Proteomics of the extremotolerant yeast Meyerozyma guilliermondii 4LYP0 isolated from the Yanamate tailings Cerro de Pasco (Peru) upon exposure to Cu2+, Cd2+, and Cr6＋ ions

Macedo-Prada D.; Iwai L.K.; Espinoza-Culupú A.; Montoni F.; Huamantalla-Huamán M.; Jara-Peña E.; Sánchez-Rojas T. · Journal of Proteomics (2026) · DOI: 10.1016/j.jprot.2026.105658

Resumen

Meyerozyma guilliermondii 4LYP0, a yeast isolated from the Yanamate mine tailings in Cerro de Pasco - Peru, was investigated to characterize its proteomic response to heavy metal exposure. This work provides the first comprehensive proteomic profile of a native M. guilliermondii strain exposed to Cu2+, Cd2+, and Cr6＋. Metal concentrations were selected based on measurable growth effects, and microscopy confirmed visible stress-related changes in cell morphology. Using label-free quantitative mass spectrometry, we identified 496 differentially abundant proteins (DAPs) in response to the metals. Network analyses of DAPs revealed that commonly proteins showing increased DAPs were mainly involved in oxidoreductase activity and aminoacyl-tRNA synthetases, and ATP-binding proteins indicated the activation of redox balancing, translational reprogramming, and energy-dependent detoxification pathways. Metal-specific responses included the upregulation of proteins involved in amino acid biosynthesis in Cu2+ treated cells (A5DCG0, A5DP23, A5DEL5, A5DLT8), longevity regulation under Cd2+ stress (AD5QN0, A5DE29), and acetate metabolism upon Cr6＋ exposure (A5DN62, A5D1A7). This study represents the first proteomic characterization of M. guilliermondii from Peru under heavy metal stress and provides new insights into the molecular basis of oxidative stress tolerance and its potential application in metal-rich or contaminated environments. Significance of the study: This study provides the first proteomic characterization of Meyerozyma guilliermondii 4LYP0, an extremotolerant yeast isolated from mining-contaminated environments in the Peruvian Andes. The analysis of its proteomic adaptation under heavy metal stress reveals valuable insights into the molecular strategies employed by extremotolerant yeasts to survive in metal-rich environments. A total of 496 differential abundance proteins were identified, including those involved in oxidoreductase activity, such as amino acid biosynthesis, longevity regulation, and acetate metabolism. These results highlight of this yeast to maintain redox homeostasis and metabolic flexibility under toxic metal conditions. Moreover, these findings expand the current understanding of eukaryotic microbial responses to oxidative stress and contribute to the broader field of environmental proteomics. From an applied perspective, elucidating these adaptive mechanisms enhances the potential use of M. guilliermondii as a biotechnological model for metal tolerance, detoxification, and bioremediation. The proteomic insights obtained her e open perspectives for engineering or selecting yeast strains optimized for industrial wastewater treatment, biosorption, or metal recovery. Furthermore, this work underscores the importance of expanding proteomic investigations in native extremotolerant microorganisms from underexplored ecosystems, such as the high Andes of Peru, to enhance our global understanding of microbial resilience in metal-impacted environments.

Instituciones: Universidad Nacional Mayor de San Marcos