Aug 2026· Journal of Proteome Research· Vol 25 9, pp.
4796-4810
· 0 citations· 106 references
Medicine
TL;DR
Findings indicate that Paracoccidioides brasiliensis adapts to acidic environments through coordinated regulation of proteostasis, metabolism, signaling, host-cell interaction, and membrane homeostasis, supporting survival and virulence potential in acidic host microenvironments.
Abstract
Paracoccidioidomycosis (PCM) is a neglected systemic mycosis whose etiologic agents must adapt to acidic host niches such as phagolysosomes. Here, we used quantitative liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based proteomics to define the response of Paracoccidioides brasiliensis to acidic stress (pH 4.5) versus control pH (6.5) after 5 and 24 h. We identified and quantified 4374 proteins, including 327 and 722 differentially abundant proteins at 5 and 24 h, respectively, revealing time-dependent proteomic reprogramming. Enrichment analyses highlighted proteolysis, protein metabolism, organonitrogen metabolism, MAPK- and SNF1-like signaling, central carbon metabolism, tyrosine metabolism, and ergosterol biosynthesis as major acid-responsive processes. Complementary assays showed pH-dependent extracellular proteolytic activity, increased adhesion to A549 pulmonary epithelial cells, and dynamic ergosterol remodeling. The proteomic data further indicated increased abundance of moonlighting proteins linked to adhesion and metabolic enzymes associated with ATP generation and melanin precursor production. Together, these findings indicate that P. brasiliensis adapts to acidic environments through coordinated regulation of proteostasis, metabolism, signaling, host-cell interaction, and membrane homeostasis, supporting survival and virulence potential in acidic host microenvironments.
Paracoccidioidomycosis (PCM) is a major systemic mycosis in Latin America caused by Paracoccidioides brasiliensis, yet the contribution of aspartic proteases to fungal physiology and pathogenicity remains poorly understood. Here, we employed data-independent acquisition (DIA)-based quantitative proteomics to investigate the impact of pepstatin A-mediated inhibition of aspartic proteases on the P. brasiliensis proteome. High-coverage analysis identified up to 21,156 peptides and approximately 3000 proteins per condition, revealing progressive and time-dependent proteomic remodeling after inhibitor exposure. Differential abundance analysis demonstrated changes in proteins associated with membrane organization, protein turnover, RNA metabolism, stress adaptation, and cellular homeostasis. Functional enrichment analyses indicated modulation of metabolic processes, oxidative phosphorylation-associated proteins, and other biological functions related to fungal adaptation. Proteins associated with autophagy-related processes were differentially regulated, while MDC staining revealed temporal changes in acidic vesicle formation, suggesting alterations in vesicle-associated responses. Additionally, pepstatin A treatment reduced reactive oxygen species (ROS) production, consistent with changes in proteins related to oxidative metabolism. The inhibitor also impaired fungal adhesion to A549 pulmonary epithelial cells, indicating that aspartic proteases may influence host-pathogen interactions through mechanisms beyond adhesin abundance alone. Collectively, these findings provide a systems-level view of the cellular responses induced by aspartic protease inhibition and highlight the importance of these enzymes in regulating P. brasiliensis adaptation, homeostasis, and pathogenic potential.
Sarah Fernandes Lima, W. Segura, Leonardo Brogliato de Moraes et al.· Proteomics· 0 citations
Although Akanthomyces attenuatus JEF-147 exhibits high virulence against the two-spotted spider mite (Tetranychus urticae), its molecular mechanisms remain poorly understood. This study investigated fungal gene expression during early pathogenesis to elucidate how JEF-147 overcomes host defenses. Treatment on adults significantly suppressed descendant nymph populations. RNA-sequencing revealed time-dependent transcriptomic shifts: at 36-h after treatment, DEGs were primarily associated with transcription and translation, whereas 72-h samples showed activation of genes related to pathogenesis and stress management. Pathway analysis indicated that 72-h DEGs were enriched in metabolic pathways, suggesting JEF-147 maximizes energy production (TCA cycle and oxidative phosphorylation) and reinforces cell walls (glucan biosynthesis). The fungus actively utilizes host-derived fatty acids and proteins while maintaining homeostasis via the glutathione pathway. Furthermore, enrichment in vacuolar degradation pathways including autophagy and endocytosis in 72-h samples suggests active digestion of host nutrients. It was partially supported via LC-MS/MS analysis of fungal supernatants from a saprophytic culture. Our results suggest a two-stage infection strategy: an initial 36-h phase focused on hyphal growth and penetration, followed by a 72-h transition to counteracting host defenses through up-regulation of virulence and stress management-related genes. This work provides critical insights into the infection mechanisms of mite-pathogenic fungi.
Yejin Choi, Suyeon Jin, Gahyeon Song et al.· Journal of Invertebrate Path...· 0 citations
Comparative toxicoproteomics provides comparative mechanistic insight into how CMIT and PHMG induce distinct epithelial stress responses and identifies candidate protein markers that may support future in vitro assessment of biocide-induced pulmonary toxicity.
Ye-Eun Jeong, Min-Jeong Jeon, H. Youn et al.· Toxicology in Vitro· 0 citations
Deciphering the metabolic basis of high-yield antibiotic production in Streptomyces is crucial for strain optimization. Atmospheric and room-temperature plasma (ARTP) mutagenesis of Streptomyces xinghaiensis sf106 generated a mutant with a 30% increase in tylosin-equivalent concentration (μg/mL). 4D-FastDIA quantitative proteomics identified 279 differentially abundant proteins enriched in the Type I polyketide synthase (PKS) pathway, with increased abundance of key macrolide-biosynthesis-related proteins. Lysine-acetylome profiling identified 1152 differentially abundant acetylation sites and revealed altered acetylation of enzymes involved in fatty acid metabolism and the tricarboxylic acid (TCA) cycle, suggesting adjustments in central metabolism associated with acyl-CoA precursor availability and energy generation. Integration of proteomic and acetylomic data suggests coordinated changes in protein abundance and lysine acetylation associated with the increased tylosin-equivalent concentration. These results highlight candidate nodes for rational metabolic engineering of S. xinghaiensis.
Under severe stress, GO and KEGG enrichment consistently revealed the reinforcement of central carbon and energy metabolism, peroxisome-associated fatty acid turnover, oxidoreductase/redox activities, and translation and nucleotide metabolic pathways.
Dingkang Wang, Li Wang, Yue Xiao et al.· Journal of Proteome Research· 0 citations
The symbiosome, a temporary plant organelle enabling nitrogen fixation in legume-rhizobia symbiosis, consists of a plant-derived symbiosome membrane (SM), symbiosome space (SS), and enclosed bacteroid. Here, we isolate and purify symbiosomes from Medicago truncatula-Sinorhizobium meliloti root nodules and perform label-free quantitative mass spectrometry to profile protein abundances in the symbiosomes. We identify 1,018 M. truncatula proteins, including 829 in the SM and 457 in the SS. Combined with transport assays, our data reveal multiple dicarboxylate transporters in the SM that potentially deliver carbon sources to bacteroids. The SM is enriched in membrane trafficking proteins, lipid raft-associated components, and receptor-like proteins, together with numerous cell wall-associated proteins, highlighting the extracellular properties of the symbiosome. Proteomic and metabolomic analyses reveal the SS as a metabolically active compartment enriched in both plant and rhizobial proteins involved in carbon and amino acid metabolism. These findings offer insights into the molecular basis of symbiotic nitrogen fixation.
Jing-Xia Wu, Zi-Hui Fan, Letao Yang et al.· Cell Reports· 0 citations
We use cookies to run the site and, with your consent, for analytics and to show ads.
See our Cookie Policy.
