Thiamine-regulated gene expression of Aspergillus oryzae thiA requires splicing of the intron containing a riboswitch-like domain in the 5'-UTR.
Exogenous thiamine regulates Aspergillus oryzae thiA, which is involved in thiamine synthesis. One of the two introns in its 5'-untranslated region (5'-UTR) contains motifs (regions A and B) highly conserved among fungal thiamine biosynthesis genes. Deletion of either region relieved the repression by thiamine and thiamine inhibited intron splicing, suggesting that regions A and B are required for efficient splicing. Furthermore, transcript splicing was essential for thiA gene expression. These observations suggest a novel gene expression regulatory mechanism in filamentous fungi, in which exogenous thiamine controls intron splicing to regulate gene expression. Interestingly, regions A and B constitute a part of a thiamine pyrophosphate-binding riboswitch-like domain that has been quite recently found in the 5'-UTR of thiA.
Kubodera
Takafumi
T
Research and Development Department, Hakutsuru Sake Brewing Co. Ltd., 4-5-5, Sumiyoshiminami-machi, Higashinada-ku, Kobe 658-0041, Japan. kubodera@hakutsuru.co.jp
Watanabe
Mutsumi
M
Yoshiuchi
Kumi
K
Yamashita
Nobuo
N
Nishimura
Akira
A
Nakai
Susumu
S
Gomi
Katsuya
K
Hanamoto
Hideo
H
D020121:5' Untranslated Regions / Q000737:chemistry / Q000235:genetics*; D001236:Aspergillus oryzae / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D004352:Drug Resistance, Microbial; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal / Q000235:genetics*; D005800:Genes, Fungal; D017930:Genes, Reporter / Q000235:genetics; D005966:Glucuronidase / Q000235:genetics / Q000378:metabolism; D007438:Introns / Q000235:genetics; D008969:Molecular Sequence Data; D009711:Nucleotides / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D011745:Pyrithiamine / Q000494:pharmacology; D012326:RNA Splicing / Q000235:genetics*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid; D013831:Thiamine / Q000378:metabolism / Q000502:physiology*
D020121:5' Untranslated Regions; D005656:Fungal Proteins; D009711:Nucleotides; D011994:Recombinant Proteins; D011745:Pyrithiamine; D005966:Glucuronidase; D013831:Thiamine