[15] performed genomic expression profiling in C. albicans exposed in vitro to blood and in vivo during infection in a standard mouse model of disseminated candidiasis and identified groups of genes highly expressed under these conditions. When compared with the dataset of predicted secretion pathway ORFs, a number of virulence-related genes were concordant, including Hwp1p and the Als family of adhesins [6, 7], Phr1p [8], Sap9p [16], Sod5p [17, 18], and Sun41p [19–21]. Thus, we identified known soluble secreted and membrane-associated secretion KU-60019 nmr pathway proteins important for virulence, supporting our approach as a method to identify
candidate virulence-related genes. We also identified orf19.3414, which is predicted to encode a secretion pathway protein homologous to the S. cerevisiae endocytosis-related gene SUR7 [1]. As we independently identified C. albicans
SUR7 in our screen for candidate virulence-related Decitabine genes, we used a reverse genetic approach to investigate the role of C. albicans SUR7 in attributes related to virulence in order to define its role in pathogenesis. Results The temperature sensitive growth defect of the Candida albicans sur7Δ mutant is partially rescued by high salt We generated a C. albicans sur7Δ homozygous null mutant by PCR-mediated gene disruption [22, 23], SMB3-H, followed by construction of an isogenic complemented strain, SMB3-R (Table 1). Before proceeding with phenotypic characterizations of the sur7Δ null mutant, we assessed the growth of each strain by calculating doubling times. Growth curves and the resulting doubling times are presented in Fig. 1 and Table 2, respectively. In rich medium, there was no statistically significant difference (p > 0.05) between the calculated doubling times of the C. albicans sur7Δ mutant, prototrophic control strain DAY185,
and the isogenic complemented strain (Fig. 1A and Table 2). Growth in response to high osmotic stress (1.0 M NaCl or 2.5 M glycerol) was the same as that of the control strains when incubated at either 30 Cytidine deaminase or 37°C (data not shown). Interestingly, when incubated at 42°C, growth of the sur7Δ null mutant strain was markedly impaired, in contrast to the control and SUR7 complemented strains (Fig. 1B). The sur7Δ null mutant grew at one-third the rate of the wild-type control strains (Table 2). Unexpectedly, the sur7Δ null mutant’s inability to grow at 42°C was partially rescued when grown under conditions of high salt (1.0 M NaCl; Fig. 1C); differences in doubling time compared to the control strains were statistically significant (p < 0.001). Table 1 Candida albicans strains used in this study.