bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inositol and Phosphate Regulate
GIT1
Transcription and Glycerophosphoinositol Incorporation in
Saccharomyces cerevisiae
Authors: Almaguer C. , Mantella D. , Perez E. , Patton-Vogt J. 
Published: August 2003

ABSTRACT

Glycerophosphoinositol is produced through deacylation of the essential phospholipid phosphatidylinositol. In
Saccharomyces cerevisiae
, the glycerophosphoinositol produced is excreted from the cell but is recycled for phosphatidylinositol synthesis when inositol is limiting. To be recycled, glycerophosphoinositol enters the cell through the permease encoded by
GIT1
. The transport of exogenous glycerophosphoinositol through Git1p is sufficiently robust to support the growth of an inositol auxotroph (
ino1Δ
). We now report that
S. cerevisiae
also uses exogenous phosphatidylinositol as an inositol source. Evidence suggests that phosphatidylinositol is deacylated to glycerophosphoinositol extracellularly before being transported across the plasma membrane by Git1p. A genetic screen identified Pho86p, which is required for targeting of the major phosphate transporter (Pho84p) to the plasma membrane, as affecting the utilization of phosphatidylinositol and glycerophosphoinositol. Deletion of
PHO86
in an
ino1Δ
strain resulted in faster growth when either phosphatidylinositol or glycerophosphoinositol was supplied as the sole inositol source. The incorporation of radiolabeled glycerophosphoinositol into an
ino1Δ pho86Δ
mutant was higher than that into wild-type,
ino1Δ
, and
pho86Δ
strains. All strains accumulated the most
GIT1
transcript when incubated in media limited for inositol and phosphate in combination. However, the
ino1Δ pho86Δ
mutant accumulated approximately threefold more
GIT1
transcript than did the other strains when incubated in inositol-free media containing either high or low concentrations of P
i
. Deletion of
PHO4
abolished
GIT1
transcription in a wild-type strain. These results indicate that the transport of glycerophosphoinositol by Git1p is regulated by factors affecting both inositol and phosphate availabilities and suggest a regulatory connection between phosphate metabolism and phospholipid metabolism.
A role for Rab27b in NF-E2-dependent pathways of platelet formation
Authors: Tiwari Sanjay , Italiano Joseph E. , Barral Duarte C. , Mules Emilie H. , Novak Edward K. , Swank Richard T. , Seabra Miguel C. , Shivdasani Ramesh A. 
Published: August 2003

AbstractMegakaryocytes release platelets by reorganizing the cytoplasm into proplatelet extensions. Fundamental to this process is the need to coordinate transport of products and organelles in the appropriate abundance to nascent platelets. The importance of the Rab family of small GTPases (guanosine 5′-triphosphatases) in platelet biogenesis is revealed in gunmetal (gm/gm) mice, which show deficient Rab isoprenylation and macrothrombocytopenia with few granules and abnormal megakaryocyte morphology. Although some Rab proteins are implicated in vesicle and organelle transport along microtubules or actin, the role of any Rab protein in platelet biogenesis is unknown. The limited number of Rab proteins with defective membrane association in gm/gm megakaryocytes prominently includes Rab27a and Rab27b. Normal expression of Rab27b is especially increased with terminal megakaryocyte differentiation and dependent on nuclear factor-erythroid 2 (NF-E2), a transcription factor required for thrombopoiesis. Chromatin immunoprecipitation demonstrates recruitment of NF-E2 to the putative Rab27B promoter. Inhibition of endogenous Rab27 function in primary megakaryocytes causes severe quantitative and qualitative defects in proplatelet formation that mimic findings in gm/gm cells. Rab27b localizes to alpha and dense granules in megakaryocytes. These results establish a role for Rab27 in platelet synthesis and suggest that Rab27b in particular may coordinate proplatelet formation with granule transport, possibly by recruiting specific effector pathways.
IL-10-inducible Bcl-3 negatively regulates LPS-induced TNF-α production in macrophages
Authors: Kuwata Hirotaka , Watanabe Yasuyuki , Miyoshi Hiroyuki , Yamamoto Masahiro , Kaisho Tsuneyasu , Takeda Kiyoshi , Akira Shizuo 
Published: August 2003

AbstractInterleukin-10 (IL-10) plays an important role in prevention of chronic inflammation in vivo. However, the molecular mechanism by which IL-10 exerts its anti-inflammatory response is poorly understood. Here, we performed a microarray analysis and identified Bcl-3 as an IL-10-inducible gene in macrophages. Lentiviral vector-mediated expression of Bcl-3 inhibited lipopolysaccharide (LPS)-induced production of tumor necrosis factor α (TNF-α), but not IL-6, in macrophages. In Bcl-3-transduced and IL-10-pretreated macrophages, LPS-induced nuclear translocation of nuclear factor κB (NF-κB) p65 was not impaired. However, DNA binding by NF-κB p50/p65 was profoundly inhibited. Nuclear localization of Bcl-3 was associated with inhibition of LPS-induced TNF-α production. Overexpression of Bcl-3 suppressed activation of the TNF-α promoter, but not the IL-6 promoter. Bcl-3 interacted with NF-κB p50 and was recruited to the TNF-α promoter, but not the IL-6 promoter, indicating that Bcl-3 facilitates p50-mediated inhibition of TNF-α expression. Furthermore, Bcl-3-deficient macrophages showed defective IL-10-mediated suppression of LPS induction of TNF-α, but not IL-6. These findings suggest that IL-10-induced Bcl-3 is required for suppression of TNF-α production in macrophages. (Blood. 2003; 102:4123-4129)
Iron loading and erythrophagocytosis increase ferroportin 1 (FPN1) expression in J774 macrophages
Authors: Knutson Mitchell D. , Vafa Mohammad R. , Haile David J. , Wessling-Resnick Marianne 
Published: August 2003

AbstractThe expression of ferroportin1 (FPN1) in reticuloendothelial macrophages supports the hypothesis that this iron-export protein participates in iron recycling from senescent erythrocytes. To gain insight into FPN1's role in macrophage iron metabolism, we examined the effect of iron status and erythrophagocytosis on FPN1 expression in J774 macrophages. Northern analysis indicated that FPN1 mRNA levels decreased with iron depletion and increased on iron loading. The iron-induced induction of FPN1 mRNA was blocked by actinomycin D, suggesting that transcriptional control was responsible for this effect. After erythrophagocytosis, FPN1 mRNA levels were also up-regulated, increasing 8-fold after 4 hours and returning to basal levels by 16 hours. Western analysis indicated corresponding increases in FPN1 protein levels, with maximal induction after 10 hours. Iron chelation suppressed FPN1 mRNA and protein induction after erythrophagocytosis, suggesting that FPN1 induction results from erythrocyte-derived iron. Comparative Northern analyses of iron-related genes after erythrophagocytosis revealed a 16-fold increase in FPN1 levels after 3 hours, a 10-fold increase in heme oxygenase-1 (HO-1) after 3 hours, a 2-fold increase in natural resistance macrophage-associated protein 1 (Nramp1) levels after 6 hours, but no change in divalent metal ion transporter 1 (DMT1) levels. The rapid and strong induction of FPN1 expression after erythrophagocytosis suggests that FPN1 plays a role in iron recycling. (Blood. 2003;102:4191-4197)
Role of Ras signaling in erythroid differentiation of mouse fetal liver cells: functional analysis by a flow cytometry–based novel culture system
Authors: Zhang Jing , Socolovsky Merav , Gross Alec W. , Lodish Harvey F. 
Published: August 2003

AbstractRas signaling plays an important role in erythropoiesis. Its function has been extensively studied in erythroid and nonerythroid cell lines as well as in primary erythroblasts, but inconclusive results using conventional erythroid colony-forming unit (CFU-E) assays have been obtained concerning the role of Ras signaling in erythroid differentiation. Here we describe a novel culture system that supports terminal fetal liver erythroblast proliferation and differentiation and that closely recapitulates erythroid development in vivo. Erythroid differentiation is monitored step by step and quantitatively by a flow cytometry analysis; this analysis distinguishes CD71 and TER119 double-stained erythroblasts into different stages of differentiation. To study the role of Ras signaling in erythroid differentiation, different H-ras proteins were expressed in CFU-E progenitors and early erythroblasts with the use of a bicistronic retroviral system, and their effects on CFU-E colony formation and erythroid differentiation were analyzed. Only oncogenic H-ras, not dominant-negative H-ras, reduced CFU-E colony formation. Analysis of infected erythroblasts in our newly developed system showed that oncogenic H-ras blocks terminal erythroid differentiation, but not through promoting apoptosis of terminally differentiated erythroid cells. Rather, oncogenic H-ras promotes abnormal proliferation of CFU-E progenitors and early erythroblasts and supports their erythropoietin (Epo)–independent growth.
HTLV-1 Rex is required for viral spread and persistence in vivo but is dispensable for cellular immortalization in vitro
Authors: Ye Jianxin , Silverman Lee , Lairmore Michael D. , Green Patrick L. 
Published: August 2003

Abstract
Human T-cell leukemia virus type 1 (HTLV-1) is associated with leukemia/lymphoma and neurologic disorders. Although the viral transcriptional activator Tax is the critical viral oncoprotein, Rex, which regulates the expression of the viral structural and enzymatic genes, is essential for efficient viral replication. Herein, we investigate the contribution of Rex in HTLV-1 immortalization of primary T cells in vitro and viral survival in an infectious rabbit animal model. A Rex-deficient HTLV-1 (HTLVRex-) was constructed and characterized for viral gene expression, protein production, and immortalization capacity. Cells transiently transfected with the HTLVRex- proviral clone produced low detectable levels of p19 Gag. 729HTLVRex- stable transfectants produced functional Tax, but undetectable levels of Rex or p19 Gag. Coculture of irradiated 729HTLVRex- cells with peripheral blood mononuclear cells (PBMCs) resulted in sustained interleukin-2 (IL-2)-dependent growth of primary T lymphocytes. These cells carried the HTLVRex- genome and expressed tax/rex mRNA but produced no detectable Rex or p19 Gag. Rabbits inoculated with irradiated 729HTLVRex- cells or 729HTLVRex- cells transiently transfected with a Rex cDNA expression plasmid failed to become persistently infected or mount a detectable antibody response to the viral gene products. Together, our results provide the first direct evidence that Rex and its function to modulate viral gene expression and virion production is not required for in vitro immortalization by HTLV-1. However, Rex is critical for efficient infection of cells and persistence in vivo.
Coagulation, inflammation, and apoptosis: different roles for protein S and the protein S–C4b binding protein complex
Authors: Rezende Suely Meireles , Simmonds Rachel Elizabeth , Lane David Anthony 
Published: August 2003

AbstractProtein S (PS) has an established role as an important cofactor to activated protein C (APC) in the degradation of coagulation cofactors Va and VIIIa. This anticoagulant role is evident from the consequences of its deficiency, when there is an increased risk of venous thromboembolism. In human plasma, PS circulates approximately 40% as free PS (FPS) and 60% in complex with C4b-binding protein (C4BP). Formation of this complex results in loss of PS cofactor function, and C4BP can then modulate the anticoagulant activity of APC. It had long been predicted that the complex could act as a bridge between coagulation and inflammation due to the involvement of C4BP in regulating complement activation. This prediction was recently supported by the demonstration of binding of the PS-C4BP complex to apoptotic cells. This review aims to summarize recent findings on the structure and functions of PS, the basis and importance of its deficiency, its interaction with C4BP, and the possible physiologic and pathologic importance of the PS-C4BP interaction.
CD25 expression on donor CD4+ or CD8+ T cells is associated with an increased risk for graft-versus-host disease after HLA-identical stem cell transplantation in humans
Authors: Stanzani Marta , Martins Sergio L. R. , Saliba Rima M. , John Lisa S. St. , Bryan Susan , Couriel Daniel , McMannis John , Champlin Richard E. , Molldrem Jeffrey J. , Komanduri Krishna V. 
Published: August 2003

AbstractGraft-versus-host disease (GVHD) occurs in an unpredictable fashion after 30% to 50% of matched-related transplantations. The presence of increased frequencies of CD4+CD25+ regulatory T cells in donor grafts has been shown to ameliorate GVHD after allogeneic transplantation in murine models. To determine whether a similar relationship exists in humans, we quantitated the coexpression of CD25 on CD4+ and CD8+ T cells within 60 donor grafts infused into matched siblings and examined GVHD incidence in the respective recipients. Recipients in whom GVHD developed received donor grafts containing significantly higher frequencies of CD4+ T cells coexpressing CD25 than those who did not (median, 9.26% vs 2.22%; P = .004). Frequencies of donor graft CD8+ T cells coexpressing CD25 were also higher (0.65% vs 0.14%; P = .002). Furthermore, transplant recipients who received grafts containing fewer CD4+CD25+ and CD8+CD25+ T cells were less likely to acquire acute GVHD, even though these donor-recipient pairs were similar to others with respect to relevant clinical variables. These data suggest that the coexpression of CD4 and CD25 may be insufficient to identify regulatory T cells in humans and that increased frequencies and numbers of CD25+ T cells in donor grafts is associated with GVHD in transplant recipients. (Blood. 2004;103:1140-1146)
Melamine-Bifunctional Metal Complex: Self-Assembly of High Ordered Organic-Inorganic Sandwich Layers via Hydrogen Bonds and π-π Interactions
Authors: Zhang Yugen , Jianmin Li , Nishiura Masayoshi , Imamoto Tsuneo 
Published: August 2003

Abstract
High ordered organic-inorganic sandwich-type supramolecular architecture [Cu(H2NTA)Cl]·2melamine·2H2O (NTA = nitrilotriacetic acid) which was assembled through double hydrogen bond arrangements of melamine-melamine and melamine-inorganic complex and also through π-π stacking is designed and X-ray structure characterized.
Electron Transfer from Zn- Protoporphyrin IX to Ruthenium Ammine Attached at His63 of Reconstituted Cytochrome b562
Authors: Hamachi Itaru , Takashima Hiroshi , Tsukiji Shinya , Shinkai Seiji , Nagamune Teruyuki , Oishi Shigero 
Published: August 2003

Abstract
Site-specific modification of Cytochrome b562 with ruthenium ammine (RuA5) at 63-His was successfully carried out. Electron transfer rate from ZnPP in the heme crevice to Ru(III)A5 coordinated to 63-His on the protein surface was determined by the laser flash photolysis.
2,6-Di-tert-butyl-4-diarylmethylene-2,5-cyclohexadiene-1-thiones. First Isolable Unannelated Thioquinone Methides
Authors: Suzuki Riho , Kurata Hiroyuki , Kawase Takeshi , Oda Masaji 
Published: August 2003

Abstract
Unannelated thioquinone methides were first synthesized as labile but isolable substances with aid of steric protection; they exhibit higher dipolar properties and stronger electron affinity than the corresponding quinone methides.
Excellent Stability of Ruthenium(II) Complex Photosensitizers during Photo-Oxidation of 1,3-Cyclopentadiene
Authors: Suzuki Masahiro , Bartels Oliver , Gerdes Robert , Schneider Gerhard , Wöhrle Dieter , Schulz-Ekloff Günter , Kimura Mutsumi , Hanabusa Kenji , Shirai Hirofusa 
Published: August 2003

Abstract
Tris(2,2′-bipyridine)ruthenium(II) and partially quaternized poly(1-vinylimidazole)-bound ruthenium(II) complexes have excellent stability during the photo-oxidation of 1,3-cyclopentadiene and can be sufficiently and repeatedly used as photosensitizers.
Comparison of Nd-Fe-B Surfaces Treated by Chemical Etching in the Absence and Presence of a Magnetic Field
Authors: Kishioka Shin-ya , Aogaki Ryoichi , Nakagawa Jun 
Published: August 2003

Abstract
The effect of magnetic field on a chemical etching of Nd-Fe-B material for permanent magnets was investigated. During magnetization, the dissolution of the material by etching was increased and the surface became flat compared with that by the etching in the absence of a magnetic field.
Synthesis and Molecular Structures of Novel Isopropyl-substituted Oligosilanes
Authors: Tanaka Ryoji , Unno Masafumi , Matsumoto Hideyuki 
Published: August 2003

Abstract
The cyclotetrasilane [(i-Pr)2Si]4 reacts with K in benzene in the presence of 18-crown-6 to give the 1,4-dipotassio compound K[(i-Pr)2Si]4 K (1). The reaction of 1 with (i-Pr)2SiCl2 and Me3SiCl leads to the formation of the sterically crowded oligosilanes, [(i-Pr)2Si]5 (2) and Me3Si[(i-Pr)2Si]4SiMe3 (3), respectively. The molecular structures of the resulting oligosilanes, 2 and 3, display some unusual features.
Photoinduced Deposition of Size-Controlled Gold Nanoclusters onto the Self-Assembled Monolayer of 1,9-Nonanedithiol
Authors: Sumida Takayuki , Murakoshi Kei , Yanagida Shozo 
Published: August 2003

Abstract
Gold nanoclusters are formed photochemically in organic solvent to give nanometer-scale islands on the self-assembled monolayer (SAM) of 1,9-nonanedithiol. The size and shape are variable by choosing electron-donating organic solvents. In ethanol, the plate-like nanoclusters are produced with layer-by-layer growth to give atomically flat top. The nano-structures are formed in N,N-dimethylformamide to give larger size than those in ethanol under comparable conditions.
Computational Studies on the Reactions of N2O with O(3P) and CO
Authors: Tsuchiya Kentaro , Kamiya Kenshu , Shiina Hiroumi , Oya Masaaki 
Published: August 2003

Abstract
We performed ab initio molecular orbital calculations to derive rate expressions for the reactions of N2O with O(3P) and CO. Major products of the O(3P) + N2O reactions are predicted to be NO + NO. Comparisons of calculated and experimental rate constants indicate good agreement exists with the most recent experimental values.
Synthesis, Crystal Structure and Non-linear Optical Properties of [WSe4{Cu(dppm)}4][ClO4]2·MeCN
Authors: Zhang Qian-Feng , Raj S Shanmuga Sundara , Fun Hoong-Kun , Xin Xin-Quan 
Published: August 2003

Abstract
The reaction of Cu(MeCN)4[ClO4], dppm (bis(diphenylphosphino)methane) and [Et4N]2[WSe4] in DMF-CH2Cl2, affords the cationic cluster [WSe4{Cu(dppm)}4]2+ whose structure was shown by X-ray analysis that four edges of the tetrahedral WSe4 core are bridged by a square arrangement of four Cu(I) atoms with the dppm ligands bridging the edges. The cluster compound exhibits a strong optical limiting effect with threshold of 0.3 J·cm−2.
Origin of π-Facial Diastereoselection in Hydride Reduction of Piperidones. The Importance of Ground-State Effects
Authors: Tomoda Shuji , Senju Takatoshi 
Published: August 2003

Abstract
The exterior frontier orbital extension model (the EFOE Model) strongly suggested that the ground-state conformation (steric effects) and the anisotropic frontier orbital (LUMO) extension over π-faces may be the origin of the π-facial diastereoselection in hydride reductions of substituted piperidones.
Excellent Activity of Ultrafine Co-B Amorphous Alloy Catalyst in Glucose Hydrogenation
Authors: Li Hui , Li Hexing , Wang Weijiang , Deng Jing-Fa 
Published: August 2003

Abstract
The ultrafine Co-B amorphous alloy, doped or undoped with Mo or W, were prepared by chemical reduction with borohydride. Its catalytic performance in liquid phase hydrogenation of glucose to sorbitol has been investigated, which revealed (i)the higher activity than that of crystalline Co and the Ni-based catalysts, and (ii)the promoting effect of Mo and W dopants on the activity.
p-Benzoquinone 2,3,5,6-Tetrakis(diisopropyl phosphonate): A Novel, Highly Bent p-Benzoquinone
Authors: Kobiro Kazuya , Shi Min , Inoue Yoshihisa 
Published: August 2003

Abstract
Multiple introduction of phosphonate groups around the quinone oxygen greatly deforms the p-benzoquinone ring through the steric and electronic repulsion. The repulsion produces not a boat but a chair conformation with a bent angle as large as 17.8°.
Tautomerism of a Nitro Derivative of N-Salicylideneaniline in Crystals
Authors: Ogawa Keiichiro , Fujiwara Toshikatsu 
Published: August 2003

Abstract
X-Ray crystallographic and electronic absorption spectroscopic studies on N-(2-hydroxy-3-nitrobenzylidene)aniline revealed that this compound exists as a mixture of the OH and NH forms with nearly the equal populations in crystals.
Unusual Products of Enamines with [60]Fullerene
Authors: Gao Xiang , Ma Sheng-Lei , Guo Li-Wei , Zhang Dan-Wei , Wu Shi-Hui , Wu Hou-Ming , Li Yong-Jiang 
Published: August 2003

Abstract
Unusual products were isolated from reactions of [60]fullerene with cyclopentenyl or cyclohexenyl pyrrolidine and piperidine. The structures of products were characterized by spectroscopic means. A possible thermoinduced electron-transfer mechanism for the new reaction was proposed.
[2,3]-Wittig Rearrangement Initiated by 1,5-Hydrogen Atom Transfer from an o-Iodophenyl Group on the α-Carbon of Allylic Ethers by Reduction with SmI2
Authors: Kunishima Munetaka , Hioki Kazuhito , Nakata Daisuke , Nogawa Shigenobu , Tani Shohei 
Published: August 2003

Abstract
Intramolecular 1,5-hydrogen atom transfer of an aryl radical generated by reduction of an o-iodophenyl group on the allylic position of allyl ethers by SmI2 regioselectively generates α-allyloxy carbanions, which undergo [2,3]-Wittig rearrangement to afford a substituted 4-phenyl-3-buten-1-ol. The effect of HMPA concentration on distribution of the 1,5-hydrogen transfer giving Wittig rearranged products and hydrogen abstraction giving reductive deiodination products is described.
Formation of a Palladalactone Complex by C–O Bond Cleavage of Diketene Promoted by a Zerovalent Palladium Complex
Authors: Kakino Ryuki , Nagayama Kazuhiro , Kayaki Yoshihito , Shimizu Isao , Yamamoto Akio 
Published: August 2003

Abstract
The reaction of diketene with [Pd(PMe3)2(styrene)] 1 at room temperature gave ([Pd(OCOCH2C=CH2)(PMe3)2]) 2 through cleavage of the C–O bond adjacent to the carbon bearing the exomethylene group. The structure of 2 was fully established by spectroscopic means, elemental analysis and single-crystal X-ray analysis. The reactivity of 2 has been investigated.
Highly Diastereoselective Aldol Synthesis from α-Iodo Ketones in Aqueous Media
Authors: Shibata Ikuya , Kawasaki Masatsugu , Yasuda Makoto , Baba Akio 
Published: August 2003

Abstract
Highly diastereoselective aldol synthesis from α-iodo ketones was promoted under aqueous conditions by a distannane system, (n-Bu3Sn)2, n-Bu2SnF2 and HMPA. Aqueous solutions of acetaldehyde, formaldehyde and pivaraldehyde were applicable to give β-hydroxy ketones effectively.
Microbial 7-OH Epimerisation of Bile Acids
Authors: Dean Mariangela , Fantin Giancarlo , Fogagnolo Marco , Medici Alessandro , Pedrini Paola , Poli Silvia 
Published: August 2003

Abstract
The microbial 7-OH epimerisation of cholic and chenodeoxycholic acids with Xanthomonas maltophilia CBS 827.97 to ursocholic and ursodeoxycholic acids with scarsity of oxygen is described. With normal pressure of oxygen the 7-ketocholic and the 7-ketochenodeoxycholic acids are obtained. No biotransformation is achieved in anaerobic conditions.