Araki K.,Kyoto Sangyo University |
Inaba K.,Kyushu University
Antioxidants and Redox Signaling | Year: 2012
Significance: Disulfide bond formation is an essential reaction involved in the folding and maturation of many secreted and membrane proteins. Both prokaryotic and eukaryotic cells utilize various disulfide oxidoreductases and redox-active cofactors to accelerate this oxidative reaction, and higher eukaryotes have diversified and refined these disulfide-introducing cascades over the course of evolution. Recent Advances: In the past decade, atomic resolution structures have been solved for an increasing number of disulfide oxidoreductases, thereby revealing the structural and mechanistic basis of cellular disulfide bond formation systems. Critical Issues: In this review, we focus on the evolution, structure, and regulatory mechanisms of endoplasmic reticulum oxidoreductin 1 (Ero1) family enzymes, the primary disulfide bond-generating catalysts in the endoplasmic reticulum (ER). Detailed comparison of Ero1 with other oxidoreductases, such as Prx4, QSOX, Erv1/2, and disulfide bond protein B (DsbB), provides important insight into how this ER-resident flavoenzyme acts in a regulated and specific manner to maintain redox and protein homeostasis in eukaryotic cells. Future Directions: Currently, it is presumed that multiple pathways in addition to that mediated by Ero1 cooperate to achieve oxidative folding of many secretory and membrane proteins in mammalian cells. The important open question is how each oxidative pathway works distinctly or redundantly in response to various cellular conditions. Antioxid. Redox Signal. 16, 790-799. © Copyright 2012, Mary Ann Liebert, Inc. 2012.
Shimamoto N.,Kyoto Sangyo University
Chemical Reviews | Year: 2013
Atomic force microscopy and its related techniques have long been struggling to squeeze into biology, although they have been essential in the semiconductor industry since their invention. However, they are now starting to exert their power after the increased need for visualization of the structures of biological molecules under physiological conditions. The new techniques also supplemented the values of X-ray crystallography and nuclear magnetic resonance (NMR) distance geometries. In addition, there are so many new versions of traditional biochemical methods, such as crosslinking and footprinting techniques. The introduction of molecular motion in biology may broaden molecular biology. The notion of the behavior of a molecule can now be more referenced by the preformative nano, and thus, this field, with the full notion of molecular motion, is termed nanobiology. Its aim is to handle the problems of how the behaviors of one or a small number of specific molecules build macroscopic and physiological phenomena.
Chiba S.,Kyoto Sangyo University |
Ito K.,Kyoto Sangyo University
Molecular Cell | Year: 2012
Bacillus subtilis MifM uses polypeptide-instructed ribosomal stalling to control translation of YidC2, a membrane protein biogenesis factor. In contrast to other stalling systems involving a single arrest point, our in vitro translation/toeprint experiments show that the B. subtilis ribosome stalls consecutively at multiple codons of MifM. This mode of elongation arrest depends on nascent chain residues at the middle of the ribosomal exit tunnel and a few (four for the maximum functionality) negative charges residing proximally to the arrest points. The latter element does not require exact amino acid sequence, and this feature may underlie the multisite stalling. The arrested nascent chains were not efficiently transferred to puromycin, suggesting that growing MifM nascent chains inhibit peptidyl transferase center after acquiring an acidic residue(s). Multisite stalling seems to provide a unique means for MifM to achieve a sufficient duration of ribosomal stalling required for the regulatory function. © 2012 Elsevier Inc.
Umetsu K.,Kyoto Sangyo University
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2010
It is shown that the derivation of the Hawking radiation from a rotating black hole on the basis of the tunneling mechanism is greatly simplified by using the technique of the dimensional reduction near the horizon. This technique is illustrated for the original derivation by Parikh and Wilczek, but it is readily applied to a variant of the method such as suggested by Banerjee and Majhi. © 2010.
Matsuzaki S.,Kyoto Sangyo University |
Yamawaki K.,Nagoya University
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2013
A new particle at around 125 GeV has been observed at the LHC, which we show could be identified with the techni-dilaton (TD) predicted in the walking technicolor and thus should be an evidence of walking technicolor. The TD is a pseudo Nambu-Goldstone boson for the approximate scale symmetry spontaneously broken by techni-fermion condensation, with its lightness being ensured by the approximate scale invariance of the walking technicolor. We test the goodness-of-fit of the TD signatures using the presently available LHC data set, and show that the 125 GeV TD is actually favored by the current data to explain the reported signal strengths in the global fit as well as in each channel including the coupling properties, most notably the somewhat large diphoton event rate. © 2013 Elsevier B.V.
Yamashita T.,Kyoto Sangyo University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2011
We present a new solution to the doublet-triplet splitting problem which also works in a supersymmetric SU(5) grand unified theory and is testable at TeV-scale collider experiments. In our model, the SU(5) symmetry is broken through the Hosotani mechanism. Thanks to the phase nature of the Hosotani breaking, the "missing VEV" can be realized even in an SU(5) model. A general and distinctive prediction of this solution is the existence of light adjoint chiral supermultiplets with masses of the supersymmetry-breaking scale. Though these fields disturb the gauge coupling unification, it can be recovered, keeping the unified gauge coupling constant perturbative, by introducing additional vectorlike particles, which may be also observed in the upcoming collider experiments. © 2011 American Physical Society.
Araki K.,Kyoto Sangyo University |
Nagata K.,Kyoto Sangyo University
Cold Spring Harbor Perspectives in Biology | Year: 2011
The endoplasmic reticulum (ER) uses an elaborate surveillance system called the ER quality control (ERQC) system. The ERQC facilitates folding and modification of secretory and membrane proteins and eliminates terminally misfolded polypeptides through ER-associated degradation (ERAD) or autophagic degradation. This mechanism of ER protein surveillance is closely linked to redox and calcium homeostasis in the ER, whose balance is presumed to be regulated by a specific cellular compartment. The potential to modulate proteostasis and metabolism with chemical compounds or targeted siRNAs may offer an ideal option for the treatment of disease. © 2011 Cold Spring Harbor Laboratory Press.
Hotta C.,Kyoto Sangyo University
Physical Review B - Condensed Matter and Materials Physics | Year: 2010
We present an effective dipolar-spin model based on the strong coupling analysis, which may explain the possible origin of "spin-liquid insulator." The issue is related to a dimer Mott insulator reminiscent of an organic triangular lattice system, κ -ET2 Cu2 (CN)3, whose gapless spin-liquid state has been discussed in the context of geometrical frustration of exchange coupling, J, between spins on dimer orbitals. It turns out that another degrees of freedom within the insulator, quantum electric dipoles on dimers, interact with each other and modify J significantly through the dipolar-spin coupling, resulting in a possible "dipolar-spin liquid." © 2010 The American Physical Society.
Ito K.,Kyoto Sangyo University |
Chiba S.,Kyoto Sangyo University
Annual Review of Biochemistry | Year: 2013
Each peptide bond of a protein is generated at the peptidyl transferase center (PTC) of the ribosome and then moves through the exit tunnel, which accommodates ever-changing segments of ∼40 amino acids of newly translated polypeptide. A class of proteins, called ribosome arrest peptides, contains specific sequences of amino acids (arrest sequences) that interact with distinct components of the PTC-exit tunnel region of the ribosome and arrest their own translation continuation, often in a manner regulated by environmental cues. Thus, the ribosome that has translated an arrest sequence is inactivated for peptidyl transfer, translocation, or termination. The stalled ribosome then changes the configuration or localization of mRNA, resulting in specific biological outputs, including regulation of the target gene expression and downstream events of mRNA/polypeptide maturation or localization. Living organisms thus seem to have integrated potentially harmful arrest sequences into elaborate regulatory mechanisms to express genetic information in productive directions. © 2013 by Annual Reviews. All rights reserved.
Kyoto Sangyo University and Horiba Ltd. | Date: 2016-10-19
The present invention provides a fluorescent protein and the like containing an amino acid sequence the same or substantially the same as the amino acid sequence shown in SEQ ID NO: 2.