Candidozyma auris is a multidrug-resistant, thermo- and osmotolerant yeast capable of persisting on biotic and abiotic surfaces, attributes likely linked to its cell wall composition. Here, seven putative genes encoding yapsins, aspartyl proteases GPI-anchored to the membrane or cell wall, were identified in the genomes of C. auris CJ97 and 20-1498, from clades III and IV, respectively. The C. auris YPS1 gene is orthologous to the SAP9 of C. albicans. The YPS7 gene is orthologous to YPS7 in C. glabrata and S. cerevisiae, so that they may share similar roles. An in silico analysis suggested an interaction between pepstatin and the catalytic domain of Yps1 and Yps7. Although this inhibitor, when combined with caffeine, had a subtle effect on the growth of C. auris, it induced alterations in the cell wall. CauYPS1 and CauYPS7 expression increased under nutrient starvation and NaCl, and at 42 °C. The transcriptome of the 20-1498 strain suggests that autophagy may play a role in thermal stress, probably degrading deleterious proteins or maintaining cell wall and vacuolar homeostasis. Therefore, CauYps1 and CauYps7 may play a role in the cell wall integrity of C. auris in stress conditions, and they could be a target of new antifungal or antivirulence agents.

Candida auris is a multidrug-resistant pathogen with a high mortality rate and widespread distribution. Additionally, it can persist on inert surfaces for extended periods, facilitating its transmissibility in hospital settings. Autophagy is a crucial cellular mechanism that enables fungal survival under adverse conditions. A fundamental part of this process is mediated by vacuolar proteases, which play an essential role in the degradation and recycling of cellular components. The present work explores the relationship between C. auris vacuolar peptidases and autophagy, aiming to establish a precedent for understanding the survival mechanisms of this emerging fungus. Thus, eight genes encoding putative vacuolar peptidases in the C. auris genomes were identified: PEP4, PRB1, PRC1, ATG42, CPS, LAP4, APE3, and DAP2. Analysis of the protein domains and their phylogenetic relationships suggests that these enzymes are orthologs of Saccharomyces cerevisiae vacuolar peptidases. Notably, both vacuolar protease gene expression and the proteolytic activity of cell-free extracts increased under nutritional stress and rapamycin. An increase in the expression of the ATG8 gene and the presence of autophagic bodies were also observed. These results suggest that proteases could play a role in yeast autophagy and survival during starvation conditions.

Candidozyma auris is a multidrug resistance opportunistic pathogen, distinguished from Candida yeasts because of their thermotolerance, osmotolerance, and persistence in biotic and abiotic surfaces, attributes that seem linked to the cell wall composition. Here, seven putative genes encoding yapsins, extracellular aspartyl proteases GPI-anchored to the membrane or cell wall, were identified in the genomes of C. auris strains CJ97 and 20-1498, from clades III and IV, respectively. C. auris YPS1 gene is orthologous to the SAP9 of C. albicans. The YPS7 gene is orthologous to YPS7 of C. glabrata and S. cerevisiae, so they could coincide in roles. The CauYPS1 and CauYPS7 expression increased under nutrient starvation, 1.5 M NaCl, and at 42oC. In silico analysis suggests the interaction of pepstatin A, an aspartyl protease inhibitor, with the catalytic domain of Yps1 and Yps7. This inhibitor, in concert with caffeine, had a subtle effect on the growth of C. auris strains. However, these compounds induce alterations in the appearance of the cell wall. Thereby, yapsins CauYps1 and CauYps7 may play a role in the cell wall integrity of C. auris in stress conditions, and they could be a therapeutic target for the design of new antifungal or antivirulence agents.