bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functional analysis of the Candida albicans ALS1 gene product
Authors: Loza Lucio , Fu Yue , Ibrahim Ashraf S. , Sheppard Donald C. , Filler Scott G. , Edwards John E. 
Published: April 2004

AbstractALS1 encodes a cell surface protein that mediates adherence of Candida albicans to endothelial cells. The predicted Als1p has an N‐terminal region, which contains a signal peptide; a middle region, which contains 20 36‐amino acid tandem repeats; and a C‐terminal region, which contains a glycosylphosphotidylinositol‐anchorage sequence. We used site‐directed mutagenesis to delineate the regions in Als1p required for endothelial cell adherence and cell surface expression of the protein. Mutant alleles of ALS1 containing either deletions or insertions were expressed in the normally non‐adherent Saccharomyces cerevisiae. These transformants were analysed for endothelial cell adherence and cell surface expression of Als1p. We found that mutations centred around amino acid 285 in the N‐terminus completely abolished adherence, but had no effect on cell surface expression of Als1p. Deletion of 15 of the tandem repeats reduced adherence by 50%, whereas deletion of all abolished adherence completely, even though cell surface expression of the N‐terminus of Als1p was maintained. Insertions into the C‐terminus at amino acids 413 and 254 upstream of the stop codon resulted in a modest loss of adherence, while cell surface expression of Als1p was maintained. An insertion at amino acid 249 in the C‐terminus caused complete loss of both adherence and cell surface expression, even though the glycosylphosphotidylinositol‐anchorage sequence remained intact. These data suggest a model of Als1p in which the endothelial cell binding region is localized within its N‐terminus, the tandem repeats are essential for the proper presentation of the binding site, and the C‐terminus is required for localizing Als1p to the cell surface. Copyright © 2004 John Wiley & Sons, Ltd.
Interaction of 6‐phosphofructokinase with cytosolic proteins of Saccharomyces cerevisiae
Authors: Schwock Jörg , Kirchberger Jürgen , Edelmann Anke , Kriegel Thomas M. , Kopperschläger Gerhard 
Published: April 2004

AbstractHetero‐octameric 6‐phosphofructokinase (Pfk‐1) from Saccharomyces cerevisiae is composed of two types of subunits, α and β, which are encoded by the unlinked genes PFK1 and PFK2. Pfk single deletion mutants expressing only one type of subunit exhibit Pfk‐1 activity in vivo which, however, is completely lost immediately after cell disruption. In order to elucidate the preconditions of the in vivo activity of the mutant enzymes composed of either α‐ or β‐subunits, we have investigated their potential interaction with selected heat shock and cytoskeletal proteins, employing co‐immunoprecipitation and immunofluorescence microscopy. Western blot analysis identified the mitochondrial chaperonin Hsp60, as well as the cytoskeleton proteins α‐tubulin and actin, in complexes with Pfk‐1 that were co‐precipitated from a cell‐free extract of a pfk2 single deletion mutant expressing only the α‐subunit. The interaction of the corresponding mutant enzyme and Hsp60 was found to depend on the ATP concentration of the extract. Immunofluorescence microscopy displayed a conspicuously filamentous arrangement of the Pfk‐1 mutant protein, exclusively in the pfk2 single deletion mutant. The analysis of structure and activity of Pfk‐1 expressed in S. cerevisiae mutant strains defective in various heat shock proteins (TRiC/CCT, Hsp70, Hsp 104) and in the respective wild‐type background did not reveal significant differences. Copyright © 2004 John Wiley & Sons, Ltd.
Identification of genes encoding putative nucleoporins and transport factors in the fission yeast Schizosaccharomyces pombe: a deletion analysis
Authors: Chen Xue Qin , Du Xianming , Liu Jianhua , Balasubramanian Mohan K. , Balasundaram David 
Published: April 2004

AbstractIn a systematic approach to study genes that are related to nucleocytoplasmic trafficking in the fission yeast Schizosaccharomyces pombe, the open reading frames (ORFs) of 26 putative nucleoporins and transport factors were deleted. Here we report the initial characterization of these deletion mutants. Of the 26 putative genes deleted, 14 were found to be essential for viability. Null mutations of essential genes resulted in failure to either complete one round or to sustain cell division. Four of the 14 essential genes, SPBC582.11c, SPBC17G9.04c, SPBC3B9.16c and SPCC162.08c, encode putative nucleoporins and a myosin‐like protein with homologues NUP84, NUP85, NUP120 and MLP1, respectively, that are not required for viability in Saccharomyces cerevisiae, suggesting that their gene products perform critical functions in Sz. pombe. On the basis of combined drug sensitivity assays and genetic analysis we have identified five non‐essential null mutants that were hypersensitive to the microtubule depolymerizing drug thiabendazole (TBZ) and exhibited a cut phenotype upon TBZ treatment, suggesting possible involvement in microtubule function. Three of the corresponding ORFs, SPCC18B5.07c, nup40 and SPAC1805.04, encode putative nucleoporins with low similarity to the S. cerevisiae nucleoporins NUP2p, NUP53p and NUP133p, respectively. Further genetic analysis revealed that one of the nucleoporin genes, nup40, and another gene, SPCC1322.06, encoding a putative importin‐β/Cse1p superfamily protein may have a spindle checkpoint function. Copyright © 2004 John Wiley & Sons, Ltd.
Causes of mortality in captive cotton‐top tamarins (Saguinus oedipus)
Authors: Leong Kirsten M. , Terrell Scott P. , Savage Anne 
Published: April 2004

AbstractCotton‐top tamarins have been housed in captivity in the United States for over five decades. These animals initially were managed in biomedical and research facilities, and more recently have been kept in zoos as well. Although the causes of mortality in captive cotton‐top tamarins have been a topic of investigation for biomedical colonies, they have not been addressed for the North American zoo population. In this retrospective study we review the causes of mortality in the AZA Cotton‐top Tamarin Species Survival Plan (SSP)© population during 1997–2001 to assess current husbandry practices and assist in further developing effective husbandry and management programs for this endangered species. Zoo Biol 23:127–137, 2004. © 2004 Wiley‐Liss, Inc.
Monitoring stress in captive giant pandas (Ailuropoda melanoleuca): behavioral and hormonal responses to ambient noise
Authors: Owen Megan A. , Swaisgood Ronald R. , Czekala Nancy M. , Steinman Karen , Lindburg Donald G. 
Published: April 2004

AbstractAnthropogenic noise may impact captive breeding programs for endangered species. We recorded ambient noise and monitored potential behavioral and hormonal indices of stress in two captive giant pandas for 4 years. Statistical analyses were conducted for each individual separately, which allowed us to generalize only to these two animals. These preliminary findings indicate that ambient noise can have long‐lasting effects on stress indices. Days characterized by louder levels of noise were associated with increased locomotion, restless manipulation of the exit door of the enclosure, increased scratching and vocalizations indicative of agitation, and/or increased glucocorticoids excreted in urine. These general effects were modulated by several factors: 1) Brief loud noise evoked behavioral distress, but not pituitary‐adrenal activation. More chronic, moderate‐amplitude noise was associated with higher levels of glucocorticoids. 2) Some responses were frequency‐dependent, with loud low‐frequency noise having the greatest impact. 3) Female reproductive condition interacted significantly with noise amplitude for all behavioral measures, with stronger effects for the loudest acute noises. The female appeared especially sensitive to noise during estrus and lactation, and less so during pregnancy/pseudopregnancy and nonreproductive periods. Despite these statistical effects, we found no compelling evidence that these adjustments indicate substantive detrimental effects on well‐being or reproduction. Nonetheless, careful monitoring of giant pandas and other captive‐held species is advisable, especially during reproductively sensitive periods such as implantation and birth. Zoo Biol 23:147‐164, 2004. © 2004 Wiley‐Liss, Inc.
Transportation techniques for massive scleractinian corals
Authors: Petersen Dirk , Laterveer Michaël , Bergen David van , Kuenen Maureen 
Published: April 2004

AbstractTransportation techniques for scleractinian corals have been described mainly for fragments and small colonies. As part of a recent study on captive sexual reproduction of the Caribbean species Montastrea annularis and Diploria strigosa, we transported relatively large (max. diameter of 21 cm), heavy (max. weight of 9,200 g) colonies of both species from Curaçao, Netherlands Antilles, to Rotterdam, The Netherlands. A new transportation technology was applied whereby the corals were transplanted to specially designed PVC crosses to provide stabilization during transport. In two transports (November 2001 and February 2002), 100 colonies were transported submerged, in a shipping time of >35 hr. The survival rate measured 2 weeks after transport was 100%. Four and 8 months after transport, respectively, two colonies of D. strigosa died without any obvious cause. In November 2002 we observed an outbreak of Dark Spots disease (DSD) affecting two‐thirds of the colonies of M. annularis. Although the colonies did not show any symptoms when they were collected, the disease most probably was transferred when the coral were transported from the field to the laboratory. The presented method is appropriate for transporting large, heavy corals–especially for scientific purposes. In general, species‐specific properties, colony size, and transportation time determine which transportation method should be applied. In the future, there may be a shift toward transports of fragments, coral larvae, and primary polyps to reduce collections in the field. Zoo Biol 23:165–176, 2004. © 2004 Wiley‐Liss, Inc.
Comparative study on the growth of juvenile Galapagos giant tortoises (Geochelone nigra) at the Charles Darwin Research Station (Galapagos Islands, Ecuador) and Zoo Zurich (Zurich, Switzerland)
Authors: Furrer S.C. , Hatt J.M. , Snell H. , Marquez C. , Honegger R.E. , Rübel A. 
Published: April 2004

AbstractIn this study, the growth rates of a group of Galapagos giant tortoises raised in their natural habitat at the Charles Darwin Research Station (CDRS; Galapagos Islands, Ecuador) and a group of captive‐bred specimens (Zoo Zurich, Zurich, Switzerland) were compared for the first time. A great discrepancy in growth rates was observed after the first year. When the animals were 4 years old, the carapace in the Zurich specimens was approximately twice as long as that in the CDRS tortoises, and the Zurich animals weighed approximately 10 times more than the CDRS animals. The zoo diet was modified by a reduction in nutrients and an increase in fiber to produce a more natural growth rate. Zoo Biol 23:177‐183, 2004. © 2004 Wiley‐Liss, Inc.
A pathomechanical concept explains muscle loss and fatty muscular changes following surgical tendon release
Authors: Meyer Dominik C. , Hoppeler Hans , von Rechenberg Brigitte , Gerber Christian 
Published: April 2004

AbstractFollowing tendon tear, the musculo‐tendinous unit retracts permanently, looses muscle fibre volume and is infiltrated with fat. This is currently considered to be an unexplained degenerative process. In a sheep model of chronic tendon tear with delayed tendon repair (35 weeks after tendon release), we studied the nature of these muscle changes in eight experimental animals. At sacrifice (75 weeks after tendon release) the muscle had retracted by 1.7±0.5 cm (9% of entire length, P < 0.0001), the pennation angle had increased from 22±2.5° to 50±11° (P < 0.0001) and the mean muscle fibre length had shortened from 32±3 to 16±5 mm (50%, P < 0.0001). In electron and light microscopy, we found essentially normal muscle fibres with an unaltered fibre diameter and myofibrillar structure, while interstitial fat and fibrous tissue had increased from 3.9% to 45.9% (P < 0.0001) of the muscle volume.Geometric modelling showed that the increase of the pennation angle separates the muscle fibre bundles mechanically like limbs of a parallelogram. Infiltrating fat cells fill the created space between the reoriented muscle fibres which may be quantitatively calculated without affecting the structural properties of the muscle cells. Fatty infiltration is therefore not seen as a degenerative process but a necessary rearrangement of the tissue after macroarchitectural changes caused by musculo‐tendinous retraction. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
The efficiency and the conduct of European banks: Developments after 1992
Authors: Schure Paul , Wagenvoort Rien , O'Brien Dermot 
Published: April 2004

AbstractWe assess the efficiency of the European banking sector in the 5‐year period following the implementation of the Second Banking Directive of the European Union (EU). We first determine the degree of cost efficiency of EU banks in 1993–1997. After that, we explore to what extent efficient European banks are managed differently than their inefficient peers. Our datasets comprise 5 years of observations on 1347 savings and 873 commercial banks. We use the new recursive thick frontier approach (RTFA) method to establish our results. We find that structural factors, such as technological progress or increased bank competition, have lowered the cost base of banks by about 5% annually during the sample period. Managerial inability to control costs (X‐inefficiency) is with 17–25% the main source of bank inefficiency in the EU. Managerial efficiency varies a great deal within Europe, and there seems to be no tendency towards convergence. We find that small savings banks can exploit economies of scale. The EU savings bank sector would cut costs by about 3% if small savings banks merged.
The Immunophilin-Interacting Protein AtFIP37 from Arabidopsis Is Essential for Plant Development and Is Involved in Trichome Endoreduplication
Authors: Vespa Laurent , Vachon Gilles , Berger Frédéric , Perazza Daniel , Faure Jean-Denis , Herzog Michel 
Published: April 2004

Abstract
The FKBP12 (FK506-binding protein 12 kD) immunophilin interacts with several protein partners in mammals and is a physiological regulator of the cell cycle. In Arabidopsis, only one specific partner of AtFKBP12, namely AtFIP37 (FKBP12 interacting protein 37 kD), has been identified but its function in plant development is not known. We present here the functional analysis of AtFIP37 in Arabidopsis. Knockout mutants of AtFIP37 show an embryo-lethal phenotype that is caused by a strong delay in endosperm development and embryo arrest. AtFIP37 promoter::β-glucuronidase reporter gene constructs show that the gene is expressed during embryogenesis and throughout plant development, in undifferentiating cells such as meristem or embryonic cells as well as highly differentiating cells such as trichomes. A translational fusion with the enhanced yellow fluorescent protein indicates that AtFIP37 is a nuclear protein localized in multiple subnuclear foci that show a speckled distribution pattern. Overexpression of AtFIP37 in transgenic lines induces the formation of large trichome cells with up to six branches. These large trichomes have a DNA content up to 256C, implying that these cells have undergone extra rounds of endoreduplication. Altogether, these data show that AtFIP37 is critical for life in Arabidopsis and implies a role for AtFIP37 in the regulation of the cell cycle as shown for FKBP12 and TOR (target of rapamycin) in mammals.
Immunophilins and Parvulins. Superfamily of Peptidyl Prolyl Isomerases in Arabidopsis
Authors: He Zengyong , Li Legong , Luan Sheng 
Published: April 2004

Abstract
Immunophilins are defined as receptors for immunosuppressive drugs including cyclosporin A, FK506, and rapamycin. The cyclosporin A receptors are referred to as cyclophilins (CYPs) and FK506- and rapamycin-binding proteins are abbreviated as FKBPs. These two groups of proteins (collectively called immunophilins) share little sequence homology, but both have peptidyl prolyl cis/trans isomerase (PPIase) activity that is involved in protein folding processes. Studies have identified immunophilins in all organisms examined including bacteria, fungi, animals, and plants. Nevertheless, the physiological function of immunophilins is poorly understood in any organism. In this study, we have surveyed the genes encoding immunophilins in Arabidopsis genome. A total of 52 genes have been found to encode putative immunophilins, among which 23 are putative FKBPs and 29 are putative CYPs. This is by far the largest immunophilin family identified in any organism. Both FKBPs and CYPs can be classified into single domain and multiple domain members. The single domain members contain a basic catalytic domain and some of them have signal sequences for targeting to a specific organelle. The multiple domain members contain not only the catalytic domain but also defined modules that are involved in protein-protein interaction or other functions. A striking feature of immunophilins in Arabidopsis is that a large fraction of FKBPs and CYPs are localized in the chloroplast, a possible explanation for why plants have a larger immunophilin family than animals. Parvulins represent another family of PPIases that are unrelated to immunophilins in protein sequences and drug binding properties. Three parvulin genes were found in Arabidopsis genome. The expression of many immunophilin and parvulin genes is ubiquitous except for those encoding chloroplast members that are often detected only in the green tissues. The large number of genes and diversity of structure domains and cellular localization make PPIases a versatile superfamily of proteins that clearly function in many cellular processes in plants.
Transient Exposure to Ethylene Stimulates Cell Division and Alters the Fate and Polarity of Hypocotyl Epidermal Cells
Authors: Kazama Haruko , Dan Haruka , Imaseki Hidemasa , Wasteneys Geoffrey O. 
Published: April 2004

Abstract
After transient exposure to the gaseous hormone ethylene, dark-grown cucumber (Cucumis sativus) hypocotyls developed unusual features. Upon ethylene's removal, the developing epidermis showed significant increases in cell division rates, producing an abundance of guard cells and trichomes. These responses to ethylene depended on the stage of development at the time of ethylene exposure. In the upper region of the hypocotyl, where cells were least differentiated at the onset of ethylene treatment, complex, multicellular protuberances formed. Further down the hypocotyl, where stomata and trichomes were beginning to develop at the onset of ethylene exposure, an increase in the number of stomata and trichomes was observed. Stomatal complexes developing after the ethylene treatment had a significant increase in the number of stomatal subsidiary cells and the number of cells per trichome increased. Analysis of division patterns in stomatal complexes indicated that exposure to ethylene either suspended or altered cell fate. Ethylene also altered cell division polarity, resulting in aberrant stomatal complexes and branched trichomes. To our knowledge, the results of this study demonstrate for the first time that transient treatment with physiological concentrations of ethylene can alter cell fate and increase the propensity of cells to divide.
Hydraulic Analysis of Water Flow through Leaves of Sugar Maple and Red Oak
Authors: Sack Lawren , Streeter Christopher M. , Holbrook N. Michele 
Published: April 2004

Abstract
Leaves constitute a substantial fraction of the total resistance to water flow through plants. A key question is how hydraulic resistance within the leaf is distributed among petiole, major veins, minor veins, and the pathways downstream of the veins. We partitioned the leaf hydraulic resistance (R leaf) for sugar maple (Acer saccharum) and red oak (Quercus rubra) by measuring the resistance to water flow through leaves before and after cutting specific vein orders. Simulations using an electronic circuit analog with resistors arranged in a hierarchical reticulate network justified the partitioning of total R leaf into component additive resistances. On average 64% and 74% of the R leaf was situated within the leaf xylem for sugar maple and red oak, respectively. Substantial resistance—32% and 49%— was in the minor venation, 18% and 21% in the major venation, and 14% and 4% in the petiole. The large number of parallel paths (i.e. a large transfer surface) for water leaving the minor veins through the bundle sheath and out of the leaf resulted in the pathways outside the venation comprising only 36% and 26% of R leaf. Changing leaf temperature during measurement of R leaf for intact leaves resulted in a temperature response beyond that expected from changes in viscosity. The extra response was not found for leaves with veins cut, indicating that water crosses cell membranes after it leaves the xylem. The large proportion of resistance in the venation can explain why stomata respond to leaf xylem damage and cavitation. The hydraulic importance of the leaf vein system suggests that the diversity of vein system architectures observed in angiosperms may reflect variation in whole-leaf hydraulic capacity.
The CPH1 Gene of Chlamydomonas reinhardtii Encodes Two Forms of Cryptochrome Whose Levels Are Controlled by Light-Induced Proteolysis
Authors: Reisdorph Nichole A. , Small Gary D. 
Published: April 2004

Abstract
Cryptochromes are proteins related to DNA photolyases and have been shown to function as blue-light photoreceptors and to play important roles in circadian rhythms in both plants and animals. The CPH1 gene from Chlamydomonas reinhardtii was originally predicted to encode a putative cryptochrome protein of 867 amino acids with a predicted molecular mass of 91 kD (Small et al., 1995). However, western blotting with antibodies specific to the CPH1 protein revealed the presence of two proteins that migrate at apparent molecular mass of approximately 126 and 143 kD. A reexamination of the assigned intron-exon boundaries has shown that the previously assigned intron 7 is in fact part of exon 7 which leads to a predicted protein of 1,007 amino acids corresponding to a size of 104.6 kD. The two forms of CPH1 that migrate slower on SDS-PAGE presumably result from unknown posttranslational modifications. In C. reinhardtii cells synchronized by light to dark cycles, the two slow migrating forms of CPH1 protein accumulate in the dark and disappear rapidly in the light. Both red and blue light are effective at inducing the degradation of the CPH1 proteins. Proteasomes are implicated because degradation is inhibited by MG132, a proteasome inhibitor. Studies with deletion mutants indicate that the C-terminal region is important for both the posttranslational modification and the protein's stability under both light and dark conditions.