Proteomic Analysis gives Novel Insights into Candida Albicans Morphogenesis in the Wake of Ubiquitin Mutation UbEP42.

Ubiquitin is pivotal to the regulation of protein homeostasis, signal transduction, and various cellular processes. Mutations in ubiquitin can disrupt many cellular functions. In this study LC-MS/MS proteomics approach was used to explore the effects of UbEP42, a dosage dependent lethal ubiquitin mutant, on the protein profile of Candida albicans. The biological processes and metabolic pathways associated with the proteins were identified through ShinyGo 0.81 interaction analysis. Comparative proteomics analysis identified 60 downregulated and 12 upregulated proteins showing over a 2-fold change under UbEP42 expression, with wild type ubiquitin as control. The downregulated proteins include certain key enzymes enriched under oxidative stress, nitrogen compound limitation and other stressors. Significant downregulation of proteins of metabolic pathways, including the biosynthesis of aromatic amino acids was observed, indicating a compromised metabolic status. Further, another 12 proteins associated with adaptive mechanisms were significantly upregulated. Key upregulated proteins also include 1,3-β-glucanosyltransferase, high-affinity glucose transporter, sulfate adenylyltransferase and ribonucleoside-diphosphate reductase that enhance nutrient uptake, metabolic efficiency pathways of sulfur metabolism and nucleotide biosynthesis, respectively. These findings highlight a complex interplay of metabolic processes, enhancing our understanding of the mechanism of metabolic adaptability and pathogenicity of C. albicans under the expression of UbEP42.