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Gibbons JG, D’Avino P, Zhao S, Cox GW, Rinker DC, Fortwendel JR, Latge JP. Comparative Genomics Reveals a Single Nucleotide Deletion in pksP That Results in White-Spore Phenotype in Natural Variants of Aspergillus fumigatus. FRONTIERS IN FUNGAL BIOLOGY 2022; 3:897954. [PMID: 37746219 PMCID: PMC10512363 DOI: 10.3389/ffunb.2022.897954] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 05/03/2022] [Indexed: 09/26/2023]
Abstract
Aspergillus fumigatus is a potentially deadly opportunistic human pathogen. A. fumigatus has evolved a variety of mechanisms to evade detection by the immune system. For example, the conidium surface is covered in a layer of 1,8-dihydroxynaphthalene (DHN) melanin which masks the antigen macrophages use for recognition. DHN melanin also protects conidia from ultraviolet radiation and gives A. fumigatus conidia their characteristic green-grayish color. Here, we conducted genomic analysis of two closely related white-spore natural variants of A. fumigatus in comparison to two closely related green-spore isolates to identify a genetic basis of the white-spore phenotype. Illumina whole-genome resequencing data of the four isolates was used to identify variants that were shared in the white-spore isolates and different from both the green-spore isolates and the Af293 reference genome (which is also a green-spore isolate). We identified 4,279 single nucleotide variants and 1,785 insertion/deletions fitting this pattern. Among these, we identified 64 variants predicted to be high impact, loss-of-function mutations. One of these variants is a single nucleotide deletion that results in a frameshift in pksP (Afu2g17600), the core biosynthetic gene in the DHN melanin encoding gene cluster. The frameshift mutation in the white-spore isolates leads to a truncated protein in which a phosphopantetheine attachment site (PP-binding domain) is interrupted and an additional PP-binding domain and a thioesterase domain are omitted. Growth rate analysis of white-spore and green-spore isolates at 37°C and 48°C revealed that white-spore isolates are thermosensitive. Growth rate of A. fumigatus Af293 and a pksP null mutant in the Af293 background suggests pksP is not directly involved in the thermosensitivity phenotype. Further, our study identified a mutation in a gene (Afu4g04740) associated with thermal sensitivity in yeasts which could also be responsible for the thermosensitivity of the white-spore mutants. Overall, we used comparative genomics to identify the mutation and protein alterations responsible for the white-spore phenotype of environmental isolates of A. fumigatus.
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Affiliation(s)
- John G. Gibbons
- Department of Food Science, University of Massachusetts, Amherst, MA, United States
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA, United States
- Organismic & Evolutionary Biology Graduate Program, University of Massachusetts, Amherst, MA, United States
| | - Paolo D’Avino
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA, United States
| | - Shu Zhao
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA, United States
| | - Grace W. Cox
- Department of Food Science, University of Massachusetts, Amherst, MA, United States
| | - David C. Rinker
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, United States
| | - Jarrod R. Fortwendel
- Department of Clinical Pharmacy and Translational Science, University of Tennessee Health Science Center, Memphis, TN, United States
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Carballar R, Martínez-Láinez JM, Samper B, Bru S, Bállega E, Mirallas O, Ricco N, Clotet J, Jiménez J. CDK-mediated Yku80 Phosphorylation Regulates the Balance Between Non-homologous End Joining (NHEJ) and Homologous Directed Recombination (HDR). J Mol Biol 2020; 432:166715. [PMID: 33217428 DOI: 10.1016/j.jmb.2020.11.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 11/04/2020] [Accepted: 11/11/2020] [Indexed: 11/28/2022]
Abstract
There are two major pathways for repairing DNA double-strand breaks (DSBs): homologous directed recombination (HDR) and non-homologous end-joining (NHEJ). While NHEJ functions throughout the cell cycle, HDR is only possible during S/G2 phases, suggesting that there are cell cycle-specific mechanisms regulating the balance between the two repair systems. The regulation exerted by CDKs on HDR has been extensively demonstrated, and here we present evidence that the CDK Pho85, in association with the G1 cyclin Pcl1, phosphorylates Yku80 on Ser 623 to regulate NHEJ activity. Cells bearing a non-phosphorylatable version of Yku80 show increased NHEJ and reduced HDR activity. Accordingly, yku80S623A cells present diminished viability upon treatment with the DSB-producer bleomycin, specifically in the G2 phase of the cell cycle. Interestingly, the mutation of the equivalent residue in human Ku80 increases sensitivity to bleomycin in several cancer cell lines, suggesting that this mechanism is conserved in humans. Altogether, our results reveal a new mechanism whereby G1-CDKs mediate the choice between HDR and NHEJ repair pathways, putting the error prone NHEJ on a leash and enabling error free HDR in G2 when homologous sequences are available.
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Affiliation(s)
- Reyes Carballar
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Joan M Martínez-Láinez
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Bàrbara Samper
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Samuel Bru
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Elisabet Bállega
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Oriol Mirallas
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Natalia Ricco
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Josep Clotet
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain.
| | - Javier Jiménez
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain.
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Mirallas O, Ballega E, Samper-Martín B, García-Márquez S, Carballar R, Ricco N, Jiménez J, Clotet J. Intertwined control of the cell cycle and nucleocytoplasmic transport by the cyclin-dependent kinase Pho85 and RanGTPase Gsp1 in Saccharomyces cerevisiae. Microbiol Res 2017; 206:168-176. [PMID: 29146254 DOI: 10.1016/j.micres.2017.10.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 10/09/2017] [Accepted: 10/17/2017] [Indexed: 10/18/2022]
Abstract
Deciphering the molecular mechanisms that connect cell cycle progression and nucleocytoplasmic transport is of particular interest: this intertwined relationship, once understood, may provide useful insight on the diseases resulting from the malfunction of these processes. In the present study we report on findings that indicate a biochemical connection between the cell cycle regulator CDK Pho85 and Ran-GTPase Gsp1, an essential nucleocytoplasmic transport component. When Gsp1 cannot be phosphorylated by Pho85, the cell cycle progression is impaired. Accordingly, a nonphosphorylatable version of Gsp1 abnormally localizes to the nucleus, which impairs the nuclear transport of molecules, including key components of cell cycle progression. Furthermore, our results suggest that the physical interaction of Gsp1 and the Kap95 karyopherin, essential to the release of nuclear cargoes, is altered. Altogether, the present findings point to the involvement of a biochemical mechanism in the interlocked regulation of the cell cycle and nuclear transport.
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Affiliation(s)
- Oriol Mirallas
- Department of Basic Sciences, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Elisabet Ballega
- Department of Basic Sciences, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Bàrbara Samper-Martín
- Department of Basic Sciences, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Sergio García-Márquez
- Department of Basic Sciences, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Reyes Carballar
- Department of Basic Sciences, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Natalia Ricco
- Department of Basic Sciences, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Javier Jiménez
- Department of Basic Sciences, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain.
| | - Josep Clotet
- Department of Basic Sciences, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain.
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Wu F, Liu Y, Zhu Z, Huang H, Ding B, Wu J, Shi Y. The 1.9Å crystal structure of Prp20p from Saccharomyces cerevisiae and its binding properties to Gsp1p and histones. J Struct Biol 2011; 174:213-22. [DOI: 10.1016/j.jsb.2010.11.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2010] [Revised: 11/11/2010] [Accepted: 11/15/2010] [Indexed: 12/01/2022]
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Hadjebi O, Casas-Terradellas E, Garcia-Gonzalo FR, Rosa JL. The RCC1 superfamily: From genes, to function, to disease. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2008; 1783:1467-79. [DOI: 10.1016/j.bbamcr.2008.03.015] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2007] [Revised: 03/19/2008] [Accepted: 03/20/2008] [Indexed: 02/07/2023]
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Ohba T, Nishijima H, Nishitani H, Nishimoto T. Schizosaccharomyces pombe Snf2SR, a novel SNF2 family protein, interacts with Ran GTPase and modulates both RanGEF and RanGAP activities. Genes Cells 2008; 13:571-82. [PMID: 18422602 DOI: 10.1111/j.1365-2443.2008.01190.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Snf2SR, a suppressor of rna1(ts), which is a temperature-sensitive mutation in Schizosaccharomyces pombe RanGAP (GTPase activating protein), possesses both the SNF2 and the helicase domains conserved in the chromatin remodeling SNF2 ATPase/helicase protein family. We have now clarified a function of Snf2SR. Snf2SR indeed showed DNA-stimulated ATPase activity, proving that it is a member of the SNF2 ATPase/helicase family. Consistent with this role, Snf2SR was localized in the nucleus and cell fractionation analysis revealed that Snf2SR was tightly associated with the nuclear matrix. The disruption of snf2SR(+) was detrimental for a cell proliferation of S. pombe. Snf2SR that did not enhance RanGAP activity by itself, but abolished histone-H3-mediated RanGAP inhibition, as previously reported for the histone H3 methyltransferase, Clr4, another rna1(ts) suppressor. In contrast to Clr4, Snf2SR directly bound to the GDP-bound form of the S. pombe Ran homologue Spi1 and enhanced the nucleotide exchange activity of Pim1, the S. pombe RanGEF (guanine nucleotide exchange factor). Over-expression of Spi1-G18V, a Ran GTPase mutant fixed in the GTP-bound form, was lethal to S. pombe Deltasnf2SR. Together, our results indicate that Snf2SR is involved in the Ran GTPase cycle in vivo.
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Affiliation(s)
- Tomoyuki Ohba
- Department of Molecular Biology, Graduate School of Medical Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
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Sekiguchi T, Hayashi N, Wang Y, Kobayashi H. Genetic evidence that Ras-like GTPases, Gtr1p, and Gtr2p, are involved in epigenetic control of gene expression in Saccharomyces cerevisiae. Biochem Biophys Res Commun 2008; 368:748-54. [PMID: 18258182 DOI: 10.1016/j.bbrc.2008.01.133] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2008] [Accepted: 01/29/2008] [Indexed: 12/23/2022]
Abstract
Gtr1p and Gtr2p of Saccharomyces cerevisiae are members of the Ras-like GTP binding family and interact genetically with Prp20p (yeast RCC1), which is a guanine nucleotide exchange factor for Gsp1p (yeast homolog of Ran, involved in nuclear export). Recently, Gtr1p and Gtr2p were suggested to be molecular switches in the rapamycin-sensitive TOR signaling pathway. Here, we show that Gtr1p and Gtr2p genetically interact with the chromatin remodeling factor Ino80p. Gtr2p interacted physically with both Rvb1p and Rvb2p. Consistent with these results, Gtr2p localized to chromatin and could activate transcription. Gtr1p and Gtr2p were found to be involved in chromatin silencing in the vicinity of telomeres. Gtr1p and Gtr2p were required to repress nitrogen catabolite-repressed genes, which are repressed by the TOR signaling pathway. We propose that Gtr1p and Gtr2p are involved in epigenetic control of gene expression in the TOR signaling pathway.
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Affiliation(s)
- Takeshi Sekiguchi
- Department of Molecular Biology, Graduate School of Medical Science, Kyushu University, Maidashi 3-1-1, Higashi-ku, Fukuoka 812-8582, Japan
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Hayashi N, Kobayashi M, Shimizu H, Yamamoto KI, Murakami S, Nishimoto T. Mutations in Ran system affected telomere silencing in Saccharomyces cerevisiae. Biochem Biophys Res Commun 2007; 363:788-94. [PMID: 17904525 DOI: 10.1016/j.bbrc.2007.09.054] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2007] [Accepted: 09/11/2007] [Indexed: 11/29/2022]
Abstract
The Ran GTPase system regulates the direction and timing of several cellular events, such as nuclear-cytosolic transport, centrosome formation, and nuclear envelope assembly in telophase. To gain insight into the Ran system's involvement in chromatin formation, we investigated gene silencing at the telomere in several mutants of the budding yeast Saccharomyces cerevisiae, which had defects in genes involved in the Ran system. A mutation of the RanGAP gene, rna1-1, caused reduced silencing at the telomere, and partial disruption of the nuclear Ran binding factor, yrb2-delta2, increased this silencing. The reduced telomere silencing in rna1-1 cells was suppressed by a high dosage of the SIR3 gene or the SIT4 gene. Furthermore, hyperphosphorylated Sir3 protein accumulated in the rna1-1 mutant. These results suggest that RanGAP is required for the heterochromatin structure at the telomere in budding yeast.
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Affiliation(s)
- Naoyuki Hayashi
- Department of Molecular Pathology, Cancer Research Institute, Kanazawa University, Kanazawa, Ishikawa 920-0934, Japan.
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Current awareness on yeast. Yeast 2007. [DOI: 10.1002/yea.1326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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