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Showing papers by "Nagoya University published in 2001"


Journal ArticleDOI
TL;DR: The newly devised [RuCl(2)(phosphane)(2)(1,2-diamine)] complexes are excellent precatalysts for homogeneous hydrogenation of simple ketones which lack any functionality capable of interacting with the metal center.
Abstract: Hydrogenation is a core technology in chemical synthesis. High rates and selectivities are attainable only by the coordination of structurally well-designed catalysts and suitable reaction conditions. The newly devised [RuCl(2)(phosphane)(2)(1,2-diamine)] complexes are excellent precatalysts for homogeneous hydrogenation of simple ketones which lack any functionality capable of interacting with the metal center. This catalyst system allows for the preferential reduction of a C=O function over a coexisting C=C linkage in a 2-propanol solution containing an alkaline base. The hydrogenation tolerates many substituents including F, Cl, Br, I, CF(3), OCH(3), OCH(2)C(6)H(5), COOCH(CH(3))(2), NO(2), NH(2), and NRCOR as well as various electron-rich and -deficient heterocycles. Furthermore, stereoselectivity is easily controlled by the electronic and steric properties (bulkiness and chirality) of the ligands as well as the reaction conditions. Diastereoselectivities observed in the catalytic hydrogenation of cyclic and acyclic ketones with the standard triphenylphosphane/ethylenediamine combination compare well with the best conventional hydride reductions. The use of appropriate chiral diphosphanes, particularly BINAP compounds, and chiral diamines results in rapid and productive asymmetric hydrogenation of a range of aromatic and heteroaromatic ketones and gives a consistently high enantioselectivity. Certain amino and alkoxy ketones can be used as substrates. Cyclic and acyclic alpha,beta-unsaturated ketones can be converted into chiral allyl alcohols of high enantiomeric purity. Hydrogenation of configurationally labile ketones allows for the dynamic kinetic discrimination of diastereomers, epimers, and enantiomers. This new method shows promise in the practical synthesis of a wide variety of chiral alcohols from achiral and chiral ketone substrates. Its versatility is manifested by the asymmetric synthesis of some biologically significant chiral compounds. The high rate and carbonyl selectivity are based on nonclassical metal-ligand bifunctional catalysis involving an 18-electron amino ruthenium hydride complex and a 16-electron amido ruthenium species.

1,630 citations


Journal ArticleDOI
15 Apr 2001-Blood
TL;DR: Analysis of the mutation of D835 of FLT3, which corresponds to D816 of c-KIT, in a large series of human hematologic malignancies demonstrates that the FLT 3 gene is the target most frequently mutated to become constitutively active in AML.

1,123 citations


Journal ArticleDOI
TL;DR: The results indicate that chronic vascular insufficiency and, possibly, insufficient Vegf-dependent neuroprotection lead to the select degeneration of motor neurons.
Abstract: Hypoxia stimulates angiogenesis through the binding of hypoxia-inducible factors to the hypoxia-response element in the vascular endothelial growth factor (Vegf) promotor. Here, we report that deletion of the hypoxia-response element in the Vegf promotor reduced hypoxic Vegf expression in the spinal cord and caused adult-onset progressive motor neuron degeneration, reminiscent of amyotrophic lateral sclerosis. The neurodegeneration seemed to be due to reduced neural vascular perfusion. In addition, Vegf165 promoted survival of motor neurons during hypoxia through binding to Vegf receptor 2 and neuropilin 1. Acute ischemia is known to cause nonselective neuronal death. Our results indicate that chronic vascular insufficiency and, possibly, insufficient Vegf-dependent neuroprotection lead to the select degeneration of motor neurons.

1,029 citations


Journal ArticleDOI
TL;DR: It is reported that deletion of Nrl in mice results in the complete loss of rod function and super-normal cone function, mediated by S cones, and postulate that Nrl acts as a 'molecular switch' during rod-cell development by directly modulating rod-specific genes while simultaneously inhibiting the S-cone pathway through the activation of Nr2e3.
Abstract: The protein neural retina leucine zipper (Nrl) is a basic motif-leucine zipper transcription factor that is preferentially expressed in rod photoreceptors. It acts synergistically with Crx to regulate rhodopsin transcription. Missense mutations in human NRL have been associated with autosomal dominant retinitis pigmentosa. Here we report that deletion of Nrl in mice results in the complete loss of rod function and super-normal cone function, mediated by S cones. The photoreceptors in the Nrl-/- retina have cone-like nuclear morphology and short, sparse outer segments with abnormal disks. Analysis of retinal gene expression confirms the apparent functional transformation of rods into S cones in the Nrl-/- retina. On the basis of these findings, we postulate that Nrl acts as a 'molecular switch' during rod-cell development by directly modulating rod-specific genes while simultaneously inhibiting the S-cone pathway through the activation of Nr2e3.

873 citations


Journal ArticleDOI
TL;DR: The role of the Rho-Rho-kinase pathway in contractile processes of smooth muscle and in non-muscle cell functions, and the pathophysiological implications of this pathway are summarized.

766 citations


Journal ArticleDOI
TL;DR: Findings suggest that tensegrity represents a unified model of cell mechanics that may help to explain how mechanical behaviors emerge through collective interactions among different cytoskeletal filaments and extracellular adhesions in living cells.
Abstract: Alternative models of cell mechanics depict the living cell as a simple mechanical continuum, porous filament gel, tensed cortical membrane, or tensegrity network that maintains a stabilizing prestress through incorporation of discrete structural elements that bear compression. Real-time microscopic analysis of cells containing GFP-labeled microtubules and associated mitochondria revealed that living cells behave like discrete structures composed of an interconnected network of actin microfilaments and microtubules when mechanical stresses are applied to cell surface integrin receptors. Quantitation of cell tractional forces and cellular prestress by using traction force microscopy confirmed that microtubules bear compression and are responsible for a significant portion of the cytoskeletal prestress that determines cell shape stability under conditions in which myosin light chain phosphorylation and intracellular calcium remained unchanged. Quantitative measurements of both static and dynamic mechanical behaviors in cells also were consistent with specific a priori predictions of the tensegrity model. These findings suggest that tensegrity represents a unified model of cell mechanics that may help to explain how mechanical behaviors emerge through collective interactions among different cytoskeletal filaments and extracellular adhesions in living cells.

733 citations


Journal ArticleDOI
TL;DR: In this article, a coordination approach to planar exo-multidentate organic ligands (molecular panels) was proposed to assemble into large three-dimensional polyhedra through metal-coordination.

719 citations


Journal ArticleDOI
TL;DR: The rice slender mutant (slr1-1) is caused by a loss-of-function mutation of the SLR1 gene, which is an ortholog of GAI, RGA, RHT, and D8, and succeeded in producing GA-insensitive dwarf rice by transforming wild-type rice with a modified SLR 1 gene construct that has a 17–amino acid deletion affecting the DELLA region.
Abstract: The rice slender mutant (slr1-1) is caused by a single recessive mutation and results in a constitutive gibberellin (GA) response phenotype. The mutant elongates as if saturated with GAs. In this mutant, (1) elongation was unaffected by an inhibitor of GA biosynthesis, (2) GA-inducible α-amylase was produced by the aleurone layers without gibberellic acid application, and (3) endogenous GA content was lower than in the wild-type plant. These results indicate that the product of the SLR1 gene is an intermediate of the GA signal transduction pathway. SLR1 maps to OsGAI in rice and has significant homology with height-regulating genes, such as RHT-1Da in wheat, D8 in maize, and GAI and RGA in Arabidopsis. The GAI gene family is likely to encode transcriptional factors belonging to the GRAS gene superfamily. DNA sequence analysis revealed that the slr1-1 mutation is a single basepair deletion of the nuclear localization signal domain, resulting in a frameshift mutation that abolishes protein production. Furthermore, introduction of a 6-kb genomic DNA fragment containing the wild-type SLR1 gene into the slr1-1 mutant restored GA sensitivity to normal. These results indicate that the slr1-1 mutant is caused by a loss-of-function mutation of the SLR1 gene, which is an ortholog of GAI, RGA, RHT, and D8. We also succeeded in producing GA-insensitive dwarf rice by transforming wild-type rice with a modified SLR1 gene construct that has a 17–amino acid deletion affecting the DELLA region. Thus, we demonstrate opposite GA response phenotypes depending on the type of mutations in SLR1.

670 citations


Journal ArticleDOI
TL;DR: With the newly established phylogenetic relationships, crucial arguments can be advanced regarding the functions of these kinases as upstream activators of the MAPK pathways and possible activity as MAP4Ks.

603 citations


Journal ArticleDOI
TL;DR: A gene is identified, designated Humanin (HN) cDNA, which encodes a short polypeptide and abolishes death of neuronal cells caused by multiple different types of familial Alzheimer's disease genes and by Aβ amyloid, without effect on death by Q79 or superoxide dismutase-1 mutants.
Abstract: Through functional expression screening, we identified a gene, designated Humanin (HN) cDNA, which encodes a short polypeptide and abolishes death of neuronal cells caused by multiple different types of familial Alzheimer’s disease genes and by Ab amyloid, without effect on death by Q79 or superoxide dismutase-1 mutants. Transfected HN cDNA was transcribed to the corresponding polypeptide and then was secreted into the cultured medium. The rescue action clearly depended on the primary structure of HN. This polypeptide would serve as a molecular clue for the development of new therapeutics for Alzheimer’s disease targeting neuroprotection.

532 citations


Journal ArticleDOI
TL;DR: It is found that CRMP-2/TOAD-64/Ulip2/DRP-2 (refs. 2–4) level was higher in growing axons of cultured hippocampal neurons, that overexpression of CR MP-2 in the cells led to the formation of supernumerary axons and that expression of truncated CRMP -2 mutants suppressed theformation of primary axon in a dominant-negative manner.
Abstract: In cultured hippocampal neurons, one axon and several dendrites differentiate from a common immature process1. Here we found that CRMP-2/TOAD-64/Ulip2/DRP-2 (refs. 2–4) level was higher in growing axons of cultured hippocampal neurons, that overexpression of CRMP-2 in the cells led to the formation of supernumerary axons and that expression of truncated CRMP-2 mutants suppressed the formation of primary axon in a dominant-negative manner. Thus, CRMP-2 seems to be critical in axon induction in hippocampal neurons, thereby establishing and maintaining neuronal polarity.

Journal ArticleDOI
28 Jun 2001-Nature
TL;DR: The use of multiple laminar streams in a microfluidic channel to deliver membrane-permeable molecules to selected subcellular microdomains opens up avenues for non-invasively visualizing, probing and manipulating the cellular metabolic and structural machinery.
Abstract: Localized perturbation of processes that take place inside the living cell depends on molecular and spatial discrimination on a micrometre scale Here we report the use of multiple laminar streams in a microfluidic channel to deliver membrane-permeable molecules to selected subcellular microdomains This technique opens up avenues for non-invasively visualizing, probing and manipulating the cellular metabolic and structural machinery

Journal ArticleDOI
01 Mar 2001-Energy
TL;DR: In this article, the authors proposed a new type of environmentally friendly system called the organic rankine cycle (ORC), which combines a circulated thermosyphon with a turbine system, and the working fluid used in this study is an organic substance which has a low boiling point and a low latent heat for using low-grade heat sources.

Journal ArticleDOI
TL;DR: In this paper, the authors describe observations carried out by the MOA group of the Galactic bulge during 2000 that were designed to detect efficiently gravitational microlensing of faint stars in which the magnification is high and/or of short duration.
Abstract: We describe observations carried out by the MOA group of the Galactic bulge during 2000 that were designed to detect efficiently gravitational microlensing of faint stars in which the magnification is high and/or of short duration. These events are particularly useful for studies of extrasolar planets and faint stars. Approximately 17 deg2 were monitored at a sampling rate of up to six times per night. The images were analysed in real time using a difference imaging technique. 20 microlensing candidates were detected, of which eight were alerted to the microlensing community whilst in progress. Approximately half of the candidates had high magnifications (≳10), at least one had very high magnification (≳50), and one exhibited a clear parallax effect. The details of these events are reported here, together with details of the on-line difference imaging technique. Some nova-like events were also observed and these are described, together with one asteroid.

Journal ArticleDOI
TL;DR: In this article, the authors evaluate B → Kπ decay amplitudes in perturbative QCD picture and find that penguin contributions are dynamically enhanced by nearly 50% compared to those assumed in the factorization approximation.

Journal ArticleDOI
TL;DR: In this paper, the branching ratios of quark decay amplitudes with universal meson wave functions were derived for tree, penguin, and annihilation modes in the framework of the perturbative QCD factorization theorem.
Abstract: We compute the branching ratios of $\stackrel{\ensuremath{\rightarrow}}{B}K\ensuremath{\pi}$ decays in the framework of the perturbative QCD factorization theorem. Decay amplitudes are classified into the topologies of tree, penguin, and annihilation amplitudes, all of which contain both factorizable and nonfactorizable contributions. These contributions are expressed as the convolutions of hard $b$ quark decay amplitudes with universal meson wave functions. It is shown that (1) matrix elements of penguin operators are dynamically enhanced compared to those employed in the factorization assumption, (2) annihilation diagrams are not negligible, contrary to common belief, (3) annihilation diagrams contribute large strong phases, and (4) the uncertainty of the current data of the ratio $R=\mathrm{Br}{(B}_{d}^{0}\ensuremath{\rightarrow}{K}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\pi}}^{\ensuremath{\mp}})/\mathrm{Br}{(B}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\rightarrow}{K}^{0}{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}})$ and of $\mathrm{CP}$ asymmetries is too large to give a constraint of the unitarity angle ${\ensuremath{\varphi}}_{3}.$ Assuming ${\ensuremath{\varphi}}_{3}=90\ifmmode^\circ\else\textdegree\fi{}$ which is extracted from the best fit to the data of $R,$ predictions for the branching ratios of the four $\stackrel{\ensuremath{\rightarrow}}{B}K\ensuremath{\pi}$ modes are consistent with data.

Journal ArticleDOI
TL;DR: The authors' present results show that their scheme can be regarded as a technique for CAD systems to detect nodules in helical CT pulmonary images.
Abstract: The purpose of this study is to develop a technique for computer-aided diagnosis (CAD) systems to detect lung nodules in helical X-ray pulmonary computed tomography (CT) images. The authors propose a novel template-matching technique based on a genetic algorithm (GA) template matching (GATM) for detecting nodules existing within the lung area; the GA was used to determine the target position in the observed image efficiently and to select an adequate template image from several reference patterns for quick template matching. In addition, a conventional template matching was employed to detect nodules existing on the lung wall area, lung wall template matching (LWTM), where semicircular models were used as reference patterns; the semicircular models were rotated according to the angle of the target point on the contour of the lung wall. After initial detecting candidates using the two template-matching methods, the authors extracted a total of 13 feature values and used them to eliminate false-positive findings. Twenty clinical cases involving a total of 557 sectional images were used in this study. 71 nodules out of 98 were correctly detected by the authors' scheme (i.e., a detection rate of about 72%), with the number of false positives at approximately 1.1/sectional image. The authors' present results show that their scheme can be regarded as a technique for CAD systems to detect nodules in helical CT pulmonary images.

Journal ArticleDOI
TL;DR: Evidence is presented that AHK4 and its homologues (AHK3 and possibly AHK2) are receptor kinases that can transduce cytokinin signals across the plasma membrane of A. thaliana.
Abstract: Common histidine-to-aspartate (His-->Asp) phosphorelay is a paradigm of signal transduction in both prokaryotes and eukaryotes for the propagation of certain environmental stimuli, in which histidine (His)-kinases play central roles as sensors for environmental signals. For the higher plant, Arabidopsis thaliana, it was recently suggested that the His-kinase (AHK4 / CRE1 / WOL) is a sensor for cytokinins, which are a class of plant hormones important for the regulation of cell division and differentiation. Interestingly, AHK4 is capable of functioning as a cytokinin sensor in the eubacterium, Escherichia coli (Suzuki et al. 2001, Plant Cell Physiol. 42: 107). Here we further show that AHK4 is a primary receptor that directly binds a variety of natural and synthetic cytokinins (e.g. not only N(6)-substituted aminopurines such as isopentenyl-adenine, trans-zeatin, benzyl-adenine, but also diphenylurea derivatives such as thidiazuron), in a highly specific manner (K(d) = 4.55+/-0.48x10(-9) M). AHK4 has a presumed extracellular domain, within which a single amino acid substitution (Thr-301 to Ile) was shown to result in loss of its ability to bind cytokinins. This particular mutation corresponds to the previously reported wol allele (wooden leg) that causes a striking phenotype defective in vascular morphogenesis. Collectively, evidence is presented that AHK4 and its homologues (AHK3 and possibly AHK2) are receptor kinases that can transduce cytokinin signals across the plasma membrane of A. thaliana.

Journal ArticleDOI
TL;DR: The molecular cloning and biochemical identification of IPTs from Arabidopsis thaliana indicate that the small multigene family contains both types of isopentenyltransferase, which could synthesize cytokinin and mature tRNA.

Journal ArticleDOI
TL;DR: In this article, a plasmoid-induced reconnection model for solar corona was proposed, which is an extension of the classical two-ribbon-flare model referred to as the CSHKP model.
Abstract: As a key to understanding the basic mechanism for fast reconnection in solar flares, plasmoid-induced-reconnection and fractal reconnection are proposed and examined. We first briefly summarize recent solar observations that give us hints on the role of plasmoid (flux rope) ejections in flare energy release. We then discuss the plasmoid-induced-reconnection model, which is an extention of the classical two-ribbon-flare model which we refer to as the CSHKP model. An essential ingredient of the new model is the formation and ejection of a plasmoid which play an essential role in the storage of magnetic energy (by inhibiting reconnection) and the induction of a strong inflow into reconnection region. Using a simple analytical model, we show that the plasmoid ejection and acceleration are closely coupled with the reconnection process, leading to a nonlinear instability for the whole dynamics that determines the macroscopic reconnection rate uniquely. Next we show that the current sheet tends to have a fractal structure via the following process path: tearing ⇒ sheet thinning ⇒ Sweet-Parker sheet ⇒ secondary tearing ⇒ further sheet thinning ⇒ ⋯. These processes occur repeatedly at smaller scales until a microscopic plasma scale (either the ion Larmor radius or the ion inertial length) is reached where anomalous resistivity or collisionless reconnection can occur. The current sheet eventually has a fractal structure with many plasmoids (magnetic islands) of different sizes. When these plasmoids are ejected out of the current sheets, fast reconnection occurs at various different scales in a highly time dependent manner. Finally, a scenario is presented for fast reconnection in the solar corona on the basis of above plasmoid-induced-reconnection in a fractal current sheet.

Journal ArticleDOI
TL;DR: The in vitro water proton relaxivity of Gd-fullerenols is significantly higher (20-folds) than that of the commercial MRI contrast agent, Magnevist (gadolinium-diethylenetriaminepentaacetic acid,Gd-DTPA) at 1.0 T close to the common field of clinical MRI.

Journal ArticleDOI
TL;DR: The signaling pathways activated by GDNF or mutant RET are being extensively investigated to understand the molecular mechanisms of disease development and the physiological roles of the GDNF family ligands.

Journal ArticleDOI
TL;DR: The DONUT experiment has analyzed 203 neutrino interactions recorded in nuclear emulsion targets as discussed by the authors, with an estimated background of 0.34 events, consistent with the Standard Model expectation.

Journal ArticleDOI
Eiji Yashima1
TL;DR: A review of polysaccharide-based chiral stationary phases (CSPs) for the direct separation of enantiomers in high-performance liquid chromatography (HPLC) is presented in this article.

Journal ArticleDOI
TL;DR: The results suggest that AS2 and AS1 might be involved in establishment of a prominent midvein and of networks of other veins as well as in the formation of the symmetric leaf lamina, which might be related to repression of class 1 knox homeobox genes in leaves.
Abstract: The asymmetric leaves2 (as2) mutant of Arabidopsis thaliana generated leaf lobes and leaflet-like structures from the petioles of leaves in a bilaterally asymmetric manner. Both the delayed formation of the primary vein and the asymmetric formation of secondary veins were apparent in leaf primordia of as2 plants. A distinct midvein, which is the thickest vein and is located in the longitudinal center of the leaf lamina of wild-type plants, was often rudimentary even in mature as2 leaves. However, several parallel veins of very similar thickness were evident in such leaves. The complexity of venation patterns in all leaf-like organs of as2 plants was reduced. The malformed veins were visible before the development of asymmetry of the leaf lamina and were maintained in mature as2 leaves. In vitro culture on phytohormone-free medium of leaf sections from as2 mutants and from the asymmetric leaves1 (as1) mutant, which has a phenotype similar to that of as2, revealed an elevated potential in both cases for regeneration of shoots from leaf cells. Analysis by the reverse transcription-polymerase chain reaction showed that transcripts of the KNAT1, KNAT2 and KNAT6 (a recently identified member of the class 1 knox family) genes accumulated in the leaves of both as2 and as1 plants but not of wild type. Transcripts of the STM gene also accumulated in as1 leaves. These findings suggest that, in leaves, the AS2 and AS1 genes repress the expression of these homeobox genes, which are thought to maintain the indeterminate cell state in the shoot apical meristem. Taken together, our results suggest that AS2 and AS1 might be involved in establishment of a prominent midvein and of networks of other veins as well as in the formation of the symmetric leaf lamina, which might be related to repression of class 1 knox homeobox genes in leaves.

Journal ArticleDOI
TL;DR: In this article, a double-hyperfragment event has been found in a hybrid-emulsion experiment, which is identified uniquely as the sequential decay of ${}_{\ensuremath{\Lambda}ensureMath{-}0.11}+0.18}\phantom{\rule{0ex}{0ex}}
Abstract: A double-hyperfragment event has been found in a hybrid-emulsion experiment. It is identified uniquely as the sequential decay of ${}_{\ensuremath{\Lambda}\ensuremath{\Lambda}}^{6}\mathrm{He}$ emitted from a ${\ensuremath{\Xi}}^{\ensuremath{-}}$ hyperon nuclear capture at rest. The mass of ${}_{\ensuremath{\Lambda}\ensuremath{\Lambda}}^{6}\mathrm{He}$ and the $\ensuremath{\Lambda}\ensuremath{-}\ensuremath{\Lambda}$ interaction energy $\ensuremath{\Delta}{B}_{\ensuremath{\Lambda}\ensuremath{\Lambda}}$ have been measured for the first time devoid of the ambiguities due to the possibilities of excited states. The value of $\ensuremath{\Delta}{B}_{\ensuremath{\Lambda}\ensuremath{\Lambda}}$ is $1.01\ifmmode\pm\else\textpm\fi{}{0.20}_{\ensuremath{-}0.11}^{+0.18}\phantom{\rule{0ex}{0ex}}\mathrm{MeV}$. This demonstrates that the $\ensuremath{\Lambda}\ensuremath{-}\ensuremath{\Lambda}$ interaction is weakly attractive.

Journal ArticleDOI
TL;DR: TRAF6 plays essential roles in both the differentiation and maturation of osteoclasts by activating various kinases via its multiple domains under physiological conditions established by appropriate expression of TRAF6 mutants in TRAF 6‐deficient cells.
Abstract: Signals emanating from the receptor for interleukin-1 (IL-1), lipopolysaccharide (LPS) or osteoclast differentiation factor/receptor activator of NF kappa B ligand (ODF/RANKL) stimulate transcription factors AP-1 through mitogen-activated protein kinase (MAPK) activation and NF kappa B through I kappa B kinase (IKK) activation. These kinases are thought to be activated by tumor necrosis factor receptor-associated factor 6 (TRAF6). However, molecular mechanisms by which TRAF6 activates various downstream kinases remain to be elucidated. We identified functional domains of TRAF6 under physiological conditions established by appropriate expression of TRAF6 mutants in TRAF6-deficient cells. In IL-1 and LPS signaling pathways, the RING finger and first zinc finger domains are not required for NF kappa B activation but are required for full activation of MAPK. However, IL-1 and LPS signals utilize distinct regions within the zinc finger domains of TRAF6 to activate NF kappa B. Furthermore, the RING finger domain is not required for differentiation of splenocytes to multinuclear osteoclasts, but is essential for osteoclast maturation. Thus, TRAF6 plays essential roles in both the differentiation and maturation of osteoclasts by activating various kinases via its multiple domains.

Journal ArticleDOI
TL;DR: Following the identification and characterization of regulators and effectors of Rho GTPases, signal transduction pathways from cadherin to RhogTPases and, in turn, from RhoGTPases to Cadherin, are beginning to be clarified.
Abstract: Cell-cell adhesions are rearranged dynamically during tissue development and tumour metastasis. Recently, Rho-family GTPases, including RhoA, Rac1 and Cdc42, have emerged as key regulators of cadherin-mediated cell-cell adhesion. Following the identification and characterization of regulators and effectors of Rho GTPases, signal transduction pathways from cadherin to Rho GTPases and, in turn, from Rho GTPases to cadherin, are beginning to be clarified.

Journal ArticleDOI
TL;DR: Evidence is presented showing that the AHK4 His-kinase has an ability to serve as a cytokinin-responsive environmental sensor in E. coli, and a phosphorelay interaction between the Arabidopsis His- Kinase and histidine-containing phosphotransmitters (AHPs) was demonstrated for the first time.
Abstract: ;His-to-Asp (His Asp) phosphorelay mechanisms are presumably involved in propagation of certain environmental stimuli, including phytohormones, in Arabidopsis thaliana. In addition to the previously characterized Hiskinases, namely, the ETR1 family of ethylene receptors, CKI1 cytokinin-sensor, and ATHK1 osomo-sensor, this higher plant has three more His-kinases (named AHK2, AHK3, and AHK4). By employing the well-known His Asp phosphorelay systems in both the fission yeast and Escherichia coli, evidence is presented showing that the AHK4 His-kinase has an ability to serve as a cytokininresponsive environmental sensor. Taking advantage of this AHK4-dependent His Asp phosphorelay system in E. coli, a phosphorelay interaction between the Arabidopsis Hiskinase and histidine-containing phosphotransmitters (AHPs) was also demonstrated for the first time.

Journal ArticleDOI
15 Jul 2001-Blood
TL;DR: In this paper, 30 patients with chronic active Epstein-Barr virus (CAEBV) infection were analyzed, and they were divided into two clinically distinct groups, based on whether the predominantly infected cells in their peripheral blood were T cells or natural killer (NK) cells.