bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular Analyses of the Arabidopsis TUBBY-Like Protein Gene Family
Authors: Lai Chia-Ping , Lee Chang-Lung , Chen Po-Hsuan , Wu Shu-Hsing , Yang Chien-Chih , Shaw Jei-Fu 
Published: April 2004

Abstract
In mammals, TUBBY-like proteins play an important role in maintenance and function of neuronal cells during postdifferentiation and development. We have identified a TUBBY-like protein gene family with 11 members in Arabidopsis, named AtTLP1-11. Although seven of the AtTLP genes are located on chromosome I, no local tandem repeats or gene clusters are identified. Except for AtTLP4, reverse transcription-PCR analysis indicates that all these genes are expressed in various organs in 6-week-old Arabidopsis. AtTLP1, 2, 3, 6, 7, 9, 10, and 11 are expressed ubiquitously in all the organs tested, but the expression of AtTLP5 and 8 shows dramatic organ specificity. These 11 family members share 30% to 80% amino acid similarities across their conserved C-terminal tubby domains. Unlike the highly diverse N-terminal region of animal TUBBY-like proteins, all AtTLP members except AtTLP8 contain a conserved F-box domain (51–57 residues). The interaction between AtTLP9 and ASK1 (Arabidopsis Skp1-like 1) is confirmed via yeast (Saccharomyces cerevisiae) two-hybrid assays. Abscisic acid (ABA)-insensitive phenotypes are observed for two independent AtTLP9 mutant lines, whereas transgenic plants overexpressing AtTLP9 are hypersensitive to ABA. These results suggest that AtTLP9 may participate in the ABA signaling pathway.
Identification and Characterization of Respirasomes in Potato Mitochondria
Authors: Eubel Holger , Heinemeyer Jesco , Braun Hans-Peter 
Published: April 2004

Abstract
Plant mitochondria were previously shown to comprise respiratory supercomplexes containing cytochrome c reductase (complex III) and NADH dehydrogenase (complex I) of I1III2 and I2III4 composition. Here we report the discovery of additional supercomplexes in potato (Solanum tuberosum) mitochondria, which are of lower abundance and include cytochrome c oxidase (complex IV). Highly active mitochondria were isolated from potato tubers and stems, solubilized by digitonin, and subsequently analyzed by Blue-native (BN) polyacrylamide gel electrophoresis (PAGE). Visualization of supercomplexes by in-gel activity stains for complex IV revealed five novel supercomplexes of 850, 1,200, 1,850, 2,200, and 3,000 kD in potato tuber mitochondria. These supercomplexes have III2IV1, III2IV2, I1III2IV1, I1III2IV2, and I1III2IV4 compositions as shown by two-dimensional BN/sodium dodecyl sulfate (SDS)-PAGE and BN/BN-PAGE in combination with activity stains for cytochrome c oxidase. Potato stem mitochondria include similar supercomplexes, but complex IV is partially present in a smaller version that lacks the Cox6b protein and possibly other subunits. However, in mitochondria from potato tubers and stems, about 90% of complex IV was present in monomeric form. It was suggested that the I1III2IV4 supercomplex represents a basic unit for respiration in mammalian mitochondria termed respirasome. Respirasomes also occur in potato mitochondria but were of low concentrations under all conditions applied. We speculate that respirasomes are more abundant under in vivo conditions.
Repression of a Novel Isoform of Disproportionating Enzyme (stDPE2) in Potato Leads to Inhibition of Starch Degradation in Leaves But Not Tubers Stored at Low Temperature
Authors: Lloyd James R. , Blennow Andreas , Burhenne Kim , Kossmann Jens 
Published: April 2004

Abstract
A potato (Solanum tuberosum) cDNA encoding an isoform of disproportionating enzyme (stDPE2) was identified in a functional screen in Escherichia coli. The stDPE2 protein was demonstrated to be present in chloroplasts and to accumulate at times of active starch degradation in potato leaves and tubers. Transgenic potato plants were made in which its presence was almost completely eliminated. It could be demonstrated that starch degradation was repressed in leaves of the transgenic plants but that cold-induced sweetening was not affected in tubers stored at 4°C. No evidence could be found for an effect of repression of stDPE2 on starch synthesis. The malto-oligosaccharide content of leaves from the transgenic plants was assessed. It was found that the amounts of malto-oligosaccharides increased in all plants during the dark period and that the transgenic lines accumulated up to 10-fold more than the control. Separation of these malto-oligosaccharides by high-performance anion-exchange chromatography with pulsed-amperometric detection showed that the only one that accumulated in the transgenic plants in comparison with the control was maltose. stDPE2 was purified to apparent homogeneity from potato tuber extracts and could be demonstrated to transfer glucose from maltose to oyster glycogen.
Relationship between the Heat Tolerance of Photosynthesis and the Thermal Stability of Rubisco Activase in Plants from Contrasting Thermal Environments
Authors: Salvucci Michael E. , Crafts-Brandner Steven J. 
Published: April 2004

Abstract
Inhibition of net photosynthesis (Pn) by moderate heat stress has been attributed to an inability of Rubisco activase to maintain Rubisco in an active form. To examine this proposal, the temperature response of Pn, Rubisco activation, chlorophyll fluorescence, and the activities of Rubisco and Rubisco activase were examined in species from contrasting environments. The temperature optimum of Rubisco activation was 10°C higher in the creosote bush (Larrea tridentata) compared with the Antarctic hairgrass (Deschampsia antarctica), resembling the temperature response of Pn. Pn increased markedly with increasing internal CO2 concentration in Antarctic hairgrass and creosote bush plants subjected to moderate heat stress even under nonphotorespiratory conditions. Nonphotochemical quenching of chlorophyll fluorescence, the effective quantum yield of photochemical energy conversion (ΔF/Fm′) and the maximum yield of PSII (Fv/Fm) were more sensitive to temperature in Antarctic hairgrass and two other species endemic to cold regions (i.e. Lysipomia pumila and spinach [Spinacea oleracea]) compared with creosote bush and three species (i.e. jojoba [Simmondsia chinensis], tobacco [Nicotiana tabacum], and cotton [Gossypium hirsutum]) from warm regions. The temperature response of activity and the rate of catalytic inactivation of Rubisco from creosote bush and Antarctic hairgrass were similar, whereas the optimum for ATP hydrolysis and Rubisco activation by recombinant creosote bush, cotton, and tobacco activase was 8°C to 10°C higher than for Antarctic hairgrass and spinach activase. These results support a role for activase in limiting photosynthesis at high temperature.
Salt stress‐induced chloride flux: a study using transgenic Arabidopsis expressing a fluorescent anion probe
Authors: Lorenzen Inken , Aberle Thomas , Plieth Christoph 
Published: April 2004

SummarySalt stress leads to massive accumulation of toxic levels of Na+ and Cl− ions in plants. By using the recombinant fluorescent probe CLOMELEON, we demonstrate passive anion flux under salt stress. Chloride influx is restricted in the presence of divalent cations like Mg2+ and Ca2+, and completely blocked by La3+. The amount but not the rate of the reported chloride uptake is independent from the kind of corresponding permeable cation (K+ versus Na+), external pH and magnitude of osmotic stress. Cl− efflux however seems to involve stretch‐activated transport. From the influence of Ca2+ on reported changes of cytosolic anion concentrations, we speculate that transport mechanisms of Cl− and Na+ might be thermodynamically coupled under saline conditions.
Identification of Botrytis cinerea susceptibility loci in Arabidopsis thaliana
Authors: Denby Katherine J. , Kumar Pavan , Kliebenstein Daniel J. 
Published: April 2004

Summary Botrytis cinerea is a major pathogen of fruit and vegetable crops causing both pre‐ and post‐harvest grey mould. We have analysed 16 Arabidopsis thaliana ecotypes for natural variation in B. cinerea susceptibility. Susceptibility was associated with lower camalexin accumulation, and three ecotypes (Cape Verdi Islands (Cvi‐0), Slavice (Sav‐0) and Kindalville (Kin‐0)) showed differential susceptibility to the two B. cinerea isolates used. Subsequently, to better understand the genetic control of grey mould disease, we assayed the Arabidopsis Landsberg erecta (Ler) × Columbia (Col‐0) recombinant inbred population with the two isolates, and identified multiple small‐to‐medium‐effect quantitative trait loci (QTL) governing susceptibility. Interestingly, the QTL for each isolate are distinct, suggesting that different mechanisms govern defence against these two isolates. Two QTL for each isolate exhibited epistatic interactions with specific allele combinations generating heightened B. cinerea susceptibility.
Expression of rolB in tobacco flowers affects the coordinated processes of anther dehiscence and style elongation
Authors: Cecchetti Valentina , Pomponi Mirella , Altamura Maria Maddalena , Pezzotti Mario , Marsilio Sonia , D’Angeli Simone , Tornielli Giovanni Battista , Costantino Paolo , Cardarelli Maura 
Published: April 2004

SummaryThe effect of auxin on stamen and pistil development in tobacco flowers was investigated by means of the localized expression of rolB (root loci B), an Agrobacterium oncogene that increases auxin sensitivity in a cell‐autonomous fashion. When rolB is driven by the promoter of the meiosis‐specific Arabidopsis gene DMC1 (disrupted meiotic cDNA 1), expression occurs earlier in male than in female developing organs, resulting in a delay in anther dehiscence with respect to normal timing of pistil development. As a consequence of this developmental uncoupling, self‐pollination is prevented in pDMC1:rolB plants. Histological analysis of pDMC1:GFP plants indicates that in tobacco, this promoter is active not only in meiocytes but also in somatic tissues of the anther. In contrast, simultaneous expression of rolB in anther and pistil somatic tissues, achieved by expressing a construct containing rolB under the control of the promoter of the petunia gene FBP7 (floral binding protein 7), results in a concomitant delay of both anther dehiscence and pistil development without affecting self‐pollination of the plants. Analysis of plants harboring the pFBP7:GUS construct shows that in tobacco, this promoter is active not only in the ovules, as described for petunia, but also in pistil and anther somatic tissues involved in the dehiscence program. The delay in anther dehiscence and pistil development could be phenocopied by exogenous application of auxin. Jasmonic acid (JA) could not rescue the delay in anther dehiscence. These results suggest that auxin plays a key role in the timing of anther dehiscence, the dehiscence program is controlled by the somatic tissues of the anther, and auxin also regulates pistil development.
A novel polymorphism in the cytoplasmic region of the human immunoglobulin A Fc receptor gene*
Authors: Jasek M. , Mańczak M. , Sawaryn A. , Obojski A. , Wiśniewski A. , Łuszczek W. , Kuśnierczyk P. 
Published: April 2004

SummaryThe Fc receptor for immunoglobulin A (IgA), FcαRI, is expressed on several types of myeloid cells, and activates them upon ligand binding. However, binding of IgA to the extracellular domain of the receptor requires previous stimulation of the cell by cytokines, and the cytoplasmic tail of FcαRI has been shown to play a role in this. Therefore, polymorphism in this region might affect this process. However, no changes in the amino acid sequence in this region of the FcαRI have so far been reported. Here, we describe for the first time a single nucleotide polymorphism in exon 5 of the immunoglobulin A Fc receptor (FCAR) gene leading to a Ser→Gly substitution at position 248 of the mature FcαRI protein. Prediction of structural features suggests some changes that may affect the function of the protein to some extent. However, the Gly248 variant is quite common (4% homozygotes and 38% heterozygotes) in healthy population, suggesting a weak effect, if any, on function, at least in heterozygotes.
MICA polymorphism in a sample of the São Paulo population, Brazil
Authors: Marin M. L. C. , Savioli C. R. , Yamamoto J. H. , Kalil Jorge , Goldberg A. C. 
Published: April 2004

SummaryThe major histocompatibility complex (MHC) class I chain‐related A (MICA) gene, located near HLA‐B, codes for protein products with structural similarities to those of classical MHC class I genes, but which neither bind β2‐microglobulin nor present peptide. Expressed predominantly on gastrointestinal and tumour epithelial cells, they are stress‐induced and interact with C‐type lectin like receptor (NKG2D) on γδ, αβ CD8+ T cells and natural killer (NK) cells. MICA is highly polymorphic, with 54 extracellular allelic sequences described. We typed 200 healthy subjects in a sample of the São Paulo population by extended polymerase chain reaction–sequence‐specific primers (PCR‐SSP) to characterize the MICA polymorphism and analysed MICA/HLA‐B linkage disequilibrium. The MICA*008 group (g) was predominant (47%), with several HLA‐B associations. Rare combinations MICA*008g‐HLA‐B37, MICA*008g‐B72 and MICA*010‐HLA‐B52 were detected. Given the extent of this polymorphism and its possible relevance for disease association, we determined MICA and HLA‐B alleles in 33 Behçet's patients, in an attempt to clarify the associated genetic marker. Our results showed an increase of MICA*006, but not MICA*009, in the patient group (6/33) compared with controls (3/200) (18.2% vs. 1.5%; Pc = 0.005). Both alleles were always in association with HLA‐B51, suggesting that HLA‐B is indeed the primary susceptibility locus (P = 0.00008) and that MICA*006 may be an additional risk factor.
Lack of association of human chemokine receptor gene polymorphisms CCR2‐64I and CCR5‐Δ32 with autoimmune Addison's disease
Authors: Gambelunghe G. , Ghaderi M. , Gharizadeh B. , Brozzetti A. , Tortoioli C. , Del Sindaco P. , Sanjeevi C. B. , Hjelmström P. , Sirsjö A. , Nyren P. , Santeusanio F. , Falorni A. 
Published: April 2004

SummaryThe attraction of leukocytes to tissues is essential for inflammation and the initiation of the autoimmune reaction. The process is controlled by chemokines, which are chemotactic cytokines. We investigated whether human chemokine receptor gene polymorphisms, namely CCR5‐Δ32 and CCR2‐64I, are associated with susceptibility to autoimmune Addison's disease. Genotyping was performed in 56 patients and 127 healthy controls by a new method using pyrosequencing for CCR2‐64I and by polymerase chain reaction and detecting gel for CCR5‐Δ32. None of the CCR2 or CCR5 alleles was found to be associated, either positively or negatively, with disease risk. Our results indicate that the CCR2‐64I and CCR5‐Δ32 gene polymorphisms do not play a major role in conferring genetic risk for, and/or protection against, autoimmune Addison's disease.
T‐cell receptor BV gene segment polymorphisms in healthy elderly individuals from the south of Brazil
Authors: Peres A. , Hünemeier T. , Da Cruz I. M. , Nardi N. B. , Chies J. A. B. 
Published: April 2004

SummaryThe ageing of the immune system (immunosenescence) is believed to be involved in both morbidity and mortality in elderly humans due to a higher incidence of infections, autoimmune diseases, cancers and other pathological situations. As any specific immune response involves recognition of antigens by T cells, the ability to develop a given immune response is also dependent on the T‐cell repertoire available at a given time point. Different T‐cell receptor beta variable segment (BV) (TCRBV) gene segment alleles have been associated with diseases in various human populations. In the present work we analysed the allelic frequencies of four biallelic polymorphisms in TCRBV gene segments (TCRBV3S1, TCRBV13S5, TCRBV13S6 and TCRBV18) in healthy elderly human subjects (80 years old or more) from the south of Brazil, where life expectancies reach similar levels to those observed in developed countries. Except for allele 2 of the TCRBV13S6 polymorphism, which was more frequent in elderly than in young individuals (P = 0.0105), there were no differences in allele or genotype frequencies between young and elderly individuals. The data suggest that there is no direct correlation between the TCRBV3S1, TCRBV13S5 and TCRBV18 polymorphisms analysed and healthy senescence in this particular group of elderly individuals. The higher frequency of TCRBV13S6 allele 2 in healthy elderly individuals should be confirmed in other samples to establish the significance of this finding.
No significant association between mutations in exons 6 and 8 of the autoimmune regulator (AIRE) gene and inflammatory bowel disease
Authors: Török H.‐P. , Tonenchi L. , Glas J. , Schiemann U. , Folwaczny C. 
Published: April 2004

SummaryVarious autoantibodies have been described in patients with inflammatory bowel disease. The autoimmune regulator (AIRE) functions as a transcription factor in cells responsible for the induction and maintenance of immunological tolerance. In contrast to classic autoimmune disorders, polymorphisms of the AIRE gene are not associated with inflammatory bowel disease, despite the presence of disease‐specific autoantibodies.
Provision of Epstein‐Barr virus‐transformed B‐cell lines in a routine tissue typing laboratory: practicalities and applications
Authors: Bass H. , Walters R. , Darke C. 
Published: April 2004

SummaryA bank of Epstein‐Barr virus (EBV)‐transformed B‐lymphoblastoid cell lines (BCLs) has been established in this laboratory over the last 7 years. Novel, rare and unusual HLA phenotypes were highlighted during routine clinical testing and during typing of volunteer haematopoietic stem cell donors for the Welsh Bone Marrow Donor Registry. The BCLs are routinely used as laboratory reagents, as a source of DNA for reference purposes and for research work. Consenting donors are tested for hepatitis B surface antigens (HBsAg), human immunodeficiency virus (HIV) and hepatitis C virus (HCV) before their B‐lymphocytes are transformed. Strict bio‐identity checks are performed before and after transformation and after each BCL expansion. Each BCL is tested regularly for mycoplasma contamination. A total of 230 blood samples were transformed. One hundred and fifty‐nine sterile samples produced 157 BCLs (98.7% success), while 71 non‐sterile samples produced 50 BCLs (70.4% success), giving an overall success rate of 90.0%. Fifteen of the transformation failures have since been repeated successfully. Factors contributing to the high success rate and reasons for the 23 failed transformations are discussed. The successful development and use of pools of BCLs for HLA antibody screening by flow cytometry are described. Whilst certain training and health and safety issues require close attention, it is clear that EBV transformation of B lymphocytes and/or the use of BCLs is feasible in a routine tissue typing laboratory and that BCLs are a valuable resource. Careful adherence to the methods and procedures detailed here should virtually guarantee successful transformation (98.7%) from good quality, sterile whole blood samples.
The MICA‐A4 triplet repeats polymorphism in the transmembrane region confers additional risk for development of psoriatic arthritis in the Croatian population
Authors: Grubić Z. , Perić P. , Èeèuk‐Jeličić E. , Žunec R. , Štingl K. , Ćurković B. , Kerhin‐Brkljačić V. 
Published: April 2004

SummaryThe aim of this study was to investigate possible differences in the frequencies of alleles at the HLA loci and at microsatellite loci within the HLA region among patients suffering from psoriatic arthritis (PsA) and healthy controls. Fifty‐eight Croatian PsA patients (28 male and 30 female) and 157 healthy unrelated controls were typed for HLA alleles (A, B, Cw and DRB1) by the polymerase chain reaction–sequence‐specific primers (PCR‐SSP) method, while microsatellite alleles (D6S265, D6S273, MHC class I chain‐related gene (MICA) and MIB) were analysed by electrophoresis in an ALFexpress sequencer (Pharmacia Biotech, Uppsala, Sweden). The findings from this study were: (1) the frequencies of B*39 and B*57 were significantly increased in PsA patients; (2) differences in the frequencies of B*13 and B*27 were not statistically significant after correction; (3) the B*0702, B*18, and B*38 alleles were decreased in patients only before correction; (4) none of the alleles at other HLA loci tested were associated with PsA in Croatia; (5) polymorphism at D6S265, D6S273, and MIB microsatellites in patients did not show any statistically significant differences when compared to controls; (6) the increase in the MICA‐A4 allele frequency in PsA patients was independent of the B*39 and B*57 alleles.
A comparative in vitro evaluation of six von Willebrand factor concentrates
Authors: Lethagen S. , Carlson M. , Hillarp A. 
Published: April 2004

Summary.  The efficacy of von Willebrand factor (VWF) concentrates for treatment of von Willebrand disease (VWD) is dependent on their content of VWF and factor VIII (FVIII).Study objectives:  To measure the content and quality of VWF and FVIII in six VWF concentrates: Haemate‐P (Aventis Behring), Immunate (Baxter Bioscience), Koate (Bayer Corp.), 8Y (BPL), Innobrand (LFB) and Facteur Willebrand (LFB).Methods:  The VWF antigen content (VWF:Ag), ristocetin cofactor activity (VWF:RCo), collagen‐binding activity (VWF:CB), VWF multimers with electrophoresis and densitometry, FVIII activity and total protein content.Results:  Specific activity (VWF:RCo/total protein) varied considerably (4.7–129.5 IU mg−1). Activity measures, VWF:RCo and VWF:CB, correlated well, but we found no correlation between any of these and VWF:Ag. The content of high‐molecular weight multimer (HMWM) was normal or close to normal in Haemate‐P, Innobrand and Facteur Willebrand, moderately reduced in Koate and 8Y, and significantly reduced in Immunate. The HMWM content correlated significantly with the VWF:RCo/VWF:Ag ratio. Only Haemate‐P, Innobrand and Facteur Willebrand had VWF:RCo/VWF:Ag ratios >0.7. We found large differences in the content of FVIII and in the FVIII/VWF:RCo ratio. Facteur Willebrand had the lowest (0.02) and Immunate the highest (6.00) ratio.Conclusion:  Treating physicians must be aware of the large differences between different VWF concentrates and the potential clinical implications. Concentrates lacking HMWM are probably less efficient for mucosal bleedings. FVIII is most important for surgical bleedings, but concentrates with high FVIII/VWF‐ratio may induce very high FVIII levels with increased risk of thrombosis. A low FVIII content may be preferable except in case of acute surgery.