Wobble inosine tRNA modification is essential to cell cycle progression in G(1)/S and G(2)/M transitions in fission yeast.
Inosine (I) at position 34 (wobble position) of tRNA is formed by the hydrolytic deamination of a genomically encoded adenosine (A). The enzyme catalyzing this reaction, termed tRNA A:34 deaminase, is the heterodimeric Tad2p/ADAT2.Tad3p/ADAT3 complex in eukaryotes. In budding yeast, deletion of each subunit is lethal, indicating that the wobble inosine tRNA modification is essential for viability; however, most of its physiological roles remain unknown. To identify novel cell cycle mutants in fission yeast, we isolated the tad3-1 mutant that is allelic to the tad3(+) gene encoding a homolog of budding yeast Tad3p. Interestingly, the tad3-1 mutant cells principally exhibited cell cycle-specific phenotype, namely temperature-sensitive and irreversible cell cycle arrest both in G(1) and G(2). Further analyses revealed that in the tad3-1 mutant cells, the S257N mutation that occurred in the catalytically inactive Tad3 subunit affected its association with catalytically active Tad2 subunit, leading to an impairment in the A to I conversion at position 34 of tRNA. In tad3-1 mutant cells, the overexpression of the tad3(+) gene completely suppressed the decreased tRNA inosine content. Notably, the overexpression of the tad2(+) gene partially suppressed the temperature-sensitive phenotype and the decreased tRNA inosine content, indicating that the tad3-1 mutant phenotype is because of the insufficient I(34) formation of tRNA. These results suggest that the wobble inosine tRNA modification is essential for cell cycle progression in the G(1)/S and G(2)/M transitions in fission yeast.
Tsutsumi
Satoshi
S
Division of Molecular Pharmacology and Pharmacogenomics, Department of Biochemistry and Molecular Biology, Graduate School of Medicine, Kobe University, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
Sugiura
Reiko
R
Laboratory of Molecular Pharmacogenomics, School of Pharmaceutical Sciences, Kinki University, Kowakae 3-4-1, Higashi-Osaka, 577-8502, Japan.
Ma
Yan
Y
Division of Molecular Pharmacology and Pharmacogenomics, Department of Biochemistry and Molecular Biology, Graduate School of Medicine, Kobe University, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
Tokuoka
Hideki
H
Division of Molecular Pharmacology and Pharmacogenomics, Department of Biochemistry and Molecular Biology, Graduate School of Medicine, Kobe University, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
Ohta
Kazuki
K
Division of Molecular Pharmacology and Pharmacogenomics, Department of Biochemistry and Molecular Biology, Graduate School of Medicine, Kobe University, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
Ohte
Rieko
R
Division of Molecular Pharmacology and Pharmacogenomics, Department of Biochemistry and Molecular Biology, Graduate School of Medicine, Kobe University, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
Noma
Akiko
A
Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
Suzuki
Tsutomu
T
Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
Kuno
Takayoshi
T
Division of Molecular Pharmacology and Pharmacogenomics, Department of Biochemistry and Molecular Biology, Graduate School of Medicine, Kobe University, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan. Electronic address: tkuno@med.kobe-u.ac.jp.
D000483:Alleles; D000595:Amino Acid Sequence; D001483:Base Sequence; D002453:Cell Cycle; D002469:Cell Separation; D003001:Cloning, Molecular; D005434:Flow Cytometry; D007288:Inosine / Q000737:chemistry*; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D012343:RNA, Transfer / Q000737:chemistry*; D012568:Schizosaccharomyces / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D013696:Temperature
D007288:Inosine; D012343:RNA, Transfer