Aspergillus oryzae atfB encodes a transcription factor required for stress tolerance in conidia.
Using an Aspergillus oryzae EST database, we identified a gene encoding a transcription factor (atfB), which is a member of the ATF/CREB family. Expression of atfB was barely detectable during vegetative growth, but was readily detected during conidiation in solid-state culture. Microarray analyses showed that expression of many other genes, including catalase (catA), were downregulated in an atfB-disruptant. The expression of most of these genes was upregulated in the wild-type strain during the conidiation phase in solid-state culture, and the expression pattern was similar to that of atfB itself. In the absence of stress, e.g. heat-shock or hydrogen peroxide, the conidial germination ratios for the DeltaatfB strain and the wild-type strain were similar, but the stress tolerance of conidia carrying the DeltaatfB deletion was less than that of the wild-type conidia. CRE-like DNA motifs, which are bound by ATF/CREB proteins, were found in the promoters of most of the downregulated genes in the DeltaatfB strain. Thus, atfB appears to encode a transcription factor required for stress tolerance in conidia.
Sakamoto
Kazutoshi
K
National Research Institute of Brewing, 3-7-1 Kagamiyama, Higashihiroshima, Hiroshima, Japan. k.sakamoto@nrib.go.jp
Arima
Toshi-hide
TH
Iwashita
Kazuhiro
K
Yamada
Osamu
O
Gomi
Katsuya
K
Akita
Osamu
O
D000595:Amino Acid Sequence; D001236:Aspergillus oryzae / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D016384:Consensus Sequence; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D018869:Heat-Shock Response; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis; D018384:Oxidative Stress; D011401:Promoter Regions, Genetic; D016415:Sequence Alignment; D013172:Spores, Fungal / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*
D005656:Fungal Proteins; D014157:Transcription Factors; D006861:Hydrogen Peroxide