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Soragni E, Bolchi A, Balestrini R, Gambaretto C, Percudani R, Bonfante P, Ottonello S. A nutrient-regulated, dual localization phospholipase A(2) in the symbiotic fungus Tuber borchii. EMBO J 2001; 20:5079-90. [PMID: 11566873 PMCID: PMC125632 DOI: 10.1093/emboj/20.18.5079] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Important morphogenetic transitions in fungi are triggered by starvation-induced changes in the expression of structural surface proteins. Here, we report that nutrient deprivation causes a strong and reversible up-regulation of TbSP1, a surface-associated, Ca(2+)-dependent phospholipase from the mycorrhizal fungus Tuber borchii. TbSP1 is the first phospholipase A(2) to be described in fungi and identifies a novel class of phospholipid-hydrolyzing enzymes. The TbSP1 phospholipase, which is synthesized initially as a pre-protein, is processed efficiently and secreted during the mycelial phase. The mature protein, however, also localizes to the inner cell wall layer, close to the plasma membrane, in both free-living and symbiosis-engaged hyphae. It thus appears that a dual localization phospholipase A(2) is involved in the adaptation of a symbiotic fungus to conditions of persistent nutritional limitation. Moreover, the fact that TbSP1-related sequences are present in Streptomyces and Neurospora, and not in wholly sequenced non-filamentous microorganisms, points to a general role for TbSP1 phospholipases A(2) in the organization of multicellular filamentous structures in bacteria and fungi.
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Affiliation(s)
- Elisabetta Soragni
- Dipartimento di Biochimica e Biologia Molecolare, Università di Parma, Parco Area delle Scienze 23/A, I-43100 Parma and
Centro di Studio sulla Micologia del Terreno (CNR) and Dipartimento di Biologia Vegetale, Università di Torino, Vialle Mattioli 25, I-10125 Torino, Italy Present address: Center for Molecular Genetics, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0634, USA Corresponding author e-mail:
| | | | - Raffaella Balestrini
- Dipartimento di Biochimica e Biologia Molecolare, Università di Parma, Parco Area delle Scienze 23/A, I-43100 Parma and
Centro di Studio sulla Micologia del Terreno (CNR) and Dipartimento di Biologia Vegetale, Università di Torino, Vialle Mattioli 25, I-10125 Torino, Italy Present address: Center for Molecular Genetics, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0634, USA Corresponding author e-mail:
| | | | | | - Paola Bonfante
- Dipartimento di Biochimica e Biologia Molecolare, Università di Parma, Parco Area delle Scienze 23/A, I-43100 Parma and
Centro di Studio sulla Micologia del Terreno (CNR) and Dipartimento di Biologia Vegetale, Università di Torino, Vialle Mattioli 25, I-10125 Torino, Italy Present address: Center for Molecular Genetics, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0634, USA Corresponding author e-mail:
| | - Simone Ottonello
- Dipartimento di Biochimica e Biologia Molecolare, Università di Parma, Parco Area delle Scienze 23/A, I-43100 Parma and
Centro di Studio sulla Micologia del Terreno (CNR) and Dipartimento di Biologia Vegetale, Università di Torino, Vialle Mattioli 25, I-10125 Torino, Italy Present address: Center for Molecular Genetics, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0634, USA Corresponding author e-mail:
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Feldmesser M, Tucker S, Casadevall A. Intracellular parasitism of macrophages by Cryptococcus neoformans. Trends Microbiol 2001; 9:273-8. [PMID: 11390242 DOI: 10.1016/s0966-842x(01)02035-2] [Citation(s) in RCA: 170] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Cryptococcus neoformans, an encapsulated fungal pathogen, causes meningoencephalitis in immunocompromised patients. Recent in vivo studies have demonstrated that C. neoformans is a facultative intracellular pathogen, as was previously suggested by in vitro studies. For survival in macrophages, C. neoformans utilizes a novel strategy for intracellular parasitism that includes the accumulation of intracellular polysaccharide in cytoplasmic vesicles. Confirmation of the fact that C. neoformans is a facultative intracellular pathogen could provide new insights into several poorly understood areas of cryptococcal pathogenesis, including mechanisms for latency and persistence and the lack of efficacy of humoral immunity. The finding that C. neoformans replicates inside macrophages in vitro in a manner similar to that observed in vivo provides an excellent system to dissect the molecular mechanisms responsible for this unique pathogenic strategy.
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Affiliation(s)
- M Feldmesser
- Dept of Medicine, Division of Infectious Diseases, Albert Einstein College of Medicine, Bronx, NY Golding Building Room 701, 1300 Morris Park Avenue, Bronx, NY 10461, USA
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