Abstract
In this study, the ku70 and ku80 homologs from the Aspergillus niger genome were identified and their function was analyzed using targeted mutagenesis. The role of the ku80 gene in non-homologous end-joining (NHEJ) was investigated by calculating the frequency of homologous recombination. The transformation test verified that the frequency of homologous recombination significantly increased, from 1.78 to 65.6% in ku80 single deletion strains and to 100% in ku70/ku80 double deletion strains. These results suggest that the ku80 gene is important for non-homologous end-joining. Although the morphology of the ku deletion strains colonies was similar to that of the wildtype strain, mutants were more sensitive to the mutagen phleomycin. Furthermore, the purified ku80 deletion strain produced some sectored colonies on hygromycin B-containing plates. This result suggests that the ku80 gene deletion leads to genomic instability in A. niger.
Similar content being viewed by others
References
Banerjee S, Smith S, Myung K (2006) Suppression of gross chromosomal rearrangements by yKu70-yKu80 heterodimer through DNA damage checkpoints. Proc Natl Acad Sci USA 103:1816–1821
Boulton SJ, Jackson SP (1996) Identification of a Saccharomyces cerevisiae Ku80 homologue: roles in DNA double strand break rejoining and in telomeric maintenance. Nucleic Acids Res 24:4639–4648
Campbell EI, Unkles SE, Macro JA, van den Hondel C, Contreras R, Kinghorn JR (1989) Improved transformation efficiency of Aspergillus niger using the homologous niaD gene for nitrate reductase. Curr Genet 16:53–56
Critchlow SE, Jackson SP (1998) DNA end-joining: from yeast to man. Trends Biochem Sci 23:394–398
da Silva Ferreira ME, Kress MR, Savoldi M, Goldman MH, Hartl A, Heinekamp T, Brakhage AA, Goldman GH (2006) The akuB(KU80) mutant deficient for nonhomologous end joining is a powerful tool for analyzing pathogenicity in Aspergillus fumigatus. Eukaryot Cell 5:207–211
Difilippantonio MJ, Zhu J, Chen HT, Meffre E, Nussenzweig MC, Max EE, Ried T, Nussenzweig A (2000) DNA repair protein Ku80 suppresses chromosomal aberrations and malignant transformation. Nature 404:510–514
Dudasova Z, Dudas A, Chovanec M (2004) Non-homologous end-joining factors of Saccharomyces cerevisiae. FEMS Microbiol Rev 28:581–601
Hynes MJ, Corrick CM, King JA (1983) Isolation of genomic clones containing the amdS gene of Aspergillus nidulans and their use in the analysis of structural and regulatory mutations. Mol Cell Biol 3:1430–1439
Kück U, Walz M, Mohr G, Mracek M (1989) The 5′ sequence of the isopenicillin N-synthetase gene (pcbC) from Cephalosporium acremonium directs the expression of the prokaryotic hygromycin B phosphotransferase gene (hph) in Aspergillus niger. Appl Microbiol Biotechnol 31:358–365
Krappmann S, Sasse C, Braus GH (2006) Gene targeting in Aspergillus fumigatus by homologous recombination is facilitated in a nonhomologous end-joining-deficient genetic background. Eukaryot Cell 5:212–215
Lieber MR, Ma Y, Pannicke U, Schwarz K (2003) Mechanism and regulation of human non-homologous DNA end-joining. Nat Rev Mol Cell Biol 4:712–720
Meyer V, Arentshorst M, El-Ghezal A, Drews AC, Kooistra R, van den Hondel CA, Ram AF (2007) Highly efficient gene targeting in the Aspergillus niger kusA mutant. J Biotechnol 128:770–775
Mullaney EJ, Hamer JE, Roberti KA, Yelton MM, Timberlake WE (1985) Primary structure of the trpC gene from Aspergillus nidulans. Mol Gen Genet 199:37–45
Nayak T, Szewczyk E, Oakley CE, Osmani A, Ukil L, Murray SL, Hynes MJ, Osmani SA, Oakley BR (2006) A versatile and efficient gene-targeting system for Aspergillus nidulans. Genetics 172:1557–1566
Ninomiya Y, Suzuki K, Ishii C, Inoue H (2004) Highly efficient gene replacements in Neurospora strains deficient for nonhomologous end-joining. Proc Natl Acad Sci USA 101:12248–12253
Osipovich O, Durum SK, Muegge K (1997) Defining the minimal domain of Ku80 for interaction with Ku70. J Biol Chem 272:27259–27265
Pierce AJ, Hu P, Han M, Ellis N, Jasin M (2001) Ku DNA end-binding protein modulates homologous repair of double-strand breaks in mammalian cells. Genes Dev 15:3237–3242
Takahashi T, Masuda T, Koyama Y (2006) Enhanced gene targeting frequency in ku70 and ku80 disruption mutants of Aspergillus sojae and Aspergillus oryzae. Mol Genet Genomics 275:460–470
Takahashi T, Masuda T, Koyama Y (2006) Identification and analysis of Ku70 and Ku80 homologs in the koji molds Aspergillus sojae and Aspergillus oryzae. Biosci Biotechnol Biochem 70:135–143
Wang Y, Xue W, Sims AH, Zhao C, Wang A, Tang G, Qin J, Wang H (2008) Isolation of four pepsin-like protease genes from Aspergillus niger and analysis of the effect of disruptions on heterologous laccase expression. Fungal Genet Biol 45:17–27
Yelton MM, Hamer JE, Timberlake WE (1984) Transformation of Aspergillus nidulans by using a trpC plasmid. Proc Natl Acad Sci USA 81:1470–1474
Yuill E (1950) The numbers of nuclei in conidia of aspergilli. Trans Br Mycol Soc 33:324–331
Acknowledgments
This study was supported by grants from Genencor, a Danisco Division (Palo Alto, California, USA).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Zhang, J., Mao, Z., Xue, W. et al. Ku80 Gene is Related to Non-Homologous End-Joining and Genome Stability in Aspergillus niger. Curr Microbiol 62, 1342–1346 (2011). https://doi.org/10.1007/s00284-010-9853-5
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00284-010-9853-5