Characterization in Terms of the NUX Rule of G-inserted Mutant Hammerhead Ribozymes with High Level of Catalytic Power

Kuwabara, Tomoko,Warashina, Masaki,Kato, Yoshio,Kawasaki, Hiroaki,Taira, Kazunari Korean Society for Biochemistry and Molecular Biol 2001 Journal of biochemistry and molecular biology Vol.34 No.1

Attempts using in vitro and in vivo selection procedures have been made to search for hammerhead ribozymes that have higher activities than the wild-type ribozyme and also to determine whether other sequences might be possible in the catalytic core of the hammerhead ribozyme. Active sequences selected in the past conformed broadly to the consensus core sequence except at A9, and no sequences were associated with higher activity than that of the hammerhead with the consensus core, an indication that the consensus sequence derived from viruses and virusoids is probably the optimal sequence [Vaish et al. (1997) Biochemistry 36, 6495-6501]. Recently, during construction of ribozyme expression vectors, we isolated a mutant hammerhead ribozyme, with an insertion of G between A9 and G10.1, that appeared to show significant activity [Kawasaki et al. (1996) Nucleic Acids Res. 24, 3010-3016; Kawasaki et al. (1998) Nature 393, 284-289]. We, therefore, characterized kinetic properties of the G-inserted mutant ribozymes in terms of the NUX rule. We demonstrate that the NUX rule is basically applicable to the G-inserted ribozymes and, more importantly, one type of G-inserted ribozyme was very active with $k_{cat}$, value of $6.4\;min^{-1}$ in 50 mM Tris-HCl (pH 8.0) and 10 mM $MgCl_2$ at $37^{\circ}C$.

Characterization in Terms of the NUX Rule of G - inserted Mutant Hammerhead Ribozymes with High Level of Catalytic Power

(Tomoko Kuwabara),(Masaki Warashina),(Yoshio Kato),(Hiroaki Kawasaki),(Kazunari Taira) 생화학분자생물학회 2001 BMB Reports Vol.34 No.1

Attempts using in vitro and in vivo selection procedures have been made to search for hammerhead ribozymes that have higher activities than the wild-type ribozyme and also to determine whether other sequences might be possible in the catalytic core of the hammerhead ribozyme. Active sequences selected in the past conformed broadly to the consensus core sequence except at A9, and no sequences were associated with higher activity than that of the hammerhead with the consensus core, an indication that the consensus sequence derived from viruses and virusoids is probably the optimal sequence [Vaish et al. (1997) Biochemistry 36, 6495-6501]. Recently, during construction of ribozyme expression vectors, we isolated a mutant hammerhead ribozyme, with an insertion of G between A9 and 610.1, that appeared to show significant activity [Kawasaki et at (1996) Nucleic Acids Res. 24, 3010-3016; Kawasaki et al. (1998) Nature 393, 284-289]. We, therefore, characterized kinetic properties of the G-inserted mutant ribozymes in terms of the NUX rule. We demonstrate that the NUX rule is basically applicable to the G-inserted ribozymes and, more importantly, one type of G-inserted ribozyme was very active with k_(cat), value of 6.4 min^(-1) in 50 mM Tris-HCl (pH 8.0) and 10 m1VI MgCl₂ at 37℃.

Clinical features, diagnosis, and outcomes of multisystem inflammatory syndrome in children associated with coronavirus disease 2019

Kwak, Ji Hee,Lee, Soo-Young,Choi, Jong-Woon,Korean Society of Kawasaki Diseasety of Pediatric Endocrinology (KSPE), The Korean Pediatric Society 2021 Clinical and Experimental Pediatrics (CEP) Vol.64 No.2

The novel coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been spreading worldwide since December 2019. Hundreds of cases of children and adolescents with Kawasaki disease (KD)-like hyperinflammatory illness have been reported in Europe and the United States during the peak of the COVID-19 pandemic with or without shock and cardiac dysfunction. These patients tested positive for the polymerase chain reaction or antibody test for SARS-CoV-2 or had a history of recent exposure to COVID-19. Clinicians managing such patients coined new terms for this new illness, such as COVID-19-associated hyperinflammatory response syndrome, pediatric inflammatory multisystem syndrome temporally associated with COVID-19, or COVID-19-associated multisystem inflammatory syndrome in children (MIS-C). The pathogenesis of MIS-C is unclear; however, it appears similar to that of cytokine storm syndrome. MIS-C shows clinical features similar to KD, but differences between them exist with respect to age, sex, and racial distributions and proportions of patients with shock or cardiac dysfunction. Recommended treatments for MIS-C include intravenous immunoglobulin, corticosteroids, and inotropic or vasopressor support. For refractory patients, monoclonal antibody to interleukin-6 receptor (tocilizumab), interleukin-1 receptor antagonist (anakinra), or monoclonal antibody to tumor necrosis factor (infliximab) may be recommended. Patients with coronary aneurysms require aspirin or anticoagulant therapy. The prognosis of MIS-C seemed favorable without sequelae in most patients despite a reported mortality rate of approximately 1.5%.

Engineering Carrier Effective Masses in Ultrathin Quantum Wells of IrO2

Kawasaki, Jason K.,Kim, Choong H.,Nelson, Jocienne N.,Crisp, Sophie,Zollner, Christian J.,Biegenwald, Eric,Heron, John T.,Fennie, Craig J.,Schlom, Darrell G.,Shen, Kyle M. American Physical Society 2018 Physical review letters Vol.121 No.17

Superplastic Flow and Micro-Mechanical Response of Ultrafine-Grained Materials

Kawasaki, Megumi,Jang, Jae Il,Langdon, Terence G. Trans Tech Publications, Ltd. 2018 Diffusion and defect data. DDF. Pt. A, Defect and Vol.385 No.-

<P>The bulk ultrafine-grained (UFG) materials usually show superior mechanical properties. Since the occurrence of superplastic flow generally requires a grain size smaller than ~10 μm, it is anticipated that materials processed by severe plastic deformation (SPD) will exhibit superplastic ductilities when pulled in tension at elevated temperatures. Recent advances in the processing of UFG metals have provided an opportunity to extend the understanding of superplastic flow behavior to include UFG materials with submicrometer grain sizes. Recent studies showed the UFG materials demonstrated the development of plasticity in micro-mechanical response at room temperature by the significant changes in microstructure attributed to high-pressure torsion (HPT). Accordingly, this study summarizes recent results on excellent ductility and plasticity in a UFG Zn-22% Al alloy. Specifically, the alloy demonstrated the occurrence of exceptional superplastic flow at high temperature after equal-channel angular pressing and HPT and excellent room temperature plasticity of the alloy after HPT where the plasticity was evaluated by the nanoindentation technique. The significance of purity of the alloy is also considered for enhancing the ductility at room temperature.</P>

A CLUSTER SURVEY AROUND THE UNIDENTIFIED EGRET SOURCES

KAWASAKI WATARU,TOTANI TOMONORI The Korean Astronomical Society 2005 Journal of The Korean Astronomical Society Vol.38 No.2

Based on optical galaxy data, we executed a systematic search for galaxy clusters around the 15 steady unidentified EGRET GeV gamma-ray sources in high Galactic-latitude sky ([b] > $30^{\circ}$). We found a strong correlation with 3.7$\sigma$ level between close cluster pairs (merging cluster candidates) and the unidentified EGRET sources, though, in contrast, no correlation with single clusters. This result implies that merging clusters of galaxies are a possible candidate for the origin of high galactic-latitude, steady unidentified EGRET gamma-ray sources.

Apigenin inhibits larval growth of <i>Caenorhabditis elegans</i> through DAF-16 activation

Kawasaki, Ichiro,Jeong, Myung-Hwan,Oh, Bong-Kyeong,Shim, Yhong-Hee Elsevier 2010 FEBS letters Vol.584 No.16

<P><B>Abstract</B></P><P>Treatment of <I>Caenorhabditis elegans</I> with apigenin, 5,7,4′-trihydroxyflavone, induces larval growth inhibition. To understand the molecular basis of apigenin-induced larval growth inhibition, the effects of apigenin on DAF-16 activity were examined. DAF-16 was activated through nuclear translocation and the mRNA level of <I>sod-3</I>, one of the known DAF-16 target genes, was increased upon apigenin treatment. DAF-16 activity was required for the growth inhibition, since the larval growth retardation upon apigenin treatment was suppressed in <I>daf-16</I> mutants. These results indicate that apigenin acts as a stressor that activates DAF-16, which in turn inhibits larval growth.</P>

Microstructural homogeneity and superplastic behavior in an aluminum-copper eutectic alloy processed by high-pressure torsion

Kawasaki, Megumi,Lee, Han-Joo,Langdon, Terence G. Springer-Verlag 2015 JOURNAL OF MATERIALS SCIENCE - Vol.50 No.20

Inhibition of GluR Current in Microvilli of Sensory Neurons via Na ⁺ -Microdomain Coupling Among GluR, HCN Channel, and Na ⁺ /K ⁺ Pump

Kawasaki, Yasuhiro,Saito, Mitsuru,Won, Jonghwa,Bae, Jin Young,Sato, Hajime,Toyoda, Hiroki,Kuramoto, Eriko,Kogo, Mikihiko,Tanaka, Takuma,Kaneko, Takeshi,Oh, Seog Bae,Bae, Yong Chul,Kang, Youngnam Frontiers Media S.A. 2018 Frontiers in cellular neuroscience Vol.12 No.-

<P>Glutamatergic dendritic EPSPs evoked in cortical pyramidal neurons are depressed by activation of hyperpolarization-activated cyclic nucleotide-gated (HCN) channels expressed in dendritic spines. This depression has been attributed to shunting effects of HCN current (<I>I</I><SUB>h</SUB>) on input resistance or <I>I</I><SUB>h</SUB> deactivation. Primary sensory neurons in the rat mesencephalic trigeminal nucleus (MTN) have the somata covered by spine-like microvilli that express HCN channels. In rat MTN neurons, we demonstrated that <I>I</I><SUB>h</SUB> enhancement apparently diminished the glutamate receptor (GluR) current (<I>I</I><SUB>GluR</SUB>) evoked by puff application of glutamate/AMPA and enhanced a transient outward current following <I>I</I><SUB>GluR</SUB> (OT-<I>I</I><SUB>GluR</SUB>). This suggests that some outward current opposes inward <I>I</I><SUB>GluR</SUB>. The <I>I</I><SUB>GluR</SUB> inhibition displayed a U-shaped voltage-dependence with a minimal inhibition around the resting membrane potential, suggesting that simple shunting effects or deactivation of <I>I</I><SUB>h</SUB> cannot explain the U-shaped voltage-dependence. Confocal imaging of Na<SUP>+</SUP> revealed that GluR activation caused an accumulation of Na<SUP>+</SUP> in the microvilli, which can cause a negative shift of the reversal potential for <I>I</I><SUB>h</SUB> (<I>E</I><SUB>h</SUB>). Taken together, it was suggested that <I>I</I><SUB>GluR</SUB> evoked in MTN neurons is opposed by a transient decrease or increase in standing inward or outward <I>I</I><SUB>h</SUB>, respectively, both of which can be caused by negative shifts of <I>E</I><SUB>h</SUB>, as consistent with the U-shaped voltage-dependence of the <I>I</I><SUB>GluR</SUB> inhibition and the OT-<I>I</I><SUB>GluR</SUB> generation. An electron-microscopic immunohistochemical study revealed the colocalization of HCN channels and glutamatergic synapses in microvilli of MTN neurons, which would provide a morphological basis for the functional interaction between HCN and GluR channels. Mathematical modeling eliminated the possibilities of the involvements of <I>I</I><SUB>h</SUB> deactivation and/or shunting effect and supported the negative shift of <I>E</I><SUB>h</SUB> which causes the U-shaped voltage-dependent inhibition of <I>I</I><SUB>GluR</SUB>.</P>

Computation of annular capacity by Hamiltonian Floer theory of non-contractible periodic trajectories

Kawasaki, Morimichi,Orita, Ryuma American Institute of Mathematical Sciences 2017 Journal of modern dynamics Vol.11 No.-

<P>The first author [9] introduced a relative symplectic capacity C for a symplectic manifold (N, omega(N)) and its subset X which measures the existence of non-contractible periodic trajectories of Hamiltonian isotopies on the product of N with the annulus A(R) = (-R, R) x R/Z. In the present paper, we give an exact computation of the capacity C of the 2n-torus T-2n relative to a Lagrangian submanifold T-n which implies the existence of non-contractible Hamiltonian periodic trajectories on A(R) x T-2n. Moreover, we give a lower bound on the number of such trajectories.</P>