1
|
Chen D, Janganan TK, Chen G, Marques ER, Kress MR, Goldman GH, Walmsley AR, Borges-Walmsley MI. The cAMP pathway is important for controlling the morphological switch to the pathogenic yeast form of Paracoccidioides brasiliensis. Mol Microbiol 2007; 65:761-79. [PMID: 17635191 PMCID: PMC2064555 DOI: 10.1111/j.1365-2958.2007.05824.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Paracoccidioides brasiliensis is a human pathogenic fungus that switches from a saprobic mycelium to a pathogenic yeast. Consistent with the morphological transition being regulated by the cAMP-signalling pathway, there is an increase in cellular cAMP levels both transiently at the onset (< 24 h) and progressively in the later stages (> 120 h) of the transition to the yeast form, and this transition can be modulated by exogenous cAMP. We have cloned the cyr1 gene encoding adenylate cyclase (AC) and established that its transcript levels correlate with cAMP levels. In addition, we have cloned the genes encoding three Gα (Gpa1–3), Gβ (Gpb1) and Gγ (Gpg1) G proteins. Gpa1 and Gpb1 interact with one another and the N-terminus of AC, but neither Gpa2 nor Gpa3 interacted with Gpb1 or AC. The interaction of Gpa1 with Gpb1 was blocked by GTP, but its interaction with AC was independent of bound nucleotide. The transcript levels for gpa1, gpb1 and gpg1 were similar in mycelium, but there was a transient excess of gpb1 during the transition, and an excess of gpa1 in yeast. We have interpreted our findings in terms of a novel signalling mechanism in which the activity of AC is differentially modulated by Gpa1 and Gpb1 to maintain the signal over the 10 days needed for the morphological switch.
Collapse
Affiliation(s)
- Daliang Chen
- Centre for Infectious Diseases, Wolfson Research Institute, School of Biological and Biomedical Sciences, University of Durham – Queen's CampusStockton-on-Tees TS17 6BH, UK.
| | - Thamarai K Janganan
- Centre for Infectious Diseases, Wolfson Research Institute, School of Biological and Biomedical Sciences, University of Durham – Queen's CampusStockton-on-Tees TS17 6BH, UK.
| | - Gongyou Chen
- Centre for Infectious Diseases, Wolfson Research Institute, School of Biological and Biomedical Sciences, University of Durham – Queen's CampusStockton-on-Tees TS17 6BH, UK.
| | - Everaldo R Marques
- Departamento de Ciencias Farmaceuticas, Faculdade de Ciencias Farmaceuticas de Ribeirao Preto, Universidade de Sao Paulo, Av. do Cafe S/NCEP 14040-903, Ribeirao Preto, Sao Paulo, Brazil.
| | - Marcia R Kress
- Departamento de Ciencias Farmaceuticas, Faculdade de Ciencias Farmaceuticas de Ribeirao Preto, Universidade de Sao Paulo, Av. do Cafe S/NCEP 14040-903, Ribeirao Preto, Sao Paulo, Brazil.
| | - Gustavo H Goldman
- Departamento de Ciencias Farmaceuticas, Faculdade de Ciencias Farmaceuticas de Ribeirao Preto, Universidade de Sao Paulo, Av. do Cafe S/NCEP 14040-903, Ribeirao Preto, Sao Paulo, Brazil.
| | - Adrian R Walmsley
- Centre for Infectious Diseases, Wolfson Research Institute, School of Biological and Biomedical Sciences, University of Durham – Queen's CampusStockton-on-Tees TS17 6BH, UK.
- For correspondence. E-mail , ; Tel. (+44) (0)191 334 0465 or 0467; Fax (+44) (0)191 334 0468
| | - M Inês Borges-Walmsley
- Centre for Infectious Diseases, Wolfson Research Institute, School of Biological and Biomedical Sciences, University of Durham – Queen's CampusStockton-on-Tees TS17 6BH, UK.
- For correspondence. E-mail , ; Tel. (+44) (0)191 334 0465 or 0467; Fax (+44) (0)191 334 0468
| |
Collapse
|