Phosphoproteomics of Aspergillus fumigatus Exposed to the Antifungal Drug Caspofungin

Autor(es)

Mattos, Eliciane Cevolani ; Palmisano, Giuseppe ; Goldman, Gustavo H.

• Tipo de documento: Artigo Científico
• Fonte: MSPHERE; v. 5, n. 3, p. 16-pg., 2020-05-01.

Resumo

Aspergillus fumigatus is an opportunistic and allergenic pathogenic fungus, responsible for fungal infections in humans. A. fumigatus infections are usually treated with polyenes, azoles, or echinocandins. Echinocandins, such as caspofungin, can inhibit the biosynthesis of the beta-1,3-glucan polysaccharide, affecting the integrity of the cell wall and leading to fungal death. In some A. fumigatus strains, caspofungin treatment at high concentrations induces an increase of fungal growth, a phenomenon called the caspofungin paradoxical effect (CPE). Here, we analyze the proteome and phosphoproteome of the A. fumigatus wild-type strain and of mitogen-activated protein kinase (MAPK) mpkA and sakA null mutant strains during CPE (2 mu g/ml caspofungin for 1 h). The wild-type proteome showed 75 proteins and 814 phosphopeptides (corresponding to 520 proteins) altered in abundance in response to caspofungin treatment. The Delta mpkA (Delta mpkA caspofungin/wild-type caspofungin) and Delta sakA (Delta sakA caspofungin/wild-type caspofungin) strains displayed 626 proteins and 1,236 phosphopeptides (corresponding to 703 proteins) and 101 proteins and 1,217 phosphopeptides (corresponding to 645 proteins), respectively, altered in abundance. Functional characterization of the phosphopeptides from the wild-type strain exposed to caspofungin showed enrichment for transcription factors, protein kinases, and cytoskeleton proteins. Proteomic analysis of the Delta mpkA and Delta sakA mutants indicated that control of proteins involved in metabolism, such as in production of secondary metabolites, was highly represented in both mutants. Results of functional categorization of phosphopeptides from both mutants were very similar and showed a high number of proteins with decreased phosphorylation of proteins involved in transcriptional control, DNA/RNA binding, cell cycle control, and DNA processing. This report reveals novel transcription factors involved in caspofungin tolerance. IMPORTANCE Aspergillus fumigatus is an opportunistic human-pathogenic fungus causing allergic reactions or systemic infections, such as invasive pulmonary aspergillosis in immunocompromised patients. Caspofungin is an echinocandin that impacts the construction of the fungal cell wall by inhibiting the biosynthesis of the beta-1,3-glucan polysaccharide. Caspofungin is a fungistatic drug and is recommended as a second-line therapy for treatment of aspergillosis. Treatment at high concentrations induces an increase of fungal growth, a phenomenon called the caspofungin paradoxical effect (CPE). Collaboration between the mitogen-activated protein kinases (MAPK) of the cell wall integrity (MapkA) and high-osmolarity glycerol (SakA) pathways is essential for CPE. Here, we investigate the global proteome and phosphoproteome of A. fumigatus wild-type, Delta mpkA, and Delta sakA strains upon CPE. This study showed intense cross talk between the two MAPKs for the CPE and identified novel protein kinases and transcription factors possibly important for CPE. Increased understanding of how the modulation of protein phosphorylation may affect the fungal growth in the presence of caspofungin represents an important step in the development of new strategies and methods to combat the fungus inside the host. (AU)

• Processo FAPESP: 18/15549-1 - Modificações pós-traducionais nos processos biológicos e no diagnóstico da Doença de Chagas: novas abordagens metodológicas e implicações biológicas
• Beneficiário: Giuseppe Palmisano
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores - Fase 2
• Processo FAPESP: 18/18257-1 - EMU concedido no processo 14/06863-3: sistema de cromatografia líquida configurado para análise de carboidratos, aminoácidos, peptídeos e glicoproteínas
• Beneficiário: Giuseppe Palmisano
• Modalidade de apoio: Auxílio à Pesquisa - Programa Equipamentos Multiusuários
• Processo FAPESP: 17/19288-5 - Caracterização do fosfoproteoma envolvendo MAP quinases (MpkC, SakA e MpkA) de Aspergillus fumigatus mediante diferentes condições de estresse
• Beneficiário: Eliciane Cevolani Mattos
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 16/07870-9 - A influência de proteínas quinases ativadas por mitógenos (MAPK) na expressão de determinantes genéticos importantes para a virulência de Aspergillus fumigatus
• Beneficiário: Gustavo Henrique Goldman
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 14/06863-3 - Modificações pós-traducionais para o diagnóstico de câncer e doenças parasitárias: abordagens metodológicas e implicações biológicas
• Beneficiário: Giuseppe Palmisano
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores