The C2H2-type transcription factor, FlbC, is involved in the transcriptional regulation of Aspergillus oryzae glucoamylase and protease genes specifically expressed in solid-state culture
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Aspergillus oryzae produces a large amount of secreted proteins in solid-state culture, and some proteins such as glucoamylase (GlaB) and acid protease (PepA) are specifically produced in solid-state culture, but rarely in submerged culture. From the disruption mutant library of A. oryzae transcriptional regulators, we successfully identified a disruption mutant showing an extremely low production level of GlaB but a normal level of α-amylase production. This strain was a disruption mutant of the C2H2-type transcription factor, FlbC, which is reported to be involved in the regulation of conidiospore development. Disruption mutants of other upstream regulators comprising a conidiation regulatory network had no apparent effect on GlaB production in solid-state culture. In addition to GlaB, the production of acid protease in solid-state culture was also markedly decreased by flbC disruption. Northern blot analyses revealed that transcripts of glaB and pepA were significantly decreased in the flbC disruption strain. These results suggested that FlbC is involved in the transcriptional regulation of genes specifically expressed under solid-state cultivation conditions, possibly independent of the conidiation regulatory network.
KeywordsAspergillus oryzae Solid-state culture Transcription factor FlbC Glucoamylase Acid protease Gene expression regulation Conidiospore development
We are grateful to Yoji Hata for kindly providing the anti-GlaB antibody and Yukihiro Nakamura for technical advice about the tyrosinase activity assay. We also thank Takeshi Akao for technical advice about total RNA extraction from A. oryzae cultured in solid-state culture and Osamu Mizutani for kindly providing the ∆ligD::loxP pyrG − strain. This study was supported by the Program for Promotion of Basic and Applied Researches for Innovations in Bio-oriented Industry and the Science and Technology Research Promotion Program for Agriculture, Forestry, Fisheries and Food Industry.
Compliance with ethical standards
This article does not contain any study with human participants or animals performed by any of the authors.
Conflict of interest
The authors declare that they have no conflict of interest.
- Gomi K, Iimura Y, Hara S (1987) Integrative transformation of Aspergillus oryzae with a plasmid containing the Aspergillus nidulans argB gene. Agric Biol Chem 51:2549–2555Google Scholar
- Hatamoto O, Umitsüki G, Machida M, Sano M, Tanaka A, Oka C, Maeda H, Tainaka H, Ito T, Uchikawa T, Masuda T, Matsushima K (2010) Recombinant vector capable of increasing secretion of Koji mold protease. U.S. patent US7842799 B2Google Scholar
- Machida M, Asai K, Sano M, Tanaka T, Kumagai T, Terai G, Kusumoto K, Arima T, Akita O, Kashiwagi Y, Abe K, Gomi K, Horiuchi H, Kitamoto K, Kobayashi T, Takeuchi M, Denning DW, Galagan JE, Nierman WC, Yu J, Archer DB, Bennett JW, Bhatnagar D, Cleveland TE, Fedorova ND, Gotoh O, Horikawa H, Hosoyama A, Ichinomiya M, Igarashi R, Iwashita K, Juvvadi PR, Kato M, Kato Y, Kin T, Kokubun A, Maeda H, Maeyama N, Maruyama J, Nagasaki H, Nakajima T, Oda K, Okada K, Paulsen I, Sakamoto K, Sawano T, Takahashi M, Takase K, Terabayashi Y, Wortman JR, Yamada O, Yamagata Y, Anazawa H, Hata Y, Koide Y, Komori T, Koyama Y, Minetoki T, Suharnan S, Tanaka A, Isono K, Kuhara S, Ogasawara N, Kikuchi H (2005) Genome sequencing and analysis of Aspergillus oryzae. Nature 438:1157–1161CrossRefPubMedGoogle Scholar
- Suzuki K, Tanaka M, Konno Y, Ichikawa T, Ichinose S, Hasegawa-Shiro S, Shintani T, Gomi K (2015) Distinct mechanism of activation of two transcription factors, AmyR and MalR, involved in amylolytic enzyme production in Aspergillus oryzae. Appl Microbiol Biotechnol 99:1805–1815CrossRefPubMedGoogle Scholar