An Atypical ABC Transporter Is Involved in Antifungal Resistance and Host Interactions in the Pathogenic Fungus Cryptococcus neoformans
ABSTRACT ATP-binding cassette (ABC) transporters represent one of the largest protein superfamilies. Functionally diverse, ABC transporters have been implicated in many aspects of microbial physiology. The genome of the human fungal pathogen Cryptococcus neoformans encodes 54 putative ABC transporte...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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American Society for Microbiology
2022-08-01
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| Series: | mBio |
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| Online Access: | https://journals.asm.org/doi/10.1128/mbio.01539-22 |
| _version_ | 1828109795532472320 |
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| author | Christopher J. Winski Yuanyuan Qian Shahriar Mobashery Felipe H. Santiago-Tirado |
| author_facet | Christopher J. Winski Yuanyuan Qian Shahriar Mobashery Felipe H. Santiago-Tirado |
| author_sort | Christopher J. Winski |
| collection | DOAJ |
| description | ABSTRACT ATP-binding cassette (ABC) transporters represent one of the largest protein superfamilies. Functionally diverse, ABC transporters have been implicated in many aspects of microbial physiology. The genome of the human fungal pathogen Cryptococcus neoformans encodes 54 putative ABC transporters and most of them remain uncharacterized. In a previous genetic screen for fungal regulators of phagocytosis, we identified an uncharacterized gene, CNAG_06909, that modulates host interactions. This gene encoded a half-size ABC transporter of the PDR-type, and phenotypic studies of a strain with this gene deleted revealed an altered antifungal susceptibility profile, including hypersensitivity to fluconazole (FLC). This gene, which we named PDR6, localized to the endoplasmic reticulum (ER) and plasma membrane (PM), and when absent, less ergosterol was observed in the PM. Additionally, we observed that the pdr6Δ strain displayed a reduction in secreted polysaccharide capsular material. These changes to the cellular surface may explain the observed increased uptake by macrophages and the reduced intracellular survival. Finally, studies in mice demonstrated that Pdr6 function was required for the normal progression of cryptococcal infection. Taken together, this study demonstrates a novel dual role for PDR transporters in C. neoformans, which could represent a potential target for antifungal therapeutics. Furthermore, the atypical half-size transporter encoded by PDR6 is conserved in many fungal pathogens, but absent in model nonpathogenic fungi. Hence, this study provided a function for this unique group of fungal half-size PDR transporters that, although conserved, remain largely understudied. IMPORTANCE Conserved across all kingdoms of life, ABC transporters comprise one of the largest protein families. They are associated with multidrug resistance, affecting aspects such as resistance to antimicrobials or anti-cancer drugs. Despite their importance, they are understudied in fungal pathogens. In the environmental fungus Cryptococcus neoformans, a leading cause of fungal infections, only a few ABC transporters have been studied. Here, we characterized an atypical, half-size, ABC transporter of the PDR-type, that affected both antifungal resistance and host-pathogen interactions. PDR-type transporters are only present in fungi and plants, and this subgroup of half-size transporters was conserved in fungal pathogens, yet their function was completely unknown. Because the current treatments for cryptococcal infection are suboptimal, understanding the mechanisms of antifungal resistance and the host interactions that drive the infection is critical to improving the management of this disease. Here, we provide insights into these important aspects of cryptococcal pathogenesis. |
| first_indexed | 2024-04-11T11:08:43Z |
| format | Article |
| id | doaj.art-96a4fd3e836946738c0b9bfe889d5a7b |
| institution | Directory Open Access Journal |
| issn | 2150-7511 |
| language | English |
| last_indexed | 2024-04-11T11:08:43Z |
| publishDate | 2022-08-01 |
| publisher | American Society for Microbiology |
| record_format | Article |
| series | mBio |
| spelling | doaj.art-96a4fd3e836946738c0b9bfe889d5a7b2022-12-22T04:28:05ZengAmerican Society for MicrobiologymBio2150-75112022-08-0113410.1128/mbio.01539-22An Atypical ABC Transporter Is Involved in Antifungal Resistance and Host Interactions in the Pathogenic Fungus Cryptococcus neoformansChristopher J. Winski0Yuanyuan Qian1Shahriar Mobashery2Felipe H. Santiago-Tirado3Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, USADepartment of Chemistry and Biochemistry, Warren Center for Drug Discovery, University of Notre Dame, Notre Dame, Indiana, USADepartment of Chemistry and Biochemistry, Warren Center for Drug Discovery, University of Notre Dame, Notre Dame, Indiana, USADepartment of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, USAABSTRACT ATP-binding cassette (ABC) transporters represent one of the largest protein superfamilies. Functionally diverse, ABC transporters have been implicated in many aspects of microbial physiology. The genome of the human fungal pathogen Cryptococcus neoformans encodes 54 putative ABC transporters and most of them remain uncharacterized. In a previous genetic screen for fungal regulators of phagocytosis, we identified an uncharacterized gene, CNAG_06909, that modulates host interactions. This gene encoded a half-size ABC transporter of the PDR-type, and phenotypic studies of a strain with this gene deleted revealed an altered antifungal susceptibility profile, including hypersensitivity to fluconazole (FLC). This gene, which we named PDR6, localized to the endoplasmic reticulum (ER) and plasma membrane (PM), and when absent, less ergosterol was observed in the PM. Additionally, we observed that the pdr6Δ strain displayed a reduction in secreted polysaccharide capsular material. These changes to the cellular surface may explain the observed increased uptake by macrophages and the reduced intracellular survival. Finally, studies in mice demonstrated that Pdr6 function was required for the normal progression of cryptococcal infection. Taken together, this study demonstrates a novel dual role for PDR transporters in C. neoformans, which could represent a potential target for antifungal therapeutics. Furthermore, the atypical half-size transporter encoded by PDR6 is conserved in many fungal pathogens, but absent in model nonpathogenic fungi. Hence, this study provided a function for this unique group of fungal half-size PDR transporters that, although conserved, remain largely understudied. IMPORTANCE Conserved across all kingdoms of life, ABC transporters comprise one of the largest protein families. They are associated with multidrug resistance, affecting aspects such as resistance to antimicrobials or anti-cancer drugs. Despite their importance, they are understudied in fungal pathogens. In the environmental fungus Cryptococcus neoformans, a leading cause of fungal infections, only a few ABC transporters have been studied. Here, we characterized an atypical, half-size, ABC transporter of the PDR-type, that affected both antifungal resistance and host-pathogen interactions. PDR-type transporters are only present in fungi and plants, and this subgroup of half-size transporters was conserved in fungal pathogens, yet their function was completely unknown. Because the current treatments for cryptococcal infection are suboptimal, understanding the mechanisms of antifungal resistance and the host interactions that drive the infection is critical to improving the management of this disease. Here, we provide insights into these important aspects of cryptococcal pathogenesis.https://journals.asm.org/doi/10.1128/mbio.01539-22ABC transportersCryptococcus neoformansantifungal resistancehost-pathogen interactions |
| spellingShingle | Christopher J. Winski Yuanyuan Qian Shahriar Mobashery Felipe H. Santiago-Tirado An Atypical ABC Transporter Is Involved in Antifungal Resistance and Host Interactions in the Pathogenic Fungus Cryptococcus neoformans mBio ABC transporters Cryptococcus neoformans antifungal resistance host-pathogen interactions |
| title | An Atypical ABC Transporter Is Involved in Antifungal Resistance and Host Interactions in the Pathogenic Fungus Cryptococcus neoformans |
| title_full | An Atypical ABC Transporter Is Involved in Antifungal Resistance and Host Interactions in the Pathogenic Fungus Cryptococcus neoformans |
| title_fullStr | An Atypical ABC Transporter Is Involved in Antifungal Resistance and Host Interactions in the Pathogenic Fungus Cryptococcus neoformans |
| title_full_unstemmed | An Atypical ABC Transporter Is Involved in Antifungal Resistance and Host Interactions in the Pathogenic Fungus Cryptococcus neoformans |
| title_short | An Atypical ABC Transporter Is Involved in Antifungal Resistance and Host Interactions in the Pathogenic Fungus Cryptococcus neoformans |
| title_sort | atypical abc transporter is involved in antifungal resistance and host interactions in the pathogenic fungus cryptococcus neoformans |
| topic | ABC transporters Cryptococcus neoformans antifungal resistance host-pathogen interactions |
| url | https://journals.asm.org/doi/10.1128/mbio.01539-22 |
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