associated periodic tryptophan protein. Protein interactions were confirmed by co-immunoprecipitation assays and are shown in Figure 4. Table 1 P.