bluuebunny/crossref_metadata_2025_split huggingface dataset:
Increased Bcl‐2 and Reduced Bax Expression in Infected Macrophages in Slowly Progressive Primary Murine Mycobacterium tuberculosis Infection
Authors: MOGGA S. J. , MUSTAFA T. , SVILAND L. , NILSEN R. 
Published: March 2003

Mycobacterium tuberculosis
(MTB) persists in host macrophages (Mφs) because it has developed mechanisms to escape Mφ killing.
In vitro
studies have shown that MTB can induce and inhibit apoptosis by causing the expression of Bax and Bcl‐2, respectively, suggesting that the infected cells' fate depends on pro‐ and antiapoptotic signals. In the present study, we investigated the role of Bcl‐2 in MTB infection
in situ
. The aim was to study the pattern and distribution of Bcl‐2 and Bax in cellular infiltrates of MTB‐infected B6D2F1 hybrid mice and correlate the expression with the presence of MTB antigens (MAgs). Using formalin‐fixed lung tissues (
n
= 45), our results showed a significant difference in the percentage of Mφs stained for Bcl‐2 or MAgs and Bax (
P  < 0.0001). Bcl‐2 expression was increased in a population of Mφs and corresponded in intensity, colocalization and percentage with that of MAgs on the same cells, while Bax expression was reduced. In lymphocyte aggregates, Bcl‐2 and Bax did not show any differences. We conclude that overexpression of Bcl‐2 in Mφs containing MTB may be associated with intracellular survival of the bacilli, thus demonstrating one way by which MTB can escape the host's cellular response and killing.
Systematics of Hypanartia (Lepidoptera: Nymphalidae: Nymphalinae), with a test for geographical speciation mechanisms in the Andes
Authors: Willmott Keith R. , Hall Jason P. W. , Lamas Gerardo 
Published: March 2003

SummaryA taxonomic review of the Neotropical nymphaline butterfly genusHypanartiaHübner is presented, including notes on the taxonomy, biology and distribution of its component species, illustrations of all taxa and the male genitalia of all species, and the description of four new species and two new subspecies:Hypanartia celestiasp.n.,H. cinderellasp.n.,H. dione disjunctassp.n.,H. fasslisp.n.,H. trimaculatasp.n. andH. trimaculata autumnassp.n.Hypanartia arcaei(Salvin) is placed as a subspecies ofH. dione(Latreille) (stat.n.) and lectotypes are designated for eight nominal taxa. Fourteen species are recognized, with the centre of diversity being in high Andean cloud forest habitats. A cladistic analysis was conducted, based on fifty‐three illustrated characters of male genitalic and abdominal morphology, and external facies, to investigate phylogenetic relationships. The resulting phylogenetic hypothesis was used to test four different geographical mechanisms of speciation in the Andes: colonization from temperate latitudes, speciation across elevational gradients, radiation within the Andes and allopatric speciation between the Andes and other montane regions. There is evidence that speciation across an elevational gradient occurred twice, both times into elevations largely unoccupied by the genus, and in both cases followed by subsequent, elevationally sympatric,in situradiation. Differentiation in allopatry between montane regions has apparently been of recent influence only, causing infraspecific variation in two species. These results parallel several recent studies of Andean bird speciation.
Phylogenetic reassessment of the five forewing  radial‐veined tribes of Riodininae (Lepidoptera: Riodinidae)
Authors: Hall Jason P. W. 
Published: March 2003

Abstract.The relationships among the genera and tribal groupings of Riodininae with five forewing radial veins, and between these and tribes with four forewing radial veins, were examined using a phylogenetic analysis. Using the type species from all sixteen genera in the tribal groupings Eurybiini, Mesosemiini and incertae sedis (a presumed paraphyletic group of loosely related genera), and representatives from the four forewing radial‐veined riodinine tribes, thirty‐five new and traditional characters were coded from adult ecology, wing venation and pattern, the adult head and body, male and female genitalia, and early stage ecology and morphology. The majority of characters are illustrated. Phylogenetic analysis of these data produced five equally most parsimonious cladograms using equal weights and after successive weighting. The strict consensus of these confirms the monophyly of Eurybiini and Mesosemiini as currently conceived, but also indicates several higher‐level relationships not previously hypothesized. Mesosemiini is here more broadly defined to also include the entire incertae sedis section, and the tribe is divided into Mesosemiina, for the previously delimited Mesosemiini plus Eunogyra and Teratophthalma, and Napaeina, subtr.n. for the incertae sedis section minus these two genera. The following hypothesis of relationships is tentatively proposed for the basal clades of Riodininae: Mesosemiini + (Eurybiini + remainder of Riodininae). These new hypotheses, and the characters supporting them, are discussed and compared with those previously proposed.
Repression of the high‐methionine zein gene in the maize inbred line Mo17
Authors: Schickler Hedva , Benner Michael S. , Messing Joachim 
Published: March 2003

SummaryThe methionine content in maize kernels is largely determined by the level of a methionine‐rich 10 kDa protein, encoded by the gene Zps10/(22). In the maize inbred BSSS53 this gene is over‐expressed compared with its normal expression in inbred lines like W64A and W22. This is in part due to the trans‐acting factor Zpr10/(22). However, compared with the normal level of expression, this gene is under‐expressed in the inbred Mo17 and the high‐methionine zein accumulates to very low levels. Therefore, differential expression of this gene between BSSS53 and Mo17 is even larger than in other inbred lines of maize. Repression of 10 kDa zein expression in Mo17 is not due to the translatability of 10 kDa zein mRNA or a cis‐acting mutation in the mRNA and neither is it due to a change in the transcription rate per se. However, steady state levels of mRNA appear to be controlled in trans by narrowing the developmental time frame of mRNA accumulation.
A cotyledon regulatory region is responsible for the different spatial expression patterns of Arabidopsis 2S albumin genes
Authors: Da Silva Conceição Alexandre , Krebbers Enno 
Published: March 2003

SummaryThe 2S albumin genes of Arabidopsis thaliana are a model system to study gene expression during late embryogenesis. The at2S1 gene has previously been shown to be expressed essentially in the embryo axis, unlike at2S2, which is expressed throughout the embryo. Hybrid promoter constructs between at2S1 and at2S2 were introduced into Arabidopsis and used to identify a cotyledon regulatory region necessary for 2S albumin expression in palisade parenchyma and specific epidermal cells. Other promoter sequences flanking this tissue‐specific promoter element were shown to control mRNA expression levels independently of the mRNA distribution throughout the embryos. Certain hybrid promoters resulted in the alteration of the time course of expression in cotyledons. Differential expression of 2S albumin genes is discussed in terms of layered cellular organization and mitotic activity throughout the embryo.
Mutation analysis of the C‐terminal vacuolar targeting peptide of tobacco chitinase: low specificity of the sorting system, and gradual transition between intracellular retention and secretion into the extracellular space
Authors: Neuhaus Jean‐Marc , Pietrzak Maciej , Boller Thomas 
Published: March 2003

SummaryThe C‐terminal propeptide of tobacco (Nicotiana tabacum) chitinase A has been shown to be necessary and sufficient for targeting of chitinases to the plant vacuole. The sequence specificity of this vacuolar targeting peptide (VTP) has now been analysed using transient expression of chitinases in Nicotiana plumbaginifolia protoplasts. An extracellular cucumber chitinase, previously used as a secreted reporter protein in transgenic tobacco, was also secreted into the incubation medium by the transiently transformed protoplasts. Addition of six to seven amino acids at the C‐terminus to generate the VTP of tobacco chitinase A were sufficient to cause retention of most of the cucumber chitinase within the protoplasts. The chitinase A itself, as well as a mutant lacking the N‐terminal chitin‐binding domain, were retained to 80% in the protoplasts when low concentrations of the plasmid were used in the transient expression system. At high concentrations of plasmid, causing high levels of transiently expressed chitinase, retention was reduced, indicating saturation of the sorting system. Deletion of the C‐terminal methionine did not affect the intracellular location, but deletion of even a single internal amino acid of the VTP caused predominantly secretion of tobacco chitinase A. In contrast, exchanges of amino acids in the VTP as well as substitution of the VTP with random sequences had intermediary effects that covered the whole range from retention to secretion. The results suggest that the sorting system responsible for the diversion of secretory proteins to the vacuole has a low specificity for the sequence of C‐terminal targeting peptides, and that sequence changes in the VTP allow a gradual transition from vacuolar retention to secretion.
Binding of BiP to an assembly‐defective protein in plant cells
Authors: Pedrazzini Emanuela , Giovinazzo Giovanna , Bollini Roberto , Ceriotti Aldo , Vitale Alessandro 
Published: March 2003

SummaryThe binding protein (BiP) has been implicated as a mediator of protein folding and assembly in the endoplasmic reticulum of mammalian cells and has often been found in stable association with structurally defective proteins. To acquire information on the activity of BiP in plant cells, we have expressed in tobacco protoplasts the wild type form and an assembly‐defective form of bean phaseolin. Phaseolin (PHSL) is a soluble, trimeric, storage glycoprotein co‐translationally inserted into the lumen of the endoplasmic reticulum and then transported along the secretory pathway to the protein storage vacuoles. We have previously shown that a PHSL mutant in which the last 59 amino acids have been deleted (Δ363PHSL) is unable to form trimers and is retained in a pre‐Golgi compartment when synthesized in Xenopus oocytes. When transiently expressed in tobacco leaf protoplasts, wild‐type PHSL is correctly glycosylated and assembles efficiently and rapidly into trimers. Δ363PHSL is also correctly glycosylated but does not trimerize. Tobacco BiP and Δ363PHSL are co‐immunoselected using either anti‐PHSL or anti‐BiP antibodies. Under the same conditions, co‐immunoselection of BiP with wild‐type PHSL is not detectable. The BiP bound to Δ363PHSL can be released by treatment of the complex with ATP, indicating that the binding is related to the proposed function of BiP in protein folding and assembly in the endoplasmic reticulum. These data indicate that BiP stably binds structurally defective proteins in plant cells.
A NaCl‐regulated plant gene encoding a brain protein homolog that activates ADP ribosyltransferase and inhibits protein kinase C
Authors: Chen Zutang , Fu Haian , Liu Dong , Chang Pi‐Fang Linda , Narasimhan Meena , Ferl Robert , Hasegawa Paul M. , Bressan Ray A. 
Published: March 2003

SummaryA cDNA clone pCZ1, with a 1.1 kb insert, was isolated from a NaCI‐adapted tobacco cell cDNA library that encodes an apparently full‐length 29 kDa protein (251 amino acids) with a calculated pl of 5.7. The encoded peptide had a high amino acid sequence identity with bovine 14‐3‐3 protein which was originally found as an abundant protein in the animal central nervous system. Recently, proteins with sequence identity to 14‐3‐3 protein have also been found in plants, insects and yeast, and appear to have diverse physiological functions. Similar to the bovine brain 14‐3‐3 protein, the recombinant pCZ1 protein stimulated ADP‐ribosylation of protein substrate by ADP‐ribosyl‐transferase from the plant and animal pathogenic bacterium Pseudomonas aeruginosa. This recombinant protein also inhibited protein kinase C activity in vitro. Southern blot analyses indicated that most likely five genes encoding 14‐3‐3‐like proteins are present in tobacco. The pCZ1 cDNA insert hybridized to a single mRNA of 1.1 kb from cultured tobacco cells. The level of this mRNA transcript in tobacco cells was downregulated upon adaptation to NaCl but was unaffected by short‐term treatment with NaCl, ABA or ethylene. In tobacco plants, expression of transcript that hybridized to pCZ1 was tissue specific, and was most abundant in roots and flower parts. Monoclonal antibody raised against GF14 protein, a maize protein with substantial sequence identity with 14‐3‐3 protein detected two bands on SDS‐PAGE of total proteins from unadapted tobacco cells and only a single band from cells adapted to NaCl. The GF14 antibody was also used to illustrate that the G‐box element of a salt‐induced gene is associated with a 14‐3‐3‐type protein.
Molecular characterization of two Brassica napus genes related to oleosins which are highly expressed in the tapetum
Authors: Robert Laurian S. , Gerster Jean , Allard Sharon , Cass Leslie , Simmonds John 
Published: March 2003

SummaryTwo highly homologous Brassica napus flower cDNA clones, Sta 41‐2 and Sta 41‐9, were isolated and characterized. These clones were shown to correspond to genes expressed in the tapetum from the early uninucleate microspore stage to the dinucleate stage. The predicted Sta 41‐2 and Sta 41‐9 proteins possessed characteristics similar to oleosins such as a polar N‐terminal domain, a large relatively conserved hydrophobic domain and a long C‐terminal domain which consisted of four different groups of repeats. In addition, like oleosins, the Sta 41‐2 and Sta 41‐9 proteins have a basic pl, lack a signal peptide and are found in a tissue which accumulates lipids in small lipid bodies.
Genetic transformation of the C4 plant, Flaveria bidentis
Authors: Chitty Julie A. , Furbank Robert T. , Marshall Jerry S. , Chen Zhenghua , Taylor William C. 
Published: March 2003

SummaryAn efficient and rapid transformation system for the dicotyledonous C4 plant, Flaveria bidentis has been developed. The method involves Agrobacterium tumefaciens infection of explants followed by regeneration of shoots from kanamycin‐resistant callus. Shoots first appear on callus 3–4 weeks after Agrobacterium infection, with plants in soil after another 12–15 weeks. Transformation has been verified by measuring the activity of the gusA and npt‐II transgenes and by genomic Southern blots to show the stable integration of T‐DNA. Most regenerated plants show normal morphology, are self‐fertile and transgenes show expected Mendelian segregations in the next generation. This system allows one to test a number of gene constructions rapidly and should accelerate progress in studies of the cell‐specific expression of genes coding for C4 enzymes and the mechanisms regulating the activities of C4 enzymes.
Jasmonate‐induced lipoxygenase forms are localized in chloroplasts of barley leaves (Hordeum vulgare cv. Salome)
Authors: Feussner Ivo , Hause Bettina , Vörös Kirsten , Parthier Benno , Wasternack Claus 
Published: March 2003

Barley leaves respond to application of (−)‐jasmonic acid (JA), or its methylester (JM) with the synthesis of abundant proteins, so‐called jasmonate induced proteins (JIPs). Here Western blot analysis is used to show a remarkable increase upon JM treatment of a 100 kDa lipoxygenase (LOX), and the appearance of two new LOX forms of 98 and 92 kDa. The temporal increase of LOX‐100 protein upon JM treatment was clearly distinguishable from the additionally detectable LOX forms. JM‐induced LOX forms in barley leaves were compared with those of Arabidopsis and soybean leaves. Both dicot species showed a similar increase of one LOX upon JM induction, whereas, leaves from soybean responded with additional synthesis of a newly formed LOX of 94 kDa.Using immunofluorescence analysis and isolation of intact chloroplasts, it is demonstrated that JM‐induced LOX forms of barley leaves are exclusively located in the chloroplasts of all chloroplast‐containing cells. Analogous experiments carried out with Arabidopsis and soybean revealed a similar plastidic location of JM‐induced LOX forms in Arabidopsis but a different situation for soybean. In untreated soybean leaves the LOX protein was mainly restricted to vacuoles of paraveinal mesophyll cells. Additionally, LOX forms could be detected in cytoplasm and nuclei of bundle sheath cells. Upon JM treatment cytosolic LOX was detectable in spongy mesophyll cells, too. The intracellular location of JM‐induced LOX is discussed in terms of stress‐related phenomena mediated by JM.
Genetic regulation of gibberellin deactivation in Pisum
Authors: Ross John J. , Reid James B. , Swain Stephen M. , Hasan Omar , Poole Andrew T. , Hedden Peter , Willis Christine L. 
Published: March 2003

SummaryThe regulation of gibberellin (GA) deactivation was examined using the sin (slender) mutation in the garden pea (Pisum sativum L.). This mutation blocks the deactivation of GA20, the precursor of the bioactive GA1. Firstly, crosses were made to combine sin with the GA biosynthesis mutations na, lhi and le‐3. The combination sin na produced a novel phenotype, with long (‘slender’) basal internodes and extremely short (‘nana’) upper internodes. In contrast, the double mutant sin lhi was phenotypically dwarf. The mutation sin causes an accumulation of GA20 in maturing seeds, and this was unaffected by na, since the na mutation is not expressed in seeds. In contrast, lhi seeds did not accumulate GA20, since lhi imposes an early block on GA biosynthesis. Secondly, the effects of sin on several steps in GA deactivation were investigated. In maturing seeds, the mutation sin blocks two steps in GA20 metabolism, namely, GA20 to GA29, and GA29 to GA29‐catabolite. In the vegetative plant, on the other hand, sin blocked the step GA20 to GA29, but not GA29 to GA29‐catabolite; the steps GA20 to GA81 and GA20 to GA1 were also not impaired in this mutant. It is clear that the effects of sin, like those of na, are strongly organ‐specific. The presence of separate enzymes for the steps GA20 to GA29 and GA29 to GA29‐catabolite was suggested by the observation that GA8 inhibited the latter step, but not the former, and by the inability of GA20 and GA29 to inhibit each other's metabolism. It is suggested that the Sin gene may be a regulatory gene controlling the expression of two structural genes involved in GA deactivation.
ABA‐induced ion efflux in stomatal guard cells: multiple actions of ABA inside and outside the cell
Authors: MacRobbie E.A.C. 
Published: March 2003

SummaryAbscisic acid (ABA) induces a transient stimulation of 86Rb+ efflux from isolated guard cells of Commelina communis L. The form of the efflux transients produced in suboptimal conditions (low concentrations of ABA and/or high external pH at which ABA will penetrate poorly) has been compared with the full transient. In suboptimal conditions the stimulation of efflux is both delayed and reduced. The pH‐dependence of the delay before initiation of the efflux transient suggests that a threshold internal concentration of ABA is required. However in suboptimal conditions even when the threshold internal concentration is reached and a transient is triggered, the degree of stimulation is reduced, an effect which also appears to depend on internal ABA. It is suggested that the differences reflect activation of different numbers of tonoplast ion channels for release of vacuolar ions. By contrast, the same end‐state seems to be reached in optimal and suboptimal conditions, but after different times. The relative efflux stimulation during the efflux transient tracks the declining ion content; both the peak and the end of the transient are reached at the same ion content, but at different times. It is suggested that this reflects an ABA‐induced change in the set‐point of a regulated ion channel which is sensitive to ion content, perhaps a stretch‐activated channel. This effect is independent of external concentration in the range 0.1–10 µM, and pH 6 and pH 8 are equally effective, suggesting an external site of action. Thus the results suggest multiple actions of ABA, involving both internal and external receptors. Regulation of both tonoplast ion channels by internal ABA, and of a regulated channel responsive to ion content by external ABA are suggested.
Subunit E of the vacuolar H+‐ATPase of Hordeum vulgare L.: cDNA cloning, expression and immunological analysis†
Authors: Dietz Karl‐Josef , Rudloff Susanne , Ageorges Agnès , Eckerskorn Christoph , Fischer Karsten , Arbinger Bettina 
Published: March 2003

SummaryA tonoplast protein of 31 kDa apparent molecular mass (TpP 31) was isolated from two‐dimensional gels. Amino acid sequences were determined from LysC endoproteinase‐peptide fragments. Using degenerate oligonucleotides, a corresponding cDNA clone of 1034 bp was isolated from a barley leaf cDNA library. It encodes for subunit E of the vacuolar H+‐ATPase, the first one identified in plants so far. The open reading frame extends over 681 bp, encoding a gene product of 227 amino acids and a calculated molecular weight of 26 228 g mol−1. Northern and Western blot analysis indicates constitutive expression of subunit E in all plant organs with only small effects of salt stress. Localization of TpP 31 at the tonoplast was confirmed in fractions of purified vacuolar membrane obtained by free‐flow electrophoresis. Immunoprecipitation of newly synthesized 35S‐labelled membrane proteins with anti‐TpP 31 gave two additional bands with apparent molecular masses of about 53 and 62 kDa. Gel filtration after mild solubilization showed co‐purification of TpP 31 with the 55 kDa subunit of the H+‐ATPase. Both results provide evidence beyond the sequence homology that TpP 31 is a structural component of the vacuolar H+‐ATPase.
The distribution of a spliceosome protein in cereal (Triticeae) interphase nuclei from cells with different metabolic activities and through the cell cycle
Authors: Glyn M.C.P. , Leitch A.R. 
Published: March 2003

SummaryA monoclonal antibody (mAb) KSm2 and three human Sm sere, which detect the ‘D’ polypeptide in mammals and is associated with the U1, U2, U4/U6, U5, U7, U9–U12 small nuclear RNAs, have been used in Western blotting to show that the antigen is conserved in wheat (Triticum aestivum cv. Beaver). Immunocytochemistry to wheat and a barley (Hordeum vulgare) suspension culture using the mAb KSm2 has shown that the ‘D’ polypeptide occurs in interphase nuclei as speckles and foci outside the nucleoli and as tracks. Nucleoli usually had at least one focus at their periphery. Immunocytochemistry at the electron microscope level of resolution has shown that the signal occurs between chromatin axes and predominantly in the outer domain of the nucleus. Analysis of the barley suspension culture demonstrated that there was a significant increase in antigen through G1, S to G2. In the wheat meristematic cells at prophase only the foci remained, and at metaphase the distribution of foci was asymmetrical with foci occurring either at one pole or on the metaphase plate. At telophase the foci appeared to decrease in size and were incorporated non‐uniformly into the daughter nuclei because of their asymmetric distribution at metaphase. When wheat was grown at a range of temperatures, the root tip meristematic nuclei showed a number of different organization patterns. The average number of nucleoli increased and their size decreased. At the same time there was an increase in the average total area of foci as temperature increased from 4°, 10°, 25°, 34°, to 37°C. Thus the ‘D’ polypeptide distribution changes with metabolic activity and through the cell cycle.