bluuebunny/crossref_metadata_2025 huggingface dataset:
Cloning and characterization of a root specific high‐affinity sulfate transporter from Arabidopsis thaliana
Authors: Vidmar Joseph John , Tagmount Abderrahmane , Cathala Nicole , Touraine Bruno , Davidian Jean-Claude Eugène
Published: July 2002

Hst1At (accession number AB018695) was identified from the Arabidopsis thaliana sequencing project on BAC T3F12, and the corresponding cDNA was isolated by reverse transcription‐PCR. Southern blot analysis reveals a single copy of this gene. The cDNA encodes a root specific sulfate transporter of 649 amino acids. Heterologous expression of hst1At in a sulfate transport deficient yeast mutant shows that this gene encodes a high‐affinity transport system (∼2 μM). The transcript relative abundance increases in roots in response to sulfate deprivation, which correlated with increased root SO4
2− influx capacity. These patterns were reversed upon sulfate addition to the medium and were accompanied by an increased glutathione level in roots. Feeding plants with cysteine or glutathione led to similar responses. Using buthionine sulfoximine, an inhibitor of glutathione synthesis, we show that glutathione rather than cysteine controls hst1At expression.
Retinol binding protein expression is induced in HepG2 cells by zinc deficiency
Authors: Satre Michael A. , Jessen Katayoun Alavi , Clegg Michael S. , Keen Carl L.
Published: July 2002

Zinc (Zn) deficiency is often associated with low plasma vitamin A (retinol) concentrations. It has been suggested that the reduction in plasma retinol is secondary to reduced liver retinol binding protein (RBP) synthesis. In the present study, RBP expression was determined in HepG2 cells cultured in either Zn adequate media or chelated media containing varying concentrations of Zn. Levels of RBP mRNA increased in a time‐ and Zn concentration‐dependent manner such that 0.5 μM Zn‐treated cells exhibited a >7.5‐fold increase while cells treated with 15 μM Zn were increased 2.9‐fold at 72 h compared to controls. RBP protein also progressively increased by 72 h to levels >8‐fold and 3‐fold higher than controls, in 0.5 μM and 15 μM Zn‐treated cells, respectively. The increase in RBP occurred without any change in DNA concentration between groups through 72 h. The Zn deficiency‐induced elevations in RBP transcript levels could be reversed within 24–48 h of repletion in Zn adequate media. Thus, the reductions in plasma retinol observed in Zn deficiency are in part a direct consequence of the deficiency.
Direct interaction of soluble human recombinant tau protein with Aβ 1–42 results in tau aggregation and hyperphosphorylation by tau protein kinase II
Authors: Rank Kenneth B , Pauley Adele M , Bhattacharya Keshab , Wang Zhigang , Evans David B , Fleck Timothy J , Johnston Jennifer A , Sharma Satish K
Published: July 2002

We report here that aggregated β‐amyloid (Aβ) 1–42 promotes tau aggregation in vitro in a dose‐dependent manner. When Aβ‐mediated aggregated tau was used as a substrate for tau protein kinase II (TPK II), an 8‐fold increase in the rate of TPK II‐mediated tau phosphorylation was observed. The extent of TPK II‐dependent tau phosphorylation increased as a function of time and Aβ 1–42 concentration, and hyperphosphorylated tau was found to be decorated with an Alzheimer's disease‐related phosphoepitope (P‐Thr‐231). In HEK 293 cells co‐expressing CT‐100 amyloid precursor protein and tau, the release of Aβ 1–42 from these cells was impaired. Taken together, these in vitro results suggest that Aβ 1–42 promotes both tau aggregation and hyperphosphorylation.
Accelerated evolution of crotalinae snake venom gland serine proteases
Authors: Deshimaru Masanobu , Ogawa Tomohisa , Nakashima Kin-ichi , Nobuhisa Ikuo , Chijiwa Takahito , Shimohigashi Yasuyuki , Fukumaki Yasuyuki , Niwa Mineo , Yamashina Ikuo , Hattori Shosaku , Ohno Motonori
Published: July 2002

Eight cDNAs encoding serine proteases isolated from Trimeresurus flavoviridis (habu snake) and T. gramineus (green habu snake) venom gland cDNA libraries showed that nonsynonymous nucleotide substitutions have accumulated in the mature protein‐coding regions to cause amino acid changes. Southern blot analysis of T. flavoviridis genomic DNAs using two proper probes indicated that venom gland serine protease genes form a multigene family in the genome. These observations suggest that venom gland serine proteases have diversified their amino acid sequences in an accelerating manner. Since a similar feature has been previously discovered in crotalinae snake venom gland phospholipase A2 (PLA2) isozyme genes, accelerated evolution appears to be universal in plural isozyme families of crotalinae snake venom gland.
Converging antigenic structure of a recombinant viral peptide displayed on different frameworks of carrier proteins
Authors: Carbonell Xavier , Benito Antoni , Villaverde Antonio
Published: July 2002

A peptide reproducing the G‐H loop amino acid sequence of foot‐and‐mouth disease virus VP1 protein was fused to the solvent‐exposed C‐terminus of the bacteriophage P22 tailspike protein [Carbonell and Villaverde (1996) Gene, in press], a homotrimeric polypeptide with a strong β‐helical structure. This fusion does not interfere with the biological activities of the phage tail. The antigenic profile of the complex antigenic site A within the G‐H loop has been determined by competitive ELISA with a panel of monoclonal antibodies directed against different overlapping B‐cell epitopes. The antigenic data have been compared with those obtained with a set of 12 chimeric β‐galactosidases displaying the G‐H loop on different exposed regions. A high coincidence has been evidenced between the antigenicity of the viral peptide fused to the phage protein and that of some peptides inserted in an exposed loop of the activating interface of β‐galactosidase. This indicates that completely different structural frameworks of carrier proteins can provide similar constraints that allow the recombinant peptide to successfully mimic the antigenicity, and probably conformational features, of the natural peptide on the virion surface.
Site‐specific introduction of an electroactive label into a non‐electroactive enzyme (β‐lactamase I)
Authors: Di Gleria K , Halliwell C.M , Jacob C , Hill H.A.O
Published: July 2002

A cysteine residue was introduced close to the active site of β‐lactamase I by site‐directed mutagenesis to replace tyrosine‐105 and was subsequently modified with an electroactive SH‐specific reagent, N‐(2‐ferrocene‐ethyl)maleimide. The resulting modified enzyme became electroactive, showing good quasi‐reversible electrochemistry which was characteristic of the attached ferrocene moiety while retaining its specific enzymatic activity. In the presence of a suicide substrate, 6β‐iodopenicillanic acid, the redox potential shifted +20 mV suggesting that the label was sensitive to changes in the active site of the enzyme.
The effects of spermine and spermidine on the structure of photosystem II proteins in relation to inhibition of electron transport
Authors: Bograh A , Gingras Y , Tajmir-Riahi H.A , Carpentier R
Published: July 2002

Polyamines (PAs) are ubiquitous in cells of higher plants and play an important role in many biological functions. Because PAs affect photosynthetic oxygen evolution, this study is designed to investigate the interaction of spermine (Spm) and spermidine (Spd) cations with proteins of photosystem II (PSII) using PSII‐enriched submembranes fraction with polyamine concentrations of 0.01–10 mM. Fourier transform infrared (FTIR) difference spectroscopy with its self‐deconvolution and second derivative resolution enhancement as well as curve‐fitting procedures was applied, in order to determine the cation binding mode, the protein conformational changes and the structural properties of cation‐protein complexes. It is shown that at low polyamine concentration, cation‐protein interaction (H‐bonding) is through the polypeptide CO groups with no major perturbation of the protein secondary structure. As cation concentration increases, the polyamine complexation causes significant alterations of the protein secondary structure with a decrease of the α‐helical domains from 47% (uncomplexed PSII) up to 37% (cation complexes) and an increase in the β‐sheet structure from 18% (uncomplexed PSII) up to 29% (cation complexes). Correlations between the effects of polyamines on protein secondary structure and on the rate of oxygen evolution in PSII are also established.
The Caenorhabditis elegans death protein Ced‐4 contains a motif with similarity to the mammalian ‘death effector domain’
Authors: Bauer Manuel K.A , Wesselborg Sebastian , Schulze-Osthoff Klaus
Published: July 2002

In the nematode Caenorhabditis elegans apoptosis is tightly regulated by a hierarchical set of genes. Two of these, ced‐3 and ced‐9, possess mammalian homologues encoding executional ICE proteases and inhibitory Bcl‐2‐related proteins, respectively. The function of a third key player, ced‐4, is however completely unknown and no mammalian counterparts have been identified. Here we report that Ced‐4 protein contains a structural region with similarity to the mammalian death effector domain which has previously been demonstrated to act as an important protein interaction motif in the signaling pathway of the mammalian surface receptor Fas (APO‐1, CD95). Based on this finding and previously described genetic experiments, we propose that Ced‐4, similar to the mammalian proteins FADD and FLICE, may possess a function as an adaptor protein in invertebrate apoptotic pathways.
Proton release from water oxidation by photosystem II: similar stoichiometries are stabilized in thylakoids and PSII core particles by glycerol
Authors: Haumann M , Hundelt M , Jahns P , Chroni S , Bögershausen O , Ghanotakis D , Junge W
Published: July 2002

During the four‐stepped catalytic cycle of water oxidation by photosystem II (PSII) molecular oxygen is released in only one of the four reaction steps whereas the release of four protons is distributed over all steps. In principle, the pattern of proton production could be taken as indicative of the partial reactions with bound water. In thylakoids the extent and rate of proton release varies as function of the redox transition and of the pH without concomitant variations of the redox pattern. The variation has allowed to discriminate between deprotonation events of peripheral amino acids (Bohr effects) as opposed to the chemical deprotonation of a particular redox cofactor, and of water. In contrast, in thylakoids grown under intermittent light, as well as in PSII core particles the pattern of proton release is flat and independent of the pH. This has been attributed to the lack in these materials of the chlorophyll a,b‐binding (CAB) proteins. We now found that a thylakoid‐like, oscillatory pattern of proton release was restored simply by the addition of glycerol which modifies the protein–protein interaction. Being a further proof for the electrostatic origin of the greater portion of proton release, this effect will serve as an important tool in further studies of water oxidation.
Transferred nuclear Overhauser effect spectroscopy study of a peptide from the PapG pilus subunit bound by the Escherichia coli PapD chaperone
Authors: Walse Björn , Kihlberg Jan , Flemmer Karlsson Katarina , Mikael Nilsson  , Wahlund Karl-Gustav , Pinkner Jerome S , Hultgren Scott J , Drakenberg Torbjörn
Published: July 2002

Interaction of the Escherichia coli PapD chaperone with the synthetic peptide PapG308‐314 (Thr–Met–Val–Leu–Ser–Phe–Pro), corresponding to the seven C‐terminal residues of the PapG pilus subunit, was studied by transferred nuclear Overhauser effect (TRNOE) spectroscopy. The observation of cross‐peaks corresponding to either intraresidue or sequential CαH/NH and CβH/NH TRNOEs and the absence of sequential NHi/NHi+1 TRNOEs indicate that the peptide binds to PapD in an extended conformation. In addition, line‐broadening effects gave information of the peptide's mode of interaction with PapD. These observations were in excellent agreement with a recent crystal structure of a PapG peptide complexed with PapD.
Insulin receptor‐deficient cells as a new tool for dissecting complex interplay in insulin and insulin‐like growth factors
Authors: Lamothe B , Baudry A , Christoffersen C.T , De Meyts P , Jami J , Bucchini D , Joshi R.L
Published: July 2002

Cell systems derived from knockout mice for the insulin receptor (IR) or the IGF‐1 receptor (IGF‐1R) represent unique tools for dissecting complex interplay in the actions of insulin and insulin‐like growth factors through their cognate versus non‐cognate receptor. In this study, we used a fibroblast cell line derived from IR‐deficient mice to investigate metabolic and mitogenic effects of IGF‐1 and insulin. IGF‐1 was able to stimulate glucose uptake, glucose incorporation into glycogen and thymidine incorporation in such cells. Phosphatidylinositol 3‐kinase and mitogen‐activated protein kinase, two enzymes of major metabolic‐mitogenic signaling pathways, were activated upon stimulating these cells with IGF‐1. All these effects were also achieved when IR‐deficient cells were stimulated with insulin. Thus, IGF‐1R can represent an alternative receptor through which insulin might exert some of its effects.
Overexpression of hMTH1 mRNA: a molecular marker of oxidative stress in lung cancer cells
Authors: Kennedy Christopher H , Cueto Rafael , Belinsky Steven A , Lechner John F , Pryor William A
Published: July 2002

Human MutT homologue (hMTH1) mRNA was overexpressed in SV‐40‐transformed non‐tumorigenic human bronchial epithelial cells (BEAS‐2B cells) and in 11 out of 12 human lung cancer cell lines relative to normal human bronchial epithelial cells. Expression levels of hMTH1 mRNA were inversely proportional to cellular levels of 8‐oxo‐deoxyguanosine. Together, these results suggest that hMTH1 gene expression may represent a molecular marker of oxidative stress that could ultimately be used to elucidate the temporal relationships between oxidative stress, genomic instability and the development of lung cancer.
Transport of apically but not basolaterally internalized ricin to the Golgi apparatus is stimulated by 8‐Br‐cAMP in MDCK cells
Authors: Llorente Alicia , van Deurs Bo , Sandvig Kirsten
Published: July 2002

The plant toxin ricin has to be transported to the Golgi apparatus after endocytosis to exert its toxic effect. In this study we show that transport of apically endocytosed ricin to the Golgi apparatus is stimulated by 8‐Br‐cAMP in polarized MDCK cells. This stimulation is counteracted by the PKA inhibitor H‐89. In contrast, there is no increase in the transport to the Golgi apparatus of ricin internalized from the basolateral membrane. These results suggest that protein kinase A selectively regulates endosome to Golgi transport in these cells.
Effects of peroxynitrite on plasma components of the reverse cholesterol transport pathway
Authors: Graham Annette , Vinogradov Dimitri V , Owen James S
Published: July 2002

Elimination of cholesterol from arterial tissue, crucial in limiting atherogenesis, may be achieved via high‐density lipoprotein (HDL)‐mediated reverse cholesterol transport (RCT); components of this pathway can be modulated by oxidative stress. Here we have examined the relations between cholesterol efflux, esterification and transfer in human plasma treated with the powerfully reactive nitrogen species, peroxynitrite. Cellular cholesterol efflux to whole plasma, or to peroxynitrite‐modified HDL3, was relatively insensitive to peroxynitrite, as was the transfer of esterified cholesterol. However, plasma cholesterol esterification, via lecithin:cholesterol acyltransferase (LCAT), was markedly inhibited, both directly and indirectly, by peroxynitrite treatment, implying inefficient RCT follows HDL sequestration of cellular cholesterol.
Evidence for a leukotriene A4 hydrolase in Xenopus laevis skin exudate
Authors: Clamagirand Christine , Cadel Sandrine , Barre Nicole , Cohen Paul
Published: July 2002

Leukotriene A4 hydrolase is a cytosolic metalloenzyme of the arachidonic acid biosynthetic pathway responsible for leukotriene A4 conversion into leukotriene B4. In addition to its epoxide hydrolase properties, this enzyme exhibits an aminopeptidase activity which was used as an assay to monitor the purification of a novel form of leukotriene A4 hydrolase from Xenopus laevis skin exudate. This 70 kDa, secreted, form of leukotriene A4 hydrolase was identified by immunochemical cross‐reactivity with anti‐human leukotriene A4 hydrolase antibodies and by its capacity to convert leukotriene A4 into leukotriene B4. Moreover this enzyme produced a second metabolite which could be the leukotriene B4 isomer 5S,12R‐dihydroxy‐6,10‐trans‐8,14‐cis‐eicosatetraenoic acid, previously shown by Strömberg et al. (Eur. J. Biochem. 238 (1996) 599–605) to be formed by incubation of the leukotriene A4 with amphibian tissue extracts. Partial amino acid sequencing of peptides generated by endolysin C fragmentation of the purified enzyme confirmed the presence, in X. laevis skin secretions, of a related but distinct form of leukotriene A4 hydrolase which is likely to be responsible for the production of these eicosanoid metabolites of leukotriene A4.
The extended packaging sequence of MoMLV contains a constitutive mRNA nuclear export function
Authors: King Jason A. , Bridger Joanna M. , Gounari Fotini , Lichter Peter , Schulz Thomas F. , Schirrmacher Volker , Khazaie Khashayarsha
Published: July 2002

The present report shows that incorporation of defined sequences from the Moloney murine leukaemia virus (MoMLV) into Rex dependent expression vectors based on the human T‐cell leukaemia virus (HTLV‐1) allows Rex independent gene expression. Deletion mutagenesis of the MoMLV derived sequences allowed this function to be localised to a 312 nt length sequence overlapping the MoMLV gag p15/p12 open reading frame. This ‘extended packaging sequence’ has been reported to markedly increase the titre of in vitro packaged retroviral vectors. Using fluorescent in situ hybridisation combined with confocal microscopy we show that the 312 nt element can replace Rex mediated nuclear export and expression of transcripts containing HTLV‐1 cis acting repressive elements. Our observations are consistent with the extended packaging sequence of MoMLV exerting a constitutive mRNA nuclear export function.
The peptide HDEF as a new retention signal is necessary and sufficient to direct proteins to the endoplasmic reticulum
Authors: Kaletta Karin , Kunze Irene , Kunze Gotthard , Köck Margret
Published: July 2002

The key feature of tomato RNase LX localised solely outside the vacuole is the C‐terminal peptide HDEF which is very similar to known endoplasmic reticulum (ER) retention signals. For functional testing of the ER‐targeting ability of HDEF, different constructs including the complete RNase LX, two truncated forms without HDEF and the truncated chitinase FB7‐1ΔVTP C‐terminally flanked by HDEF, were expressed in Saccharomyces cerevisiae. The majority of RNase and chitinase, both containing HDEF, accumulates within the ER. However, the truncated constructs without the peptide are released into the medium. We provide compelling evidence that peptide HDEF at the C‐terminus of secretory plant proteins is a new ER retention signal in yeast and most likely in plants.
Knocking out a specific tRNA species within unfractionated Escherichia coli tRNA by using antisense (complementary) oligodeoxyribonucleotides
Authors: Kanda Takayuki , Takai Kazuyuki , Yokoyama Shigeyuki , Takaku Hiroshi
Published: July 2002

Methods for the preparation of an Escherichia coli tRNA mixture lacking one or a few specific tRNA species can be the basis for future applications of cell‐free protein synthesis. We demonstrate here that virtually a single tRNA species in a crude E. coli tRNA mixture can be knocked out by an antisense (complementary) oligodeoxyribonucleotide. One out of five oligomers complementary to tRNAAsp blocked the aspartylation almost completely, while minimally affecting the aminoacylation with other 13 amino acids tested. This ‘knockout' tRNA behaved similarly to the untreated tRNA in a cell‐free translation of an mRNA lacking Asp codons.
Mutations at specific atp6 codons which cause human mitochondrial diseases also lead to male sterility in a plant
Authors: Kempken Frank , Howad Werner , Pring Daryl R.
Published: July 2002

Defects in the human mitochondrial genetic system result in some diseases. These disorders are the result of rearrangements or point mutations in mitochondrial genes. In higher plants mutations and rearrangements in the mitochondrial DNA are believed to cause cytoplasmic male sterility (CMS), a mitochondrially inherited inability to produce viable pollen. In sorghum, formation of CMS is strongly correlated with anther‐specific loss of mitochondrial atp6 RNA editing. Here we show that this loss of atp6 RNA editing mimics point mutations at codons that cause severe disorders in humans. We conclude that (i) loss of RNA editing in sorghum anthers probably causes CMS, (ii) similarities exist in the onset of mitochondrial dysfunction in plant and human tissues, and (iii) the evolutionary appearance of RNA editing provided a mechanism to compensate for otherwise lethal point mutations.
Lipoprotein (a) stimulates mitogen activated protein kinase in human mesangial cells
Authors: Mondorf Ulrich F. , Piiper Albrecht , Herrero Martina , Bender Michael , Scheuermann Ernst H. , Geiger Helmut
Published: July 2002

Evidence suggests an important role of elevated serum lipoproteins in the progression of renal glomerulosclerosis. We report here that lipoprotein (a) (Lp(a)) increased phosphorylation and activity of mitogen activated protein kinase (MAPK) in human mesangial cells. When protein kinase C (PKC) was depleted by long‐term incubation with the phorbol 12‐O‐myristate 13‐acetate the effect of Lp(a) on MAPK activation was completely inhibited. Forskolin, a stimulator of the adenylyl cyclase, and dibutyryl‐cAMP reduced the effect of Lp(a) on MAPK phosphorylation and activation. We conclude that Lp(a) stimulates the MAPK cascade via activation of PKC and that activation of protein kinase A counteracts Lp(a) induced MAPK activation in human mesangial cells.
Impact of 9‐(2‐phosphonylmethoxyethyl)adenine on (deoxy)ribonucleotide metabolism and nucleic acid synthesis in tumor cells
Authors: Hatse Sigrid , De Clercq Erik , Balzarini Jan
Published: July 2002

Following exposure to 9‐(2‐phosphonylmethoxyethyl)adenine (an inhibitor of the cellular DNA polymerases α, δ and ϵ), human erythroleukemia K562, human T‐lymphoid CEM and murine leukemia L1210 cells markedly accumulated in the S phase of the cell cycle. In contrast to DNA replication, RNA synthesis (transcription) and protein synthesis (mRNA translation) were not affected by 9‐(2‐phosphonylmethoxyethyl)adenine. The ribonucleoside triphosphate pools were slightly elevated, while the intracellular levels of all four deoxyribonucleoside triphosphates were 1.5–4‐fold increased in 9‐(2‐phosphonylmethoxyethyl)adenine‐treated K562, CEM and L1210 cells. The effect of 9‐(2‐phosphonylmethoxyethyl)adenine on de novo (thymidylate synthase‐mediated) and salvage (thymidine kinase‐mediated) dTTP synthesis was investigated using radiolabelled nucleoside precursors. The amount of thymidylate synthase‐derived dTTP in the acid soluble pool was 2–4‐fold higher in PMEA‐treated than in untreated K562 cells, which is in accord with the 3–4‐fold expansion of the global dTTP level in the presence of 9‐(2‐phosphonylmethoxyethyl)adenine. Strikingly, 2‐derived dTTP accumulated to a much higher extent (i.e. 16–40‐fold) in the soluble dTTP pool upon 9‐(2‐phosphonylmethoxyethyl)adenine treatment. In keeping with this finding, a markedly increased thymidine kinase activity could be demonstrated in extracts of 9‐(2‐phosphonylmethoxyethyl)adenine‐treated K562 cell cultures. Also, in the presence of 200 μM 9‐(2‐phosphonylmethoxyethyl)adenine, 14‐fold less thymidylate synthase‐derived but only 3‐fold less thymidine kinase‐derived dTTP was incorporated into the DNA of the K562 cells. These data show that thymidine incorporation may be inappropriate as a cell proliferation marker in the presence of DNA synthesis inhibitors such as 9‐(2‐phosphonylmethoxyethyl)adenine. Our findings indicate that 9‐(2‐phosphonylmethoxyethyl)adenine causes a peculiar pattern of (deoxy)ribonucleotide metabolism deregulation in drug‐treated tumor cells, as a result of the metabolic block imposed by the drug on the S phase of the cell cycle.
Cyclooxygenase‐dependent signalling: molecular events and consequences
Authors: Versteeg Henri H , van Bergen en Henegouwen Paul M.P , van Deventer Sander J.H , Peppelenbosch Maikel P
Published: July 2002

Non‐steroidal anti‐inflammatory drugs (NSAIDs) currently attract large interest. Next to pain relief, NSAIDs have important anti‐thrombotic and anti‐oncogenic effects. NSAIDs exert their action by inhibition of cyclooxygenase, the enzyme responsible for the production of prostanoids. Prostanoid signal transduction is still poorly understood, but it has become clear that these inflammatory lipids influence cellular physiology at three different levels: (1) activation of a 7× transmembrane receptor coupled to heterotrimeric G proteins, (2) the inhibition of inflammation by activating corticosteroid‐like receptors, (3) participation in receptor protein tyrosine kinase signal transduction. In this review prostanoid signalling at these three different levels will be reviewed and the relevance in (patho)physiological processes will be evaluated.
Transcriptional activation of the human S100A2 promoter by wild‐type p53
Authors: Tan Mingjia , Heizmann Claus W. , Guan Kunliang , Schafer Beat W. , Sun Yi
Published: July 2002

S100A2, a calcium binding protein of the EF‐hand family, was recently identified to be inducible by etoposide, a p53 activator. A potential p53 binding site was identified in the promoter of the S100A2 gene, which binds to purified p53 as well as p53 in nuclear extract activated by etoposide. Transactivation assays using the promoter driven luciferase reporters revealed that the S100A2 promoter was transcriptionally activated by wild‐type p53, but not by p53 mutants, in a dose‐dependent as well as a p53 binding site‐dependent manner. The p53‐induced transactivation of the S100A2 promoter was enhanced by etoposide and blocked by a dominant negative p53 mutant. Furthermore, endogenous S100A2 mRNA expression is induced by etoposide in p53 positive, but not in p53 negative cells. Thus, p53 appears to positively regulate S100A2 expression.
Angiopoietin‐1 is an apoptosis survival factor for endothelial cells
Authors: Kwak Hee Jin , So June-No , Lee Song Jae , Kim Injune , Koh Gou Young
Published: July 2002

We examined the effect of angiopoietin‐1 (Ang1) on apoptosis in human umbilical vein endothelial cells (HUVECs). Ang1 (5–1000 ng/ml) dose‐dependently inhibited apoptosis under a serum‐deprived state. A significant apoptotic inhibition occurred with as low as 50 ng/ml. Two hundred ng/ml of Ang1 inhibited to approximately 50% of the control apoptotic rates for 96 h. Furthermore, an augmented antiapoptotic effect of Ang1 by the addition of 20 ng/ml vascular endothelial growth factor was observed. This Ang1‐induced strong antiapoptotic effect in endothelial cells is a novel and intriguing finding and could be an additional description of Ang1‐induced direct biological function.
Spin‐trapping agent α‐phenyl N‐tert‐butylnitrone binds to trypsin and enhances heparin‐induced inhibition of amidolytic activity and structural degradation of the enzyme
Authors: Finotti Paola , Corvaja Carlo , Pagetta Andrea
Published: July 2002

The effects of heparin on trypsin have recently been demonstrated to involve inhibition of catalytic activity and degradation of the enzyme by means of an oxidative mechanism. The possibility that α‐phenyl N‐tert‐butylnitrone protects heparin‐induced radical formation on trypsin was investigated by measuring amidolytic activity and changes in the structure of trypsin in the presence of heparin with and without α‐phenyl N‐tert‐butylnitrone. The results show that α‐phenyl N‐tert‐butylnitrone does not only prevent, but it even significantly enhances effects of heparin on the enzyme. This is due to the unique property of α‐phenyl N‐tert‐butylnitrone, independently of spin‐trapping capacity, to modify the trypsin structure by binding irreversibly to the catalytic triad, at sites distinct from those to which heparin binds.
Differential discrimination of G‐protein coupling of serotonin1A receptors from bovine hippocampus by an agonist and an antagonist
Authors: Harikumar K.G , Chattopadhyay Amitabha
Published: July 2002

We have studied the effect of guanosine‐5′‐O‐(3‐thiotriphosphate) (GTP‐γ‐S), a non‐hydrolyzable analogue of GTP, on agonist and antagonist binding to bovine hippocampal 5‐hydroxytryptamine (5‐HT)1A receptor in native membranes. Our results show that the specific binding of the agonist is inhibited with increasing concentrations of GTP‐γ‐S along with a reduction in binding affinity. In sharp contrast to this, antagonist binding to 5‐HT1A receptor shows no significant reduction and remains invariant over a large range of GTP‐γ‐S concentrations. The binding affinity of the antagonist also remains unaltered. This shows that the agonist and the antagonist differentially discriminate G‐protein coupling of 5‐HT1A receptors from bovine hippocampus.
Dissociation of the eukaryotic initiation factor‐4E/4E‐BP1 complex involves phosphorylation of 4E‐BP1 by an mTOR‐associated kinase
Authors: Heesom Kate J , Denton Richard M
Published: July 2002

mTOR immunoprecipitates contain two 4E‐BP1 protein kinase activities. One appears to be due to mTOR itself and results in the phosphorylation of 4E‐BP1 on residues T36 and T45, as shown previously by others. The other is a kinase which can be separated from mTOR and which phosphorylates 4E‐BP1 within a peptide(s) containing residues S64 and T69. This phosphorylation, which occurs predominantly on S64, results in the dissociation of 4E‐BP1 from eIF‐4E.
Synthetic peptides identify the minimal substrate requirements of tubulin polyglutamylase in side chain elongation
Authors: Westermann Stefan , Plessmann Uwe , Weber Klaus
Published: July 2002

The minimal sequence requirement of Crithidia tubulin polyglutamylase is already fulfilled by tubulin‐related peptides carrying a free α‐carboxylate on a glutamic acid residue. Since the product of each glutamylation step fulfills the substrate requirements necessary for the next cycle, very long side chains are generated with brain tubulin as a substrate. Up to 70 mol of glutamic acid was incorporated per αβ‐heterodimer. We speculate that the strict choice of a particular glutamate residue for the formation of the isopeptide bond initiating a novel side chain is made by a tubulin monoglutamylase which requires the entire tubulin as substrate.
Cysteine‐scanning mutagenesis around transmembrane segment VI of Tn10‐encoded metal‐tetracycline/H+ antiporter
Authors: Konishi Satoko , Iwaki Shinobu , Kimura-Someya Tomomi , Yamaguchi Akihito
Published: July 2002

Each amino acid in putative transmembrane helix VI and its flanking regions, from Ser‐156 to Thr‐185, of a Cys‐free mutant of the Tn10‐encoded metal‐tetracycline/H+ antiporter (TetA(B)) was individually replaced by Cys. All of the cysteine‐scanning mutants showed a normal level of tetracycline resistance except for the S156C mutant, which showed moderate resistance, indicating that there is no essential residue located in this region. All 20 mutants from S159C to W178C showed no reactivity with N‐ethylmaleimide (NEM), whereas the mutants of the flanking regions from S156C to H158C and F179C to T185C were highly or moderately reactive with NEM. These results indicate that like transmembrane helices III and IX, the transmembrane helix VI comprising residues Ser‐159–Trp‐178 is totally embedded in the hydrophobic environment.
Structural and functional modularity of voltage‐gated potassium channels
Authors: Patten Craig D. , Caprini Marco , Planells-Cases Rosa , Montal Mauricio
Published: July 2002

Sequence similarity among known potassium channels indicates the voltage‐gated potassium channels consist of two modules: the N‐terminal portion of the channel up to and including transmembrane segment S4, called in this paper the ‘sensor’ module, and the C‐terminal portion from transmembrane segment S5 onwards, called the ‘pore’ module. We investigated the functional role of these modules by constructing chimeric channels which combine the ‘sensor’ from one native voltage‐gated channel, mKv1.1, with the ‘pore’ from another, Shaker H4, and vice versa. Functional studies of the wild type and chimeric channels show that these modules can operate outside their native context. Each channel has a unique conductance–voltage relation. Channels incorporating the mKv1.1 sensor module have similar rates of activation while channels having the Shaker pore module show similar rates of deactivation. This observation suggests the mKv1.1 sensor module limits activation and the Shaker pore module determines deactivation. We propose a model that explains the observed equilibrium and kinetic properties of the chimeric constructs in terms of the characteristics of the native modules and a novel type of intrasubunit cooperativity. The properties ascribed to the modules are the same whether the modules function in their native context or have been assembled into a chimera.
Thymosin β4 serves as a glutaminyl substrate of transglutaminase. Labeling with fluorescent dansylcadaverine does not abolish interaction with G‐actin1
Authors: Huff Thomas , Ballweber Edda , Humeny Andreas , Bonk Thomas , Becker Cord-Michael , Müller Christian S.G. , Mannherz Hans Georg , Hannappel Ewald
Published: July 2002

Thymosin β4 possesses actin‐sequestering activity and, like transglutaminases, is supposed to be involved in cellular events like angiogenesis, blood coagulation, apoptosis and wound healing. Thymosin β4 serves as a specific glutaminyl substrate for transglutaminase and can be fluorescently labeled with dansylcadaverine. Two (Gln‐23 and Gln‐36) of the three glutamine residues were mainly involved in the transglutaminase reaction, while the third glutaminyl residue (Gln‐39) was derivatized with a low efficiency. Labeled derivatives were able to inhibit polymerization of G‐actin and could be cross‐linked to G‐actin by 1‐ethyl‐3‐[3‐(dimethylamino)propyl]carbodiimide. Fluorescently labeled thymosin β4 may serve as a useful tool for further investigations in cell biology. Thymosin β4 could provide a specific glutaminyl substrate for transglutaminase in vivo, because of the fast reaction observed in vitro occurring at thymosin β4 concentrations which are found inside cells. Taking these data together, it is tempting to speculate that thymosin β4 may serve as a glutaminyl substrate for transglutaminases in vivo and play an important role in transglutaminase‐related processes.
Molecular cloning and characterization of the Arabidopsis thaliana α‐subunit of elongation factor 1B
Authors: Héricourt François , Jupin Isabelle
Published: July 2002

Using a PCR‐based approach, we have isolated two Arabidopsis thaliana cDNA clones (α1 and α2) encoding the α‐subunit of translation elongation factor 1B (eEF1Bα). They encode open reading frames of 228 and 224 amino acids respectively, with extensive homology to eEF1Bα subunits from different organisms, particularly in the C‐terminal half of the protein. They both lack a conserved phosphorylation site that has been implicated in regulating nucleotide exchange activity. Using a plasmid shuffling experiment, we demonstrated that both α1 and α2 clones are able to complement a mutant yeast strain deficient for the eEF1Bα subunit. This provides evidence that Arabidopsis encodes at least two functional isoforms of this subunit, termed eEF1Bα1 and eEF1Bα2. A third cDNA clone was isolated that appeared to result from an alternative splicing event of the eEF1Bα1 gene.
Reappraisal of the association between the DRD2 gene, alcoholism and addiction
Authors: Gorwood P. , Batel P. , Gouya L. , Courtois F. , Feingold J. , Adès J.
Published: July 2002

We analysed the impact of the TaqI A1 allele of the D2 dopamine receptor gene on the risk for alcoholism, trying to depict three explanations frequently proposed to explain discrepancies in association and linkage studies: that the A1 allele may act as a marker rather than as a vulnerability factor, that stratification biases and unevaluated controls may explain positive results, and that the A1 allele is modifying the phenotype rather than increasing the risk for alcoholism. We thus tested another (dinucleotide STRP) marker within the DRD2 gene, selected a new homogenous sample of 113 alcoholic patients and 49 unaffected controls strictly matched for ethnic origins, and systematically assessed both samples with a semi-structured interview to detect (in both samples) alcohol dependence, but also such related traits as specificities of complications.

The frequency of the A1 allele was not significantly different between alcoholics and controls but when comparing different subgroups of alcoholics, the A1 allele was significantly more frequent in alcoholic patients with somatic complications (OR = 3.00, CI[1.37-6.62]), social and professional complications (OR=2.72, CI[1.25-5.90]), or with co-morbid dependence (OR = 2.88, 95% IC [1.16-7.15]). The association for co-morbid dependence and somatic complications was also positive when taking into consideration both STRP and TaqIA polymorphisms.

The A1 allele does not increase the risk for alcoholism per se in our sample, but may be involved in a related trait which is partially dependent on the diagnosis of alcoholism, through a disequilibrium with another close mutation.
EXCERPTS FROM A CNM'S JOURNAL: KOSOVO, WINTER 2000
Authors: Hammes Barbara
Published: July 2002

Diary excerpts chronicle the experiences of a nurse‐midwife on assignment in Kosovo with Doctors of the World, USA, during the winter of 2000.
NURSE‐MIDWIVES' KNOWLEDGE AND PROMOTION OF LACTATIONAL AMENORRHEA AND OTHER NATURAL FAMILY‐PLANNING METHODS FOR CHILD SPACING
Authors: Fehring Richard J. , Hanson Lisa , Stanford Joseph B.
Published: July 2002

The purpose of this study was to describe and assess certified nurse‐midwives' (CNMs) knowledge and promotion of two modalities for child spacing, natural family‐planning (NFP) and the lactational amenorrhea method (LAM). One thousand two hundred CNMs were randomly selected from a national membership list and mailed a 24‐item questionnaire on NFP and LAM. Of the 514 respondents (42.8% return rate), 450 (87.5%) were currently practicing as CNMs. Respondents had an average age of 46 years, with an average of 10 years of practice. CNMs ranked NFP as the ninth most used and the eighth most effective family‐planning method in their practice, with an average perceived method‐effectiveness of 88% and use‐effectiveness of 70%. Although most respondents felt somewhat prepared during their education program to provide NFP, only 22% would offer NFP as a family‐planning option for child spacing.
Clinical features of homozygous FIG4‐p.Ile41Thr Charcot‐Marie‐Tooth 4J patients
Authors: Lafontaine Maxime , Lia Anne‐Sophie , Bourthoumieu Sylvie , Beauvais‐Dzugan Hélène , Derouault Paco , Arné‐Bes Marie‐Christine , Sarret Catherine , Laffargue Fanny , Magot Armelle , Sturtz Franck , Magy Laurent , Magdelaine Corinne
Published: January 2021

We describe the clinical, electrodiagnostic, and genetic findings of three homozygous FIG4‐c.122T>C patients suffering from Charcot‐Marie‐Tooth disease type 4J (AR‐CMT‐FIG4). This syndrome usually involves compound heterozygosity associating FIG4‐c.122T>C, a hypomorphic allele coding an unstable FIG4‐p.Ile41Thr protein, and a null allele. While the compound heterozygous patients presenting with early onset usually show rapid progression, the homozygous patients described here show the signs of relative clinical stability. As FIG4 activity is known to be dose dependent, these patients’ observations could suggest that the therapeutic perspective of increasing levels of the protein to improve the phenotype of AR‐CMT‐FIG4‐patients might be efficient.
In silico mechanically mediated atom transfer radical polymerization: A detailed kinetic study
Authors: Liu Jie , Wang Tian‐Tian , Luo Zheng‐Hong , Zhou Yin‐Ning
Published: January 2021

Mechanically mediated atom transfer radical polymerization (mechanoATRP) utilizing ultrasound to generate activators and improve the diffusivity of macromolecular chains is introduced as an innovative externally controlled ATRP. Herein, a comprehensive kinetic model with free volume theory based “series” encounter pair model accounting for diffusional limitations on termination, activation, and deactivation is developed for the mechanoATRP of methyl acrylate. Comparative study by using different diffusion models, for example, wp model and reduced composite kt model, as well as constant apparent kjapp model confirms the goodness of the as‐developed model. Critically, mechanochemically induced reduction rate coefficient kr,s as a key kinetic parameter is associated with experimental conditions excluding the sonication effect by a fitting equation for the first time. In silico tracking of polymer dispersity with the help of kinetic model shows a better result compared with that by the classical dispersity equation. By defining an ultrasonic factor γj, a qualitative analysis for the effect of ultrasound conditions on the diffusional limitation in mechanoATRP is presented.
α‐tACS over the somatosensory cortex enhances tactile spatial discrimination in healthy subjects with low alpha activity
Authors: Saito Kei , Otsuru Naofumi , Yokota Hirotake , Inukai Yasuto , Miyaguchi Shota , Kojima Sho , Onishi Hideaki
Published: January 2021

Introduction

Spontaneous oscillations in the somatosensory cortex, especially of the alpha (8 − 14 Hz) and gamma (60 − 80 Hz) frequencies, affect tactile perception; moreover, these oscillations can be selectively modulated by frequency‐matched transcranial alternating current stimulation (tACS) on the basis of ongoing oscillatory brain activity. To examine whether tACS can actually improve tactile perception via alpha and gamma modulation, we measured the effects of 10‐Hz and 70‐Hz tACS (α‐ and γ‐tACS) on the left somatosensory cortex on right‐finger tactile spatial orientation discrimination, and the associations between performance changes and individual alpha and gamma activities.

Methods

Fifteen neurologically healthy subjects were recruited into this study. Electroencephalography (EEG) was performed before the first day, to assess the normal alpha‐ and gamma‐activity levels. A grating orientation discrimination task was performed before and during 10‐Hz and 70‐Hz tACS.

Results

The 10‐Hz tACS protocol decreased the grating orientation discrimination threshold, primarily in subjects with low alpha event‐related synchronization (ERS). In contrast, the 70‐Hz tACS had no effect on the grating orientation discrimination threshold.

Conclusions

This study showed that 10‐Hz tACS can improve tactile orientation discrimination in subjects with low alpha activity. Alpha‐frequency tACS may help identify the contributions of these oscillations to other neurophysiological and pathological processes.
Synthesizing data by transferring information in data‐intensive regions to enhance process monitoring performance in data‐scarce region
Authors: Lyu Yuting , Chen Junghui , Song Zhihuan , Zhang Qinghua
Published: January 2021

Sufficient data are necessary for valid process monitoring results. However, modern industrial processes sometimes switch to new modes to meet the changes in market demand. The available data in such a new mode are initially quite scarce and it brings huge obstacles to data‐based model construction. In this paper, a novel data synthesis method based on variational autoencoders is proposed to generate synthetic data for the data‐scarce region. The proposed method utilizes not only the original data in the data‐scarce region but also the data in other data‐intensive regions, which share some common information with the scarce data. To avoid model biases caused by the data imbalance between these regions, a model correction mechanism is also developed. Once the ultimate synthetic data of the data‐scarce region are acquired, they are combined with the original data to establish a local monitoring model. Finally, the effectiveness of the proposed method is demonstrated through a real ammonia synthesis process.
Restrictive vs liberal red blood cell transfusion strategies in patients with acute myocardial infarction and anemia: Rationale and design of the REALITY trial
Authors: Ducrocq Gregory , Calvo Gonzalo , González‐Juanatey José Ramón , Durand‐Zaleski Isabelle , Avendano‐Sola Cristina , Puymirat Etienne , Lemesle Gilles , Arnaiz Joan Albert , Martínez‐Sellés Manuel , Rousseau Alexandra , Cachanado Marine , Vicaut Eric , Silvain Johanne , Karam Carma , Danchin Nicolas , Simon Tabassome , Steg Philippe Gabriel ,   REALITY investigators
Published: January 2021

Background

Anemia is common in patients with acute myocardial infarction (AMI), and is an independent predictor of mortality. The optimal transfusion strategy in these patients is unclear.

Hypothesis

We hypothesized that a “restrictive” transfusion strategy (triggered by hemoglobin ≤8 g/dL) is clinically noninferior to a “liberal” transfusion strategy (triggered by hemoglobin ≤10 g/dL), but is less costly.

Methods

REALITY is an international, randomized, multicenter, open‐label trial comparing a restrictive vs a liberal transfusion strategy in patients with AMI and anemia. The primary outcome is the incremental cost‐effectiveness ratio (ICER) at 30 days, using the primary composite clinical outcome of major adverse cardiovascular events (MACE; comprising all‐cause death, nonfatal stroke, nonfatal recurrent myocardial infarction, or emergency revascularization prompted by ischemia) as the effectiveness criterion. Secondary outcomes include the ICER at 1 year, and MACE (and its components) at 30 days and at 1 year.

Results

The trial aimed to enroll 630 patients. Based on estimated event rates of 11% in the restrictive group and 15% in the liberal group, this number will provide 80% power to demonstrate clinical noninferiority of the restrictive group, with a noninferiority margin corresponding to a relative risk equal to 1.25. The sample size will also provide 80% power to show the cost‐effectiveness of the restrictive strategy at a threshold of €50 000 per quality‐adjusted life year.

Conclusions

REALITY will provide important guidance on the management of patients with AMI and anemia.