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| Author(s): |
Fausto Bruno dos Reis Almeida
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Ribeirão Preto. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Medicina de Ribeirão Preto (PCARP/BC) |
| Defense date: | 2013-08-30 |
| Examining board members: |
Maria Cristina Roque Antunes Barreira;
Maria Celia Jamur;
Marcio Lourenço Rodrigues;
Nilce Maria Martinez Rossi
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| Advisor: | Maria Cristina Roque Antunes Barreira |
| Abstract | |
Paracoccidioides brasiliensis is the etiological agent of paracoccidioidomycosis, the most prevalent systemic mycosis in Latin America. The P. brasiliensis pathogenicity can be influenced by some fungal components, such as lipids, polysaccharides and glycoproteins. Glycosylation of proteins is important for their secretion, function, stability and immunogenicity. N-glycosylated proteins have been characterized in most species, from yeast to mammals. ln this thesis, we show that in P. brasiliensis yeasts, N-glycans play an important role in the activity of a fungal N-acetyl-β-D-glucosaminidase (NAGase), which is involved in the growth and morphogenesis of the fungus. We also found that inhibition of N-glycosylation does not interfere on the catalytic activity of α- and β1,3-glucanase, but plays an important influence on the activity of α-1,4-amylase produced by yeast and mycelial cells. Since α-1,4-amylase is involved in the generation of oligosaccharides that are essential to α-glucan synthesis, we postulate that, beyond NAGase, α-1,4-amylase can be co-responsible for the impaired P. brasiliensis growth and morphogenesis that occur when the process of N-glycosylation is inhibited by tunicamycin. We conclude that N-glycosylation is crucial for essential fungal biological processes. The aspects of P. brasiliensis glycobiology here approached may contribute to a better comprehension of paracoccidiodomycosis pathogenesis. (AU) | |
| FAPESP's process: | 09/51197-3 - Role of N-glycans in activities developed by paracoccin |
| Grantee: | Fausto Bruno dos Reis Almeida |
| Support Opportunities: | Scholarships in Brazil - Doctorate |