Analysis of Expressed Sequence Tags from the Fungus Aspergillus oryzae Cultured Under Different Conditions

Abstract

We performed random sequencing of cDNAs from nine biologically or industrially important cultures of the industrially valuable fungus Aspergillus oryzae to obtain expressed sequence tags (ESTs). Consequently, 21 446 raw ESTs were accumulated and subsequently assembled to 7589 non-redundant consensus sequences (contigs). Among all contigs, 5491 (72.4%) were derived from only a particular culture. These included 4735 (62.4%) singletons, i.e. lone ESTs overlapping with no others. These data showed that consideration of culture grown under various conditions as cDNA sources enabled efficient collection of ESTs. BLAST searches against the public databases showed that 2953 (38.9%) of the EST contigs showed significant similarities to deposited sequences with known functions, 793 (10.5%) were similar to hypothetical proteins, and the remaining 3843 (50.6%) showed no significant similarity to sequences in the databases. Culture-specific contigs were extracted on the basis of the EST frequency normalized by the total number for each culture condition. In addition, contig sequences were compared with sequence sets in eukaryotic orthologous groups (KOGs), and classified into the KOG functional categories.

Molecular Cloning ofocpOEncoding Carboxypeptidase O ofAspergillus oryzaeIAM2640

“…Gene AO090020000351 is one of the predicted genes encoding an extracellular serine-type carboxypeptidase. According to the results of an EST analysis of A. oryzae RIB40 (http://riodb.ibase.aist.go.jp/ffdb/ index.html), 26) a transcript of AO090020000351 was found in hyphae cultured not only in liquid media but also in solid media such as soy bean and rice. On the other hand, transcripts of other predicted genes encoding extracellular serine-type carboxypeptidase were found in hyphae cultured only in liquid or solid medium.…”

Characterization of a fungal thioesterase having claisen cyclase and deacetylase activities in melanin biosynthesis

“…A BlastP search of the sequenced A. oryzae genome (Machida, et al, 2005) for proteins similar to Ayg1p revealed a potential functional complement in this heterologous host, the transcription of which was supported under standard laboratory conditions by detection of an expressed sequence tag (AoEST6890) from a conidial cDNA library (Akao, et al, 2007). Furthermore, the purified Pks1 SAT monodomain was found to selectively transfer acetyl in disparity with labeledprecursor incorporation experiments .…”

Membrane transporter proteins are involved in Trichophyton rubrum pathogenesis

“…This result was expected because MFS transporters are a ubiquitous group of proteins involved in the transport of a wide range of compounds, including external elements and toxins (Saier et al, 1999;Vardy et al, 2004). In the Aspergillus oryzae genome, 63.9 % of transporters are MFS type, involved in secondary metabolism (Akao et al, 2007). The analysis of a gene encoding MFS transporter-like protein (CTB4) in Cercospora nicotianae provided genetic evidence to support its role in virulence by cercosporin accumulation (Choquer et al, 2007).…”