Hiroyuki Hori

Learn More
BACKGROUND Parkinson's disease (PD) is a common neurodegenerative disorder in older people, and half of the world's older population lives in Asia. However, the epidemiology of PD in Asian countries is poorly understood. This review assembles evidence on the prevalence and incidence of PD in Asian countries and identifies gaps in our present knowledge. (More)
Foreign RNA serves as pathogen-associated molecular pattern (PAMP) and is a potent immune stimulator for innate immune receptors. However, the role of single bacterial RNA species in immune activation has not been characterized in detail. We analyzed the immunostimulatory potential of transfer RNA (tRNA) from different bacteria. Interestingly, bacterial(More)
N(7)-methylguanine at position 46 (m(7)G46) in tRNA is produced by tRNA (m(7)G46) methyltransferase (TrmB). To clarify the role of this modification, we made a trmB gene disruptant (DeltatrmB) of Thermus thermophilus, an extreme thermophilic eubacterium. The absence of TrmB activity in cell extract from the DeltatrmB strain and the lack of the m(7)G46(More)
Transfer RNA (m(1)G37) methyltransferase (TrmD) catalyzes methyl-transfer from S-adenosyl-L-methionine to the N(1) atom of G37 in tRNA. In Escherichia coli cells, TrmD methylates tRNA species possessing a G36G37 sequence. It was previously believed that G36 was the positive determinant of TrmD recognition. In the current study, we demonstrate that TrmD from(More)
Cleavage of introns from precursor transfer RNAs (tRNAs) by tRNA splicing endonuclease (EndA) is essential for tRNA maturation in Archaea and Eukarya. In the past, archaeal EndAs were classified into three types (α'2, α4 and α2β2) according to subunit composition. Recently, we have identified a fourth type of archaeal EndA from an uncultivated archaeon(More)
Pseudouridine at position 55 (Ψ55) in eubacterial tRNA is produced by TruB. To clarify the role of the Ψ55 modification, we constructed a truB gene disruptant (ΔtruB) strain of Thermus thermophilus which is an extreme-thermophilic eubacterium. Unexpectedly, the ΔtruB strain exhibited severe growth retardation at 50 °C. We assumed that these phenomena might(More)
In Crenarchaea, several tRNA genes are predicted to express precursor-tRNAs (pre-tRNAs) with canonical or non-canonical introns at various positions. We initially focused on the tRNA(Thr) species of hyperthermophilic crenarchaeon, Aeropyrum pernix (APE) and found that in the living APE cells three tRNA(Thr) species were transcribed and subsequently matured(More)
Stress response mechanisms that modulate the dynamics of tRNA degradation and accumulation from the cytoplasm to the nucleus have been studied in yeast, the rat hepatoma and human cells. In the current study, we investigated tRNA degradation and accumulation in HeLa cells under various forms of stress. We found that initiator tRNA(Met) (tRNA(iMet)) was(More)
Since the SPOUT superfamily was defined by homology between the SpoU and TrmD families [Anantharaman, V. et al., J. Mol. Microbiol. Biotechnol., 4, 71-75 (2002)], many crystal structures have been solved and numerous new homologous sequences have been found in the superfamily. Therefore, nowadays, we can consider enzyme function and/or evolution process of(More)