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Liu KH, Shen WC. Sexual Differentiation Is Coordinately Regulated by Cryptococcus neoformans CRK1 and GAT1. Genes (Basel) 2020; 11:genes11060669. [PMID: 32575488 PMCID: PMC7349709 DOI: 10.3390/genes11060669] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 06/05/2020] [Accepted: 06/16/2020] [Indexed: 12/02/2022] Open
Abstract
The heterothallic basidiomycetous fungus Cryptococcus neoformans has two mating types, MATa and MATα. Morphological progression of bisexual reproduction in C. neoformans is as follows: yeast to hyphal transition, filament extension, basidium formation, meiosis, and sporulation. C. neoformans Cdk-related kinase 1 (CRK1) is a negative regulator of bisexual mating. In this study, we characterized the morphological features of mating structures in the crk1 mutant and determined the genetic interaction of CRK1 in the regulatory networks of sexual differentiation. In the bilateral crk1 mutant cross, despite shorter length of filaments than in the wild-type cross, dikaryotic filaments and other structures still remained intact during bisexual mating, but the timing of basidium formation was approximately 18 h earlier than in the cross between wild type strains. Furthermore, gene expression analyses revealed that CRK1 modulated the expression of genes involved in the progression of hyphal elongation, basidium formation, karyogamy and meiosis. Phenotypic results showed that, although deletion of C. neoformans CRK1 gene increased the efficiency of bisexual mating, filamentation in the crk1 mutant was blocked by MAT2 or ZNF2 mutation. A bioinformatics survey predicted the C. neoformans GATA transcriptional factor Gat1 as a potential substrate of Crk1 kinase. Our genetic and phenotypic findings revealed that C. neoformansGAT1 and CRK1 formed a regulatory circuit to negatively regulate MAT2 to control filamentation progression and transition during bisexual mating.
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Edouarzin E, Horn C, Paudyal A, Zhang C, Lu J, Tong Z, Giaever G, Nislow C, Veerapandian R, Hua DH, Vediyappan G. Broad-spectrum antifungal activities and mechanism of drimane sesquiterpenoids. MICROBIAL CELL 2020; 7:146-159. [PMID: 32548177 PMCID: PMC7278516 DOI: 10.15698/mic2020.06.719] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Eight drimane sesquiterpenoids including (-)-drimenol and (+)-albicanol were synthesized from (+)-sclareolide and evaluated for their antifungal activities. Three compounds, (-)-drimenol, (+)-albicanol, and (1R,2R,4aS,8aS)-2-hydroxy-2,5,5,8a-tetramethyl-decahydronaphthalene-1-carbaldehyde (4) showed strong activity against C. albicans. (-)-Drimenol, the strongest inhibitor of the three, (at concentrations of 8 – 64 µg/ml, causing 100% death of various fungi), acts not only against C. albicans in a fungicidal manner, but also inhibits other fungi such as Aspergillus, Cryptococcus, Pneumocystis, Blastomyces, Saksenaea and fluconazole resistant strains of C. albicans, C. glabrata, C. krusei, C. parapsilosis and C. auris. These observations suggest that drimenol is a broad-spectrum antifungal agent. At a high concentration (100 μg/ml) drimenol caused rupture of the fungal cell wall/membrane. In a nematode model of C. albicans infection, drimenol rescued the worms from C. albicans-mediated death, indicating drimenol is tolerable and bioactive in metazoans. Genome-wide fitness profiling assays of both S. cerevisiae (nonessential homozygous and essential heterozygous) and C. albicans (Tn-insertion mutants) collections revealed putative genes and pathways affected by drimenol. Using a C. albicans mutant spot assay, the Crk1 kinase associated gene products, Ret2, Cdc37, and orf19.759, orf19.1672, and orf19.4382 were revealed to be involved in drimenol's mechanism of action. The three orfs identified in this study are novel and appear to be linked with Crk1 function. Further, computational modeling results suggest possible modifications of the structure of drimenol, including the A ring, for improving the antifungal activity.
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Affiliation(s)
- Edruce Edouarzin
- Department of Chemistry, 1212 Mid Campus Drive North, Kansas State University, Manhattan, KS 66506 USA
| | - Connor Horn
- Division of Biology, 1717 Claflin Road, Kansas State University, Manhattan, KS 66506 USA
| | - Anuja Paudyal
- Division of Biology, 1717 Claflin Road, Kansas State University, Manhattan, KS 66506 USA
| | - Cunli Zhang
- Department of Chemistry, 1212 Mid Campus Drive North, Kansas State University, Manhattan, KS 66506 USA
| | - Jianyu Lu
- Department of Chemistry, 1212 Mid Campus Drive North, Kansas State University, Manhattan, KS 66506 USA
| | - Zongbo Tong
- Department of Chemistry, 1212 Mid Campus Drive North, Kansas State University, Manhattan, KS 66506 USA
| | - Guri Giaever
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC Canada V6T 1Z3
| | - Corey Nislow
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC Canada V6T 1Z3
| | - Raja Veerapandian
- Division of Biology, 1717 Claflin Road, Kansas State University, Manhattan, KS 66506 USA
| | - Duy H Hua
- Department of Chemistry, 1212 Mid Campus Drive North, Kansas State University, Manhattan, KS 66506 USA
| | - Govindsamy Vediyappan
- Division of Biology, 1717 Claflin Road, Kansas State University, Manhattan, KS 66506 USA
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