This gene has a nearly identical homolog in C. immitis, CIMG_03142, that was upregulated 3.6 fold in day 2 spherules and 3.39 fold in day 8 spherules. Whiston et al. also found it to be upregulated in spherules . Another H. capsulatum gene that is required for yeast formation is α glucan synthase (AGS1) gene . This enzyme catalyzes the production of α (1,3) glucan in the cell wall that obscures the β (1,3) glucan and prevents activation of innate immunity via the dectin-1 receptor . C. immitis has an AGS1 gene (CIMG_13256) that was upregulated in the day 8 spherule (2.48 fold) but not day 2 spherules. Whiston et al. found this gene to be upregulated
1.93 fold in spherules compared to mycelia . There is no literature describing the relative amounts of α (1,3) glucan and β (1,3) glucan in C. immitis mycelia or spherules. We know, however, that there is enough exposed β (1,3) glucan Selleckchem Nirogacestat in Coccidioides spherules to stimulate macrophages to produce cytokines via dectin-1 . Two genes buy Stattic coding for transcription factors, Ryp2 and Ryp3, have been found to be essential for conversion from filaments to yeast in H. capsulatum. These genes are overexpressed in the yeast phase of H. capsulatum. C. immitis has nearly identical this website homologs of these genes but they were not overexpressed
in either day 2 or day 8 spherules, suggesting that they may not be required for the transformation from mycelium to spherule. Gene disruption experiments in B. dermatitidis have shown that a histidine kinase, DRK1, is required for the transformation from filaments to yeast . It is not clear from the literature whether or not this gene is overexpressed in the B. dermatitidis yeast phase. C. immitis has a very closely related homolog of this gene (CIMG_04512) but it was not up or down regulated in day 2 or day 8 spherules. In another dimorphic pathogenic fungus, S. schenckii, the calcium/calmodulin kinase I gene (SSMK1) was found to be required for formation of yeast . There are two genes in C. immitis that are highly homologous to the S. schenckii SSMK1 gene; neither
one of these was up- or downregulated in day 2 or day 8 spherules. A number of studies have been done studying the transcriptome of P. brasiliensis[66, 67]. One study identified http://www.selleck.co.jp/products/Y-27632.html the 4-HPPD gene to be required for P. brasiliensis conidia to convert to yeast . They found that the 4-HPPD gene expression was upregulated in the yeast form and that a biochemical inhibitor of this enzyme, nitisinone, inhibited mycelium conversion to yeast. 4-HPPD (E.C. 1.13.1127) is an enzyme that converts 4-hydroxyphenylpyruvate to homogentisate that is involved in the synthesis of tyrosine, phenylalanine, and ubiqinone (KEGG, whttp://www.genome.jp/keg). There are two homologs of the 4-HPPD in the C. immitis genome, which have significantly different sequences.